David Friedel

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.

High yield of same-session EUS-guided liver biopsy by 19-gauge FNA needle in patients undergoing EUS to exclude biliary obstruction

BACKGROUND EUS-guided liver biopsy by Trucut yields variable specimen adequacy at high cost, limiting its utility. A modified EUS-guided technique with reliable adequacy could be a viable alternative to standard techniques in cost-effective clinical settings. OBJECTIVE To describe our experience with EUS-guided liver biopsy by 19-gauge FNA, non-Trucut, needle in a cost-effective setting: patients with abnormal liver test results of unclear etiology referred for EUS to exclude biliary obstruction in whom an unrevealing EUS would have prompted a next-step liver biopsy by the referring physician. DESIGN Prospective case series. SETTING Tertiary-care teaching hospital. PATIENTS Consecutive patients with abnormal liver tests referred for EUS. INTERVENTIONS EUS-guided liver biopsy by 19-gauge FNA needle (non-Trucut). MAIN OUTCOME MEASUREMENTS Diagnostic yield, specimen adequacy, and complications. An adequate specimen was defined as a length of 15 mm or longer and 6 or more complete portal tracts (CPTs). RESULTS Between July 2008 and July 2011, 22 of 31 consecutive patients meeting inclusion criteria underwent unrevealing EUS with same-session EUS-guided liver biopsy by 19-gauge FNA needle. A median of 2 FNA passes (range 1-3) yielded a median specimen length of 36.9 mm (range 2-184.6 mm) with a median of 9 CPTs (range 1-73 CPTs). EUS-guided liver biopsies yielded a histologic diagnosis and adequate specimens in 20 of 22 patients (91%). Expanded experience led to improved specimen adequacy. There were no complications. LIMITATION Small study size. CONCLUSIONS EUS-guided liver biopsy by using a 19-gauge FNA needle appears to be feasible and safe and provides excellent diagnostic yield and specimen adequacy.

Per-oral endoscopic myotomy for achalasia: An American perspective

Achalasia is an uncommon esophageal motility disorder characterized by the selective loss of enteric neurons leading to absence of peristalsis and impaired relaxation of the lower esophageal sphincter. Per-oral endoscopic myotomy (POEM) is a novel modality for the treatment of achalasia performed by gastroenterologists and surgeons. It represents a natural orifice transluminal endoscopic surgery (NOTES) approach to Heller myotomy. POEM has the minimal invasiveness of an endoscopic procedure that can duplicate results of the surgical Heller myotomy. POEM is conceptually similar to a surgical myotomy without the inherent external incisions and post-operative care associated with surgery. Initial high success and low complications rates promise a great future for this technique. In fact, POEM has been successfully performed on patients with end-stage achalasia as an initial treatment reserving esophagectomy for those without good response. The volume of POEMs performed worldwide has grown exponentially. In fact, surgeons who have performed Heller myotomy have embraced POEM as the preferred intervention for achalasia. However, the niche of POEM remains to be defined and long term results are awaited. We describe our experience with POEM having performed the first POEM outside of Japan in 2009, the evolution of our technique, and give our perspective on its future.

Endoscopic approaches to treatment of achalasia

Endoscopic therapy for achalasia is directed at disrupting or weakening the lower esophageal sphincter (LES). The two most commonly utilized endoscopic interventions are large balloon pneumatic dilation (PD) and botulinum toxin injection (BTI). These interventions have been extensively scrutinized and compared with each other as well as with surgical disruption (myotomy) of the LES. PD is generally more effective in improving dysphagia in achalasia than BTI, with the latter reserved for infirm older people, and PD may approach treatment results attained with myotomy. However, PD may need to be repeated. Small balloon dilation and endoscopic stent placement for achalasia have only been used in select centers. Per oral endoscopic myotomy is a newer endoscopic modality that will likely change the treatment paradigm for achalasia. It arose from the field of natural orifice transluminal endoscopic surgery and represents a scarless endoscopic approach to Heller myotomy. This is a technique that requires extensive training and preparation and thus there should be rigorous accreditation and monitoring of outcomes to ensure safety and efficacy.

Endoscopic-Ultrasound-Guided Fine-Needle Aspiration and the Role of the Cytopathologist in Solid Pancreatic Lesion Diagnosis

Endoscopic ultrasound (EUS) is the most sensitive imaging modality for solid pancreatic lesions. The specificity, however, is low (about 75%). It can be increased to 100% with an accuracy of 95% by the addition of fine-needle aspiration (FNA). Cytopathology plays an important role. The final diagnosis is based upon the correlation of clinical, EUS, and cytologic features. A close interaction with the cytopathologist is required in improving the diagnostic yield. In this paper, we present an overview of the role of EUS-guided FNA and importance of close interaction with the cytopathologist. Day to day examples of different solid pancreatic lesions have been presented at the end.

Endoscopic suture repair of a large mucosal perforation during peroral endoscopic myotomy for treatment of achalasia

Mucosal perforations occur in about 10% to 15% of peroral endoscopic myotomy (POEM) procedures and are usually closed with clips. However, accidental perforations because of submucosal fibrosis from prior Botox (Allergan Inc., Irvine, CA) injections, balloon dilations (BDs), or other manipulations can be difficult to close (Fig. 1). A 40-year-old man with stage 2, type I achalasia and multiple prior BDs underwent POEM for dysphagia. Extensive submucosal fibrosis from prior BDs made extension of the tunnel at the gastroesophageal junction challenging. The first mucosal perforation at the squamocolumnar junction was closed immediately with endoclips. A second accidental perforation occurred after the tunnel extended into the cardia. Closure was postponed until the myotomy was completed because there was concern of tunnel narrowing, hindering the myotomy. However, at the completion of the myotomy, the cardia perforation dramatically enlarged, likely because of the CO2 insufflation within the tunnel. Given its large size and poor tissue quality, endoscopic suturing was used to successfully close this

Per-oral endoscopic myotomy: Major advance in achalasia treatment and in endoscopic surgery

Per-oral endoscopic myotomy (POEM) represents a natural orifice endoscopic surgery (NOTES) approach to laparoscopy Heller myotomy (LHM). POEM is arguably the most successful clinical application of NOTES. The growth of POEM from a single center in 2008 to approximately 60 centers worldwide in 2014 with several thousand procedures having been performed attests to the success of POEM. Initial efficacy, safety and acid reflux data suggest at least equivalence of POEM to LHM, the previous gold standard for achalasia therapy. Adjunctive techniques used in the West include impedance planimetry for real-time intraprocedural luminal assessment and endoscopic suturing for challenging mucosal defect closures during POEM. The impact of POEM extends beyond the realm of esophageal motility disorders as it is rapidly popularizing endoscopic submucosal dissection in the West and spawning offshoots that use the submucosal tunnel technique for a host of new indications ranging from resection of tumors to pyloromyotomy for gastroparesis.

Outcomes of endoscopic-ultrasound-guided cholangiopancreatography: a literature review.

Endoscopic retrograde cholangiopancreatography (ERCP) can fail in 3–10% of the cases even in experienced hands. Although percutaneous transhepatic cholangiography (PTC) and surgery are the traditional alternatives, there are morbidity and mortality associated with both. In this paper, we have discussed the efficacy and safety of endoscopic-ultrasound-guided cholangiopancreatography (EUS-CP) in decompression of biliary and pancreatic ducts. The overall technical and clinical success rates are around 90% for biliary and 70% for pancreatic duct drainage. The overall EUS-CP complication rate is around 15%. EUS-CP is, however, a technically challenging procedure and should be performed by an experienced endoscopist skilled in both EUS and ERCP. Same session EUS-CP as failed initial ERCP is practical and may result in avoidance of additional procedures. With increasing availability of endoscopists trained in both ERCP and EUS, the role of EUS-CP is likely to grow in clinical practice.

Endoscopic full-thickness resection for GI stromal tumors

Most upper GI subepithelial tumors (SETs) are GI stromal tumors (GISTs), potentially malignant tumors. National Comprehensive Cancer Network guidelines recommend surgery for suspected GISTs 2 cm or larger and endoscopic surveillance of those smaller than 2 cm. This approach creates a large burden of surgery and endoscopy for small SETs, the majority of which are low risk. This situation motivated endoscopists, mostly from Asia, to use endoscopic submucosal dissection (ESD) to “excavate”muscularis propria (MP)-based SETs. However, such enucleation may leave microscopic residual tumor within the MP and is not applicable to tumors with an extraluminal component. Novel closure devices and methods spawned by natural orifice transluminal endoscopic surgery research have led to development of endoscopic full-thickness resection (EFTR) techniques for SETs. EFTR can achieve complete en bloc resection of MP-based SETs along with the associated MP, thus ensuring R0 curative resection of tumors smaller than 5 cm. We present 1 of our 25 full-thickness SET resections, the first of such cases in the United States, performed by a gastroenterologist with 4 years of per-oral endoscopic myotomy and 7 years of ESD experience. Complete en bloc full-thickness endoscopic resection of a 4.5-cm dumbbell-shaped gastric GIST with a large extraluminal component was achieved in 68 minutes with no adverse events. Primary closure was achieved by using the omental patch method. There was no evidence of recurrence at 16-month follow-up. Advantages of EFTR include (1) incisionless approach; (2) resection of SETs in areas that challenge laparoscopic “wedge” resection such as the gastroesophageal junction, esophagus, and gastric cardia; and (3) reliable diagnosis and mitotic rate assessment, which, along with complete resection, obviates lifelong endoscopic surveillance for low-risk tumors (Fig. 1; Video 1, available online www.giejournal.org).

Closing Perforations and Postperforation Management in Endoscopy: Esophagus and Stomach

Luminal perforation after endoscopy is a dreaded complication that is associated with significant morbidity and mortality, longer and more costly hospitalization, and the specter of potential future litigation. The management of such perforations requires a multidisciplinary approach. Until recently, surgery was required. However, nowadays the endoscopist has a burgeoning armamentarium of devices and techniques that may obviate surgery. This article discusses the approach to endoscopic perforations in the esophagus and stomach.