Gastric per-oral endoscopic myotomy for refractory gastroparesis: A detailed description of the procedure, our experience, and review of the literature. Surg Endosc. 2018;32:3421-3431. [PMID: 29435752 DOI: 10.1007/s00464-018-6112-5]

New Applications for Submucosal Tunneling in Third Space Endoscopy: A Comprehensive Review

Third space endoscopy (TSE), a type of natural orifice transluminal endoscopic surgery, was first introduced a decade ago, and since then, has revolutionized the field of therapeutic endoscopy. TSE involves tunneling into the submucosal space between the intestinal mucosa and the muscularis propria. By accessing this "third space," endoscopists can perform minimally invasive myotomies, resections, and dissections while maintaining the mucosa and preventing full-thickness perforation. TSE procedures can be used to treat motility disorders as well as neoplasms throughout the gastrointestinal tract, which were traditionally conditions that would require open or laparoscopic surgery. The main TSE procedures include peroral endoscopic myotomy, gastric peroral endoscopic myotomy, Zenker peroral endoscopic myotomy, submucosal tunneling for endoscopic resection, endoscopic submucosal tunnel dissection, peroral endoscopic tunneling for restoration of the esophagus, and per-rectal endoscopic myotomy. Some of those procedures have now been accepted as viable alternative to surgical techniques due to their limited invasiveness, safety and cost. This review will explore the different techniques recently added to our arsenal while describing their potential efficacy and limitations.

Safety and efficacy of prophylactic gastric open peroral endoscopic myotomy for prevention of post-ESD stenosis: A case series (with video)

OBJECTIVE

Endoscopic resection of over 3/4 of the lumen of the antrum or pylorus is a known risk factor for post-endoscopic submucosal dissection (ESD) stenosis. Local or systemic steroids may reduce the risk of stenosis, but their overall role in stenosis prevention remains controversial. We aimed to evaluate the efficacy and safety of prophylactic gastric open peroral endoscopic myotomy (GO-POEM) in preventing post-ESD stenosis.

METHODS

Ten patients who underwent GO-POEM during or immediately after ESD in the Presbyterian Medical Center between June 2017 and November 2020 were included. All patients underwent excision of over 3/4 of the lumen of the antrum or pylorus. GO-POEM was performed without submucosal tunneling.

RESULTS

Well-differentiated tubular adenocarcinoma, tubulovillous adenoma with high-grade dysplasia, and tubular adenoma with low-grade dysplasia were diagnosed in three, one, and six patients, respectively. GO-POEM was performed successfully in all the 10 patients. Stenosis could not be evaluated in one patient, whereas one of the remaining nine patients developed post-ESD stenosis. GO-POEM decreased the risk of post-ESD stenosis in the other eight patients. Two patients presented with intraprocedural bleeding, both of whom were managed endoscopically successfully.

CONCLUSIONS

Prophylactic GO-POEM may be a novel, effective and safe treatment modality for preventing post-ESD stenosis in the stomach. Well-designed, multicenter studies with large sample sizes are needed to confirm our results.

Principles of Intramural Surgery

Intramural surgery is a minimally invasive surgical technique based on flexible endoscopy. The first step involves the initial mucosal incision for entry point. Then a submucosal tunnel is dissected to the site of the target anatomy. The procedure performed may include myotomy or lesion removal. When complete, the initial mucosal incision is closed. This technique separates the mucosal flap from the surgical site, minimizing the risk of full-thickness perforation and gastrointestinal leakage. Peroral endoscopic myotomy is the most studied application of intramural surgery but other procedures have emerged. This article explores principles of intramural surgery and summarizes its applications.

Outcomes of per oral endoscopic pyloromyotomy in gastroparesis worldwide

Per oral endoscopic pyloromyotomy (POP), also known as gastric per-oral endoscopic myotomy (GPOEM), is a novel procedure with promising potential for the treatment of gastroparesis. As more data emerge and the procedure is becoming more recognized in clinical practice, its safety and efficacy need to be carefully evaluated. Appropriate patient selection for favorable clinical success prediction after GPOEM also needs additional research. This review aims to systemically summarize the existing data on clinical outcomes of POP. Symptomatologic responses to the procedure, its adverse effects, procedural techniques, and predictive factors of clinical success are also discussed.

Technical Aspects of Peroral Endoscopic Pyloromyotomy

Gastric peroral endoscopic pyloromyotomy (G-POEM or POP) is a feasible and effective procedure for the treatment of refractory gastroparesis. G-POEM is a technically demanding endoscopic procedure. As of yet, there is no consensus on the technique. A variety of techniques have been reported in published studies. The essential technical steps of the procedure are (1) establishment of submucosal tunnel in gastric antrum, (2) identification of the pyloric muscular ring, (3) selective circular myotomy, and (4) a 2.5-cm to 3.0-cm length of myotomy. There are still some technical questions unanswered, and more studies are needed to establish standardized techniques and possible improvement of outcomes.

Outcomes of Per Oral Endoscopic Pyloromyotomy in the United States

Per oral endoscopic pyloromyotomy (POP) has emerged as an endoscopic intervention for refractory gastroparesis. Early experience in the United States showed exciting clinical response rate, reduced gastroparesis symptoms, improved quality of life, and decreased gastric-emptying time during midterm follow-up up to 18 months. One recent study also showed that the number of patient emergency room visits and hospitalizations decreased significantly after POP. The procedure is technically feasible and safe. As more data become available, it is important to identify patients who would benefit most from this novel procedure.