Comparison of Outcomes for Single vs Double Pyloromyotomy for Gastroparesis Randomized Controlled Trial

Gastroparesis is a chronic disease of the stomach that causes delayed gastric emptying without stenosis. It is a chronic alteration of gastric motility that leads to a delay in stomach emptying. It is an underdiagnosed condition. The prevalence is estimated at around 3% in the United States (mean age of 37.7 years, with an F: M ratio of 4:1. It is mainly an idiopathic condition; however, it can also be caused by diabetes mellitus and post-surgical conditions, such as fundoplication, vagotomy, bariatric surgery, and esophagectomy. Less frequently by conditions like post-infectious gastro-paresis, neurological or autoimmune diseases. The clinical symptoms of gastroparesis include nausea, vomiting, early satiety, post-prandial fullness, bloating, belching, and upper abdominal discomfort. The gastroparesis cardinal symptoms index (GCSI) is a reliable, reproducible, and valid instrument for measuring symptom severity in patients with gastroparesis. It is based on three sub-scales (post-prandial fullness/early satiety-4 items; nausea/vomiting-3 items; bloating-2 items), and each item ranges from 0 (none) to 5 (severe). GCSI is not a diagnostic tool, but it is helpful to measure the severity of the disease and the post-treatment improvement. Though the prevalence of gastroparesis has significantly increased over the last decade, management is still challenging. Patients with mild symptoms can be referred for dietary modifications coupled with medical therapy with prokinetics, especially metoclopramide. However, the response to prokinetics decreases over time. Moreover, these drugs have side effects, such as extrapyramidal symptoms and amenorrhea. Surgical approaches have been proposed; however, the invasive nature of those procedures and the low rate of clinical success have made them less favorable. Endoscopic interventions have also been described, including intra-pyloric injection of botulinum toxin, endoscopic gastrojejunostomy, and transpyloric stenting. For patients with refractory (persistent symptoms for >6 months refractory to medical therapy) and severe gastroparesis based on GCSI > 2, gastric per-oral endoscopic myotomy can be considered. In 2013, the first human gastric per-oral endoscopic myotomy (G-POEM) was performed. It was inspired by the per-oral endoscopic myotomy technique, with a similar dissection method, that allows pyloromyotomy. The technical steps of G-POEM involve mucosal incision about 5 cm from the pylorus with the creation of access to the submucosal plane after detaching the planes by injection of lifting solution; creation of the submucosal tunnel with dissection technique up to the duodenal bulb and exposure of the pylorus; verification of the integrity of the mucosal surface; pyloromyotomy and closure of the mucosal flap with multiple endoclips. In the single pyloromyotomy group, a selective circular pyloromyotomy is performed at the 6 or 7 o'clock position after identifying the pyloric ring. In the double pyloromyotomy group, another selective cut is performed at the 4 or 5 o'clock position to keep at least 1 cm between the two pyloromyotomies.

Only one retrospective case-controlled study compares single versus double pyloromyotomy at G-POEM for refractory gastroparesis. It showed a higher clinical response rate with double pyloromyotomy when compared with single pyloromyotomy in a 3- to 6-month follow-up period.

In this randomized controlled prospective multicenter study, the aim is to compare clinical outcomes and the efficacy of single versus double pyloromyotomy in G-POEM for refractory and severe gastroparesis. Prospective subjects will be approached regarding study inclusion either during a pre-endoscopy visit or shortly before the planned endoscopy procedure. If the latter, the prospective subject will be approached during intake and before being brought to the back for the procedure. The prospective subjects will be approached before any pre-procedure medication is administered. The study will be explained in detail and, if the prospective participant agrees, an informed consent form - HIPAA Research Authorization will be taken.

Prospective subjects will be randomized into one of two study groups: Single pyloromyotomy vs Double pyloromyotomy G-POEM using a computer-generated random sequence (prepared by the UAMS Biostatistics group) that will be placed in sealed envelopes. The envelopes will accompany the informed consent form will be opened after obtaining informed consent from the patients to determine their group assignment. The patient will open the envelop and hand it to the endoscopist performing the procedure.

Once randomized, the subjects will undergo the scheduled endoscopic procedure as planned.

Subjects will be followed up in the clinic at 3 months, 6 months, and 12 months (one year) after procedure per routine care.