Faculty Bibliography

Endoscopic submucosal dissection (ESD) represents an organ-preserving alternative to surgical resection of early gastric cancer. However, even with ESD yielding en-bloc resection specimens, there are concerns regarding tumor spread such as with larger lesions, ulcerated lesions, undifferentiated pathology and submucosal invasion. Sentinel node navigational surgery (SNNS) when combined with ESD offers a minimally invasive alternative to the traditional extended gastrectomy and lymphadenectomy if lack of lymph node spread can be confirmed. This would have a clear advantage in terms of potential complications and quality of life. However, SNNS, though useful in other malignancies such as breast cancer and melanoma, may not have a sufficient sensitivity for malignancy and negative predictive value in EGC to justify this as standard practice after ESD. The results of SNNS may improve with greater standardization and more involved dissection, technological innovations and more experience and validation such that the paradigm for post-ESD resection of EGC may change and include SNNS.

BACKGROUND & AIMS/OBJECTIVE: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:/hr. RESULTS:/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.

BACKGROUND:Ileocecal valve (ICV) lesions are difficult to resect endoscopically and patients are often referred for laparoscopic colectomy. ICV involvement has been shown to be related to technical failure and tumor recurrence after endoscopic mucosal resection (EMR) and represents a challenge for endoscopic submucosal dissection (ESD). Few publications have focused specifically on endoscopic management of ICV lesions. METHODS:We developed a novel ESD technique, the "doughnut resection," for circumferential ICV adenomas with terminal ileum involvement. Two circumferential mucosal incisions are performed, one in the ileum and the other in the cecum, followed by submucosal dissection of the disk of tissue between the two incisions around a guiding stent placed across the valve that helps guide the dissection as it crosses the valve orifice. The lesion is removed en bloc in the shape of a "doughnut" with two concentric assessable lateral margins. The underwater ESD technique and a gastroscope were used to facilitate the resection. RESULTS:Seven patients received the doughnut resection. The median patient age was 67 years. All patients had prior biopsy and three had prior endoscopic resection (1-6 times). The median specimen diameter was 4.5 cm (range 3-8). All resections were en bloc and R0. There was no perforation, delayed bleeding, or other clinically significant adverse events. After a median follow-up of 21 months (range 12-32), there was no tumor recurrence. CONCLUSION/CONCLUSIONS:The "doughnut resection" is a feasible, safe, and effective method to remove circumferential ICV lesions endoscopically even for patients with multiple prior tumor manipulations.

AIM/OBJECTIVE:To systematically review clinical presentation, diagnosis, and therapy of achalasia, focusing on recent developments in high-resolution esophageal manometry (HREM) for diagnosis and peroral endoscopic myotomy (POEM) for therapy. METHODS:Systematic review of achalasia using computerized literature search via PubMed and Ovid of articles published since 2005 with keywords ("achalasia") AND ("high resolution" or "HREM" or "peroral endoscopic myotomy" or "POEM"). Two authors independently performed literature searches and incorporated articles into this review by consensus according to prospectively determined criteria. RESULTS:Achalasia is an uncommon esophageal motility disorder, usually manifested by dysphagia to solids and liquids, and sometimes manifested by chest pain, regurgitation, and weight loss. Symptoms often suggest more common disorders, such as gastroesophageal reflux disease (GERD), thus often delaying diagnosis. Achalasia is a predominantly idiopathic chronic disease. Diagnosis is typically suggested by barium swallow showing esophageal dilation; absent distal esophageal peristalsis; smoothly tapered narrowing ("bird's beak") at esophagogastric junction; and delayed passage of contrast into stomach. Diagnostic findings at high-resolution esophageal manometry (HREM) include: distal esophageal aperistalsis and integrated relaxation pressure (trough LES pressure during 4 s) > 15 mmHg. Achalasia is classified by HREM into: type 1 classic; type 2 compartmentalized high pressure in esophageal body, and type 3 spastic. This classification impacts therapeutic decisions. Esophagogastroduodenoscopy is required before therapy to assess esophagus and esophagogastric junction and to exclude distal esophageal malignancy. POEM is a revolutionizing achalasia therapy. POEM creates a myotomy via interventional endoscopy. Numerous studies demonstrate that POEM produces comparable, if not superior, results compared to standard laparoscopic Heller myotomy (LHM), as determined by LES pressure, dysphagia frequency, Eckardt score, hospital length of stay, therapy durability, and incidence of GERD. Other therapies, including botulinum toxin injection and pneumatic dilation, have moderately less efficacy and much less durability than POEM. CONCLUSION/CONCLUSIONS:This comprehensive review suggests that POEM is equivalent or perhaps superior to LHM for achalasia in terms of cost efficiency, hospital length of stay, and relief of dysphagia, with comparable side effects. The data are, however, not conclusive due to sparse long-term follow-up and lack of randomized comparative clinical trials. POEM therapy is currently limited by a shortage of trained endoscopists.

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.