DDW 2009 - Endo Research Update
Update on Endoscopic Research Presented at 2009 Digestive Disease Week
Edited by Jonathan Cohen, MD, New York University School of Medicine
| Topic | Reporter Name |
|---|---|
| Introduction | |
| Colon Cancer Screening | Reporter: Paul Feuerstadt, MD Hospital: Montefiorey |
| Advances in Capsule Endoscopy | Reporter: Gina Sam, MD Hospital: NYU |
| Ethical, Racial, and Gender Disparities in Endoscopy: Yes We Can Do Better | Reporter: Gina Sam, MD Hospital: New York University |
| Novel Technologies For the Diagnosis of GI Disorders: From the Bench to the Endoscopy Unit | Reporter: David Wan, MD Hospital: New York University |
| Advances in Endoscopic Practice: Improving Quality and Reducing Complications | |
| Colonoscopy: When, What, and How to Find Polyps | Reporter: Gina Sam, MD Hospital: New York University |
| Endoscopic Outcomes | Reporter: Gina Sam, MD Hospital: New York University |
| Diagnostic and Therapeutic Techniques in Colonoscopy | Reporter: Mohit Jindal, MD Hospital: SUNY Downstate |
| Endoscopic Approaches To Barrett’s Esophagus | Reporter: Ketan Kulharni, MD Hospital: Duke University |
| Clinically Relevant Advances in Management of Gastric Neoplasms | Reporter: Gina Sam, MD Hospital: New York University |
| Hemostasis in Endoscopy: How to Stop the Flood? | Reporter: Gina Sam, MD Hospital: New York University |
| Beyond Bread and Butter Cholangiography | Reporter: Mike Harris, MD Hospital: SUNY Stonybrook |
| Esophageal Potpourri | Reporter: Douglas Weine Hospital: Cornell University |
| Endoscopic Alternatives To Surgical Therapy | Reporter: Juan Carlos Bucobo, MD Hospital: SUNY Stonybrook |
| Best Practices: Quality in Colonoscopy | |
| Interventional EUS Outcomes: Here’s the Beef | Reporter: Theodor Pitea, MD Hospital: St. Luke’s Roosevelt |
| Controversial Issues in Pancreatic Endotherapy | Reporter: David Wan, MD Hospital: New York University |
| Deep Enteroscopy Outcomes and Therapeutics | Reporter: Gina Sam, MD Hospital: New York University |
| EUS Potpourri | Reporter: Gina Sam, MD Hospital: New York University |
| Image Enhanced Colonoscopy: From the Pathogenesis to the Diagnosis of Colonic Disorders | |
| New and Emerging Technologies in EUS: What’s Hot? | Reporter: Teodor Pitea Hospital: St. Lukes Roosevelt |
| Metal Stenting: The Good, the Bad, and the Ugly | Reporter: Gina Sam, MD Hospital: New York University |
Introduction
The following report is the forth annual overview of the endoscopic research presented at Digestive Disease Week as reported by GI fellows from the New York City area training programs. This year, the abstracts selected for oral presentation at 22 ASGE topic fora as well as the scientific papers presented at the ASGE Plenary session are included in this review. Readers will note that this is just a sample of the breadth of innovative scientific work in the area of endoscopic research presented at DDW. However, the abstracts covered in this review should provide a good snapshot of the current areas of investigation—from initial reports of new techniques, to carefully controlled trials subjecting new methods to rigorous validation, to presentations of data addressing many of the key clinical practice issues we face today.
Special thanks are due to all of the fellows who contributed the reports that comprise this summary. In particular, the efforts of Gina Sam, MD of New York University School of Medicine should be recognized for her help in organizing the effort this year.
Section 1: Colon Cancer Screening
This session discussed several methodologies and new technological advances and their impact on colon cancer screening.
The FOBT-Pos-Finger Followed By FOBT-6-Pack May Be a Viable Screening Policy for Colorectal Cancer
Many asymptomatic patients are referred to the gastroenterologist for further workup of a single fecal occult blood test being positive in a primary care doctors office. The goal of this study was to compare the long term outcome of patients who either had a negative follow-up six sample guaiac test (all received flexible sigmoidoscopy with full colonoscopic exam only if adenoma found on sigmoidoscopy) with those who had a positive follow-up six sample test (all received a colonoscopy). 230 patients with a single positive stool guaiac test in the primary care doctor’s office were enrolled between 1985 and 1994 and all participants returned the six sample stool guaiac test with 33 having at least one positive guaiac test and 197 being all negative. The mean age and follow-up for patients was 65 and 11 years, respectively. Of those who were positive on six sample testing, 52% had adenomas and 24% colorectal cancer (CRC) identified by colonoscopy. In the six pack negative cohort, flexible sigmoidoscopy identified 19% of patients with an adenoma and 2% with colorectal cancer. Despite no patients dying from colorectal cancer, median survival for those with cancer was 6.2 years compared with 13.7 years for those without and colorectal cancer was the only predictor of survival. Finally, the 6 sample testing did not affect survival. The authors concluded that single sample in-office guaiac testing followed by regular six sample analysis is a viable way of cancer screening.
Is American College of Radiology Recommendations for CT Colonography Reporting Suitable for Asia?
The US Multi-Society Task Force recommendations for CT Colonography follow-up of polyps being detected include lesions < 5 mm not being reported and a 3 year follow-up for patients with one or two polyps 6 to 9 mm in size. This study retrospectively applied these guidelines in screening for advanced colorectal neoplasia (ACN) in 5747 patients who underwent colonoscopy for various indications at multiple centers throughout Asia. 28.2% of these patients had a polyp detected with a complete histological assessment. The rates of ACN detected based upon size included 3.7%, 11.8% and 64.0% for 1-5 mm, 6-9 mm and greater than 10 mm, respectively. Of all the ACN found, CT colonography guidelines would not report 8.4% (size 1-4 mm) and 8.7% would not receive a polypectomy. CT colonography would incorrectly classify 8.4% (entire population), 11.8% (persons aged 50 or older) and 14.3% (screening patients aged 50 and older) of patients as normal when they actually have ACN. In addition, polypectomy would be delayed at least 3 years in 8.7%, 8.4% and 7.1% of the entire cohort, patients 50 and older and screening patients 50 and older, respectively. The study concludes that 1 in 6 ACN would be missed and/or delayed for treatment if these guidelines were applied to an Asian population.
Colonoscopy Versus Virtual Colonoscopy: a Systematic Review and Meta-Analysis of Patient Preference, Acceptance, and Satisfaction
A meta-analysis focusing on patient preference, satisfaction and acceptance of CT and magnetic resonance colonography (CT/MR colonography) versus conventional colonoscopy was presented. A MEDLINE literature search was conducted and articles were selected. Studies included were prospective, retrospective or cross sectional in design containing a direct comparison of patient satisfaction with, acceptance of and preference for colonoscopy versus non-invasive imaging techniques. 19 total studies including over 5500 patients met inclusion criteria with 10 being from gastroenterology or general medicine literature and 9 from radiological journals. Fourteen studies found that patients preferred CT/MR colonography over conventional colonoscopy including all 9 published in radiological journals compared with 6/10 from other disciplines of medicine. CT/MR colonography was more frequently preferred (55.7% vs. 31.3%) and patients were significantly more satisfied with this procedure. There were no significant changes to these findings when confounding for procedure indication, study objective, survey method, CTC method or publication date. Importantly, 4 studies of CT/MR colongraphy with limited bowel preparations reported a strong patient preference for indirect imaging as a screening modality. Most studies used unvalidated measurement methods and this might lead to publication bias as was observed in the difference in findings between gastroenterological journals and radiological journals.
Randomized, Controlled Trial of the Use of Magnesium Citrate with Polyethylene Glycol Electrolyte Lavage Solution for Morning Colonoscopy Preparation
A randomized, single-blinded, controlled study was presented comparing three bowel preparations for colonoscopy. These preparations included 4 liters of polyethylene-glycol electrolyte lavage solution (PEG-ELS) starting at 10 PM the night prior to the procedure (group 1), split dose PEG-ELS with 2 liters starting at 8 PM the night before the procedure and 2 liters starting at 5 AM the day of the procedure (group 2) and magnesium citrate (250 cc) starting at 8 PM the night prior to the procedure followed by 2 L of PEG-ELS starting at 5 AM the day of the colonoscopy (group 3). 232 consecutive patients participated with the endoscopists being blinded to the type of preparation the patient received. The quality of bowel preparation was rated according to the Aronchick scale (excellent, good, fair, poor and inadequate). There were no significant differences in compliance or sleep difference among the three cohorts. Nausea, abdominal distension and the sum of symptom scores were significantly higher in groups 1 and 2 compared with group 3. Significant differences were seen for both patient satisfaction rates between each group and patients willingness to choose the same preparation for a future colonoscopy with rates of 48.1%, 62.0% and 93.2% for groups 1, 2 and 3 respectively. According to the Aronchick scale, group 1 showed significantly worse bowel preparations compared with the other groups and the only “inadequate” preparations were found in this cohort. Groups 2 and 3 did not differ significantly when comparing overall preparation. Magnesium citrate plus 2 liters of PEG-ELS achieved the best patient satisfaction rate, lowest symptom score with a superior cleansing effect to 4 L PEG-ELS and comparable cleansing effect to split dose PEG-ELS.
Influence of Endoscopy Unit Procedure Volumes On Polyp Detection Rates
This investigator presented a study assessing whether high volume procedure days affect polyp detection rates. This was a retrospective time series analysis from the entire year of 2007 (excluding weekends and holidays) at a single tertiary care hospital with three endoscopists. Patients were grouped into “high volume days” of 18 procedures or more and “low volume days” of 16 or less. Any day with exactly 17 procedures was excluded. 3085 total procedures (1381 colonoscopies) were identified with a mean number of procedures per day of 17 and 35 high volume days compared with 204 low volume days. During high volume days polypectomy detection rates were significantly higher (21%) compared with low volume days (16.1%). The overall percentage of colonoscopies compared with upper endoscopies on high volume days was similar to the percentage on low volume days. The study concludes that polypectomy rates are not adversely affected by high procedure volumes.
Improved Adenoma Detection Rates Using High Definition Colonoscopes Versus Standard Definition Colonoscopes
Recent studies have not shown significant differences in adenoma detection rates between standard definition (SD) and high definition (HD) colonoscopes. This presentation discussed a retrospective study comparing SD and HD in a large patient population who underwent average risk screening colonoscopies by experienced colonoscopists (at least 100 colonoscopies with both SD and HD) at a tertiary care center. 2011 cases were performed using either Olympus (Olympus America Inc, Center Valley, PA) 160 series colonoscopes or Olympus 180 series colonoscopes. HD polyp detection rates (46.9% vs. 45.9%) and cancer/advanced adenoma detection rates (2.7% vs. 1.7%) were higher than SD but these differences were not statistically significant. HD detected adenomas at a significantly higher rate than SD (26.9% vs. 26.2%, OR 1.23 CI 1.01-1.51). This study contrasts with many of the recent comparisons of HD versus SD since there were higher pathology detection rates using HD technology and the investigator believes this was because this study had many more procedures evaluated compared with prior studies. The presenter theorizes that a study larger than the one presented might show significant differences in polyp and advanced adenoma/cancer detection rates. Finally, it was hypothesized that HD might increase adenoma detection rates without increasing overall non-adenoma detection rate.
Section 2: Advances in Capsule Endoscopy
Does Capsule Endoscopy Improve Outcomes in Obscure GI Bleeding: Randomized Controlled Trial of Capsule Endoscopy vs. Dedicated Small Bowel Radiography
This study was a randomized trial of Capsule Endoscopy (CE) vs. dedicated small bowel contrast radiography (SB) to assess outcomes in patients with obscure GI bleeding. The hypothesis of the study was that improved diagnostic yield of CE would lead to a decrease in further bleeding. Patients enrolled had a history of GI bleeding and negative EGD, colonoscopy, and push enteroscopy and was randomly assigned to CE or SB. Overt bleeding included patients with melena or hematochezia with an anemia vs. occult bleeding which included patients with iron deficiency anemia without celiac disease or other cause of bleeding; positive FOBT required in pre-menopausal women). Patients returned at 1,2,3,6,9, and 12 months for follow-up visits and hemoglobin. The primary endpoint was further bleeding, defined as overt or occult bleeding requiring subsequent hospitalization or transfusion or associated with hemoglobin drop after stabilization of > 2 g/dl (and hemoglobin in the anemic range). The study had a sample size of 136 patients (54 overt, 82 occult). The mean age was 53 yrs (range 23-78); 79 (58%) were female and 50 (37%) used NSAIDs. Ninety-one (67%) patients were hospitalized for obscure bleeding pre-randomization (91% of overt, 51% of occult). Positive findings on initial study were identified in 20/66 (30%) with CE (2 others had blood without lesions) and 5/70 (7%) with SB (p=0.0007). The most common findings were erosions/ulcers (N=15) on CE and diverticula (N=3) on SB. The 83 patients without further bleeding followed for > 2 months, all but 8 patients (CE: 4, SB: 4) had hemoglobin increase ≥ 2 g/dl (or into normal range) as compared to baseline. This study concluded that the diagnostic yield with capsule endoscopy may not translate into improved outcomes in a population with obscure GI bleeding because most patients do well whether or not abnormalities are identified.
In Vivo Trial of Driving System for Capsule Endoscopy Using a Magnetic Field
The purpose of this study was to develop a driving system for CE using a magnetic field, in collaboration with Professor Ohtsuka, Faculty of Science and Technology, Rhukoku University. This is a report of a successful experience of in vivo examination of the stomach of a dog using remotely controlled CE. A small magnet is placed in an alternating current magnetic field, the magnet will vibrate. When the vibration is transmitted to a fin, it allows the vibration of this magnet to be converted to an impelling force. Using this principle, a medical micromachine has been developed with the aim of remote-controlled operation, mainly applied in the gastrointestinal tract. They developed a driving system for CE by attaching the capsule endoscopy to this medical micromachine, and performed the following experiments. (1) Operated this driving system for CE by remote control in the stomach of a dog under sedation, and obtained endoscopic images using a real time monitoring system. (2) Placed a hemostatic clip on the posterior wall of the greater curvature of the upper body of the stomach, and recorded images of this clip. (3)Placed clips at two other sites in the stomach, and asked a CE operator, who was unfamiliar with the sites of the clips, to identify the sites, shapes, and colors of the clips. (1) The operator was able to obtain endoscopic images with driving CE in the stomach of a dog in vivo, in any desired direction, by remote control. (2) The CE system produced clear images of the clips placed in the stomach. (3) The operator was able to easily identify the sites, shapes, and colors of the clips. After completion of the examination, the animal was found to have no apparent adverse effect on health. This study conclude that there is the possibility of clinical application of this driving system, controlled by a magnetic field, for CE.
A New Extracorporeal Magnetic Navigation Tool for Capsule Endoscopy
This study addresses the issue that 25% of conventional capsule endoscopy failed to observe the entire small bowel. The incomplete examination was commonly due to the delayed gastric transit. Many preparations and right lateral position after ingestion were proposed to improve this incomplete examination rate. The purpose of this study was to develop an extracorporeal magnetic capsule navigation tool without preparation to implement complete small intestinal observation by shortening gastric transit time. The following is the method used:
- Electric currents required for an original handmade magnetic coil navigator were clarified to remotely control a capsule endoscope device (PillcamSB-2; Given Imaging Limited, Yoqneam, Israel).
- They examined the interference between electro-magnetic power of navigator and capsule endoscopic magnetic switch or endoscopic images.
- Two volunteers obtained informed consent underwent capsule endoscopy under monitoring by a real-time viewer and their gastric transit time through stomach was investigated.
They found that extracorporeal magnetic navigator was available for capsule endoscopy to patients without any intracorporeal magnetic metals or pacemaker.
Capsule Endoscopy (CE) Appears to Be Underutilized n Evaluating Obscure Gastrointestinal Bleeding (OGIB)
The purpose of this study was to evaluate the utilization of CE in the diagnostic workup of OGIB following a negative standard endoscopic evaluation. They found that there was underutilization of CE (less than 50% of expected CE procedures) in the evaluation of patients suspected to have OGIB
Negative Capsule Endoscopy Does Not Predict Lower Rebleeding Rate in the Long Term: A Study to Evaluate the Long-Term Clinical Outcomes of Patients with Obscure Gastrointestinal Bleeding After Capsule Endoscopy Guided Therapy
The purpose of this study was to determine the long-term (>1 year) outcome in patients who underwent CE to investigate OGIB. The study found that the rebleeding rate of negative CE study was not inferior to that of positive CE study, which warrants close observation with these patients. However, specific treatment according to CE findings was associated with a lower rate of recurrent bleeding in the long term.
Distribution of Small Intestinal Mucosal Injuries with Short-Term Administration of Non-Steroidal Anti-Inflammatory Drugs
The purpose of this study was to investigate the types and distribution of small intestinal injuries induced by short-term NSAID medication. 55 healthy male volunteers between 20 to 45 years of age and with no history of surgery were enrolled. All study subjects were first examined by baseline capsule endoscopy. Subjects then undertook a 14-day regimen of NSAID medication (diclofenac sodium, 25 mg; 3 times daily) with proton-pump inhibitors as gastroprotection (omeprazole, 20 mg; once daily). After 14 days, subjects underwent post-treatment capsule endoscopy and were assessed for three types of small intestinal injuries: denuded areas, erosions, and ulcers. Baseline endoscopy revealed 6 mucosal lesions in 6 out of 53 subjects (11.3%), consisting of 3 denuded areas and 3 erosions in the small intestine. Post-treatment endoscopy identified 636 lesions in 32 out of 53 subjects (60.3%) on NSAID medication; including 115 denuded areas in 16 subjects (30.1%), 498 erosions in 22 subjects (41.5%) and 23 ulcers in 8 subjects (15.1%). The majority of denuded areas (90.0%: 103/115) were located in the oral side, erosions were found throughout the small intestine, and all ulcers in the anal side. The impact of short-term NSAID medication on the small intestine differed between the oral and anal side, with most denuded areas identified in the oral side and all ulcers in the anal side. There was no association found between erosions and denuded areas.
Section 3: Ethical, Racial, and Gender Disparities in Endoscopy: Yes We Can Do Better
Disparities in Surveillance Colonoscopy Participation Determining Gender and Race Specific Targets for Future Quality Improvement Interventions
The purpose of this study was to determine the race- and gender-specific barriers, to surveillance colonoscopy, in Charleston, SC after a polypectomy for adenoma(s). 170 patients were identified from the adenoma prevalence study who had an adenoma removed but did not return for surveillance colonoscopy within the expected timeframe. Patients were contacted by telephone and asked to rate their agreement (5-point Likert scale) with 14 statements, encompassing 4 dimensions of possible barriers: 1) financial (including lack or loss of insurance), 2) communication failures (including knowing how to set up the procedure), 3) compliance (including being too busy, or aversion to the procedure), and 4) understanding (of procedure’s importance). The study found that 56 patients were able to be contacted and agreed to participate. Of those, 11 (20%) were African American [AA] and 26 (46%) were male. AAs were more likely than whites to cite "financial reasons" or "lack of insurance" for failure to return for surveillance (9% vs. 2%). AAs were twice as likely to state they were unaware that they were supposed to come back (36% vs. 16%), or claim that they had not been contacted (36% vs. 16%) or re-referred (54% vs. 23%). Women were five times more likely than men to "never want to have another colonoscopy” (20% vs. 4%). AAs and women were more likely to agree that screening colonoscopy’s goal is “to remove polyps before they become cancer” and to agree that “colonoscopy after polyps are removed is important.” The study concluded that AAs who failed to return for surveillance colonoscopy had a greater understanding of the purpose for surveillance than their white counterparts, but may have been more likely to expect to be contacted before returning; they were five times more likely to cite financial reasons for not returning. Women had a better understanding of the importance of surveillance colonoscopy than men, but 1 in 5 had an aversion to repeat procedures.
Colon Polyps > 9mm Detected By Colonoscopy Screening in Asymptomatic Hispanic an Asian/Pacific Islander Patients: Results from the National Endoscopic Database
The purpose of this study was to measure and analyze the prevalence and location of polyps sized > 9 mm in diameter in asymptomatic white, Asian/Pacific Islander and Hispanic patients who receive colonoscopy screening. The study found that there was no significant difference in prevalence of polyps > 9mm in white and Hispanic patients (6.2% vs. 5.8%; p=0.11; adjusted OR 0.94; 95% CI 0.85-1.03). Asian/Pacific Islander men and women had a lower prevalence of polyps > 9mm compared to white men and women (4.1% vs. 6.2%; p=0.0004; adjusted OR 0.67; 95% CI 0.52-0.86). When analyzed by decade of age, 60-69 year-old Asians had similar rates of large polyps compared to 50-59 year-old whites. The study concluded that compared to whites, Hispanic men and women undergoing screening colonoscopy have a similar risk of polyps > 9mm, whereas Asian/Pacific Islanders have a lower risk. These data suggest that screening colonoscopy might be deferred until age 60 years in average-risk Asian/Pacific Islanders.
The Effect of Acculturation On Colorectal Polyp Prevalence Among Hispanics
The purpose of this study was to determine the risk of colonic lesions according to acculturation (change in behavior and values that occurs when an immigrant group comes into contact with another group) status among Hispanics. The study found that acculturation was a significant independent predictor of colon pathology among Hispanics, and was associated with a certain dietary profile.
Time Trends and Racial Disparities in the Stage of Diagnosis of Esophageal Adenocarcinoma (EAC) in the United States
The purpose of this study was to determine the trends in the stage of diagnosis of EAC and also assess racial disparities in the stage of diagnosis of EAC. Updated results (up to 2005) of this population-based study suggest that the incidence rates of EAC continue to rise in whites and blacks. Currently, significantly more EAC are diagnosed at the local and regional stage along with a significant decrease in the distant and unstaged cancers in whites; however, a similar trend was not seen among blacks.
Physician and Gender Differences Among the Patient-Physician Discussion Prior to Open Access Colonoscopy
The purpose of this study was to examine the patient-physician discussion prior to Open Access Colonoscopy (OAC) and to assess areas to improve Colorectal Cancer Screening (CRCS) compliance. The study concluded that despite the time devoted by PCPs, patients do not feel well informed about CRCS. One important finding was that women are least likely to be informed about the CRCS process.
Colorectal Cancer Screening Above Age 75: Outcomes of Colonoscopies in Symptomatic African American and Hispanic Adults
The purpose of this study was to evaluate the outcome of colonoscopies in symptomatic adults > 75 years of age. The study concluded that colonoscopy has an overall low yield in symptomatic African American and Hispanic patients greater than 75 years of age with previous normal screening colonoscopies. Although cancer detection rates were high, the advanced stages of cancer at diagnosis limited the benefit of detection in a significant proportion. This data seems to underscore the importance of earlier detection in this population prior to the development of symptoms.
Section 4: Novel Technologies For the Diagnosis of GI Disorders: From the Bench to the Endoscopy Unit
This session discussed a variety of emerging technologies that may aid in the diagnosis of GI diseases such as Barrett’s Esophagus, small intestinal diseases, and pre-neoplastic gastric lesions. The technologies included tethered capsule endoscopes, ingestible event markers, suctioning devices, auto-fluorescence, NBI, and optical frequency imaging.
A Swallowable Tethered Capsule Endoscope for Diagnosing Barrett’s Esophagus
This study discussed an ingestible, tethered capsule for the visualization and biopsy of suspected Barrett’s. Without the need for sedation, an operator uses a thin cable for real-time control of a three-component device that consists of anchoring, imaging, and biopsy subsystems. The anchoring subsystem is an inflatable region lined with adhesives modeled after gecko feet that enhance friction and secures the capsule while imaging and biopsies can occur. The biopsy module uses vacuum channels that the clinician can use to suction a region of interest and then align a sharp blade for tissue sampling. Currently, each capsule can only take and store four biopsies each time. Preliminary in vitro testing in excised porcine esophagi has demonstrated the viability of the concept. Future in vivo porcine testing is planned.
Ingestible Event Marker System – A Novel, Physiologically-Sized Device Platform for Frequent, Repeated Use
With the limits that the large sizes of current capsule studies impose on measuring internal physicochemical parameters, a new disposable, physiologically-sized device that ideally can measure physiologic transit time with accuracy and low-cost was discussed. This 1mm by 1mm ingestible event marker (IEM) that transmits a signal is activated by stomach fluid and is accompanied by a wearable receiver. Thirty healthy subjects were used at a single site. In a human feasibility study, multiple active and inactive IEMs were ingested under various conditions including different times of the day, meal compositions (high carbohydrate, protein, lipid). Technical performance was high as active IEMs were positively detected (96.7%) and dummy IEMs were not detected (100%). The time-to-detection and IEM transmittal times were 1.0 min and 7.3 minutes. BMI, activity, meal type did not appear to be significantly associated with accurate detection, but post-prandial state seemed to lower detection accuracy. No adverse events were noted. The authors claim that the IEM system is promising as a physiologic platform that can longitudinally track physical, chemical, and behavioral conditions and may assist in assessing GI motility and transit disorders.
Suction Parameters for the Development of a Robotic Endoscope for Traversing the Small Intestine
Mihir Wagh presented this new technology that uses suction as a means of locomotion within the small intestine. This study assessed the feasibility of these suction-assisted self-advancing robotic endoscope and determined the greatest amount of holding force while minimizing tissue damage in traversing the small intestine. The apparatus consists of two suction devices (1 fixed, 1 movable) attached to the outside of an endoscope. By suctioning with the fixed tip, the scope is anchored, then the movable tip is advanced and suctions distal mucosa towards it, The next step is to release the fixed tip and then to pull the distal mucosa affixed to the movable tip over the scope. These steps are repeated to continually advance the scope. In tests using excised segments of cadaveric swine small intestines, forces up to 3.89 Newtons were applied and was highly dependent on tip design. Even at high vacuum pressures, no intestinal trauma was seen. Theoretical concern for intussusception was raised by the audience, but none has been seen in preliminary studies. Future in vivo studies are needed.
The Clinical Utility of Tandem Auto-Fluorescence (AFI) and Narrow Band Imaging (NBI) in Patients with Barrett’s Esophagus (BE)
Ajay Bansal presented this study combining the broad-based technique of AFI and focused examination of NBI in evaluating BE. AFI looks for abnormal purple fluorescence while NBI locates irregular/distorted mucosal and vascular patterns. Patients undergoing surveillance of endoscopic treatment of BE were evaluated with white light, AFI, and zoom NBI in tandem fashion. Biopsies were taken from abnormal-looking areas as well as normal-appearing areas at distant sites. The primary endpoint was detection of high-grade dysplasia or esophageal adenocarcinoma. Overall, 25 patients with a mean age of 61 yrs were prospectively enrolled, all males and Caucasians. Mean Prague C&M were 3.5cm and 5.4cm respectively. Patient-based analysis showed AFI (Sensitivity 57%, Specificity 61% PPV 36%, NPV 79%), AFI + zoom NBI (Sensitivity 57%, Specificity 61%), and zoom NBI (Sensitivity 83%, Specificity 63% PPV 42%, NPV 92%). Area-based analysis showed AFI (Sensitivity 69%, Specificity 72% PPV 46%, NPV 88%), AFI + zoom NBI (Sensitivity 50%, Specificity 75%), and zoom NBI (Sensitivity 75%, Specificity 81% PPV 47%, NPV 94%). Given the results, the authors suggest AFI may not have adequate sensitivity, zoom NBI had higher sensitivity, but was biased by preceding AFI examination. Thus, until more trials studying these techniques are available, a high definition endoscopic exam remains good practice.
Detection of Pre-Neoplastic Gastric Lesions in a High Risk Chinese Cohort Using Endoscopic Autofluorescence Imaging Followed By Narrow Band Imaging Versus Standard White Light Endoscopy – Prospective Randomized Double Blind Crossover Study
This prospective randomized double-blind crossover study compared combined AFI and NBI modalities vs. standard white light endoscopy (WLE) for detecting pre-neoplastic gastric lesions such as intestinal metaplasia and mucosal atrophy in a high risk cohort. Sixty-five patients, age > 50 years with dyspepsia were assessed by both AFI/NBI and WLE in randomized order and then identified and random biopsies from the antrum, body, incisura, and cardia were examined by two expert pathologists in blinded fashion. One patient was excluded by a diagnosis of gastric cancer. In the other 64 patients, 146 lesions were identified by AFI/NBI and 82 lesions were seen on WLE. For abnormal mucosal changes, false positives were 45.3% and 38.2% for AFI/NBI and WLE respectively. For abnormal mucosal changes, false negatives were 39.2% and 27.1% for AFI/NBI and WLE respectively. The operating characteristics of AFI/NBI for intestinal metaplasia were sensitivity and specificity of 68.4% and 23.1%, whereas for WLE they were 34.2% and 65.4%. The operating characteristics of AFI/NBI for mucosal atrophy were sensitivity and specificity of 32.3% and 78.8%, whereas for WLE they were 12.9% and 87.9%. Overall sensitivity for any abnormal mucosal changes was 72.2% for AFI/NBI and 61.8% for WLE. The authors conclude that AFI/NBI increases the detection of gastric intestinal metaplasia.
Guided Esophageal Surveillance Biopsy with a Laser Marking Optical Frequency Domain Imaging System
Melissa Suter described a second-generation optical frequency domain imaging (OFDI) system in guiding esophageal surveillance biopsies. This technology provides visualization of subsurface microstructures analogous to ultrasound, with resolution <10 micrometers, and 2mm penetration. Using a balloon catheter, this high-resolution cross-sectional imaging modality can detect and diagnose esophageal pathology. Notably, regions of interest can now be marked by using lasers. This feasibility study tested in swine in vivo. The success and safety parameters of laser marking were assessed. Ideal settings were determined to be 400mW, 1480 nm laser applied for 2-seconds. 68 random targets were placed in the esophagi of 3 swine and the laser-induced marks were correctly placed on either side of the targets with an accuracy of 97.06% and these marks were also endoscopically visible. The authors concluded that OFDI is feasible and potentially could be used for esophageal surveillance in the future, and a human pilot study in the esophagus is anticipated.
Section 5: Advances in Endoscopic Practice: Improving Quality and Reducing Complications
Balanced Propofol Sedation Versus Fentanyl and Midazolam Titrated to Moderate Sedation for EGD - A Prospective, Randomized Clinical Trial
This randomized comparison of balanced propofol sedation [BPS] , a combination of propofol with low doses of benzodiazepine and opiate, with standard sedation undergoing EGD found that BPS achieved a significantly improved analogue scale of patient satisfaction [99 vs 88 on a 100 point scale] and shorter recovery times [11 vs. 26 minutes] compared to sedation with standard agents alone. While only 81 patients had been randomized so far, no adverse events or desaturation < 85% have occurred in either group.
Do Proton Pump Inhibitors Prevent Bleeding from Ulcers After Endoscopic Submucosal Dissection or Endoscopic Mucosal Resection?
This meta-analysis of randomized trials of proton pump inhibitors [PPIs] or vs other acid suppressants or no acid suppressions after EMR and ESD showed that PPI use was associated with reduced ulcer bleeding compared to other medication or no treatment [4.5% vs 10.9%]. There was not enough data included in the studies to determine whether other variables such as rates of surgical reintervention or hospital length of stay.
The Clinical Value of the Duodenal Biopsy: a Nation-Wide Clinicopathologic Analysis of 20,000 Patients
The authors of this study analyzed the duodenal biopsy specimens from a large set of data from 20, 461 patients in an effort to assess the yield of such biopsies in clinical practice. When sprue was suspected, 71% of biopsies were abnormal; in contrast, in all other cases overall, 82% of biopsies were normal. A significantly higher finding of villous atrophy was found among paitents undergoing investigation for anemia than those having EGD for other indications [1.4% vs 0.9%]. In the absence of endoscopic abnormalities, anemia, or suspected sprue, the likelihood of clinically useful duodenal histopathology was 5-10%
A Randomized, Double-Blinded, Placebo-Controlled Trial of Promethazine and Diphenhydramine As Adjunct Sedatives for Endoscopic Ultrasound (EUS) and Endoscopic Retrograde Cholangiopancreatography (ERCP): Interim Analysis Results
These authors conducted a randomized controlled trial in which patients undergoing EUS and ERCP received pretreatment with promethazine, diphenhydramine or placebo before standard sedation with meperidine and midazolam. This study was intended to address settings in which there are obstacles to the use of propofol. Among the 175 randomized to date, both study agents led to significant though clinically small reductions in dosages of meperidine and midazolam. Similar rates of adverse events were observed. Similar time to sedation was observed. The promethazine did lead to longer recovery time, and in this interim analysis, trended to reduce the incomplete procedure rate. Of note, 83% of the cases in this study were EUS.
A Comparison of Split Dose Polyethylene Glycol-Electrolyte Solution + Simethicone Versus Standard Overnight Fast for Small Bowel Cleansing Prior to Capsule Endoscopy (CE)
In an effort to address the common problem of suboptimal small bowel visualization on capsule endoscopy (CE), these authors conducted a retrospective chart review of consecutive patients undergoing a polyethylene glycol electrolyte solution split dose prep plus cimethicone and compared prep quality on CE to that of a control group previously graded after undergoing a standard overnight fast prep for CE. While this was not a tandem study or a randomized comparison, the full prep group has satisfactory cleansing achieved significantly more than the fast alone group [90% vs 65%]. Despite this, there was no difference in the frequency of any CE finding in the two prep groups, casting the clinical importance of the improved visualization in doubt.
Risk of Immediate and Delayed Complications with Percutaneous Gastrostomy and Jejunostomy Tubes in Patients Receiving Bevacizumab
These authors address the safety questions surrounding the performance of PEG and PEJ tube placements in patients who have been receiving the drug Bevacizumab. They retrospectively reviewed the charts of 83 such patients, 92% of whom had PEGs placed, mainly for enteral feeding or gastric decompression in roughly half for each indication. Three patients experienced major complications, including only one procedure associated adverse event—a case of pneumatosis and portal vein air. Two bleeds requiring transfusion occurred but these occurred at 105 and 30 days post procedure and were from the tumor in one case and hemobilia in the other. The authors concluded that starting this medication following PEG or PEJ is safe and performing PEG or PEJ among patients who received Bevacizumab within 60 days is safe.
Section 6: Colonoscopy: When, What, and How to Find Polyps
To Continue or to Stop Clopidogrel for Screening Colonoscopy: Clinical Experience and Comparison of the Alternatives Using Decision Models
The purpose of this study was to compare the management strategies in patients taking clopidogrel (an irreversible platelet inhibitor) for coronary stenting within the past year. The study concluded that the most cost-effective strategy is to continue clopidogrel and resect polyps <1cm during the procedure. If the patient has a modest risk of mortality from post-polypectomy bleeding, the benefit of this strategy is eliminated. For lower risk patients, the mortality from clopidogrel interruption, performing screening off clopidogrel is more cost effective.
Assessing the Efficacy of Cold Biopsy Forceps Polypectomy for Diminutive Polyps
The purpose of this study was to assess the efficacy of cold biopsy forceps poplypectomy (CBFP) in achieving complete resection of diminutive polyps. The preliminary data from this study suggests that CBFP is an ineffective modality for complete resection of diminutive polyps. Further studies are needed to confirm these findings.
Can We Really Expect a Therapeutic Benefit After Two Preventive Colonoscopies?: a Retrospective VA Medical Center Study
The purpose of this study was to determine the yield for advanced neoplasia (AN) at the 3rd colonoscopy. The study found that patients with consecutive colonoscopies at least 3 years apart, at least one of which was free of TAs, are at an exceedingly low risk of developing AN during the interim period between the 2nd and 3rd colonoscopy. Therefore, they suggested that surveillance interval guidelines should be revised for this group of patients. In addtion, the study concluded that patients with at least one TA at both of the previous two colonoscopies should definitely continue to undergo surveillance colonoscopies, at least at the recommended intervals.
Does the Location of Adenoma At Baseline Predict the Location of Subsequent Recurrence? Evidence from the Polyp Prevention Trial
The purpose of this study was to examine whether the baseline location of adenoma predicts the location of subsequent recurrence. The study concluded that there is a proximal shift of metachronous adenomas and subjects with adenomas in both distal and proximal colon are at the highest risk of adenoma recurrence.
Morphologic Reclassification of Large Hyperplastic Polyps Into Serrated Polyps with Malignant Potential
The purpose of this study was to determine the number of serrated colon polyps that may have been misclassified as hyperplastic polyps in the recent past, understand the characteristics of these polyps and improve the histological identification of serrated polyps in the future. The study found in this group the following: 1)23% of ≥ 10 mm "hyperplastic" polyps were reclassified as serrated polyps in agreement with the percentage reported in the literature. 2) Serrated polyps were found predominantly in the left colon. 3) Increased awareness of serrated polyps amongst pathologists should lead to reclassification of hyperplastic polyps and a shorter surveillance interval for these pre-malignant lesions.
Large Tubular Adenomas, Villous Polyps, and Lesions with High Grade Dysplasia: Can We Really Be Comfortable Waiting 3 Years Before Repeat Colonoscopy?: a Retrospective VA Medical Center Study
The purpose of this study was to evaluate the appropriate interval for surveillance following polypectomy with removal of TA ≥10mm, TA with villous features, or TA with HGD. The study found that patients with TAs ≥ 10mm and polyps with villous features found on initial screening colonoscopy represent a special population that should be considered for surveillance colonoscopy before the recommended 3 year interval. The current 3 year surveillance interval appears to be appropriate after removal of HGD lesions, but further investigation is necessary.
Section 7: Endoscopic Outcomes
Surveillance in a Prospectively Followed Cohort of Patients with Barrett Esophagus in the Netherlands: a Cost-Effectiveness Analysis
The purpose of this study was to evaluate the cost-effectiveness of different intervals of surveillance in BE and to identify critical variables, based on a prospectively followed Dutch BE cohort. It was a multicenter cohort study (CYBAR study). The study comprised of 710 BE patients, including patients with no dysplasia (ND; n=601) or low-grade dysplasia (LGD; n=109) at baseline. They performed endoscopic surveillance according to the ACG guidelines. Using pre-specified misclassification rates, the true transition rates from ND to LGD, high-grade dysplasia (HGD) and EAC were estimated by a Multi-State-Markov model, based on the observed transition rates in this cohort. The estimated true transition rates and misclassification rates were incorporated in a decision analytic model. With this model they included quality of life data and real costs (3% discount rate). They also evaluated strategies for surveillance were every 1, 2, 3, 4 or 5 years and no surveillance in BE with baseline ND or LGD, with esophagectomy being performed if HGD or EAC was diagnosed. The incremental cost-effectiveness ratios (ICER) were calculated for each strategy. They found that with 2 years of follow-up, the incidence of EAC was 0.7% and the annual true transition rate from ND to LGD was 3%, from LGD to HGD 21% and from HGD to EAC 43%. In BE patients with ND or LGD, all evaluated surveillance strategies were cost-effective vs. less intensive alternatives. The most intensive strategy (i.e. yearly) was a cost-effective alternative compared to 2-yearly surveillance, with an ICER of $27,800/quality-adjusted life year (QALY) gained in patients with ND and an ICER of $6,650/QALY gained in patients with LGD. Sensitivity analyses showed that the true transition rates for ND to LGD, HGD or EAC were the most critical factors for the cost-effectiveness of this model. If these rates were halved, yearly surveillance was no longer cost-effective, but 2-yearly surveillance was. The study concluded based on the transition rates that yearly surveillance seems a cost-effective strategy and will become even more cost-effective when patients with HGD or mucosal EAC will be treated endoscopically. This analysis also shows that progression risks are the most critical components for decision making regarding surveillance in BE.
The Economics of Complex Endoscopic Procedures in a Tertiary Care Medical Center
The purpose of this study was to determine the economics of complex endoscopic procedures with unestablished CPT codes in the endoscopy unit of a tertiary care medical center. They used the medical records of all patients who underwent complex endoscopic procedures with unestablished CPT codes (codes ending in digits 99) at their institution between August 2004 and April 2008. Data was recorded about the type and duration of procedure, CPT code, payer information, professional charges and revenue from each procedure. The study found that 226 procedures comprised of 100 antegrade double balloon endoscopies (DBE), 37 retrograde DBE, 35 endoscopic mucosal resections (EMR) and submucosal dissection (ESD), 11 esophageal needle knife stricturoplasties, 11 procedures on pancreatic pseudocyst, 5 endoscopic closures of gastrogastric fistula, 5 endoscopic tightening of gastrojejunal anastomosis and 22 other procedures, many of which were various combinations of ERCP and EUS. The mean duration of procedure was 75 minutes and the average revenue generated per procedure was $639. The average duration of antegrade DBE, retrograde DBE, EMR/ESD, esophageal needle knife stricturoplasty and procedures on pancreatic pseudocyst and was 75 minutes, 92 minutes, 57 minutes, 53 minutes and 110 minutes respectively. The average revenue generated from antegrade DBE, retrograde DBE, EMR/ESD, esophageal needle knife stricturoplasty and procedures on pancreatic pseudocyst were $454, $563, $827, $234 and $1668 respectively. The duration of procedure and the reimbursement correlated poorly (coefficient 0.09). The study concluded that complex endoscopic procedures require specialized infrastructure, extensive training and expertise and frequently take longer than routine procedures. In addition many of these procedures do not have established CPT codes.
Return On Investment Analysis of Double Balloon Enteroscopy: Implications for Financial Reimbursement and Program Establishment
The purpose of this study was to evaluate the actual financial outcomes compared to the predicted Return On Investment (ROI) hypothesized values at a tertiary care center one year after adopting a Double Balloon Enteroscopy (DBE) program. Before the study, the University of Wisconsin Hospital and Clinics technology had an assessment committee review the available DBE literature to model a ROI analysis. During a one year time period (7/07-6/08), following establishment of a DBE program, they conducted a retrospective comparison of the predicted and actual financial experience. The study found that ROI analysis was based on a 5 year time frame and projected a net present value, defined as the total cash flow generated over 5 years expressed in today’s dollar discounted at the determined cost of capital, to be $64,623. Based on this net present value and the capital expenditures to establish the program, the projected internal rate of return was 24.6 %. The study concluded that the total first year volume of cases were overestimated; however, the percent margin for profit was similar between the predicted and actual outpatient values. In addition, they found that there was a significant difference in cost for care between the outpatient and inpatient DBE cases, with outpatient cases being more profitable due to less consumption of resources compared to an inpatient stay. Based on the findings of this study, it suggested that gastroenterologists who are interested in establishing a DBE program need to be aware of the financial implications, which can best be evaluated by a ROI analysis
The Impact of On-Site Cytopathology On the Clinical Evaluation and Management of Patients Who Undergo EUS-Guided Fine Needle Aspiration for Suspected Pancreatic Cancer
The purpose of this study was to evaluate on-site cytopathology assessment on the management of patients who undergo EUS-guided FNAB for suspected pancreatic cancer. The diagnostic yield, outcome and cost analysis of all patients who underwent EUS-guided FNA for a solid pancreatic mass were assessed at 2 tertiary referral centers over a 6-month period. Cases with (n=55; 21M; 68.3±1.5 yrs) and without (n=56; 22M; 67.4±1.5 yrs) on-site cytology interpretation were reviewed and compared. The study found that the presence of on-site cytology interpretation was associated with a: (i) better diagnostic yield (98% vs. 39%; P<0.001); (ii) fewer FNA passes (2 vs. 4; P<0.001); (iii) diminished requirement for repeated EUS-guided FNA (1/55 vs. 8/56; P0.01); and (iv) diminished requirement for further investigations and CT-guided biopsy (0/55 vs. 15/56; P=0.002); but a similar procedure time (35.3±1.6 vs. 33.2±0.9 min). In addition, hospital stay of the in-patients (~25% of both groups) who had the FNAB without on-site cytology was prolonged by 9.8±1.8 days due to the need for repeated or further investigations. After EUS-guided FNA, the patients with on-site cytology examination had their treatment plan formulated (2.3±0.2 vs. 18.6±1.8 days, P<0.0001) and surgery (14.3±1.5 vs. 29.6±2.2 days, P<0.002) significantly earlier than those without on-site cytology examination. In the group without on-site cytology, 14 (25%) patients had surgery and 8 (14%) patients were palliated without a tissue diagnosis of pancreatic cancer. The estimated cost incurred from further investigations and prolonged hospital stay in the group without on-site cytology assessment was US$97,440. The study concluded that on-site cytopathology substantially improved the diagnostic yield of EUS-guided FNAB, facilitated treatment decisions, shortened time-to-surgery, avoided unnecessary investigations and reduced cost to the health care system.
Projected Growth Rate of Anesthesiologist-Delivered Sedation in Colonoscopy and EGD in the United States: 2009- 2011
Due to the rise in anesthesiologist participation for endoscopic procedures including colonoscopy and esophagogastroduodenoscopy (EGD), there will be an increase in the use of sedative agents such as propofol which currently require delivery by an anesthesiologist. The purpose of the study was to determine the implications in the use of anesthesiologist-delivered sedation have economic as well as clinical implications. They compiled claims data from i3 Innovus for the period 2003-2007 on the use rate of anesthesiologists in colonoscopy and EGD. The anesthesiologist participation rates were calculated at the three-digit zip code level. The resulting sample of 3,714 observations was linked to the Bureau of Health Professions’ Area Resource File (ARF), allowing us to control for sociodemographic factors and provider supply characteristics that might affect anesthesiologist-delivered sedation. Multivariable regression analyses were performed to identify factors predicting anesthesiologist participation in these procedures and to forecast use rates for the years 2009-2011. The study found that the anesthesiologist use increased at an average annual rate of 23.1% for colonoscopies and 21.8% for EGDs. In 2003, the average participation rate of anesthesiologists was 8.6% in colonoscopies and 9.0% in EGDs. By 2007, these figures increased to 23.3% and 23.1%, respectively. Anesthesiologist participation rates in colonoscopy are projected to be 30.6% in 2009, 34.3% in 2010, and 38.0% in 2011. Corresponding projections for EGDs are 30.2% in 2009, 33.7% in 2010, and 37.2% in 2011. Growth in anesthesiologist participation rates varied by census region: for colonoscopy, average growth rates were highest in the Northeast (41.2%), followed by the South (29.4%), the Midwest (16.9%) and the West (4.4%). A similar pattern emerged for EGD, with anesthesiologist growth rates highest in the Northeast (43.8%), followed by the South (26.3%), the Midwest (15.6%) and the West (6.3%). For both colonoscopy and EGD, anesthesiologist participation rates were significantly greater in areas having a higher percentage of older (>=45 years of age) patients, higher per capita income and lower unemployment rates. The study concluded that anesthesiologists, hence such sedative agents as propofol, is projected to grow substantially for both colonoscopies and EGDs in the United States and may add significantly to the overall cost of performing these procedures in the years to come.
Errors in Endoscopy
The purpose of this study was to determine the core issues regarding patient safety and endoscopic errors, and to compare the malpractice indemnity of GI’s compared to other specialists who also perform endoscopies. A retrospective analysis of a nationwide endoscopy-related malpractice claims files from Physicians Insurers Association of America (PIAAA) from January 1985 to December 2006 was performed. The study found that of 316 closed claims, the most common procedures involved were colonoscopy, ERCP, and sigmoidoscopy with average indemnity of $237,632, $344,297, and $330,000 respectively. Over 98% of closed claims involved physical injury and most were severe - 26% resulted in death, and an additional 40% caused significant or major disability. Claimants were more often female (180 versus 129 closed claims) and over age 50 (205 versus 107). The majority of claims involved either improper performance (for example, perforation from a colonoscopy, 51%) or diagnosis error (17.3%). There were relatively few meritless claims (10%) lacking evidence of error. Among 21 cases involving colon cancers, both right and left sided cancers were equally represented. Colorectal surgeons and family practice physicians who perform endoscopies cost more than GI’s in terms of average indemnity per claim. The study concluded that awards and settlements on alleged injuries resulting from errors in endoscopy differ according to specialty of the endoscopist.
Section 8: Diagnostic and Therapeutic Techniques in Colonoscopy
Authors from different parts of the world shared their knowledge and experience in this topic forum, including the role of urgent colonoscopy in acute LGI bleeding, management options for intermediate size polyps seen on CTC and current advances in resection of flat and difficult colonic neoplasms.
Safety and Efficacy of Colonoscopy to Treat Diverticular Bleeding - Long-Term Outcomes of a Large Multicenter Cohort
Kaltenbach and colleagues presented the outcomes of 250 patients with acute severe LGIB cohort who underwent first-line urgent colonoscopy for diverticular bleeding. Colonoscopy was performed after a rapid bowel prep, and diverticular bleeding stigmata (active bleeding, non-bleeding visible vessel, adherent clot and erosion at the diverticular site) were treated with clips. 64 patients had suspected diverticular bleeding, but only 28 had confirmed diverticular bleeding with identifiable bleeding stigmata [active bleeding (12), non-bleeding visible vessel (3), adherent clot (9) and erosion (4)]. Successful primary hemostasis with clips was achieved in 25 (93%) patients. There were no complications. Of these 25, none had rebleeding at 30 days, and 6 (24%) had late rebleeding during follow-up of 35 +/- 18 months. Mean hospital stay was significantly shorter after successful hemostatic therapy. Thus, first-line colonoscopy in acute severe LGIB has a high yield for diverticular bleeding, and safe and effective endoscopic hemostatic therapy can be applied in patients with bleeding stigmata. The study underscores the drift of colonoscopy from just a diagnostic tool to a front-line therapeutic modality in cases of acute diverticular bleeding.
Pathology of the 6-9mm Polyp Found in a CT Colonography Screening Program: Implications for CT Polyp Surveillance vs. Resection
CT colonography for CRC screening remains a hotly debated topic. For patients at the University of Wisconsin Hospital and Clinics, if any polyp > 10mm is found on CTC, they are referred for colonoscopy with polypectomy and polyps < or = 5mm are not reported in isolation. Dureja and colleagues attempted to shed some light onto the gray zone of 6-9mm polyps detected on CT colonography. Patients with such polyps (and no polyp >9mm in size) were offered surveillance with CTC in 1-2 years vs. same day colonoscopy and polypectomy. During 3.5 yrs, total 304 patients were referred from CTC for colonoscopy. Total 234 polyps measuring 6-9mm were found; 123(58%) were adenomas, 12(5%) were advanced adenomas (villous features, serrated adenomas, or high grade dysplasia), and 99 (42%) were non-adenomatous. No cancers were found. 110 patients, with the largest polyp measuring 6-9 mm on CTC chose same day colonoscopy and polypectomy. In these patients, colonoscopy showed 130 polyps >6mm in size. Of the 130 polyps, 77 (59%) were adenomas, 2 of which (1.5%) had advanced histological features and 53 polyps (41%) were non-adenomatous. The authors concluded that a “large number” (40%) of 6-9mm polyps seen on CT will be non-adenomatous, and that in patients with their largest polyp 6-9mm on CTC, only 2 (1.5%) will have advanced histology, suggesting that CTC surveillance would be a viable option for such patients. However, given no set surveillance interval for CTC, and a significant number of the polyps in question showing adenomas (59%), more data is needed to supplement current knowledge. These data do however provide patients with important knowledge of the real risks involved in not removing 6-9 mm polyps detected on CTC. The cost implications of repeating the CTC in a very short interval as an alternative with possible optical colonoscopy at that time anyway was also not addressed.
Normalized Distance Along the Colon Centerline: a Method for Correlating Polyp Location On CT Colonography and Optical Colonoscopy
Can the location of a polyp detected on CTC be predicted so that it can be located during a subsequent OC? Summers and colleagues tried to answer this question, and studied 152 polyps in 121 patients. Polyp location on CTC was measured as its normalized distance along the colon centerline (NDACC), which was calculated as: distance of polyp from anorectal junction measured along the centerline divided by the total length of the colon at CTC. Then, during OC, polyp location was predicted by multiplying the polyp’s NDACC with the colon length at OC. Colon lengths are different on CTC and optical colonoscopy. Further, colon length also differs between prone and supine CTC. Mean colon length at OC, prone CTC and supine CTC were about 97cm, 173cm and 179cm, respectively. The authors were able to predict the polyp location to within 10cm of its actual location in 71% of the supine CTC’s and 75% of the prone CTC’s. As suggested by the authors, the method is certainly simple and easy to implement. Going by these results, CTC would not be able to tell the polyp location reliably for 25-30% of polyps. We know that the current miss rates of polyps during OC is in the same range, and for polyps >5mm it is even less, about 10%. Also, the range of colon length at OC during this study was 75cm-119cm, which points to a potential shortcoming of measurement of actual colon length with a straight vs looped colonoscope. So how much this computation would add to the thoroughness of polyp detection at optical colonoscopy is unclear. Another important parameter to test would be the time required on optical colonoscopy to locate isolated 6-9 mm polyps found on CTC.
The Australian Multicentre Colonic Endoscopic Mucosal Resection Database (AMCEMRD) - Progress Towards a More Comprehensive Understanding of EMR and Its Outcomes for Laterally Spreading Tumors (LSTS) of the Colon in a Western Population
Moss and colleagues presented interim results from their ongoing prospective multi-center study on outcomes of EMR for colonic LSTs > or =2cm in size. Data is from 87 patients with LSTs measuring 2cm-8cm in size (mean 3.4cm), 43% of which were in the right colon. EMR was attempted in 95% cases mostly by snare cautery after submucosal injection of normal saline or indigo carmine. Median procedure time was 20 minutes and en bloc resection was possible in 35%. 1 patient had perforation treated by primary surgical anastomosis, and 3 had delayed bleeding requiring hospitalization. Histology: Tubulovillous/Villous 49%, Tubular 33%, Sessile Serrated Adenoma (SSA) 16%, Hyperplastic 1%. High grade dysplasia (HGD) was present in 25%. HGD was significantly associated with larger lesions and increasing Kudo pit pattern. Submucosal invasion was present in 5 cases and was more likely in non-granular (3/15) vs granular appearing (2/72) lesions. Surgical specimens from patients with SMI showed no cancer in 1, T1N0M0 in 2 and 2 patients were awaiting surgery. Thus, piecemeal EMR can be effective for majority of LSTs. Further results from this ongoing study will be eagerly awaited.
A Multi-Center Retrospective Study of 1,111 Colorectal Endoscopic Submucosal Dissections (ESD)
ESD in increasingly being applied in the treatment of colorectal neoplasms. Saito and colleagues reported retrospective multi-center data of >1000 ESDs. Histologically there were 357 tubular adenomas, 519 intramucosal cancers, 112 superficial submucosal (sm) cancers, 101 sm deep cancers, 15 carcinoid tumors and one MALT-lymphoma. Macroscopically, 419 LST-NGs, 537 LST-Gs, 30 depressed, 62 protruded, 44 recurrent and 19 SMTs. En-bloc resection was possible in 88% and the curative resection rate was 89%. Mean procedure time was about 2 hours and mean resected specimen size was about 4cm (range 0.6-15cm). Remarkable from the study were the complication rates: 58 (5.2%) cases had perforations during the procedure, 4 cases had delayed perforations and 4 had post-op bleeding. Total of 5 patients with perforation required emergency surgery. Furthermore, the perforation rate was low at high volume centers (2-9%), but much higher at the two centers performing <50 ESD cases (36% and 13%, respectively). It is interesting to review this study in light of the Australian study above. Indeed, ESD has high en bloc resection and curative rates, but given longer procedure times and much higher complication, ESD may become irrelevant for difficult colorectal neoplasms, especially if the EMR technique can be further refined. This study also emphasizes the importance of operator experience and training if colorectal ESD is to be undertaken.
Colonoscopic Full-Thickness Resection Followed By Tissue Apposition - An Option for Recurrent Colon Polyps Tethered to the Colonic Wall with Scar Tissue
Taking it up a notch from the prior study, Gottumukkala and colleagues have been trying to perfect the technique of colonic full thickness resection (CFTR) followed by successful tissue apposition, in an animal model. They suggest that this could be an effective and safe technique for polyps that are not completely removable by snare, especially if they are tethered to the colon wall with scar tissue. After creation of a 2cm hole in the distal colon of 20 pigs (10 on mesenteric side and 10 on anti-mesenteric side) by full thickness resection that was achieved by an IT knife cut followed by use of grasping forceps and a snare to resect the specimen. Following this, tissue apposition system with T-tags was used to close the defect. The animals were sacrificed at 2 weeks to evaluate for complications. CFTR was successful in all cases, and suture closure was successful in 19 (95%). At necropsy after 2 weeks, 1 animal had evidence of peritonitis with a 2mm hole at the suture site. 2 of 132 T-tags were inserted into adjacent viscera, but none of the animals had evidence of any injury to adjacent organs. This bold experimental technique could certainly be an option for tethered benign colonic neoplasms. And success at closure of full thickness defects in the viscera is of great interest in this time when NOTES is gaining momentum. Ultimately, such techniques will need to compare favorably in terms of efficacy and complication rates with minimally invasive laparoscopic surgery for such lesions not amenable to EMR.
Section 9: Endoscopic Approaches To Barrett’s Esophagus
This forum involved the presentation of abstracts which focused on the management of Barrett’s esophagus (BE), from evaluation of BE to ablation to endoscopic mucosal resection (EMR).
Endoscopic Radiofrequency Ablation of Barrett’s Esophagus: Safety and Efficacy Outcomes in 429 Patients Treated in a Multi-Center Community Practice Registry
The authors presented their experience for radiofrequency ablation (RFA) for dysplastic and non-dysplastic BE in a community practice. Subjects had BE (median 3cm) with either non-dysplastic, LGD or HGD BE and RFA was performed every 2-4 months with follow-up (median follow-up 20 months) biopsies at each endoscopy after RFA. No serious adverse events were seen among 429 patients included (788 procedures), although 9 strictures occurred (1.1% by procedure). Among those patients with greater than 1 yr follow-up (n=137), complete remission of dysplasia and intestinal metaplasia was seen in 100% and 77% of patients, respectively. The authors conclude that RFA demonstrated a favorable safety and efficacy profile in this large cohort of patients treated in the community setting. Limitations included that surveillance, biopsy protocols and management was not standardized among participating gastroenterologists. Furthermore, pathology was not read at a centralized location.
Endoscopic Therapy in 1059 Patients with High Grade Dysplasia and Early Adenocarcinoma in Barrett’s Esophagus-Lessons We Have Learned
The authors presented 5 year follow-up data from a large prospective study investigating the efficacy and safety of endoscopic treatment of BE. Among 1059 patients (n=106 HGD and n=953 mucosal adenoCA) treatment included EMR and photodynamic therapy. Median follow-up of 56 months and 2142 EMRs and 140 photodynamic therapy procedures were performed. Complete remission of neoplasia was achieved in 90.5% and 93.5% when excluding patients with submucosal carcinoma. Recurrence or metachronous neoplasia was observed in 12.9%. However, endoscopic re-treatment was successful in 81.5% of these patients resulting in a long term complete remission rate of 88.3% (90% for mucosal CA). The authors conclude that excellent long term results can be achieved in the appropriate patients with HGD or early adenocarcinoma using endoscopic therapy alone.
Barrett’s Esophagus Ablation with Multipolar Electrocoagulation; Long Term Follow-Up
The authors presented their experience with ablation of BE using mulitpolar electrocoagulation (MPEC). 166 patients were included in the study, out of which 139 completed at least 10 years of follow-up. Areas of BE were identified using magnification chromoendoscopy using acetic acid and treated with MPEC (40W with 10Fr gold probe). All patients were placed on PPI after ablation. After ablation, patients were annually followed with magnification chromoendoscopy and 4 quadrant biopsies were taken every 2cm in areas identified at baseline as BE. Only 4.8% of patients developed complications, non requiring hospitalization, and recurrent BE, buried or visual, occurred in 4.8% of patients. No patients developed HGD or cancer during follow-up. The authors conclude that MPEC for BE is safe and effective.
Complications of Endoscopic Mucosal Resection for Barrett’s Esophagus in a Specialized Unit
The authors presented the results and complications of EMR in a large consecutive series from a single large volume unit. 99% of all procedures were performed by a single endoscopist. Between 1995 to 2008, 2513 EMR procedures were performed in 681 patients and 31% of these patients also underwent PDT. 77% of EMR procedures were performed using the Olympus kit, 5% using the band & snare technique, 18% using the Wilson Cooke Duette kit. There were no perforations. Bleeding occurs in 8 sessions (0.58%). Mean size of EMR specimens in patients with and without bleeding were 1.2cm and 1.1cm, respectively (p>0.1). The authors conclude that this is the largest experience of EMR for BE reported and confirms, in experienced hands, the procedure is safe. Limitations include the fact that this study represents the work of one endoscopist and may not be generalizable.
Results from a Large Prospective Series of Acetic Acid Enhanced Chromoendoscopy in Evaluation of Barrett’s Neoplasia. Is It Time to Change Our Practice?
The authors presented their study evaluating the role of acetic acid chromoendoscopy in the assessment of Barrett’s neoplasia. Data was prospectively collected on patients with BE who underwent chromoendoscopy from 2004-2008. Patients were first examined with white light endoscopy, and subsequently acetic acid (2%) was sprayed to evaluate the pit pattern of Barrett’s mucosa. This was classified as normal, neoplastic or invasive cancer by the endoscopist and afterwards targeted biopsies as well as quadrantic biopsies every 2cm were taken. Among 190 patients, there was excellent correlation (r=0.98) between predicted histology on chromoendoscopy and histology. There was a significant difference (p=0.001) between the pre-chromoendoscopic diagnosis and post chromoendoscopy assisted histology. Chromoendoscopy had a false positive rate of 12% and false negative rate of 2%. The authors concluded that chromoendoscopy significantly improves the diagnosis of dysplasia and cancer in BE patients and the false positive rate is low.
What Are the Outcomes of Endoscopic Radiofrequency Ablation for Very Long Segments of Barrett Esophagus Containing Neoplasia?
The authors presented their results assessing the safety and efficacy of RFA for BE>10cm containing dysplasia. Eligible patients included those with BE with LGD, HGD or early cancer. Patients underwent EMR for visible lesions, followed by RFA every 2-3 months until complete remission achieved. 26 consecutive patients were included, 16 with HGD and 10 with LGD. At entry, 13 pts (50%) had a proximal reflux-associated stenosis and after RFA, 27% had a non-transmural laceration. All patients were able to complete RFA and one patient developed dysphagia after RFA requiring dilation. At the time of presentation, 14 patients completed therapy, 3 patients discontinued treatment due to poor neosquamous regeneration and 9 patients are still under treatment with RFA. Among patients completing therapy 9 (n=14), no recurrence of neoplasia was seen after a median of 9 months of follow-up. No buried BE was found in 752 neosquamous biopsies. The authors concluded that very long segments of BE can be treated with RFA, however in these patients there may be an increase incidence of poor wound healing likely.Section 10: Clinically Relevant Advances in Management of Gastric Neoplasms
Evaluation of Complications of Endoscopic Submucosal Dissection in Gastric Tumors: Analysis in 482 Patients
The purpose of this study was to determine the complications of endoscopic submucosal dissection (ESD) which has recently facilitated en bloc removal of widely spread lesions in the stomach. This was a retrospective study aimed to determine factors which influenced serious complications of ESD. They performed ESD for 482 cases (males: females, 353:129; age: 71.0 ± 8.6 years) from December, 2001 to March, 2007. 40 patients had delayed bleeding, 19 patients with perforation, and 5 patients with stricture. The risk factors of patients who received ESD in gastric mucosal tumors for complications were evaluated focusing on resected size, location and operation time, and experience of endoscopists who performed ESD. They also evaluated patients background characteristics including sex, age, BMI, postoperative white blood-cell count (WBC), postoperative C-reactive protein (CRP), drug history of anticoagulant, and underlying diseases of cerebrovascular disorder, ischemic heart disease, liver dysfunction, renal dysfunction, hyperuricemia, hypertension and diabetes mellitus. The study found that regarding post bleeding, a significant risk factor was resected size (P <0.0001). Odds ratio was 8.2 in higher than 51mm as a result of multivariate logistic regression analysis. In terms of perforation, the two risk factors was operation time (P=0.0002) and postoperative WBC (P=0.009). For operation time, the odds ratio was 10.8 in longer than 2 hours as a result of multivariate logistic regression analysis. For postoperative WBC, the odds ratio was 16.0 in >13000/μl. The number of patients who developed strictures was small and only comprised of 5cases. There was no significant risk factor for stricture development, but stricture was limited in the cases with circumferential or subcircumferential resection in the antrum. The study concluded that risk factors for complications of ESD were resected size and operation time, and patients backgrounds including underlying disease were not related to complications.
The Diagnostic Usefulness of Immunohistochemical Staining (IHCS) in Submucosa-Invasive Early Gastric Cancer After Endoscopic Submucosal Dissection (ESD)
IHCS is a useful tool to predict phenotype and prognosis in early gastric cancer. The purpose of this study was to evaluate the clinical differences between SM1 cancer and deeper invaded cancer. From March 2003 to June 2008, 54 patients who received ESD of submucosal gastric cancer were investigated. All pathologic specimens had IHCS to evaluate any differences between 2 groups. groups There were 27 patients in each group. The SM1 group had 6 cases of well differentiated (22.2%), 15 cases of moderately differentiated (55.6%), 4 cases of undifferentiated (14.8%) and mixed type pathology were 2 cases(7.4%). The deeper Group has pathology as follows; well differentiated 2 (7.4%), moderately differentiated 9 (33.3%), undifferentiated 11(40.7%) and mixed type were 5 (18.5%). SM1 group showed intestinal dominant and deeper group had gastric dominant phenotypes (p<0.05). In addition, it was found that the vascular invasion was less noted in SM1 group (p<0.05). There were no significant differences between two groups in expressions of D2-40, VEGF, ki-67, desmin, factor VIII related antigen and lymphatic invasion. Of all 54 patients, D2-40 negative patients had no lymphatic invasion (0/27, p<0.01], VEGF or Factor-VIII related Ag negative patients had no vascular invasion (0/23, 0/32, respectively, p<0.05). Both of VEGF and D2-40 positive group shows 61.1% of lymphatic invasion (11/18) and Both negative group shows no lymphatic invasion (0/14, p<0.05) 11 cases with positive markers of VEGF and D2-40 had surgery. One case of deeper group had nodal metastasis (9.1%). The study concluded that IHCS shows differences between SM1 and deeper group in mucin phenotype and vascular invasion. Of all groups, D2-40, VEGF has high specificity of predictors of lymphatic invasion and Factor VIII related Ag of vascular invasion.
Clinical and Endoscopic Characteristics of Gastric Cancer Missed By Upper Gastrointestinal Endoscopy
Gastric cancer may be missed by upper gastrointestinal endoscopy (UGIE) but the clinical and endoscopic characteristics of the missed cancers have not been investigated. The purpose of this study was to determine the reasons for the misdiagnosis of gastric cancers by UGIE and to investigate the clinical as well as endoscopic characteristics of the gastric cancers not diagnosed by UGIE. They identified 802 UGIE in 630 consecutive gastric cancer patients with a confirmed tissue diagnosis between 2004 and 2008. All UGIE were reviewed and included for analysis if the procedures were performed without a prior diagnosis of gastric cancer. A non-diagnostic UGIE was defined as a negative UGIE performed between 30 days and 3 years before the diagnosis of gastric cancer. They analyzed the cancer-related and endoscopy-related characteristics associated with the non-diagnostic UGIE. The study found a total of 397 procedures (in 311 patients) and identified 86 non-diagnostic UGIEs (in 51 patients with 22 early and 29 advanced cancers). The non-diagnostic rate was 21.66% (86/397). They determined that the three probable reasons for missing the diagnosis: (1) the lesion was not detected in 57 UGIE (66.28%), (2) the lesion was misinterpreted without a biopsy in 11 UGIE (12.79%), and (3) the lesion was misinterpreted and not followed up with a false-negative biopsy in 18 UGIE (20.93%). Non-diagnostic UGIE was associated with early gastric cancer (odds ratio [OR] =1.82 after adjustment for diameter of the cancer, p=0.048), small cancer size (OR=1.17 for each centimeter shorter in diameter after adjustment for invasion depth, p=0.025), and Borrmann type III or IV in patients with advanced cancers (compared with Borrmann type I or II, p<0.001). Among the endoscopists who performed at least 10 UGIE in patients with undiagnosed gastric cancers, the missing rate varied significantly from 10% to 42.9% (p=0.019 between these two endoscopists). Non-diagnostic UGIE was significantly associated with an inspection time less than 3 minutes (OR=2.84 after adjustment for different endoscopists, p=0.001). 5) The study concluded that gastric cancer missed by UGIE is not uncommon. Failure to detect the lesion, misinterpretation, and inadequate follow-up are the main reasons of the non-diagnostic UGIE. Characteristics of the gastric cancers missed by UGIE are early cancer, small size, and Borrmann type III or IV in advanced cancers. Endoscopy-related characteristics include the specific endoscopist and an inspection time less than 3 minutes.
Importance of Diagnostic Endoscopic Resection to Compensate Histological Discrepancy Between Endoscopic Forceps Biopsy and Resected Specimens in Superficial Gastric Neoplasms
Endoscopic forceps biopsy is a basic diagnostic modality for the histologic diagnosis of superficial gastric neoplasms. The purpose of this study was to assess the limitation of forceps biopsy, and to investigate the diagnostic role of endoscopic resection (ER) in superficial gastric neoplasms. From December 2006 to November 2008, a total of 195 patients with superficial gastric neoplasms detected by surveillance endoscopy were enrolled for this study. They underwent an endoscopic forceps biopsy and the subsequent ER (endoscopic mucosal resection or endoscopic submucosal dissection). They analyzed the clinical and endoscopic characteristics of the patients and compared the histologic results of forceps biopsy specimens with those of the ER specimens. The study found a total of 209 lesions in 195 patients. The total histological discrepancy rate was 50.7% (50.3%, 85/169 lesions) in adenoma, 52.5%, 21/40 lesions in EGC). In 108 cases of low grade adenoma diagnosed by forceps biopsy, final diagnosis was changed after ER in 44 (40.7%) cases (20 high grade adenoma, 12 gastric cancer, 12 gastritis) (p<0.05). Among various endoscopic features, the size (>20 mm in diameter) and the surface color (red-colored lesion) of the lesion were significantly associated with the histologic discrepancy (p < 0.05). In 40 cases of EGC diagnosed by forceps biopsy, type of differentiation was changed in 20 cases (50%), and one EGC revealed high grade adenoma. The study concluded that the histologic discrepancy rate between the endoscopic forceps biopsy and ER specimens was as high as 50%, and endoscopic forceps biopsy is insufficient method to decide therapeutic plan in superficial gastric neoplasms. Therefore, superficial neoplastic lesions in the stomach should be completely resected by ER for complete diagnosis and definitive treatment.
Endoscopic Management of Type I Gastric Carcinoid and Recurrence Rate
Type I gastric carcinoids (TIGC) are “rare” neuroendocrine neoplasms arising from ECL cells in the background of atrophic body gastritis, due to gastrin growth effects. The diagnosis of TIGC is often accidental as patients may be asymptomatic, and these tumors are usually benign. The purpose of this study was to determine the safety of a conservative management of TIGC patients, and their recurrence rate after endoscopic removal. The study was a prospective study with consecutive patients with TIGC (diagnosis of gastric well-differentiated neuroendocrine tumor associated with atrophic body gastritis) who had at least one gastroscopy after the first diagnosis. It excluded those patients who had treatments other than endoscopical resection (polypectomy or mucosectomy). The study found that 29 patients (69% females), median age 65 (23-81), median fasting gastrin 625 pg/ml (43,6-2800; nv<40 pg/ml). 68% had dyspepsia, 76% had anemia (45% pernicious anemia). 21 patients (72%) had polypoid carcinoids (median diameter: 6 mm; 2-20) and 8 (28%) had intramucosal carcinoid. Multiple polypoid lesions in 13 patients (45%). Associated severe atrophy in 19 cases (65%), but also mild atrophy in 14%. The median follow-up was 43 months (3-99). No patients died and of the 26 patients who had at least 1 CT-scan or MRI, none had evidence of either local or distant invasion/metastasis. A median of 5 endoscopies performed per patient (2-9) after diagnosis. The recurrence rate of TIGC was 55% (16/29). The median time of first recurrence was 6 (3-54) months from diagnosis; all the patients with recurrence had polyps, 50% multiple. A second recurrence occurred in 10/29 patients (34,5%), after a median of 14,5 (5-51) months from diagnosis and 7 (2-19) from previous carcinoid removal. Neither demographics, biochemical (gastrin, chromogranin-A values)or histological features could distinguish between the 16 recurrent and the 13 non-recurrent patients. The study concluded that TIGC is a benign condition despite the high recurrence rate. Endoscopic polyp removal and subsequent follow-up with is safe and is recommended in the first three years after diagnosis, while radiological evaluation is not necessary.
Diagnosis of Chronic Atrophic Fundal Gastritis By Autofluorescence Imaging Videoendoscopy
The diagnosis of atrophic fundal gastritis is important for assessing risk of gastric cancer and understanding the pathogenesis of gastric diseases. Autofluorescence imaging videoendoscopy (AFI) may enable detection of mucosal features not apparent by conventional white-light endoscopy. The purpose of this study was to estimate the diagnostic accuracy of AFI in atrophic fundal gastritis, and to determine how colors in the AFI images relate to histological changes of gastritis. 77 patients who underwent gastroscopy by AFI were enrolled. Images of the gastric body in AFI and white-light mode were taken to assess extent of gastritis, and biopsies were taken from each green (n=119) and purple (n=146) mucosa. The diagnostic accuracy of green mucosa for chronic fundal gastritis was evaluated as a main outcome measurement. The study found that the accuracy of green mucosa for activity, inflammation, atrophy and intestinal metaplasia was 55%, 62% 76% and 76%, respectively. Green areas in the gastric body exhibited more inflammation, atrophy and intestinal metaplasia, whereas purple areas rarely contained atrophy and intestinal metaplasia. The kappa statistic for inter- and intra-observer agreement of AFI on diagnosis of extent of atrophic gastritis was 0.66 and 0.47, respectively. The study concluded that AFI could diagnose the extent of atrophic fundal gastritis as a green area in the gastric body, with higher reproducibility compared with white-light endoscopy. In addition, they concluded that AFI may be a useful adjunct to identify patients at high risk of developing gastric cancer.
Section 11: Hemostasis in Endoscopy: How to Stop the Flood?
Endoscopic Hemostasis with High-Frequency Soft Coagulation for Bleeding Gastric Ulcer: Comparison with Metallic Hemoclips in a Prospective, Randomized Study
The endoscopic high-frequency soft coagulation (ICC200 or 350, VIO300D;ERBE,Germany) was recently developed in Japan and is available for management of gastric bleeding in cases of bleeding gastric ulcers and bleeding during endoscopic submucosal dissection. The purpose of this this study was to evaluate the efficacy of hemostasis with soft coagulation for bleeding gastric ulcers by comparing with hemoclips in a prospective, randomized trial. This study concluded that the soft coagulation method is efficacious. The initial hemostasis ratio was not different between two tested groups. The time required to achieve hemostasis was shorter in the patients treated by soft coagulation and the rebleeding rate tended to be less compared to hemoclips, which might indicate usefulness of soft coagulation method for bleeding.
Effect of Type of Endoscopic Hemostasis and Adjuvant Intravenous Esomeprazole On Peptic Ulcer Re-Bleeding
This was a double-blind, randomized clinical trial (NCT00251979), i.v. esomeprazole (80mg infusion over 30min, then 8mg/h for 71.5h) compared with matching placebo for prevention of re-bleeding after successful endoscopic hemostasis of a single (≥5mm diameter; Forrest class Ia, Ib, IIa, or IIb) bleeding gastric or duodenal ulcer. The study found that the type of endoscopic hemostasis in PUB pts with high-risk stigmata had no relevant effect on re-bleeding rates in this study. This suggests that significant improvements or trends for reduced re-bleeding were seen with adjuvant esomeprazole regardless of whether endoscopic treatment was administered as monotherapy or combination therapy.
Is There a Subgroup of Patients with Forrest IB (Oozing) Peptic Ulcer Bleeding At Increased Risk of Re-Bleeding?
This study is a report of the re-assessment by the study Endpoint Committee (EpC) of re-bleeding among patients (pts) with Forrest Ib (oozing) ulcers to determine whether a subgroup indeed exists that exhibits increased risk of re-bleeding. The study concluded that among PUB, pts with Forrest Ib (oozing) ulcers, a subgroup with both a clot or a visible vessel and oozing appears to have an increased risk of re-bleeding vs those with only oozing and no additional stigmata. Modification of the Forrest Ib classification may therefore increase its precision in identifying PUB pts with a higher risk of re-bleeding.
Optimizing Monopolar Coagulation Therapy for Non-Variceal Upper Gastrointestinal Bleeding
The purpose of this study is to determine the optimal performance characteristics of an endoscopic monopolar electrocautery device for the upper GI tract. The study concluded that the optimal settings for monopolar coagulation during upper endoscopy appear to be 25 watts with durations of therapy between 3 to 5 seconds. Monopolar coagulation is an alternative modality for endoscopic management of non-variceal upper gastrointestinal bleeding.
The Use of N-2-Butyl Cyanoacrylate As a Rescue Therapy for Re-Bleeding and Uncontrollable Bleeding from Esophageal Varices
The purpose of this study was to use of N-2-butyl cyanoacrylate as a rescue therapy for uncontrollable bleeding and re-bleeding from esophageal varices. The study concluded that the use of N-2-butyl cyanoacrylate injection in esophageal varices as a rescue therapy in cases of uncontrolled bleeding or re-bleeding is an effective and safe endoscopic technique with less morbidity and mortality than other rescue modalities.
Magnification Endoscopy Can Help in Improving Characterization of Visible Vessels in Peptic Ulcer Bleeding: a Pilot Study
The purpose of this study was to investigate the role of magnification endoscopy (ME) in improving the characterization of exposed vessels in ulcer hemorrhage. The study found that in patients with peptic ulcer bleeding and exposed vessels in the ulcer crater, magnification endoscopy allows clear visualization of the vessel wall and provide detailed clues to further characterize the lesion in terms of recurrent bleeding risk.
Long-Term Endoscopic Obliteration with Cyanoacrylate Glue for Isolated Gastric Variceal Bleeding - a 15-Year Prospective
This is a 15- year prospective study that evaluated the efficacy and safety of modified endoscopic obliteration with cyanoacrylate glue adopted for the management of isolated gastric variceal bleeding. The study found that endoscopic obliteration with cyanoacrylate glue is highly effective for the management of the isolated gastric variceal bleeding, and is associated with few complications, both in the short-term and in the long-term. The prognosis of the patients depends on the severity of the underlying liver disease.
Section 12: Beyond Bread and Butter Cholangiography
This ASGE topic forum primarily focused on advanced imaging modalities of the hepatobiliary tree. An additional abstract was presented which compared endoscopic sphincterotomy (ES) to ES coupled with endoscopic balloon dilatation (ESBD) in removing large common bile duct stones. Dr. Gregory Ginsburg summarized the forum with a state-of-the-art lecture concluding that advanced endoscopists need to develop a new paradigm in pattern recognition during cholangioscopy. He also added we should add ESBD to our endoscopic armamentarium in removing large common bile duct stones.
Diagnostic Accuracy of a New Shortened Peroral Cholangioscope in Indeterminate Biliary Strictures and Filling Defects
The investigators prospectively enrolled 58 patients with either indeterminate biliary strictures or filling defects with a 95 cm prototype cholangioscope inserted via the lateral port of a duodenoscope. The cholangioscope offered four way tip deflection and had a 3.5 mm outer diameter with a 1.5 mm working channel. The aims of the study were to determine the diagnostic accuracy in visualization/characterization of indeterminate strictures. Endoscopic features suggesting malignancy included strictures with “circular stenosis” and “irregular surface or margins”. Forty patients had indeterminate strictures. 16/17 malignant strictures and 21/23 benign strictures were correctly classified using the endoscopic criteria listed above (sensitivity 94.1%; specificity 91.3%). Endoscopic guided biopsy yielded malignant histology in 11/17 strictures (sensitivity 64.7%). Of the 18 patients with filling defects, 16 had stones that were removed with conventional methods or visually guided laser lithotripsy. The authors concluded the new shortened peroral cholangioscope was an accurate tool in differentiating indeterminate strictures/filling defects and improved histologic yield with directed biopsy.
It Looks Like Cholangiocarcinoma – But is It? Cholangioscopy Using a Cholangioscopy System for Diagnosis of Cholangiocarcinoma in Patients with Primary Sclerosing Cholangitis
This abstract focused on diagnosing cholangiocarcinoma (CC) in patients with underlying primary sclerosing cholangitis (PSC) using the SpyGlass™ (Boston Scientific, Natick, MA) cholangioscopy system. Eleven patients with PSC were followed for a mean of 7 months. The bile duct lesions were then assessed and characterized using known cholangioscopic features of CC including polypoid or intraductal masses, tapered narrowing, ductal ulceration, and torqued tumor vessels. All patients were successfully imaged and had stenosis of either the common hepatic duct or common bile duct. 11/17 patients were found to have predefined cholangioscopic features of CC, however none of the stenoses demonstrated torqued tumor vessels or ductal ulceration. All strictures were brushed and biopsied and no evidence of malignancy was noted. The authors concluded that SpyGlass™ cholangioscopy is an effective means of evaluating bile duct strictures in patients with underlying PSC. However, in the absence of torqued tumor vessels and ductal ulceration, the other predetermined cholangioscopic features of CC are not necessarily predictive of CC.
3D Imaging of Intrahepatic Strictures During Endoscopic Retrograde Cholangiography (ERC): First Clinical Data
Using a 150° rotational C-arm, the investigators in this study examined computer generated 3-D reconstruction of cholangiographic images taken in seven patients undergoing ERCP with intra-hepatic biliary strictures. ERCP was successfully completed in all patients. Using 3-D construction, improved visualization of stricture length, location, and degree was achieved successfully. The investigators concluded that 3-D reconstruction may improve tumor staging and allow more focused therapeutic interventions to complex strictures. Important issues raised included radiation exposure and the theoretical increase in infection given opacification of all intra-hepatic segments (which may not be drainable).
Adding Balloon Sphincteroplasty to Sphincterotomy in Endoscopic Removal of Large Bile Duct Stones – A Randomized Controlled Trial
This abstract from China compared removal of large common bile duct stones via ERCP with ES versus ESBD. The primary outcome was ductal clearance at first endoscopy. Secondary outcomes included time of procedure, complications, and need for mechanical lithotripsy. 42 patients were randomized to each arm and both groups were similar for stone size, bile duct diameter, concomitant NSAID/aspirin use, age, and presence of peri-ampullary diverticulum. Patients with pre-cut assess sphincterotomy, cirrhosis, and septic shock were excluded. Conventional measures were used for stone extraction after ES or ESBD. A 15 mm Boston Scientific CRE balloon (Natick,MA) was used for sphincteroplasty and inflated to the size of the duct. No differences were noted in the primary outcome (ES=92%, ESBD=88% p=0.71). No difference in time (ES= 25±- 13 min, ESBD= 28±13 min; p=0.28), need for mechanical lithotripsy (ES=36%, ESBD=26%; p=0.035), or rates of complications. The authors concluded ESBD is as safe and similar in efficacy in removing large bile duct stones and does increase procedure time significantly.
Intraductal Ultrasonography Can Discriminate Between Sclerosing Cholangitis Associated with Autoimmune Pancreatitis and Primary Sclerosing Cholangitis
The aim of this retrospective Japanese study evaluated intraductal ultrasound (IDUS) in differentiating sclerosing cholangitis associated with autoimmune pancreatitis (SC-AIP) from PSC. The investigators used a 20 MHz over the guidewire probe (Olympus, Tokyo,Japan) for IDUS. A total of 17 patients were studied (8 PSC, 9 AIP) and all had IDUS performed from the hilum to the papilla. IDUS features were evaluated including symmetric thickness (89% SC-AIP vs. 25% PSC), wall thickness (3.0±1.0 mm SC-AIP vs. 2.1 ±0.7 mm PSC), presence of a heterogeneous internal echo (66.7% SC-AIP vs. 22.2% PSC, and presence of lateral mucosal lesions continuous to the hilum (55.6% SC-AIP vs. 11.1% PSC). The authors concluded that symmetrical thickness of the bile duct, a heterogeneous internal echo, and the presence of lateral mucosal lesions continuous to the hilum were significantly more detected in SC-AIP than PSC cases (P<0.05).
Video Cholangiopancreatoscopy (CP) with Narrow Band Imaging (NBI): Spectrum of Mucosal and Vascular Patterns with Pancreaticobiliary (PB) Pathology
This ongoing prospective study from the University of Colorado evaluated the use of NBI during CP. The aims of the study were to determine if NBI improved CP findings and to provide descriptive terminology of CP-NBI findings for a variety of PB pathology. A total of 19 patients were evaluated with CP-NBI using an Olympus CHF-Y0002 (Olympus, Tokyo,Japan) cholangioscope with a prototype duodenoscope. The authors concluded the following: 1) video CP enhances detection of tumor vessels (NBI enhanced imaging of tumor vessels in 2 patients and detected tumor vessels missed in one patient with white light cholangioscopy), 2) the presence of pseudodiverticulae are secondary to cholestasis and can be seen in both benign and malignant disease, 3)band-like scarring is a benign feature, 4)low papillary projections may be stent induced or seen with IPMN and cholangiocarcinoma, and 5)long term follow up is needed to determine the predictive value of video CP-NBI findings.
Section 13: Esophageal Potpourri
This topic forum included the presentation of six abstracts dealing with a variety of esophageal issues including new cutting edge endoscopic therapies.
First Clinical Experience of Submucosal Endoscopic Esophageal Myotomy for Esophageal Achalasia with No Skin Incision
This abstract discussed the current management of esophageal achalasia and described a new endoscopic management for this problem. Currently the Heller-Dor myotomy is the surgery of choice for esophageal achalasia but requires at least 5 skin incisions. The authors described the use of a modified Pascricha technique as per-oral endoscopic myotomy (POEM) for esophageal achalasia in one patient. This technique involves a longitudinal mucosal incision in the esophagus into the submucosal space that is tunneled down to the gastric cardia using techniques of ESD. The thickened esophageal muscle bundle is totally dissected, and the mucosal entry is closed using an endoscopic clipping device. The patient?s post procedure barium swallow demonstrated total release of the thickened LES. This is the first reported successful clinical case of POEM.
Predictive Factor of Local Recurrence After Endoscopic Resection of Large Esophageal Squamous Cell Carcinoma
Endoscopic resection (ER) is increasingly being used for the treatment of esophageal cancer. This study investigated the pre-treatment risk factors for local recurrence after ER of large esophageal cancers. ER using endoscopic mucosal resection (EMR) or endoscopic submucosal dissection (ESD) was indicated for lesions without ulcer or obvious protrusion suggesting invasion to a deeper part of the submucosal layer. From September 1994 to June 2007, the group treated 449 esophageal cancers in 302 patients by endoscopic resection. 106 lesions met the study inclusion criteria: (1) lesions measuring 20 mm or more in diameter, (2) tumor invasion depth of m1-sm1 without lymphovascular involvement, (3) histologically proven squamous cell carcinoma, (4) no additional treatment immediately after ER, and (5) follow-up longer than 1 year, with more than two follow-up endoscopies. At a median follow-up of 34 months there were 12 (11.3%) local recurrences, one from ESD group and 11 from EMR group. There was no significant association between local recurrence and age (P=0.27), gender (P=0.17), multiple iodine-unstained lesions (P=0.79), tumor size (P=0.15), or circumferential spread of tumor (P=0.054). However, the endoscopic resection method was significantly associated with local recurrence (P=0.011). The authors concluded that to minimize local recurrence, esophageal squamous cell carcinoma measuring 20 mm or more in diameter should be treated by ESD.
Long-Term Outcomes of Endoscopic Submucosal Dissection for Superficial Esophageal Squamous Cell Neoplasms
Similar to the previous study, this study evaluated the long-term outcomes of ESD for superficial esophageal squamous cell neoplasms (ESCN). From January 2002 to July 2008, 107 consecutive superficial ESCNs, which were proven as or suspicious of squamous cell carcinoma, in 84 patients were treated by ESD. En bloc and complete resection rates were 100% and 87.9%, respectively. Perforation accompanied with mediastinal emphysema was observed in 4 patients (3.9%). No patient experienced massive bleeding. In the median observation duration of 632 days, fifteen patients experienced esophageal benign stricture with dysphagia which was successfully managed by median two sessions (range, 1-20) of balloon dilatation. One patient had local recurrence at the 6th month after ESD. In two patients with m3 carcinomas, distant metastases were observed at the 18th and the 9th month after ESD, respectively. In observation duration, three patients died from esophageal carcinoma. The 5-year disease-specific survival rates of A group and B group were 100% and 84.9%. The authors concluded that ESD could become a curable treatment for superficial ESCNs.
Erroneous EGD-Guided Placement of the pH Capsule Is Common - Time to Hold the Applause?
The authors? aim was to determine the accuracy of EGD-guided Bravo capsule placement using manometry as the gold-standard. They comment that the recommended EGD-guided placement of the Bravo pH capsule is 6 cm proximal to the squamocolumnar junction (SCJ) which corresponds to 5 cm above the proximal border of the manometric LES. The analyzed all patients undergoing high resolution esophageal manometry on the same day prior to EGD-guided Bravo capsule placement between 1/07 and 8/08. They used a validated conversion factor of 4 cm subtracted from the manometric nares-proximal border LES distance to calculate mouth-LES distance. Then 5 cm was subtracted to obtain estimated accurate Bravo location (EL) from the mouth.
Actual capsule attachment location (AL) from the incisors was obtained from the EGD report. Difference between AL and EL is the error in placement. Accurate placement for AL was defined as placement within ± 3 cm of the EL. The study examined 147 patients, and accurate placement of the capsule was seen in only 91/147 (62%) patients.
In patients with an inaccurate placement it was more often placed too proximal to the EL (52/56 =92.9% or 35.4% of all patients undergoing capsule placement) rather than too distal (4/56=7.1%). Despite these results, misplacement did not effect the % of patients with a positive pH study for the study group.
Benign Refractory Esophageal Strictures: Preliminary Results from the BEST (Biodegradable Esophageal Stent) Study
This study evaluated the use of a new biodegradable stent (BD Ella Stent) for the treatment of refractory benign esophageal strictures. Twelve patients with benign esophageal were treated by placement of a biodegradable BE Ella stent. The patients had undergone a mean of 6.8 dilating sessions before stenting. Patients were followed at regular interval and endoscopy was scheduled at months 1, 2, 3, 6 and afterwards in case of dysphagia recurrence. Stents were successfully placed in all patients. No early complications occurred. Pre-stenting mean dysphagia score was 2.8. After a median follow-up of 22 weeks, mean dysphagia score was 0.25 with 10/12 patients free of dysphagia and 2 patients with persistent but mild dysphagia. Stent migration was observed in 2 patients (17%). In this preliminary evaluation, the biodegradable appeared to be successful in relieving dysphagia in a small group of patients with refractory benign esophageal strictures.
Complications of Long-Term Esophageal Stenting in the Management of Benign Perforations
This study investigated the value of self-expandable metal stent (SEMS) placement for non-malignant esophageal defects. This was a prospective single center observational study of 32 patients. The majority of perforations were iatrogenic (n=19), other causes included Boerhaave’s syndrome (n=9), trauma (n=1), foreign body (n=1) and anastomotic leakage (n=2). Three patients received a fully-covered SEMS and 29 patients received a partially-covered SEMS. Placement was technically successful in all patients. Three patients with Boerhaave’s syndrome required an esophagectomy because of immediate stent failure. The overall 90 day mortality rate was 19%. Stent migration occurred in 10 patients after a median of 12 days, requiring stent reposition (n=4), additional stent insertion (n=3) stent removal (n=1), or no intervention (n=2). Twelve patients required 16 additional stents for either persistent leakage during stent therapy (n=8) or after SEMS extraction (n=8). A total of 31 endoscopic stent extractions were performed with the majority performed within the first 6 weeks. The extractions within 6 weeks were without complications but complications occurred in half of the extractions performed after 6 weeks. The authors concluded that in patients with a benign esophageal perforation, stenting is effective and surgery can be avoided in 72% of the patients. However, it is important to be aware that complications due to SEMS removal can be prevented by removal of the SEMS within 6 weeks after insertion.
Section 14: Endoscopic Alternatives To Surgical Therapy
This session featured abstracts presenting novel endoscopic techniques, which may eventually emerge as feasible alternatives to traditional surgery. Dr. Pankaj J. Pasricha concluded the session with his State-of-the-Art Lecture, ?The Gastroenterologist as Surgeon: What Do You Want to Be When You Grow Up?? In his lecture, he wittily contemplated the various techniques presented in this topic forum along with other innovative procedures as performed by the surgeon (?the eagle?) and the endoscopist (?the snake?).
Randomized Comparative Trial of Transesophageal Endoscopic Versus Thoracoscopic Removal of Marked Mediastinal Lymph nodes in a Long-Term Animal Survival Study
This randomized porcine model study presented by Annette Fritscher-Ravens compared transesophageal endoscopic vs thoracoscopic lymph node removal for sampling potentially malignant lymph nodes. This study supported by a grant from NOSCAR evaluated a new anchoring device for NOTES lymphadenectomy, in addition to, a technique for lymph node creation in a porcine model utilizing a graphite injection. Lymph nodes were created in the mediastinum of 12 pigs, which were confirmed by EUS two weeks later. EUS-guided anchor (through a 19-gauge needle) and T-tag were fired into selected lymph nodes prior to randomization. Endoscopic lymph node resection required a 1.5-2.0 cm full-thickness esophageal incision following identification of the t-tag and anchoring device, in addition to node removal and resection. Thoracoscopic lymph node resection was performed by standard techniques. All marked nodes were detected and retrieved, in both study arms. Full-thickness esophageal incision resulted in bleeding in one case and was treated endoscopically. There was no statistical difference in time for lymph node resection between both groups. Thoracoscopic resection equaled 42± 28min, with a larger amount of the time spent finding the marked lymph node. Meanwhile, endoscopic resection equaled 48 ± 15min, with a larger amount of the time spent in incision repair. This study showed that endoscopic transesophageal removal of mediastinal lymph nodes is possible using a new anchoring device, with similar safety and duration of procedure compared to thoracoscopic removal.
Endoscopic Magnetic Anastomosis Device for Palliation of Malignant Gastric Outlet Obstruction: Short Term Results of a Prospective Multicenter Study
Jeanin E. Van Hooft presented the short-term results of this prospective multicenter pilot study investigating the safety and feasibility of a novel endoscopic technique for the creation of a gastro-jejunal anastomosis using the Cook Magnetic Anastomosis Device? in the treatment of symptomatic malignant gastro-duodenal obstruction in end-stage peri-gastroduodenal malignancies. Secondary outcome measures were the improvement in tolerance of oral feeding using the Gastric Outlet Obstruction Scoring System (GOOSS), the rate of stent migration and the duration of patency of the stented anastomosis. Patients were followed for 180 days, until stent occlusion, recurrence of gastric outlet obstruction, surgical resection or death. Eighteen patients (out of a total of forty patient planned for enrollment) have been included so far with the successful deployment/ alignment of the magnets in fifteen patients and successful stent placement in twelve patients. Complications included stent perforation in 1/12 patients and stent migration in 3/12 patients and the GOOSS score improved from 0.6 to 2.0. The mean time to the creation of an anastomosis was 11.8 days (8-21 days). Stent perforation and migration are issues which need to be resolved in the final phases of the study. The eventual development of a type of anastomosis which has no tendency to close and therefore does not need a stent is still to be developed. This study showed that endoscopic gastro-jejunostomy creation with the Cook Magnetic Anastomosis Device? is feasible and offers a promising alternative to a surgical gastro-jejunal anastomosis.
T-Bar Assisted Endoscopic Submucosal Dissection (ESD): A New Technique
Makoto Nishimura*, Susumu Shinoura, Reiko Ashida, Raman Muthusamy, John G. Lee, Kenneth J. Chang
A Novel Lumenal Apposition Device for Therapeutic Endoscopy
Kenneth F. Binmoeller described the design and features of a new Lumenal Apposition Device (LAD) composed of a collapsible braided structure delivered through a 10.5 Fr catheter for use in interventional endoscopic procedures. The proximal anchors form a dual-flanged anchor capable of holding adjacent tissues in close apposition while the proximal and distal flanges hold soft tissue in firm apposition without causing pressure necrosis. Bench-top measurements of the pressure exerted on tissue by the LAD flanges were obtained and chronic porcine survival studies were conducted, in which an LAD was placed between the stomach and gall bladder of four survival animals. Flange pressure, tissue reaction and bile drainage was measured or monitored. The force exerted by the LAD flanges was 0.15-0.20 lbs, based on a tissue thickness of 8mm. Animals were free of infection and showed no behavioral changes for the duration of the study. The LAD was well tolerated by both the stomach and gall bladder tissue, which was confirmed by EUS exam and on necropsy. There were no acute complications, the LAD did not dislodge nor displace. Following device removal, fistula was formed without leak. The authors conclude that this novel luminal apposition device extends the reach of therapeutic endoscopy to the extraintestinal organs by enabling a robust and reliable conduit between lumens in and around the GI tract.
Endoscopic Closure of Duodenal Perforations By Means of An Over the Scope Clip (OTSC): A Randomized Controlled Porcine Study
Hans U. Rudolph presented the results of this randomized controlled porcine study evaluating endoscopic closure of duodenal perforations during endoscopy. A 1-cm duodenal perforation was endoscopically created in twenty-four domestic pigs using needle knife incision. The pigs were randomized to either surgical repair by open laparotomy or endoscopic closure using a Twin Grasper and a 12mm traumatic Over The Scope Clips (OTSC). Pressurized leak tests of the perforation closures were performed following necropsy. Pressurized leak tests were also performed in an ex vivo evaluation of hand-sewn closures of 1cm large scalpel incisions (n=18) and of healthy duodenal tissue (n=18). The mean time for endoscopic closure was 5 min and there were no complication during any of the closure procedures. All OTSC and surgical closures showed complete incorporation and closure of the duodenal needle-knife incisions. Pressurized leak test showed a mean burst pressure of 166 mmHg for OTSC closures and a mean burst pressure of 143 mmHg for surgical sutures. Ex vivo hand-sewn sutures of 1cm scalpel incisions exhibited a mean burst pressure of 81 mmHg and ex vivo duodenal tissue exhibited a burst pressure of 247. OTSC closures were comparable to surgical closures (p=0.461) and superior to ex vivo hand-sewn closures (p<0.01). In vivo surgical closures were superior to ex vivo hand-sewn closures (p<0.01). The authors concluded that endoscopic closure by means of the OTSC system allowed adequate closure with ease, with results comparable to in vivo surgical sutures and seems suitable for full-thickness closure of 1-cm large duodenal perforations.
Section 15: Best Practices: Quality in Colonoscopy
Optical Biopsy At Colonoscopy: Are We Ready? DISCARD Study: Early Results
Ana Ignjatovic, Noriko Suzuki, Maggie Vance, Thomas Guenther, Nicky Palmer, Brian P. Saunders
The authors presented the preliminary results of this study which considered the ability of the endoscopist to rely upon the endoscopic enhanced image to determine the recommended surveillance interval and compare this with the information obtained from the actual histopathology of the removed lesions. Of 141 small polyps resected, optical diagnosis was correct in 95% of adenomas and 92% of hyperplastic polyps. Histopathology results did not change the predicted appropriate interval of next surveillance exam for the 57 patients enrolled in the study to date. These data raise the possibility that optical diagnosis using high resolution white light, narrow band imaging or chromoendoscopy may one day eliminate the need for a portion of histopatholgic analysis with potential major resulting cost savings.
More Large Polyps Are Seen On Screening Colonoscopy with Deep Sedation Compared with Moderate Conscious Sedation
This paper explored the CORI database to compare the large polyp detection rate between patients designated at deep vs moderate sedation. Significantly more large polyps > 9mm were found under deep sedation as compared with under moderate sedation [7.2 vs 6%] after controlling for potential confounding variables. While this finding will require confirmation with prospective study, these findings offer provocative evidence that deeper sedation might indeed confer benefit beyond high patient satisfaction.
A Prospective Randomized Controlled Trial (RCT) of Water Infusion in Lieu of Air Insufflation vs. Usual Air Insufflation in Scheduled Unsedated Colonoscopy in United States (US) Veterans
In this randomized trial of water infusion vs. standard air insufflation for unsedated colonoscopy, the water infusion technique led to a significant increase in cecal intubation [100% vs 78% ] and decreased need for position changes . It remains to be seen the effects of this novel and low technology technique upon large polyp detection due to concomitant benefits upon effective prep and upon cecal intubation in difficult examinations conducted under conscious sedation.
Can Quality Indicators for Colonoscopy Be Derived from Administrative Data? Identifying Predictors of New or Missed Cancers After Colonoscopy
These authors explored how physician factors might be associated with the risk of having a missed colorectal cancer on colonoscopy. Factors associated with increased risk of missed cancers in this retrospective analysis include non-gastroenterologist/non-surgeon colonosocpist and office based setting for the procedures. High endoscopist complete colonoscopy rates and high polypectomy rates were associated with lower rates of missed cancers, particularly proximal lesions.
Efficacy of Oblique Transparent CAP with Colonoscope for Trainees Analyzed with Magnetic Endoscope Imaging (MEI): a Preliminary Report
This study is a randomized comparison of colonoscopy performed with or without a transparent cap among 2 trainees with over 150 case experience prior to the study. The authors found significantly shorter cecal intubation times when the cap was utilized, but no differences in cecal intubation rate or pain experienced.
Comprehensive Validation of the Boston Bowel Preparation Scale
The Boston Bowel Prep applies a 4 point standardized scale to rate the prep quality in each of 3 segments. This study was conducted first to test inter and intra-rater reliability of the ratings via review of videotaped examinations. It was then applied prospectively in 990 colonoscopies. As would be expected from a true assessment of colon prep as assessed upon withdrawal, fewer polyps were seen when lower prep scores were recorded in both the left and right colons. The importance of having a reliable easy to use score might probe valuable both as a standard for future comparisons of various preparation regimens as well as a tool for quality assessment of examinations in clinical practice.
Section 16: Interventional EUS Outcomes: Here?s the Beef
Over the last years new exciting areas for interventional EUS have been described but more data is still needed in order to appropriately evaluate the efficacy and safety of this new procedures. This session was focused on reviewing some of the new studies looking at improving accuracy of EUS diagnosis and mostly at safety and efficacy of EUS treatment of pancreatic cystic tumors or biliary and pancreatic duct obstruction.
Enhanced Harmonic Endoscopic Ultrasound (EH-EUS) for assessment of pancreatico-biliary malignancy
This abstract evaluated the accuracy of EH-EUS in staging of pancreatico-biliary malignancies. They enrolled 60 patients and compared Harmonic-EUS with EH-EUS. Final diagnosis was made by surgery in 25 patients. Tumor staging seems to be more accurate with EH-EUS then H-EUS (91.7% to 70%). Was concluded that EH-EUS may help delineate with more accuracy the anatomic tissues layers (mucosa, submucosa and vessels).
EUS-Guided Ethanol Lavage with Paclitaxel Injection (EUS-EP) for Cystic tumors of the pancreas: Long term (more then one year) follow-up
This abstract evaluated the efficacy and safety of EUS treatment of cystic tumors of the pancreas specifically uni-locular cysts with confirmed size growth during observation period. Thirty-three patients were enrolled and followed for a median of 16.8 months. The results showed 22 patients had complete resolution of the cysts and 5 with partial resolution. Two patients had continued growth and were sent for surgery (found to have oligolocular cysts with focal mucinous epithelial lining). There was only one case of mild pancreatitis. This data suggests that EUS with Ethanol Lavage and Paclitaxel injection is safe and efficacious especially for patients with smaller cysts and lower CEA levels.
Accuracy of Endoscopic Ultrasound (EUS), Endobronchial Ultrasound (EBUS) and Bronchoscopy (TBNA) Guided Fine Needle Aspiration (FNA) in patients with enlarged anterior and posterior mediastinal lymph nodes.
This was a large prospective double blind study aimed to evaluate the accuracy of EUS-FNA, EBUS-FNA and TBNA or the combination of methods in staging of NSC-LCA.
362 patients with CT-chest or PET positive nodes were enrolled and split in 3 groups based on the location of the nodes (EUS accessible, EBUS accessible or TBNA accessible). Then EUS-FNA was performed by a gastroenterologist followed by EBUS-FNA performed by a pulmonologist in all patients, each blinded to the results. TBNA was performed only in the third group (subcarinal nodes only). Accuracy was determined after surgery and staging or after 6 months follow-up with CT.
The data from this study confirms that the combination of EUS-FNA and EBUS-FNA has a statistically significant higher sensitivity and negative predictive value then TBNA or EUS/EBUS alone in all groups. This encourages a combined approach with EUS+EBUS FNA (sensitivity of 98%, NP of 98%) in all patients with mediastinal lymph nodes.
EUS-Guided Biliary Drainage with One-Step Placement of newly Designed Fully Covered Metal Stent for Malignant Biliary Obstruction: A prospective feasibility study.
This abstract focused of the safety and efficacy of biliary drainage using EUS guided placement of fully covered self-expandable metal stents (FCSEMS). Twelve patients were enrolled after failed ERCP. Using linear EUS an 8 F stent was placed successfully in all patients with a median procedure time of 25 min. Seven patients had intra-hepatic approach and 5 extra-hepatic. Two patients had mild pneumoperitoneum in the intra-hepatic approach and were managed conservatively. There were no bile leaks in both groups. During a median of 4 months follow up there were no incidence of stent migration or stent occlusion.
Although from a small sample, this data suggests that bile drainage using EUS placement of FCSEMS is safe and effective when ERCP is unsuccessful.
Single-Operator EUS-Guided Cholangiopancreatography (EUSCP) for Difficult Pancreaticobiliary Access: A Single Center 5 year Experience
This is retrospective review of 34 cases that underwent EUS guided pancreaticobiliary access at University of Denver Colorado. Overall technical success was achieved in 28 (82%) patients and was as high as 95% in the biliary cases (18 of 19). PD access was achieved in 67% (10 0f 15) cases. The five cases with failed PD access had non-dilated PD in 2 cases and non-traversable stricture in 3 cases.
Complications occurred in 5 of 34 patients (15%) and included respiratory failure in one patient and pneumoperitoneum in 2 cases after BD access. Pain flair developed in one case and peripancreatic fluid collection in another after PD access (required PTC drainage).
This data suggests that EUSCP is safe and effective so it should be considered as an alternative to PTC especially for biliary duct access when ERCP failed.
Is Endoscopic Ultrasound Guided Brachytherapy (EUS-BrTx) Useful for the treatment of Recurrent malignant lymph nodes?
This is a report on safety, feasibility and efficacy of EUS-BrTx on a small series of patients from one center. There were 4 patients with esophageal CA and one with duodenal CA that had confirmed malignant lymph nodes. Placement of radioactive seeds was successful in all patients during first session with one of the patient required multiple sessions. Overall eleven nodes were treated with no related complications. The median number of seeds implanted was 3.5 (1 to 12). On follow up 7 (63%) nodes decreased in size or disappeared, 2 (18.2%) nodes did not changed size and 2 (18.2%) nodes increased in size.
This data suggests that EUS-BrTx is a safe and feasible procedure with an 82% control rate for locally recurrent node disease.
Section 17: Controversial Issues in Pancreatic Endotherapy
This topic forum addressed various issues of pancreatic endotherapy. The role of pancreatic endotherapy was studied in settings such as prophylaxis of pancreatic fistula post-distal pancreatectomy and idiopathic recurrent pancreatitis. The use of ERCP in diagnosis was also examined in assessing autoimmune pancreatitis. Other topics included describing pancreatic stent-induced duct injury and the use of carbon dioxide compared with air insufflation in ERCP.
Endoscopic Pancreatic Sphincterotomy and Stenting for Preoperative Prophylaxis of Pancreatic Fistula After Distal Pancreatectomy
Pancreatic fistula (PF) is the most common (0-61%) postoperative complication of distal pancreatectomy (DP) and endoscopic pancreatic stenting has been an effective treatment. In the case-control study, 25 patients who had a preoperative endoscopic pancreatic sphincterotomy before DP were compared with 23 patients without preoperative endosopic management before DP was performed by the same surgeon in all cases. PF was defined as an amylase level in surgical fluid more than 5-fold the serum level. DP was done for adenocarcinoma in 26 cases, neuroendocrine tumor in 7, IPMN in 3, cystadenoma in 4, focal pancreatitis or pancreatic pseudocyst in 8. Sphincterotomy was successfully performed in all cases; a 5 French stent was placed in all but two cases. The group with preoperative endoscopic therapy had no cases of PF, while the control group has 5 patients (22%) with a PF. Thus, the authors conclude that prophylactic pancreatic sphincteromy and stenting is safe and prevents PF development after distal pancreatectomy, but a prospective trial is warranted.
Utility of Endoscopic Retrograde Pancreatogram (ERP) to Diagnose Autoimmune Pancreatitis (AIP): An International, Double Blind, Randomized, Multicenter Study
Given that various diagnostic criteria differ on the role of ERP, this multicenter double-blind, randomized study was undertaken to determine the performance characteristics for ERP to diagnose AIP. In the Phase I Study, 200 ERPs of AIP, chronic pancreatitis, and pancreatic cancer were screened for quality by a single experienced endoscopist. A final set of 40 pancreatograms (20 AIP, 10 chronic pancreatitis, 10 pancreatic cancers) were arranged in random order and presented to 21 reviewers (US n = 8, UK n = 8, Asia n = 5) blinded to clinical data or diagnoses. The specificity for AIP was high at different centers: USA 92%, UK 95%, Asia 89% (p-value NS) whereas the sensitivity varied widely from USA 33%, UK 40%, Asia 71% (p-value < 0.05). The inter-observer agreement was poor in the US and UK, but fair in Asia. The four top performing readers had a sensitivity of 92% and specificity of 94%, well out-performing the others. In the Phase II Study, the inputs and diagnostic criteria developed by the top Phase I performers were incorporated into a teaching module that was re-sent to the 21 readers. The pancreatographic features of AIP per the best readers were (1) long stricture (>1/3rd of MPD or 6cm) (2) lack of upstream dilatation (3) multiple, non-contiguous strictures (4) side branches arising from the strictures region. Now, the specificity for AIP decreased and was USA 84%, UK 83%, Asia 80% (p-value NS) whereas the sensitivity increased as was USA 65%, UK 63%, Asia 91% (p-value < 0.05). The inter-observer agreement was fair across the board. The authors concluded that using ERP alone may by limited in diagnosing AIP, but may be helpful when combined with other diagnostic criteria.
The Therapeutic Strategy for Autoimmune Pancreatitis Is Subject to Endoscopic Features of the Duodenal Papilla
This study tried to determine the predictive factors and endoscopic features for spontaneous remission and relapse of autoimmune pancreatitis (AIP). They took 53 (40 male/13 female, mean age 67 years) consecutive AIP patients and various factors influencing the course of AIP. A univariate analysis revealed a significant association of spontaneous remission with serum negativity for IgG (<1800 mg/dL), the absence of obstructive jaundice, absence of underlying diabetes, and the absence of swelling of the duodenal papilla and localized as opposed to diffuse pancreatic swelling (p<0.05). A multivariate analysis revealed the absence of swollen duodenal papilla as the only significant independent factor predicting spontaneous remission in these cases (OR = 1.96, P = 0.022). A multivariate analysis revealed that the presence of a swollen duodenal papilla (OR = 14.8, p = 0.0182) and the presence of extra-pancreatic lesions (OR = 12.7, p = 0.0258) as independent risk factors for relapse. The authors suggest that status of the duodenal papilla may be useful in determining corticosteroid administration.
Idiopathic Recurrent Pancreatitis (IRP): Long Term Success of Pancreatic Endotherapy
Marc Catalano described the 5-year experience of 106 patients with acute recurrent pancreatitis. Potential pathophysiology includes relative flow obstruction and intermittent sphincter of Oddi dysfunction and treatment is controversial. All patients underwent extensive laboratory, radiographic testing, ERCP with sphincter of Oddi manometry. 30 patients were then defined as having IRP (11 men, 19 women, mean age 50.4); 25 patients were analyzed for this study. Endoscopic therapy (PD stent, sphincterotomy, or both) was determined based on physician and patient preferences. Outcomes such as acute pancreatitis, number of ER visits/hospitalizations, and complications were measured. The results showed that 30 patients received a total of 93 stents, and most were 7Fr stents. Twelve of 30 patients had endoscopic sphincterotomy (ES) (biliary ES = 4, pancreatic ES = 4, and dual ES = 4). Mean follow-up was 8.86 years. 52% had complete resolution of acute pancreatitis episodes, 36% had greater than 50% reduction in acute pancreatitis episodes, while 12% had no improvement or worsening episodes. Postprocedure pancreatitis occurred in 9.8%, stent migration in 63.6% of 5Fr stents. In patients with incomplete resolution of acute pancreatitis, ES provided definitive treatment in 50% of patients. Patients with chronic pain, those with 7 Fr stents, and older patients may be predictors of response. In conclusion, the authors stated that pancreatic stent therapy in IRP results in improvement in the vast majority of patients, and randomized trials are needed to reveal the optimal endoscopic treatment option.
Pancreatic Stent-Induced Ductal Injury: Clinical Presentation and Outcomes of Endoscopic Therapy
Yan Bakman presented their experience with pancreatic stent-induced ductal injury, a clinically entity of unknown significance and response endoscopic therapy. At their single referral center, 8 patients were referred for symptomatic PD stent-induced injury, initially placed for prevention of post-ERCP pancreatitis. At initial outside ERCP, all had small caliber PD (< or = 3mm). All had conventional polyethylene 5F (n = 6) or 7F stents (n=2) <4cm in length in place for <2 weeks, except for one patient lost to follow up with stent in place for one year. At a mean interval of 18 months after initial ERCP, patients had recurrent abdominal pain requiring hospitalization, 71% had acute recurrent pancreatitis and 38% were on daily narcotics. By secretin MRCP/EUS/ERCP, all had a PD stricture within 2cm of the papilla and 63% with upstream PD dilatation (mean 4.6mm). 67% of patients with normal baseline EUS had a follow-up EUS with changes suggestive of chronic pancreatitis. All patients were treated with pancreatic sphincterotomy, balloon dilatation of stricture, and placement of multiple 3-5F soft polymer pancreatic stents. Six required multiple ERCPs for therapy. 50% had sustained clinical responses with resolution of pain, 13% with fair response with repeated ERCP, and 25% with poor response necessitating total pancreatectomy with islet autotransplant. The authors concluded that PD-stent induced ductal injury that are clinical relevant can occur after a brief interval of stenting. They felt that endoscopic therapy can be effective, but some patients develop irreversible damage.
A Randomized, Controlled, Double-Blind Trial of Air vs Carbon Dioxide Insufflation During ERCP
Evan Dellon et al compared the impact air vs carbon dioxide insufflation during ERCP on patient comfort. In colonoscopy, results have consistently shown less pain and distension with carbon dioxide use. This was the planned interim analysis of a randomized, controlled, double-blind trial. 78 patients were randomized to receive either carbon dioxide or air insufflation and then abdominal pain was assessed on a 100mm visual analogue scale pre- and 1, 3, 6, and 24 hours post-ERCP, and abdominal girth pre- and post-ERCP. Other outcomes such as pCO2 levels were measured with transcutaneous capnography and procedural complications. The results demonstrated that both groups had comparable baseline characteristics and indications for ERCP. The mean pain scores and abdominal girth between the air and CO2 groups were not statistically significant, though a possible trend favoring air was seen at various time points. Additionally, there were no statistically differences between the groups. However, more complications overall were detected in the air group compared with the CO2 group, with some related to respiratory compromise or CO2 retention. In summary, so far, there were no significant differences between pain scores or abdominal distention between the two groups.
State-of-the-Art Lecture: To Stent of Not to Stent: Is There Still a Question?
Evan Fogel discussed the role of stenting in preventing post-ERCP pancreatitis. He identified known risk factors for post-ERCP pancreatitis including female sex, sphincter of Oddi dysfunction, younger age, normal bilirubin, no chronic pain, prior history of post-ERCP pancreatitis, and more recently current alcohol use and former smoker. Dr. Fogel reviewed important studies by Tarnasky, Fazol, and others all showing the reduction of post-ERCP pancreatitis with pancreatic duct stent placement. In a meta-analysis of 481 patients, stents reduce the rate from 15 to 5% with a NNT of 10, and severe pancreatitis was nearly eliminated. Studies have also shown that stents have shown benefit in ampullary tumor resections, sphincter of Oddi dysfunction and suspected sphincter of Oddi dysfunction.
Section 18: Deep Enteroscopy Outcomes and Therapeutics
Prospective Multicenter Trial Comparing Double Balloon Enteroscopy (DBE) and Single Balloon Enteroscopy (SBE) in Patients with Suspected Small Bowel Disorder
The purpose of this study was to compare Double Balloon Enteroscopy (DBE) with Single Balloon Enteroscopy (SBE). The study authors concluded that with the DBE technique the rate of complete enteroscopy had been approximately three fold higher than with the SBE technique going along with a higher diagnostic yield. Therefore, the authors regard DBE as the gold standard procedure for deep small bowel endoscopic investigation. It should be noted, however, that all procedures in this study were done with the Fujinon enteroscope using one or two balloons and a comparison with instruments designed specifically for SBE was not performed in this study.
Severe Complications of Spiral Enteroscopy in the First 1750 Patients
The purpose of this study was to publish all recognized serious complications occurring during spiral enteroscopy. The study found that the overall severe complication rate was 0.4% and a perforation rate of 0.34%. All of the perforations were recognized immediately when the scope tip visualized the peritoneum. Perforations may be minimized by advancing the enteroscope only when the lumen is clearly visualized.
Spiral Enteroscopy: Prospective Multicenter U.S. Trial in Patients with Small Bowel Disorders
The goal of this study was to determine the performance, yield and safety of SE in patients with suspected or established small bowel pathology. The study found that spiral enteroscopy appears to be safe and effective for evaluation of the small bowel. The procedure duration was 45.0 minutes for all procedures, and 35.4 minutes for diagnostic procedures. These times and the depth of insertion (250cm) compare favorably with other deep enteroscopy techniques (DBE,SBE).
Influence of Fluoroscopy On Insertion Depth, Proceeding Duration and Diagnostic Yield During Double-Balloon Enteroscopy via the Oral Route: Results of a Prospective Randomized Trial in 156 Patients
The purpose of this study was to determine whether the use of fluoroscopy may lead to a higher insertion depth or to a shorter duration of proceeding during double balloon enteroscopy. This study concluded that double-balloon enteroscopy via the oral route and with the use of fluoroscopy, is able to provide about 30 cm of additional insertion depth. In addition, it must be noted that without fluoroscopy, deep insertion into the small bowel can be achieved in experienced hands with similar results for procedure duration and diagnostic yield
30-Month Follow-Up After Double Balloon Enteroscopy in Patients with Obscure Gastrointestinal Hemorrhage
The purpose of this study was to determine the long-term outcome after DBE. The study found that 30 months post-DBE for obscure GI bleeding, the majority of patients (67%) who were contacted did not have recurrent bleeding, require transfusions or iron therapy. This study did not provide an explanation about how interventions performed during DBE may have influenced this subsequent rate of occult bleeding. Patients with normal initial DBE examinations or AVMs were most likely to experience recurrent bleeding. It is unclear from this methodology if the recurrent bleeds were due to missed culprit lesions on the normal initial DBE or recurrent bleeding AVM?s in new locations from the one?s initially treated.
Findings and Clinical Impact of Primary Balloon Assisted Enteroscopy in Patients with Obscure Gastrointestinal Bleeding
The purpose of this study was to evaluate the diagnostic and therapeutic outcome of OGIB patients, following a primary BAE approach. The study found that there was a high prevalence of small bowel abnormalities with a primary BAE approach in OGIB patients. In patients with a likely cause of bleeding, therapy seems successful at mid-term follow-up. In selected patients, retreatment was deemed necessary for total resolution of OGIB. The high frequency of spontaneous resolution of anemia in patients with no cause found during BAE, suggests that we are in need of a better patient selection.
Section 19: EUS Potpourri
A Simple Scoring System Predicts Which Patients with Esophageal Cancer Benefit from Endoscopic Ultrasound for Lymph Node Classfication
The purpose of this study was to
- Develop a simple, non-EUS based scoring system (called ?CEP score?) for LN classification in EC
- (2) Determine in a subsequent cohort if ?CEP score? can select those Esophageal Cancer (EC) patients (pts) most likely to benefit from EUS
- (3) Assess the contribution of PET scan to LN classification and morphology, histopathologic type and grade.
The study concluded the following:
Pts with CEP score <10 are unlikely to benefit from EUS for LN classification; only 6% are pN1, and none are recognized by EUS
- Conversely, pts with a CEP score over 20 have a 100% likelihood of being pN1
- EUS is most likely to be of benefit for LN classification in those pts with CEP score 10-20, since in this group LN status is most in doubt (36% are pN1
- PET scan is insensitive to the presence of pN1
This is clinically important because endoscopist diagnosing EC can use a simple scoring system (‘CEP score’) to determine which patients are most likely to benefit from EUS for LN classification.
Endoscopic Ultrasonography (EUS) Strain Ratio (SR-EUS) vs. Contrast-Enhanced EUS (CE-EUS) for the Diagnosis of Focal Pancreatic Solid Lesions
The purpose of this study was to compare prospectively the ability of the SR-EUS and CE-EUS to differentiate between benign and malignant focal pancreatic lesions. This study concluded that in this small group of patients, CE-EUS was superior to SR-EUS for the differentiation between benign and malignant focal pancreatic lesions.
Endoscopic Ultrasound-Guided Fine Needle Aspiration in Solid Pancreatic Tumors: a Prospective Randomized Comparison of 19-Gauge and 22-Gauge Aspiration Needles
The purpose of this study was to compare EUS-FNA results using 19-gauge aspiration needle with those using 22-gauge aspiration needle without an onsite cytopathologist with regard to diagnostic accuracy and sample quality in patients with solid pancreatic mass. The study concluded that the diagnostic accuracy of EUS-FNA using a 19-gauge needle was significantly higher than that using a 22-gauge needle when an onsite cytopathologist was not present. EUS-FNA using a 19-gauge aspiration needle obtained a larger amount of sample with fewer needle passages. EUS-FNA with a 19-gauge aspiration needle may be a valuable method for the diagnosis of pancreatic masses.
The Yield of Endoscopic Ultrasound-Guided Fine Needle Aspiration with a 19-Gauge Needle for the Diagnosis of Autoimmune Pancreatitis
The purpose of this study was to evaluate the yield of EUS-FNA with a 19-gauge needle for the diagnosis of AIP. The study concluded that EUS-FNA with a 19-gauge needle and histopathological examination of the obtained material were useful to confirm the diagnosis of AIP.
EUS FNA of Distant Extra-Vascular Migratory Metastasis (EVMM) and Tumor Thrombosis
The purpose of this study was to examine the capability and safety of EUS FNA for diagnosing distant perivascular tumor infiltration and tumor thrombus in CT positive and negative (i.e. microinvasion) patients. Most of these cases were patients with primary pancreatic neoplasms. The study found that CT and EUS can identify peri- and intravascular tumor extension remote from the primary tumor and not resulting from gross infiltration. EUS can detect microinvasion (1-3mm) not seen on helical CT.
Ratio of Pancreatic Duct Caliber to Width of Pancreatic Gland By Endosonography Is Predictive of Pancreatic Cancer
The purpose of this study was to determine if the ratio of pancreatic duct (PD) diameter/to pancreatic gland (PG) (=0.4) as measured by EUS is predictive of pancreatic cancer. The study found that the ratio of pancreatic duct caliber to width of pancreatic gland by endosonography is predictive of pancreatic cancer. This sign should be considered for routine use by endosonographers as an aid to improve EUS diagnostic capability of pancreatic cancer when evaluating patients with suspected pancreatic disorders
Section 20: Image Enhanced Colonoscopy: From the Pathogenesis to the Diagnosis of Colonic Disorders
Is Hood-Assisted Colonoscopy More Effective Than Narrow Band Imaging for Colorectal Adenoma Detection?
These authors compared the use of a transparent hood attached to the tip of a colonoscope to Narrow Band Imaging [NBI] in adenoma detection. They randomized 107 patients with colon polyps seen under standard white light colonoscopy to have a second colonoscopy using one of the two methods. The hood arm detected 31% more adenomas than the initial examination, a significant increase; the NBI examination did not significantly increase the number of polyps seen on the index examination, leading the authors to conclude that the use of a transparent hood, in this case a retractable one, was a superior means of finding more adenomas to NBI.
In Vivo Molecular Imaging of VEGF in Gastrointestinal Cancer Using Confocal Laser Endomicroscopy
This study used a VEGF-A targeted with alexa fluor 488-labeled antibodies injected into nude mice in which tumors were created using human colorectal cancer cell lines. Using this technique, confocal laser endomicroscopy was able to detect the VEGF stains in 93% of tumors but not in healthy tissue. The combination of molecular markers with presently available confocal endomicroscopy systems holds interest for future potential human application in assessing colorectal cancers for evidence of neovascularization in vivo during colonoscopy.
Usefullness of Our Endocytoscopic Classification in the Colorectum
Dr. Kudo presented this paper outlining a new classification system for findings during endocytoscopy [EC] in the colon using an integrated endocytoscope ultra high magnification to 450x. In this study, histopathological significance of the patterns described in this classification were determined. Very high positive predictive values [87-100%] were found for each of the 6 groups of EC findings.
Confocal Laser Endomicroscopy for the In Vivo Identification, Localization and Quantification of Tissue Based Bacteria in Patients with Different Types of Colitis
These authors utilized confocal laser microscopy to assess for the presence of bacteria in the mucosa of 179 patients with inflammatory bowel disease and compared the findings to targeted biopsies with fluorescence in sity hybridization. They were able to demonstrate the translocation of bacteria in @ 60% of patients with crohn?s, ulcerative colitis, and infectious colitis, but only 14% of controls. Histopathology confirmed the confocal findings in all cases. Translocation was predominant in the rectum in ulcerative colitis patients and right colon for Crohn?s disease patients and throughout the colon in infectious cases. Of note, the bacterial findings were in the absence of macroscopic changes visible under standard white light colonoscopy.
A Prospective Randomized Study On Computed Virtual Chromoendoscopy Versus Conventional Colonoscopy for Detection of Small Colorectal Adenomas
This study compared white light colonoscopy to FICE virtual chromoendoscopy in the detection of small adenomas. 135 patients were randomized; 7 patients with poor bowel prep were excluded. The number of patients with polyps, adenomas were similar in the 2 groups; however the FICE group did detect significantly more patients with small adenomas that the white light [44.4% vs. 21.5%]. Withdrawal times were similar.
High Definition Plus Colonoscopy Combined with I-Scan Is Superior in the Detection and Characterization of Colorectal Neoplasias Compared to Standard Video Colonoscopy - a Prospective Randomized Trial
This comparison of optical contrast colonoscopy using the high definition I-Scan instrument to standard resolution white light colonoscopy was performed on 200 patients presenting for either screening or occult blood in the stool. The authors found that high definition plus found significantly more total neoplastic lesions, and more patients with neoplasia [adenoma detection rater]. Of particular interest, using the surface enhancement mode with the high definition scope, more flat neoplastic lesions were seen. High accuracy of predictions based on the I-scan endoscopic appearance [95%] was achieved when compared to histopathology in these expert hands compared to 76% accuracy for standard white light colonoscopy. These results contrast with a number of previously reported comparisons between white light and high resolution optical contrast examinations in detecting adenomas. It is important to emphasize the comparison to standard resolution white light colonoscopy rather than to high resolution white light examinations which may account for some of the observed significant higher yield. Such high accuracy of diagnostic prediction is consistent with what as been achieved with all of the high resolution optical contrast technologies in experienced hands, and may have large implications for reducing the need and tremendous associated costs of obtaining histopathologic confirmation for every lesion that is removed
Section 21: New and Emerging Technologies in EUS: What?s Hot?
As EUS is being used more and more for various therapeutic interventions, this session was used to explore new applications for EUS based procedures inside and outside the GI tract. From management of Gastric varices using glue and coils to placement of intrahepatic porto-systemic shunts and from placement of fiducials for radiation treatment of prostate cancer to management of pelvic/prostatic abscesses ?interventional EUS is getting hotter and hotter.
Endoscopic Ultrasound-Guided Drainage of Pelvic and Prostatic Abscesses
This is a small prospective study looking at safety and efficacy of trans-rectal EUS-guided drainage of pelvic and prostatic abscesses. Ten patients were enrolled when traditional radiological drainage methods failed. There were 5 peri-rectal, 3 peri-colonic and 2 prostatic abscesses with a mean diameter of 62 x 55 mm. Successful EUS-guided aspiration of fluid was done in 5 patients (two required dilatation with TTS balloon) and placement of plastic stent was achieved in 3 patients. There were no immediate complications and all 3 stents were removed at 7 days with confirmed abscess resolution. One patient had follow up surgical drainage 7 days after EUS fluid aspiration. Follow up EUS at 3 months showed no evidence recurrence in all other nine patients. This data suggest that EUS-guided drainage of pelvic abscess is a safe and effective intervention and may help avoiding unwanted surgery.
EUS-Guided Fiducial Placement Prior to Targeted Radiation Therapy in Obese Prostate Cancer Patients As An Alternative to Abdominal US Prostate Localization: Results of a Single- Center Experience
This abstract describes the experience of one center with the EUS-guided fiducial placement in 16 obese patients with prostate cancer. Gold markers were placed using the 19G FNA needle in four-quadrant manner. Successful placement was achieved in all patients and a total of 71 fiducials were inserted as per protocol (7/16 patients had additional fiducial placement for adequate prostate delineation). No complication encounter during or soon after the procedure. This data suggest that EUS-guided fiducial placement is feasible and safe in obese patients with prostate CA.
Forward-View, Forward-Array Curvilinear Echoendoscope to Diagnose and Sample Right-Sided Colonic Lesions
This abstract focused on the safety and feasibility of evaluating right sided colonic lesions using a prototype forward-array /view echoendoscope (XGIF-UCT160, Olympus). Eight patients were included (6 cecal and 2 ascending colon lesions). Cecum was reached in all exams within 10 min of insertion and median procedure time was 42 min. EUS-FNA was performed in 4 cases and delivered a diagnosis in 75% (one non-diagnostic FNA was due to calcified lymph node). There were no procedure related complications. In conclusion using the prototype forward view-forward array echoendoscope is safe and feasible in diagnostic of right side colonic lesions. One potential limitation is the shorter scope length (125 cm).
A New Alternative for TIPS: EUS-Guided Creation of Intrahepatic Porto-Systemic Shunt (IPSS)
This is an animal model study evaluating the feasibility and safety of EUS-guided placement of IPSS between hepatic vein and portal vein. Ten pigs were used for successful placement of IPSS. Eight pigs were sacrificed immediately post procedure to asses for placement and acute complications. All stents were in good position and there was no intraperitoneal bleeding. Two animals were followed for 2 weeks and did well, showing no signs of complications. In conclusion, EUS-guided IPSS placement seems feasible and safe in the porcine model. One potential limitation is that portal pressure in humans is much higher then that in porcine model, so the risk of bleeding may be higher.
EUS-Guided Therapy of Bleeding Gastric Varices (GV)
This study focused on feasibility, safety and efficacy of EUS-Guided treatment of GV using cyanoacrylate (CYA) and/or coils (InterLock, Boston Scientfic). Eleven gastric varices were treated (5 active bleeding and 6 with stigmata of recent bleed) in nine patients. Glue (CYA) alone was injected in 6 varices (range 1-3 ml). Coils alone were placed in 3 varices and a combination of coils&glue was used in 2 varices. There were no immediate complications and no rebleeding has been reported on follow-up.
This data suggest that EUS-guided treatment of GV is feasible, safe and very effective. One other advantage is that visualization with the EUS is not impaired by blood in the stomach.
EUS-Guided In Vivo Microdialysis of Pancreas: A Novel Technique of Potential Diagnostic and Therapeutic Application
This study explored the feasibility and possible application of EUS-Guided Microdialysis of pancreas using beagle dogs. Microdialysis probe is able to measure dynamic temporal variations of non-protein bound substances in the extracellular fluid, when these products are unstable in systemic circulation. Using the 19G FNA needle the microdialysis probe was placed into the pancreatic parenchyma. The probe broke when placement was attempted in 2 dogs due to fragile material. Measurements of 5FU concentrations using the microdialysis probe were successful in 6 dogs and had values of more than 100x of the cut-off value. There were no complications associated with the procedure. New applications for this technology remain to be uncovered.
Section 22: Metal Stenting: The Good, the Bad, and the Ugly
Full Covered Metal Biliary Stents for Treatment of Biliary Complications After Liver Transplantation
This study considered the role of removable fully covered metal stents in the management of biliary complications post-liver transplantantion with duct to duct anastamosis in which standard ERCP and PTC attempts failed to resolve the complication. 13 patients who otherwise would have required surgery underwent placement of these stents, including 9 OLT, 3 living related recipient and one split liver recipient. Indications were stenosis in 9 and leak plus stenosis in 4. Metal stents were removed in 3 months in all 13 patients. All but one showed full resolution of the complication, though 1 of these did have a recurrent stenosis requiring further intervention. The use of covered removable metal stenting in this setting was shown to be feasible and promising from this pilot study.
A Prospective Randomized Trial and a Cost-Effectiveness Analysis of Plastic Versus Covered Self-Expandable Metal Stent in Patients with Benign Biliary Stricture
This study compared the strategies of multiple parallel plastic stenting vs. 3 months of covered metal stenting of benign post-operative strictures in 24 patients from 4 centers. The metal stent group underwent fewer ERCP?s [17 vs 12.6] and longer symptom free periods than patients treated with plastic stents. Cost analysis for total costs including hospital stays was $6232 vs $3123, significantly lower in the metal stenting group.
Risk of Post-ERCP Pancreatitis with Placement of Self-Expandable Metallic Stents: a Retrospective, Cohort Analysis
This study was a retrospective analysis of 544 patients, 248 of whom received self-expandable metallic stents [SEMS] and 296 plastic stents [PS], including 102 with covered metallic stents, to determine if the use of metal stents was associated with a difference in the rate of post-ERCP pancreatitis. The multivariate anaylsis was performed in 2 ways to control for known risk factors for pancreatitis in the first instance, and for the use of protective pancreatic duct stents in the second instance. They found that the SEMS ws associated with higher rates of pancreatitis than plastic stents [7.3 vs. 1.3%]. EBS for SEMS was not performed in 19% but this did not predispose to pancreatitis. Nor was there a difference between covered and uncovered SEMS or when multiple SEMS were deployed.
A Comparison of Outcomes Among Secondary Covered, Uncovered Metalic and Plastic Stent for Occluded Biliary Metallic Stent for Malignant Distal Biliary Obstruction
This paper addressed the best management strategy for occulded biliary metallic stents in cases of distal obstruction. Retrospective review of 72 patients included 40 treated with a new covered SEMS inside the occluded stent, 22 with uncovered SEMS, and 10 with plastic stents. The authors found that the insertion of a metal stent in stent with at least one of the two being a covered stent was associated with longer stent patency than bare stent inside bare stent or [339 vs. 170 days ] and longer than plastic inside metal [339 vs 225 days]. The covered group has the longest survival overall from insertion to death, also significant.
A Multicenter Analysis of Safety and Outcome of Removal of Covered Self-Expandable Metal Stents (CSEMS) During Endoscopic Retrograde Cholangiopancreatography (ERCP)
This multi-center study investigated the safetly and outcome of endoscopic removal of Viabil covered SEMS via ERCP in 36 patients. 11 of these were for malignant strictures and 16 for benign strictures, and 9 were for bile leak or ductal injury. 5 of the 36 were placed intraductally. All 36 were successfully removed with either a forceps in 8 or a snare in 28. Stents were in situ for a median of 106 days [6-355]. Of note 4 of 36 had developed secondary strictures at the time of stent removal. These were found at the distal margins of intraductally placed stents in 2 or at a site of stent angulation in 1and a site of a malignancy which had a restenosis and leak upon covered SEMS removal. These adverse events were successfully treated with more stenting.
Uncovered Versus Covered Self-Expanding Metallic Stents for Inoperable Malignant Distal Biliary Obstruction: a Prospective Randomized Multicenter Study
These authors conducted a randomized multi-center trial of uncovered vs. covered SEMS for malignant distal bile duct obstruction. 76 patients were randomized from 6 centers. The median patencies of the 2 stents did not differ [195 vs 227 days]. The rate of adverse events including pancreatitis, cholangitis, or cholecystitis was also not significantly different between uncovered [10.5%] and covered [26.5%], though it is uncertain if this study was sufficiently powered to detect a difference in complication rates.
| Major A (A) | Major B (B) | Minor (Min) |
| Hyperechoic foci + shadowing MPD calculi |
Lobularity + honeycombing | Cysts; dilated MPD>3.5 mm; irregular PD; dilated side branch>1mm; hyperechoic duct wall; strands; non-shadowing hyperechoic foci; lobularity with non-contagious lobules |
Classification:
| Most consistent with CP | Suggestive of CP | Indeterminate of CP | Normal |
| 1(A)+>3(Min);1(A)+1(B);2(A) | 1(A)+<3(Min); (B)+>3(Min); >5(Min) | >2 but <5 (Min); (B) | <2(Min) |
Cytologic Evaluation of Cystic Pancreatic Lesions (CPL): Comparison of EchoBrush Vs. Standard EUS-FNA Techniques in a Blinded Prospective Study
This prospective study by Gill KR et al compared the diagnostic yield of EchoBrush with standard FNA in cystic pancreatic lesions. The cysts were aspirated to 50% volume by FNA, followed by the EchoBrush and then the remaining fluid was aspirated to cyst collapse. The pathologists were blinded to the samples and evaluated intracellular mucin (ICM) and grade of dysplasia. Out of 22 patients the EchoBrush identified ICM in 6 whom had negative FNAs. Of those with ICM 2 were found to have high grade dysplasia by EchoBrush alone. The study suggested that EchoBrush may have higher yield for the diagnosis of ICM and dysplasia then standard FNA.
Neural Network Analysis of Dynamic Sequences of EUS Elastography Used for the Differential Diagnosis of Chronic Pancreatitis and Pancreatic Cancer
Saftoiu et al used EUS elastography to differentiate benign (normal or chronic pancreatitis) and malignant (adenocarcinoma and NETs) tissue characteristics. They utilized the publicly available ImageJ software to calculate hue histograms and established the sensitivity, specificity and accuracy between confirmed benign and malignant tissue as 91%, 87% and 89% respectively. Using these results they trained a neural network to classify benign vs malignant disease and achieved a 95-97% average performance. As shown for the differentiation of benign and malignant lymph nodes this study demonstrated the promise of EUS elastography in distinguishing malignant from benign lesions and points to its potential role in better targeting of biopsies.
Section 16: New Imaging in the Upper GI Tract
This session focused primarily on endoscopic techniques which could better predict histology in diseases such as Barrett’s esophagus, GERD, and submucosal lesions in the upper GI tract. The overall theme was the concept of virtual biopsies thereby transitioning the endoscopist to the “endopathologist” utilizing these new techniques.
Confocal Laser Endomicroscopy for In Vivo Diagnosis of Barrett’s Esophagus and Associated Neoplasia: An Ongoing Prospective Study
An Italian study which took 39 patients (35 with known BE) and compared fluroscein aided confocal laser microendoscopy to histologic findings. The confocal images were classified using the Kiesslich Confocal Barrett Classification. The accuracy was 80.2% and the agreement was substantial (X= 0.74). They concluded that this technique increases the yield of biopsies as compared to the standard of care random 4 quadrant technique with an impressive ~ 96% sensitivity.
Confocal Laser Endomicroscopy in Barrett’s Esophagus and Associated Neoplasia: A Prospective Randomized Controlled Crossover Trial
The purpose of this crossover study done at Johns Hopkins compared targeted mucosal biopsies via confocal laser endomicroscopy (CLE) with standard 4 quadrant random biopsies in 30 patients with either known or possible Barrett’s esophagus. One group consisted of those who were referred for high grade dysplasia and the other routine surveillance. They found that the mean number of biopsies taken in the was significantly lower in the CLE group as compared to the standard group (10.75 vs. 28.4, p=0.004). The overall diagnostic yield was significantly higher in the CLE group as compared to the standard group (32.4% vs. 19.7%, p=0.03).
In Vivo Imaging of the Living Cancer Cell and Evaluation for Tissue Atypia Using Endocystoscopy: ECA (Endocytoscopic Atypia) Classification in the Esophagus and Stomach
This Japanese study by Dr. Inoue and colleagues used endocytoscopy to distinguish cellular features (in particular nuclear morphology) with the aide of tissue staining in 130 patients containing superficial esophageal and gastric lesions. The changes were characterized using the endocytoscopic atypical classification, a five tier classification assessing nuclear morphology where ECA-1 is normal and ECA-5 is cancer. ECA 1-3 were considered benign and ECA 4-5 were malignant. The overall accuracy in distinguishing benign vs. malignant lesions was 87.1 %. The PPV and NPV was 86% and 89.7% respectively. The researchers concluded that this technique may have the potential to make histologic diagnosis without actual biopsy and that this technique may be more important to those patients who are anticoagulated.
High Definition Endoscopy (HD+) with I-Scan and Lugol’s Solution for the Detection of Inflammation and Neoplasia in Patients with GERD
This German study assessed 41 patients with heartburn and compared standard high definition (HD) endoscopy vs. enhanced imaging with either chromoendoscopy (via Lugol’s solution) or I-Scan. I-Scan utilizes a new EPKi processor (Pentax, Japan) which allows physicians to better assess the mucosal topography and vasculature of the epithelium with the touch of a button. Using the LA classification, they found a non-significant trend in detecting mucosal breaks with I-scan as compared to standard HD endoscopy (12 vs 8, p=ns). More importantly was a statistically significant increase in the number of mucosal breaks detected with chromoendoscopy (21 vs 8, p = 0.029). A secondary endpoint was the detection of circumferential lesions which were detected more with chromoendoscopy followed by I-scan and standard HD endoscopy (70 vs. 41 vs. 19, p < .001). The authors point out that although the enhanced imaging detected more lesions, there was no increase in the amount of neoplastic changes.
Digital Image Analysis (DIA) Is a Useful Adjunct to Endosonographic Diagnosis of Submucosal Lesions (SML) of the Gastro-Intestinal Tract
Dr. Das and colleagues from the Mayo Clinic performed this retrospective study evaluating submucosal lesions in the upper GI tract by reviewing EUS images. The aim was to see whether subtle changes in the EUS morphology could be better detected via changes in pixel patterns (utilizing a software program) and hence predict “virtual” histology without need for biopsy. A total of 46 patients with histologically documented SML’s consisting of GIST (28), lipoma (8), and carcinoids (10). Using three types of pixel distribution they found that DIA had a sensitivity of between 79-90% and a specificity of 77-81%, concluding that this technique is a useful adjunct to EUS in diagnosing SML’s.
In Vivo 3D Comprehensive Microscopy of the Human Esophagus for the Management of Barrett’s Patients
This study from Harvard evaluated using optical frequency domain imaging (OFDI) in the management of Barrett’s esophagus. Using a special fiberoptic probe, three-dimensional microscopic views of the inner surfaces of vessels and organs were obtained. Forty patients were investigated with this technique examining ~ 6 cm of the distal esophagus. The researchers found that in 92% (37) patients achieved satisfactory imaging when correlated to histology, concluding that this technique is a potential means of obtaining a “virtual biopsy”.
Section 17: ASGE Plenary Session, Part I
The first group of endoscopic papers presented in the ASGE Plenary Session addressed some of the most pressing topics in endoscopy, in particular related to cost-effective strategies of colorectal cancer prevention, as relates to the management of small polyps found on colonosocpy and on CTC. A novel low-tech way to facilitate colonoscope passage was presented along with a meticulous survival animal study comparing various methods of perforation closure.
Cost Savings of Removing Diminutive Polyps Without Histologic Assessment
This interesting study out of Indiana University examined the cost savings of using “real-time” histology, as opposed to pathologic evaluation, to determine the classification of small polyps. Since most colorectal polyps are dimunitive (< 6mm in size) and rarely contain cancer, the histologic reports are mainly used to guide post-polypectomy colonoscopy intervals. The study evaluated 4474 colonoscopies in which at least one diminutive polyp was removed, each of which was evaluated by both “real-time” histology and pathology. They found that by using “real-time” histology, $181 could be saved per colonoscopy, with $116 million in annual savings in the US. Only 3% of patients with polyps would be mislabeled using on-site assessment, and only 12% would be scheduled for follow-up at a non-recommended interval (of which, most would undergoing surveillance at a too early interval). Less than 1 in 1100 patients with a diminutive polyp removed would have an undetected cancer in any removed polyp. Based on this data, it may be more effective to not send small polyps for pathologic examination.
American College of Radiology (ACR) Recommendations for CT Colonography (CTC) Interpretation: Implications for Resection of High Risk Adenoma Findings
This study, also out of Indiana University, evaluated the implications of the ACR recommendations for CT colonography. The ACR recommends that polyps ≤ 5mm in size not be reported on CT colonography studies, while patients with 1 or 2 polyps 6-9 mm in size can be offered “CTC surveillance” in 3 years in lieu of polypectomy. In this study, 10,780 polyps were removed endoscopically from 10,034 patients over a 5 year interval. There were 774 patients fit the category of 1 or 2 polyps 6-9 mm in size and no polyps ≥ 10 mm in size. Of these patients, 184 actually had either 3 or more adenomas ≤ 9 mm in size or an advanced adenoma ≤ 9mm in size or both findings. There were 269 patients who had no polyps ≥ 6mm, but had either 3 adenomas ≤ 5mm or an advanced adenoma ≤ 5mm or both. They concluded that if CTC were used in this population according to ACR interpretation recommendations, then a significant number of patients with high risk adenoma findings would be incorrectly interpreted as either being normal or would have polypectomy delayed at least 3 years.
Water Immersion Vs Conventional Colonoscopy Insertion: a Randomized Controlled Trial Showing Promise for Minimal-Sedation Colonoscopy
This study assessed the feasibility of minimal-sedation colonoscopy using a water immersion colonoscopy insertion technique. Using the water immersion technique, 300cc of tap water, instead of air, is instilled in the rectum. Ninety-eight patients at the Palo Alto VAMC were randomized for either water immersion or standard technique of colonoscopy, and premedicated with 2mg midazolam. Procedure “success” was defined as completion of the colonoscopy to the cecum without additional medication or attending physician intervention. The researchers found that cecal intubation time was significantly shorter in the water group, although intubation rate was not. Less sedation was needed in the water group. There was also a trend towards increased procedure “success” in the water group, especially for procedures performed by fellows. Patient satisfaction survey responses did not significantly differ between the groups. They concluded that the water immersion significantly improved cecal intubation time while using less sedation and without sacrificing patient satisfaction. It will be interesting to see if this technique is more widely adopted.
Clip Closure Versus Endoscopic Suturing Versus Thoracoscopic Repair of An Esophageal Perforation: Randomized Comparative Long Term Survival Study in a Porcine Model
This study out of Germany evaluated different methods of closing a full thickness gastrointestinal wall incision, as would be necessary for NOTES. Clip closure (CC) has been used in some patients, but surgical repair (TC) remains the gold standard. A new endoscopic suturing (EC) technique has been reported in animal models. This study compared the 3 techniques on a standardized 2 cm esophageal incision performed in 18 pigs (6 in each group). The pigs survived for 6 weeks after closure. They were then re-evaluated endoscopically before pathologists performed post-mortem examinations with histology and morphometric analysis. The researchers found that esophageal repair was successful in all groups. At autopsy CC showed the best results with hardly any periesophageal adhesions. Two animals died of mediastinitis (1 EC animal due to food having refluxed into the mediastinal space during repair and 1 TC pig due to suture inadequacy). On histology, EC actually performed significantly better than either TC or CC, with shorter and less wide defects with fibrous replacement. They concluded that CC and EC had no more complications than TC, and EC actually was significantly better histologically. The results are encouraging and suggest that endoscopic esophageal wall repair may be feasible.
Section 18: ASGE Plenary Session Part 2
The second set of endoscopic research abstracts included a carefully conducted animal trial in the emerging field of NOTES, a randomized trial to determine the optimal hemostasis technique in the era of hemoclips, a compilation of a tremendous volume of experience in non-anesthesiologist administration of propofol, and a randomized trial of CO2 insufflation for ERCP. A common thread to these papers is the application of good scientific methodology to address questions that are timely and clinically important areas for the present and future of the field.
A Prospective Randomized Controlled Trial of NOTES versus Laparoscopic Distal Pancreatectomy, Preliminary Results.
This study compared outcomes of endoscopic natural orifice vs. laparoscopic distal pancreatectomy in pigs. Standard laparoscopic distal pancreatectomy has a reported morbidity up to 52% with leaks occuring in up to 30% of cases. The authors aimed to compare a NOTES procedure to a laparoscopic procedure with relatively high risk in an attempt to detect a potential difference in complications. After a run-in phase, 28 pigs were randomized to the two groups. This was an 8 day survival study. One animal died in each of the 2 groups. No leaks occurred in the endoscopic group and one leak was observed in the laparoscopic arm. Endoscopic distal pancreatectomy was more time consuming. This study demonstrated that endoscopic transgastric distal pancreatectomy is feasible and could be done safely in a pig model. At least in this survival animal model, non-inferiority of this method was demonstrated.
Hemostasis of Very High Risk Patients with Severe Non-Variceal UGI Hemorrhage Comparing Injection Hemoclipping with Injection MPEC.
Dr Jensen presented the results of this trial which was notable for the focus on a population of patients with very high co-morbidity, a group often excluded from controlled hemostasis trials. The purpose was to compare efficiency and safety of the two hemostasis methods in this high risk population. This was an intention to treat analysis. Excluded patients were those with malignancy, varices, and angiomatous disease. All patients received PPI and H. Pylori treatment if indicated. Thirty-two patients were in the Epi: MPEC arm and forty-seven in the Epi: Boston Scientific Hemoclipping arm. The number of patients with clinical decompensation and hypotensive shock were the same. One perforation was noted in the Epi: MPEC arm. The re-bleed rate was 43% in the EPI:MPEC arm and was 20% in the Epi:Clip arm. Failure of hemostasis was 23% in the Epi: MPEC arm and 3.5% in the Epi:clip group. Surgery for re-bleed was needed in 20% of the epi: MPEC and only 3.5 % of the epi:clip group. The main observation was that the combination of Epinephrine and hemoclipping appears to be superior to the combination of Epinephrine and MPEC and should be considered in the treatment of severe, non-variceal hemorrhagic upper gastrointestinal bleeds.
Non-Anesthesiologist Administered Propofol Sedation for Endoscopic Procedures: A Worldwide Safety Review.
This was a robust literature review performed with the goal of providing safety data for the use of propofol by non-anesthesiologists. Of 519, 627 cases of non-anesthesiologist administered propofol for GI procedures, there were three deaths, one of which was in a patient with severe mitral regurgitation, one with metastatic pancreatic cancer and one with a history of IVDA. Additionally there were 5 endotracheal intubations which were required, 1 seizure reported. 349 Bag-Mask ventilations out of 462, 055 cases were reported of which no intubations were required in this group. All complications occurred in upper endoscopic procedures. No complications occurred in lower GI procedures. Limitations of review include the underreporting of adverse events and the dose of propofol which was given was not always documented in the reviews. The main point of this literature review is that non-anesthesiologist administered propofol is safe and effective. Outcomes from this analysis (limited by retrospective nature) were better than the currently used non-anesthesiologist administered combination of opioid and benzodiazepines.
Carbon Dioxide (C02) Insufflation During ERCP for the reduction of Post-Procedure Pain: Preliminary Results of a Randomized, Double-Blind Controlled Trial.
CO2 diffuses 35 times more quickly than nitrogen (major component in air). These authors conducted a study to determine whether insufflation with CO2 leads to any difference in pain experienced 1 hour following ERCP than when air insufflation is used. The Ez- EM CO2 insufflator was used at 3 liters/min. Patients were monitored for pain and nausea. They were treated for pain when pain scores exceeded 4. Waist circumference to monitor for abdominal distention and follow-up phone interviews were performed. 105 patients were enrolled in this study to date. One hour post procedure pain was significantly less in the CO2 arm but no change was noted on post procedure day 1. Waist circumference was also significantly greater in the air insufflation group. More pain meds were needed in the air group but this difference was not significant. The authors concluded that CO2 insufflation for ERCP is safe and the observed benefits in post-procedure pain could theoretically influence patient satisfaction and need for hospital admission.
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