North American Expert Consensus on the Post-procedural Care of Patients After Per-oral Endoscopic Myotomy Using a Delphi Process.

BACKGROUND & AIMS: There is significant variability in the immediate post-operative and long-term management of patients undergoing per-oral endoscopic myotomy (POEM), largely stemming from the lack of high-quality evidence. We aimed to establish a consensus on several important questions on the after care of post-POEM patients through a modified Delphi process. METHODS: A steering committee developed an initial questionnaire consisting of 5 domains (33 statements): post-POEM admission/discharge, indication for immediate post-POEM esophagram, peri-procedural medications and diet resumption, clinic follow-up recommendations, and post-POEM reflux surveillance and management. A total of 34 experts participated in the 2 rounds of the Delphi process, with quantitative and qualitative data analyzed for each round to achieve consensus. RESULTS: A total of 23 statements achieved a high degree of consensus. Overall, the expert panel agreed on the following: (1) same-day discharge after POEM can be considered in select patients; (2) a single dose of prophylactic antibiotics may be as effective as a short course; (3) a modified diet can be advanced as tolerated; and (4) all patients should be followed in clinic and undergo objective testing for surveillance and management of reflux. Consensus could not be achieved on the indication of post-POEM esophagram to evaluate for leak. CONCLUSIONS: The results of this Delphi process established expert agreement on several important issues and provides practical guidance on key aspects in the care of patients following POEM.

Is peroral endoscopic myotomy the new gold standard for achalasia therapy?

Our review focuses on critical analysis of the literature to determine whether peroral endoscopic myotomy (POEM) is poised to replace laparoscopic Heller myotomy (LHM) as the new "gold standard" for achalasia therapy. POEM matches or exceeds the efficacy of LHM. The difference in objective gastroesophageal reflux disease (GERD) between POEM and LHM is modest at best and dissipates with time. Post-POEM GERD can be easily managed medically in most patients without long-term GERD sequelae or the need for surgical fundoplication. Emerging POEM technique modifications can further decrease GERD. Endoscopic antireflux procedures such as transoral incisionless fundoplication (TIF) or POEM + F (POEM + fundoplication) can be used in the rare cases of medication-refractory GERD, but their long-term efficacy remains in question. In this comprehensive review, we summarize the current status of POEM with emphasis on GERD evaluation, prevention, treatment, and comparative data vs. LHM. Based on this analysis, it appears that POEM is indeed the new gold standard in the therapy of achalasia.

Initial multicenter experience using a novel endoscopic tack and suture system for challenging GI defect closure and stent fixation (with video).

BACKGROUND AND AIMS: Closure of endoscopic resection defects can be achieved with through-the-scope clips, over-the-scope clips, or endoscopic suturing. However, these devices are often limited by their inability to close large, irregular, and difficult-to-reach defects. Thus, we aimed to assess the feasibility and safety of a novel through-the-scope, suture-based closure system developed to overcome these limitations. METHODS: This was a retrospective multicenter study involving 8 centers in the United States. Primary outcomes were feasibility and safety of early use of the device. Secondary outcomes were assessment of need for additional closure devices, prolonged procedure time, and technical feasibility of performing the procedure with an alternative device(s). RESULTS: Ninety-three patients (48.4% women) with mean age 63.6 ± 13.1 years were included. Technical success was achieved in 83 patients (89.2%), and supplemental closure was required in 24.7% of patients (n = 23) with a mean defect size of 41.6 ± 19.4 mm. Closure with an alternative device was determined to be impossible in 24.7% of patients because of location, size, or shape of the defect. The use of the tack and suture device prolonged the procedure in 8.6% of cases but was considered acceptable. Adverse events occurred in 2 patients (2.2%) over a duration of follow-up of 34 days (interquartile range, 13-93.5) and were mild and moderate in severity. No serious adverse events or procedure-related deaths occurred. CONCLUSIONS: The novel endoscopic through-the-scope tack and suture system is safe, efficient, and permits closure of large and irregularly shaped defects that were not possible with established devices.

POEM, GPOEM, and ZPOEM.

Our tripartite narrative review discusses Peroral Endoscopic Myotomy (POEM), gastric POEM (GPOEM) and POEM for Zenker's diverticula (ZPOEM). POEM is the prototypical procedure that launched the novel "3rd space endoscopy" field of advanced endoscopy. It revolutionized achalasia therapy by offering a much less invasive version of the prior gold standard, the laparoscopic Heller myotomy (HM). We review in detail indications, outcomes, technique variations and comparative data between POEM and HM particularly with regard to the hotly debated issue of GERD. We then proceed to discuss two less illustrious but nevertheless important offshoots of the iconic POEM procedure: GPOEM for gastroparesis and ZPOEM for the treatment of hypopharyngeal diverticula. For GPOEM, we discuss the rationale of pylorus-directed therapies, briefly touch on GPOEM technique variations and then focus on the importance of proper patient selection and emerging data in this area. On the third and final part of our review, we discuss ZPOEM and expound on technique variations including our "ultra-short tunnel technique". Our review emphasizes that, despite the superiority of endoscopy over surgery for the treatment of hypopharyngeal diverticula, there is no clear evidence yet of the superiority of the newfangled ZPOEM technique compared to the conventional endoscopic myotomy technique practiced for over two decades prior to the advent of ZPOEM.

AGA Clinical Practice Update on Endoscopic Management of Perforations in Gastrointestinal Tract: Expert Review.

BEST PRACTICE ADVICE 1: For all procedures, especially procedures carrying an increased risk for perforation, a thorough discussion between the endoscopist and the patient (preferably together with the patient's family) should include details of the procedural techniques and risks involved. BEST PRACTICE ADVICE 2: The area of perforation should be kept clean to prevent any spillage of gastrointestinal contents into the perforation by aspirating liquids and, if necessary, changing the patient position to bring the perforation into a non-dependent location while minimizing insufflation of carbon dioxide to avoid compartment syndrome. BEST PRACTICE ADVICE 3: Use of carbon dioxide for insufflation is encouraged for all endoscopic procedures, especially any endoscopic procedure with increased risk of perforation. If available, carbon dioxide should be used for all endoscopic procedures. BEST PRACTICE ADVICE 4: All endoscopists should be aware of the procedures that carry an increased risk for perforation such as any dilation, foreign body removal, any per oral endoscopic myotomy (Zenker's, esophageal, pyloric), stricture incision, thermal coagulation for hemostasis or tumor ablation, percutaneous endoscopic gastrostomy, ampullectomy, endoscopic mucosal resection (EMR), endoscopic submucosal dissection (ESD), endoluminal stenting with self-expanding metal stent (SEMS), full-thickness endoscopic resection, endoscopic retrograde cholangiopancreatography (ERCP) in surgically altered anatomy, endoscopic ultrasound (EUS)-guided biliary and pancreatic access, EUS-guided cystogastrostomy, and endoscopic gastroenterostomy using a lumen apposing metal stent (LAMS). BEST PRACTICE ADVICE 5: Urgent surgical consultation should be highly considered in all cases with perforation even when endoscopic repair is technically successful. BEST PRACTICE ADVICE 6: For all upper gastrointestinal perforations, the patient should be considered to be admitted for observation, receive intravenous fluids, be kept nothing by mouth, receive broad-spectrum antibiotics (to cover Gram-negative and anaerobic organisms), nasogastric tube (NGT) placement (albeit some exceptions), and surgical consultation. BEST PRACTICE ADVICE 7: For upper gastrointestinal tract perforations, a water-soluble upper gastrointestinal series should be considered to confirm the absence of continuing leak at the perforation site before initiating a clear liquid diet. BEST PRACTICE ADVICE 8: Endoscopic closure of esophageal perforations should be pursued when feasible, utilizing through-the-scope clips (TTSCs) or over-the-scope clips (OTSCs) for perforations <2 cm and endoscopic suturing for perforations >2 cm, reserving esophageal stenting with SEMS for cases where primary closure is not possible. BEST PRACTICE ADVICE 9: Endoscopic closure of gastric perforations should be pursued when feasible, utilizing TTSCs or OTSCs for perforations <2 cm and endoscopic suturing or combination of TTSCs and endoloop for perforations >2 cm. BEST PRACTICE ADVICE 10: For large type 1 duodenal perforations (lateral duodenal wall tear >3 cm), being cognizant of the difficulty in closing them endoscopically, urgent surgical consultation should be made while the feasibility of endoscopic closure is assessed. BEST PRACTICE ADVICE 11: Because type 2 periampullary (retroperitoneal) perforations are subtle and can be easily missed, the endoscopist should carefully assess the gas pattern on fluoroscopy to avoid delays in treatment and request a computed tomography scan if there is a concern for such a perforation; identified perforations of this type at the time of ERCP may be closed with TTSCs if feasible and/or by placing a fully covered SEMS into the bile duct across the ampulla. BEST PRACTICE ADVICE 12: For the management of large duodenal polyps, endoscopic mucosal resection (EMR) should only be performed by experienced endoscopists and endoscopic submucosal dissection (ESD) only by experts because both EMR and ESD in the duodenum require proficiency in resection and mucosal defect closure techniques to manage immediate and/or delayed perforations (caused by the proteolytic enzymes of the pancreas). BEST PRACTICE ADVICE 13: Endoscopists should be aware that colon perforations occurring during diagnostic colonoscopy are most commonly located in the sigmoid colon due to direct trauma from forceful advancement of the colonoscope. Such tears recognized at the time of colonoscopy may be closed by TTSCs or OTSCs if the bowel preparation is good and the patient is stable. BEST PRACTICE ADVICE 14: Although colon perforation is responsive to various endoscopic tools such as TTSC, OTSC, and endoscopic suturing, perforations in the right colon, especially in the cecum, have been relegated to using only TTSCs because of inability to reach the site of the perforation with an endoscopic suturing device or OTSC if the colon is tortuous or unclean. Recently a new suture-based device for defect closure has been introduced allowing deep submucosal and intramuscular enhanced fixation through a standard gastroscope or colonoscope. BEST PRACTICE ADVICE 15: Patients with perforations who are hemodynamically unstable or who have suffered a delayed perforation with peritoneal signs or frank peritonitis should be surgically managed without any attempt at endoscopic closure. BEST PRACTICE ADVICE 16: In any adverse event including perforation, it is paramount to ensure accurate documentation, prompt discussion with the patient and family, and swift reporting to the quality officer (or equivalent) and risk management team of the institution (in major adverse events).

Peroral endoscopic myotomy: 10-year outcomes from a large, single-center U.S. series with high follow-up completion and comprehensive analysis of long-term efficacy, safety, objective GERD, and endoscopic functional luminal assessment.

BACKGROUND AND AIMS: Peroral endoscopic myotomy (POEM) is becoming the treatment of choice for achalasia. Data beyond 3 years are emerging but are limited. We herein report our 10-year experience, focusing on long-term efficacy and safety including the prevalence, management, and sequelae of postoperative reflux. METHODS: This was a single-center prospective cohort study. RESULTS: Six hundred ten consecutive patients received POEM from October 2009 to October 2019, 160 for type 1 achalasia (26.2%), 307 for type II (50.3%), 93 for type III (15.6%), 25 for untyped achalasia (4.1%), and 23 for nonachalasia disorders (3.8%). Two hundred ninety-two patients (47.9%) had prior treatment(s). There was no aborted POEM. Median operation time was 54 minutes. Accidental mucosotomies occurred in 64 patients (10.5%) and clinically significant adverse events in 21 patients (3.4%). No adverse events led to death, surgery, interventional radiology interventions/drains, or altered functional status. At a median follow-up of 30 months, 29 failures occurred, defined as postoperative Eckardt score >3 or need for additional treatment. The Kaplan-Meier clinical success estimates at years 1, 2, 3, 4, 5, 6, and 7 were 98%, 96%, 96%, 94%, 92%, 91%, and 91%, respectively. These are highly accurate estimates because only 13 patients (2%) were missing follow-up assessments. One hundred twenty-five patients (20.5%) had reflux symptoms more than once per week. At a median of 4 months, the pH study was completed in 406 patients (66.6%) and was positive in 232 (57.1%), and endoscopy was completed in 438 patients (71.8%) and showed reflux esophagitis in 218 (49.8%), mostly mild. CONCLUSIONS: POEM is exceptionally safe and highly effective on long-term follow-up, with >90% clinical success at ≥5 years.

Learning Curve for Endoscopic Submucosal Dissection With an Untutored, Prevalence-Based Approach in the United States.

BACKGROUND & AIMS: Endoscopic submucosal dissection (ESD) is widely used in Asia to resect early-stage gastrointestinal neoplasms, but use of ESD in Western countries is limited. We collected data on the learning curve for ESD at a high-volume referral center in the United States to guide development of training programs in the Americas and Europe. METHODS: We performed a retrospective analysis of consecutive ESDs performed by a single operator at a high-volume referral center in the United States from 2009 through 2017. ESD was performed in 540 lesions: 449 mucosal (10% esophageal, 13% gastric, 5% duodenal, 62% colonic, and 10% rectal) and 91 submucosal. We estimated case volumes required to achieve accepted proficiency benchmarks (>90% for en bloc resection and >80% for histologic margin-negative (R0) resection) and resection speeds >9cm2/hr. RESULTS: Pathology analysis of mucosal lesions identified 95 carcinomas, 346 premalignant lesions, and 8 others; the rate of en bloc resection increased from 76% in block 1 (50 cases) to a plateau of 98% after block 5 (250 cases). The rate of R0 resection improved from 45% in block 1 to >80% after block 5 (250 cases) and ∼95% after block 8 (400 cases). Based on cumulative sum analysis, approximately 170, 150, and 280 ESDs are required to consistently achieve a resection speed >9cm2/hr in esophagus, stomach, and colon, respectively. CONCLUSIONS: In an analysis of ESDs performed at a large referral center in the United States, we found that an untutored, prevalence-based approach allowed operators to achieve all proficiency benchmarks after ∼250 cases. Compared with Asia, ESD requires more time to learn in the West, where the untutored, prevalence-based approach requires resection of challenging lesions, such as colon lesions and previously manipulated lesions, in early stages of training.

Statement for gastroesophageal reflux disease after peroral endoscopic myotomy from an international multicenter experience.

It has been 10 years since peroral endoscopic myotomy (POEM) was reported for the first time, and POEM has currently become the standard treatment for achalasia and related disorders globally because it is less invasive and has a higher curative effect than conventional therapeutic methods. However, there are limited studies comparing the long-term outcomes of POEM with those of conventional therapeutic methods, particularly in the occurrence of gastroesophageal reflux disease (GERD) after therapy. With this background, we held a consensus meeting to discuss the pathophysiology and management of GERD after POEM based on published papers and experiences of each expert and to discuss the prevention of GERD and dealing with anti-acid drug refractory GERD. This meeting was held on April 27, 2018 in Tokyo to establish statements and finalize the recommendations using the modified Delphi method. This manuscript presents eight statements regarding GERD after POEM.

A task and performance analysis of endoscopic submucosal dissection (ESD) surgery.

BACKGROUND: ESD is an endoscopic technique for en bloc resection of gastrointestinal lesions. ESD is a widely-used in Japan and throughout Asia, but not as prevalent in Europe or the US. The procedure is technically challenging and has higher adverse events (bleeding, perforation) compared to endoscopic mucosal resection. Inadequate training platforms and lack of established training curricula have restricted its wide acceptance in the US. Thus, we aim to develop a Virtual Endoluminal Surgery Simulator (VESS) for objective ESD training and assessment. In this work, we performed task and performance analysis of ESD surgeries. METHODS: We performed a detailed colorectal ESD task analysis and identified the critical ESD steps for lesion identification, marking, injection, circumferential cutting, dissection, intraprocedural complication management, and post-procedure examination. We constructed a hierarchical task tree that elaborates the order of tasks in these steps. Furthermore, we developed quantitative ESD performance metrics. We measured task times and scores of 16 ESD surgeries performed by four different endoscopic surgeons. RESULTS: The average time of the marking, injection, and circumferential cutting phases are 203.4 (σ: 205.46), 83.5 (σ: 49.92), 908.4 s. (σ: 584.53), respectively. Cutting the submucosal layer takes most of the time of overall ESD procedure time with an average of 1394.7 s (σ: 908.43). We also performed correlation analysis (Pearson's test) among the performance scores of the tasks. There is a moderate positive correlation (R = 0.528, p = 0.0355) between marking scores and total scores, a strong positive correlation (R = 0.7879, p = 0.0003) between circumferential cutting and submucosal dissection and total scores. Similarly, we noted a strong positive correlation (R = 0.7095, p = 0.0021) between circumferential cutting and submucosal dissection and marking scores. CONCLUSIONS: We elaborated ESD tasks and developed quantitative performance metrics used in analysis of actual surgery performance. These ESD metrics will be used in future validation studies of our VESS simulator.

Spiral enteroscopy-assisted ERCP in bariatric-length Roux-en-Y anatomy: a large single-center series and review of the literature (with video).

BACKGROUND: Deep enteroscopy-assisted ERCP (DEA-ERCP) in post-bariatric Roux-en-Y (RY) anatomy is challenging. Laparoscopy-assisted ERCP (LA-ERCP) and EUS-directed transgastric ERCP (EDGE) are technically easier and faster but are more invasive and morbid procedures. Therefore, we have used DEA-ERCP as our first-line approach, reserving EDGE and LA-ERCP for cases in which adjunctive techniques that cannot be performed through an enteroscope are required (eg, EUS-FNA, sleeve sphincter of Oddi manometry), or DEA-ERCP failures. The 2 main methods for DEA-ERCP are balloon- and spirus-assisted. Current literature on spiral enteroscopy ERCP (SE-ERCP) in bariatric RY anatomy is scant with low success rates reported. Our center has nearly exclusively used SE-ERCP for bariatric patients. Here, we report one of the largest such series to date. METHODS: This is a retrospective cohort study of consecutive patients with bariatric-length RY anatomy who had SE-ERCP from December 2009 to October 2016 at a tertiary care center, by one operator (S.N.S.). Primary outcomes included success at reaching the papilla, cannulation success, success of desired therapeutic intervention, and overall SE-ERCP success. RESULTS: Thirty-five SE-ERCPs were performed (28 in bariatric RY gastric bypass and 7 other long-limb RY surgical reconstructions). The papilla was reached in 86% (30/35) of cases. Cannulation success in patients in whom deep cannulation was indicated (28/30) was 100% (28/28 cases, including the 24 cases with native papilla). Therapeutic ERCP success was 100% (28/28). Overall SE-ERCP success was 86% (30/35). Median length of stay was 3 days. Median procedure time was 189 minutes. Reasons for SE-ERCP failures included RY anastomosis stricture, adhesions (2), long Roux limb, and redundant small bowel. Two of these patients underwent interventional radiology-guided percutaneous biliary drainage, 2 patients had laparoscopy-assisted ERCP, and 1 patient had EUS-guided antegrade cholangioscopy with sphincteroplasty and stone clearance. There were no adverse events. CONCLUSION: With sufficient allotted time (median procedure time ∼3 hours) and high operator experience (a single-operator volume that exceeds that of other published series), SE-ERCP is safe and effective in bariatric, long-limb RY patients with an overall success rate of 86%, which is higher than previously reported.

Per-oral endoscopic myotomy in patients with or without prior Heller's myotomy: comparing long-term outcomes in a large U.S. single-center cohort (with videos).

BACKGROUND AND AIMS: Heller's myotomy (HM) is one of the most effective treatments for esophageal achalasia. However, failures do exist, and the success rate tends to decrease with time. The efficacy of rescue treatments for patients with failed HM is limited. A few small-scale studies have reported outcomes of per-oral endoscopic myotomy (POEM) in these patients. We conducted this study to systematically assess feasibility, safety, and efficacy of POEM on patients who have had HM. METHODS: Patients at least 3 months out from POEM were selected from our prospective database: 318 consecutive POEMs performed from October 2009 to October 2016. The efficacy and safety of POEM were compared between the 46 patients with prior HM and the remaining 272 patients. RESULTS: Patients with prior HM had longer disease history, more advanced disease, more type I and less type II achalasia, lower before-POEM Eckardt scores, and lower before-POEM lower esophageal sphincter (LES) pressure (all P < .01). Procedure parameters and follow-up results (clinical success rate, Eckardt score, LES pressure, GERD score, esophagitis, and pH testing) showed no significant difference between the 2 groups. For the 46 HM-POEM patients, no clinically significant perioperative adverse events occurred. Their overall clinical success rate (Eckardt score ≤3 and no other treatment needed) was 95.7% at a median follow-up of 28 months. CONCLUSION: POEM as a rescue treatment for patients with achalasia who failed HM is feasible, safe, and highly effective. It should be the treatment of choice in managing these challenging cases at centers with a high level of experience with POEM.

Gastric Per Oral Endoscopic Myotomy (G-POEM) for the Treatment of Refractory Gastroparesis: Early Experience.

BACKGROUND: Gastric per oral endoscopic myotomy (G-POEM) of the pylorus is a technique that is recently being used to treat gastroparesis. Our aim was to report our experience in performing G-POEM for refractory gastroparesis of different etiologies and determine symptom improvement. METHODS: Thirteen patients undergoing G-POEM are reported. Pre- and post-procedure gastric emptying study (GES) and PAGI-SYM for symptom severity were obtained. Patients underwent G-POEM by creating a submucosal tunnel starting in the greater curvature of the distal antrum and extending it to the beginning of the duodenal bulb, followed by a full thickness pyloromyotomy. RESULTS: All 13 gastroparesis patients successfully underwent G-POEM (one diabetic [DGp], four idiopathic [IGp], eight postsurgical [PSGp]). Postsurgical patients included 4 s/p esophagectomy for esophageal cancer, 3 s/p Nissen fundoplication, and 1 s/p esophagectomy for achalasia. There were no procedure-related side effects. Of 11 patients completing follow-up questionnaires, eight were improved subjectively (four patients reported considerably better, four patients somewhat better, one unchanged, and two worse). Individual symptom severity scores tended to improve, particularly vomiting, retching, and loss of appetite. Of six patients that had post-G-POEM GES; GES improved in four, unchanged in one, and worsened in one). CONCLUSIONS: G-POEM for treatment of refractory gastroparesis appears to be a feasible and safe technique that can be successfully performed in patients with a variety of etiologies including different types of postsurgical gastroparesis. Our initial experience suggests that the majority of patients report some improvement in symptoms, particularly symptoms of vomiting, retching, and loss of appetite. Further experience is needed to determine the efficacy and safety of G-POEM and predict those who best respond to this treatment.

Per oral endoscopic myotomy for the treatment of achalasia.

Per oral endoscopic myotomy (POEM) represents the culmination of natural orifice transluminal endoscopic surgery (NOTES) research, and its most successful application to date. Over a thousand POEMs have been performed globally with remarkable results in terms of clinical efficacy and safety. PURPOSE OF REVIEW: We examine the most recent literature concerning POEM since the last two comprehensive analyses [Natural Orifice Surgery Consortium for Assessment and Research (NOSCAR) White Paper, ASGE Preservation and Incorporation of Valuable endoscopic Innovations (PIVI)], and integrate this literature in the consensus POEM guidelines and perspective. These current works are largely centered on POEM operator learning curve, comparison of POEM and laparoscopic Heller myotomy (LHM) and extended application of POEM. RECENT FINDINGS: POEM and LHM are comparable in terms of efficacy (diminished dysphagia and Eckardt score) and complications including GERD. POEM has been successfully performed in a wide variety of patients including children, those with prior achalasia therapy and those with spastic esophageal disorders. SUMMARY: POEM has been validated as a treatment for achalasia. Issues remain regarding its longer term efficacy in comparison with LHM. Subsequent comparison trials are needed. VIDEO ABSTRACT: http://links.lww.com/COG/A14.

The light at the end of the tunnel: a single-operator learning curve analysis for per oral endoscopic myotomy.

BACKGROUND: Per oral endoscopic myotomy (POEM) represents a natural orifice transluminal endoscopic surgery approach to Heller myotomy. Our center was the first to offer POEM outside of Japan, allowing us to accumulate what is likely the highest single-operator POEM volume in the United States. OBJECTIVE: To define the POEM learning curve of a gastroenterologist by using a larger data set and more detailed statistical analysis than used in 2 other reports of POEM performed by surgeons. DESIGN: Prospective cohort study. SETTING: Tertiary-care academic medical center. PATIENTS: We analyzed the first 93 consecutive POEMs on patients with achalasia aged >18 years without contraindications to POEM performed by a single operator from October 2009 to November 2013. INTERVENTIONS: (1) Efficiency estimation via cumulative sum (CUSUM) analysis, (2) mastery estimation via penalized basis-spline regression and CUSUM analysis, (3) correlation of operator experience with clinical outcomes (Eckardt score improvement, lower esophageal sphincter pressure reduction) and technical errors (accidental mucosotomy rate), and (4) unadjusted and adjusted regression analysis to assess how patient characteristics affected procedure time by using a generalized linear model. MAIN OUTCOME MEASUREMENTS: Clinical outcomes, procedure time, technical errors. RESULTS: Efficiency was attained after 40 POEMs and mastery after 60 POEMs. When we used the adjusted regression analysis, only case number (operator experience) significantly affected procedure time (P < .0001). Improvements in clinical outcomes were excellent but not significantly affected by operator experience, as was the case with accidental mucosotomies. Procedure time was not significantly affected by age, sex, achalasia stage, baseline lower esophageal sphincter pressure, baseline Eckardt score, prior treatment of achalasia, prior botulinum toxin injection, incidence of accidental mucosotomies, length of myotomy, or type of knife used (all P > .05). LIMITATIONS: Our analysis may underestimate the number of POEMs required to achieve mastery for operators with limited or no endoscopic submucosal dissection experience. CONCLUSION: These results offer thresholds for efficiency and mastery of a single gastroenterologist operator that may guide the efforts of novice POEM operators.

International multicenter experience with peroral endoscopic myotomy for the treatment of spastic esophageal disorders refractory to medical therapy (with video).

BACKGROUND: Limited data exist on the use of peroral endoscopic myotomy (POEM) for therapy of spastic esophageal disorders (SEDs). OBJECTIVE: To study the efficacy and safety of POEM for the treatment of patients with diffuse esophageal spasm, jackhammer esophagus, or type III (spastic) achalasia. DESIGN: Retrospective study. SETTING: International, multicenter, academic institutions. PATIENTS: All patients who underwent POEM for treatment of SEDs refractory to medical therapy at 11 centers were included. INTERVENTIONS: POEM. MAIN OUTCOME MEASUREMENTS: Eckardt score and adverse events. RESULTS: A total of 73 patients underwent POEM for treatment of SEDs (diffuse esophageal spasm 9, jackhammer esophagus 10, spastic achalasia 54). POEM was successfully completed in all patients, with a mean procedural time of 118 minutes. The mean length of the submucosal tunnel was 19 cm, and the mean myotomy length was 16 cm. A total of 8 adverse events (11%) occurred, with 5 rated as mild, 3 moderate, and 0 severe. The mean length of hospital stay was 3.4 days. There was a significant decrease in Eckardt scores after POEM (6.71 vs 1.13; P = .0001). Overall, clinical response was observed in 93% of patients during a mean follow-up of 234 days. Chest pain significantly improved in 87% of patients who reported chest pain before POEM. Repeat manometry after POEM was available in 44 patients and showed resolution of initial manometric abnormalities in all cases. LIMITATIONS: Retrospective design and selection bias. CONCLUSION: POEM offers a logical therapeutic modality for patients with SEDs refractory to medical therapy. Results from this international study suggest POEM as an effective and safe platform for these patients.

The role of molecular analysis in the diagnosis and surveillance of pancreatic cystic neoplasms.

CONTEXT: Molecular analysis of pancreatic cyst fluid obtained by EUS-FNA may increase diagnostic accuracy. We evaluated the utility of cyst-fluid molecular analysis, including mutational analysis of K-ras, loss of heterozygosity (LOH) at tumor suppressor loci, and DNA content in the diagnoses and surveillance of pancreatic cysts. METHODS: We retrospectively reviewed the Columbia University Pancreas Center database for all patients who underwent EUS/FNA for the evaluation of pancreatic cystic lesions followed by surgical resection or surveillance between 2006-2011. We compared accuracy of molecular analysis for mucinous etiology and malignant behavior to cyst-fluid CEA and cytology and surgical pathology in resected tumors. We recorded changes in molecular features over serial encounters in tumors under surveillance. Differences across groups were compared using Student's t or the Mann-Whitney U test for continuous variables and the Fisher's exact test for binary variables. RESULTS: Among 40 resected cysts with intermediate-risk features, molecular characteristics increased the diagnostic yield of EUS-FNA (n=11) but identified mucinous cysts less accurately than cyst fluid CEA (P=0.21 vs. 0.03). The combination of a K-ras mutation and ≥2 loss of heterozygosity was highly specific (96%) but insensitive for malignant behavior (50%). Initial data on surveillance (n=16) suggests that molecular changes occur frequently, and do not correlate with changes in cyst size, morphology, or CEA. CONCLUSIONS: In intermediate-risk pancreatic cysts, the presence of a K-ras mutation or loss of heterozygosity suggests mucinous etiology. K-ras mutation plus ≥2 loss of heterozygosity is strongly associated with malignancy, but sensitivity is low; while the presence of these mutations may be helpful, negative findings are uninformative. Molecular changes are observed in the course of cyst surveillance, which may be significant in long-term follow-up.

International multicenter experience with an over-the-scope clipping device for endoscopic management of GI defects (with video).

BACKGROUND: The over-the-scope clip (OTSC) provides more durable and full-thickness closure as compared with standard clips. Only case reports and small case series have reported on outcomes of OTSC closure of GI defects. OBJECTIVE: To describe a large, multicenter experience with OTSCs for the management of GI defects. Secondary goals were to determine success rate by type of defect and type of therapy and to determine predictors of treatment outcomes. DESIGN: Multicenter, retrospective study. SETTING: Multiple, international, academic centers. PATIENTS: Consecutive patients who underwent attempted OTSC placement for GI defects, either as a primary or as a rescue therapy. INTERVENTIONS: OTSC placement to attempt closure of GI defects. MAIN OUTCOME MEASUREMENTS: Long-term success of the procedure. RESULTS: A total of 188 patients (108 fistulae, 48 perforations, 32 leaks) were included. Long-term success was achieved in 60.2% of patients during a median follow-up of 146 days. Rate of successful closure of perforations (90%) and leaks (73.3%) was significantly higher than that of fistulae (42.9%) (P < .05). Long-term success was significantly higher when OTSCs were applied as primary therapy (primary 69.1% vs rescue 46.9%; P = .004). On multivariate analysis, patients who had OTSC placement for perforations and leaks had significantly higher long-term success compared with those who had fistulae (OR 51.4 and 8.36, respectively). LIMITATIONS: Retrospective design and multiple operators with variable expertise with the OTSC device. CONCLUSION: OTSC is safe and effective therapy for closure of GI defects. Clinical success is best achieved in patients undergoing closure of perforations or leaks when OTSC is used for primary or rescue therapy. Type of defect is the best predictor of successful long-term closure.

EUS-guided biliary drainage by using a standardized approach for malignant biliary obstruction: rendezvous versus direct transluminal techniques (with videos).

BACKGROUND: EUS-guided biliary drainage (EGBD) can be performed via direct transluminal or rendezvous techniques. It is unknown how both techniques compare in terms of efficacy and adverse events. OBJECTIVE: To describe outcomes of EGBD performed by using a standardized approach and compare outcomes of rendezvous and transluminal techniques. DESIGN: Retrospective analysis of prospectively collected data. SETTING: Two tertiary-care centers. PATIENTS: Consecutive jaundiced patients with distal malignant biliary obstruction who underwent EGBD after failed ERCP between July 2006 and December 2012 were included. INTERVENTION: EGBD by using a standardized algorithm. MAIN OUTCOME MEASUREMENTS: Technical success, clinical success, and adverse events. RESULTS: During the study period, 35 patients underwent EGBD (rendezvous n = 13, transluminal n = 20). Technical success was achieved in 33 patients (94%), and clinical success was attained in 32 of 33 patients (97.0%). The mean postprocedure bilirubin level was 1.38 mg/dL in the rendezvous group and 1.33 mg/dL in the transluminal group (P = .88). Similarly, length of hospital stay was not different between groups (P = .23). There was no significant difference in adverse event rate between rendezvous and transluminal groups (15.4% vs 10%; P = .64). Long-term outcomes were comparable between groups, with 1 stent migration in the rendezvous group at 62 days and 1 stent occlusion in the transluminal group at 42 days after EGBD. LIMITATIONS: Retrospective analysis, small number of patients, and selection bias. CONCLUSION: EGBD is safe and effective when the described standardized approach is used. Stent occlusion is not common during long-term follow-up. Both rendezvous and direct transluminal techniques seem to be equally effective and safe. The latter approach is a reasonable alternative to rendezvous EGBD.

Novel technique of auto-tunneling during peroral endoscopic myotomy (with video).

BACKGROUND: Peroral endoscopic myotomy (POEM) was developed to reduce lower esophageal sphincter pressure in patients with achalasia. POEM is technically challenging and time consuming. The creation of an esophageal submucosal tunnel is a major and integral part of the procedure. Dissection of the submucosal fibers is a lengthy task. OBJECTIVE: To present our initial experience with the use of a novel gel with dissecting properties for facilitating submucosal tunneling during POEM. SETTING: Johns Hopkins Hospital. INTERVENTION: POEM. RESULTS: The gastroscope was successfully introduced into the submucosal space in all pigs. The gel in the submucosal space was easily suctioned through the working channel of the gastroscope and did not interfere with endoscopic visualization. The esophageal submucosal tunnel was noted to be already formed upon entry into the submucosal space in all 5 pigs. Esophageal submucosal dissection was not required in any case. "Auto-tunneling" by the dissecting gel stopped at the level of the lower esophageal sphincter. Further tunneling into the gastric cardia was needed in all pigs. The average procedure (including myotomy) time was 28 minutes. LIMITATIONS: Animal experiments. CONCLUSION: Gel consistently resulted in efficient auto-tunneling without any complications. This gel has the potential to revolutionize POEM and endoscopic submucosal dissection if its safety and efficacy are replicated in other animal studies and subsequently in human trials.