Gastroplasty With Endoscopic Myotomy (GEM) for the Treatment of Obesity: Preliminary Efficacy and Physiologic Results

Endoscopic sleeve gastroplasty (ESG) is a commonly performed endoscopic bariatric and metabolic therapy.1Kumar N. Abu Dayyeh B.K. Lopez-Nava G.B. et al.Endoscopic sutured gastroplasty: procedure evolution from first-in-man cases through current technique.Surg Endosc. 2018; 32: 2159-2164Crossref PubMed Scopus (59) Google Scholar,2Jirapinyo P. Thompson C.C. Endoscopic bariatric and metabolic therapies: surgical analogues and mechanisms of action.Clin Gastroenterol Hepatol. 2017; 15: 619-630Abstract Full Text Full Text PDF PubMed Scopus (61) Google Scholar The procedure uses endoscopic suturing of the greater curvature with reduction of gastric volume. Mean total weight loss (TWL) is approximately 15.6%, with a 77% response rate (≥10% TWL) at 1 year.3Sharaiha R.Z. Hajifathalian K. Kumar R. et al.Five-year outcomes of endoscopic sleeve gastroplasty for the treatment of obesity.Clin Gastroenterol Hepatol. 2021; 19: 1051-1057Abstract Full Text Full Text PDF PubMed Scopus (28) Google Scholar Proposed mechanisms of ESG include early satiation due to reduced fundal accommodation from gastric shortening and prolonged satiety due to delayed gastric emptying from impeded food breakdown and mixing of chyme secondary to gastric body sutures.4Abu Dayyeh B.K. Acosta A. Camilleri M. et al.Endoscopic sleeve gastroplasty alters gastric physiology and induces loss of body weight in obese individuals.Clin Gastroenterol Hepatol. 2017; 15: 37-43Abstract Full Text Full Text PDF PubMed Scopus (143) Google Scholar We propose a novel endoscopic bariatric and metabolic therapy procedure—gastroplasty with endoscopic myotomy (GEM)—in which a pylorus-sparing antral myotomy is performed before traditional ESG (Figure 1) to weaken the antral pump, which is a major physiologic component of gastric emptying. The GEM procedure represents a novel endoscopic bariatric and metabolic therapy that addresses several aspects of gastric motility to delay emptying and induce durable weight loss. The procedure consists of the following 3 steps: (1) pylorus-sparing antral myotomy via a submucosal tunneling technique to weaken the antral pump and impede emptying, (2) a running suture at the level of the incisura to separate the antrum from the gastric body and to minimize tension on the myotomy access site closure, and (3) a standard ESG in the gastric body to reduce mixing and limit accommodation (Figure 2). The pylorus-sparing antral myotomy technique was performed in a nonsurvival porcine model before this study. Furthermore, because gastric peroral endoscopic myotomy and tunneled stricturoplasty have been described previously and well-studied, it was deemed appropriate to proceed with this human pilot study. The aims of the study were to assess technical feasibility, safety, short-term efficacy and response rate, and effect of GEM on gastric emptying assessed using a gastric emptying breath test (Cairn Diagnostic, Brentwood, TN) and Gastroparesis Cardinal Symptom Index. Patients with obesity who had attempted lifestyle modification were recruited. Patients who had diabetes, symptomatic gastroparesis, or were on an anticoagulant, antiplatelet agent, or weight loss medication were excluded. The study was conducted under a research protocol (P001757). All results were reported using mean ± SD. A total of 6 patients underwent GEM. Baseline age and body mass index were 35 ± 7 years and 39.6 ± 6.6 kg/m2, respectively. At baseline, 5 of 6 patients (83%) had a normal gastric emptying rate, with a T1/2 of 68 ± 19 minutes and 1 of 6 (17%) had delayed emptying with a T1/2 of 204 minutes. All patients underwent GEM successfully. Three cases (50%) were performed using a partial-thickness myotomy and 3 (50%) using a full-thickness myotomy technique. Average tunnel and myotomy lengths were 9.0 ± 1.1 cm and 7.7 ± 1.4 cm, respectively. Mucosotomy sites were closed using running sutures (numbers of sutures and stitches, 1 ± 1 and 8 ± 2, respectively). Average numbers of sutures and stitches placed per sleeve were 8 ± 1 and 50 ± 7, respectively. After the procedure, gastric length, measured from the gastroesophageal junction to the incisura, was shortened by 16.0 ± 3.5 cm, representing a 67% ± 14% reduction from baseline. Average length of stay was 1.8 ± 2.3 days. At 1 and 3 months after GEM, patients experienced 11.5% ± 2.9% and 14.8% ± 2.5% TWL (both, P < .0001), respectively. All patients achieved >10% TWL at 3 months. The adverse event rate was 17% (1 of 6); 1 patient was readmitted for nausea, which was treated conservatively. At 1- and 3-month follow-up, no patients endorsed upper gastrointestinal symptoms. At 2 weeks after GEM, the proportion of patients with delayed gastric emptying increased from 17% (1 to 6) to 100% (6 to 6) (P = .02), with the T1/2 increasing from 90 ± 58 minutes to 204 ± 18 minutes (P < .0001). The mean postprandial fullness/early satiety subscale on Gastroparesis Cardinal Symptom Index increased significantly (0.2 ± 0.3 to 1.0 ± 0.5; P = .01), although the total Gastroparesis Cardinal Symptom Index did not change significantly (0.4 ± 0.4 to 0.6 ± 0.3; P = .63) (Table 1).Table 1Baseline Characteristics, Procedure Details, and Follow-UpCase no.Age, ySexBaseline BMI, kg/m2GEM procedure details%TWLGastric emptying breath test, T1/2, minPylorus-sparing antral myotomy length, cmESG, no. of sutures/no. of stitchesAt 1 moAt 3 moPre GEMPost GEM142F46.18 (partial thickness)10/6110.615.373.8188.7238F34.98 (full thickness)8/5311.714.258.2185.3342F37.99 (partial thickness)8/496.710.597.6216.1428F38.45 (full thickness)6/3911.418.1204.0208.1529F48.88 (full thickness)8/4813.215.258.1193.3628F31.68 (partial thickness)8/4715.515.549.9230.1BMI, body mass index; F, female. Open table in a new tab BMI, body mass index; F, female. Video 1 demonstrates the GEM procedure. First, a pylorus-sparing antral myotomy was performed. Submucosal injection was performed immediately distal to the incisura along the greater curvature using a T-type HybridKnife (ERBE USA, Marietta, GA) and 6% hetastarch solution was mixed with methylene blue. A horizontal mucosal incision was then made to allow access into the submucosal space. Of note, the horizontal orientation was chosen to facilitate subsequent sutured closure. Next, submucosal tunneling was performed using the same T-type HybridKnife. The tunneling was stopped at the distal antrum before the pylorus. Pylorotomy was not performed, as this would have accelerated rather than delayed gastric emptying. Subsequently, myotomy was performed along the greater curvature using either a T-type HybridKnife or junior SB knife (Olympus, Central Valley, PA) when full-thickness myotomy was planned. The myotomy ended approximately 2 cm distal to the access site. The mucosotomy access site was then closed using the Overstitch endoscopic suturing device (Apollo Endosurgery, Austin, TX) via an unlocked running pattern. Subsequently, a running suture was placed at the level of the incisura starting from the anterior aspect of the stomach, moving down the greater curvature, and ending on the posterior aspect of the stomach. This suture serves to isolate the antrum, as well as to limit the amount of tension applied to the access site closure from subsequent ESG U stitches. A traditional ESG procedure was then performed in the gastric body using an alternating U and interrupted suture pattern. The U stitches serve to both narrow and shorten the stomach, and the interrupted stitches serve to further narrow the stomach, as well as reinforce the U stitches. The final endoscopy revealed a tight sleeve in the gastric body, securely closed access site in the antrum, and intact pylorus. Combining a pylorus-sparing antral myotomy with traditional ESG appears technically feasible and safe. The procedure is associated with consistent and significant delay in gastric emptying, significant weight loss, and high response rate. The addition of myotomy to ESG may mitigate issues related to suture loss and provide more predictable and durable outcomes. This pilot work will serve to plan further physiologic-based studies. eyJraWQiOiI4ZjUxYWNhY2IzYjhiNjNlNzFlYmIzYWFmYTU5NmZmYyIsImFsZyI6IlJTMjU2In0.eyJzdWIiOiJmZGFjM2MwNzI1OWIwMjk4NmE3ZDgwZDA2ZDViNjcyMyIsImtpZCI6IjhmNTFhY2FjYjNiOGI2M2U3MWViYjNhYWZhNTk2ZmZjIiwiZXhwIjoxNjcwOTA2NjMyfQ.Aq29JQ1mswVim0LA8I7z0E7l32N0-E3TWvTMqqSAcfBSywWBuIY6FsYzZMkh4aim2YHxYSuJxKj5Se4Db-tt2EUX9aUEinyhJfm1_zFEnFOEOpPoMCRBqTyK_Mnvse8y2wuOSeZ2so53Pu_hwKXwHVcYLA34arcKWVYJSSpNXECssRSnIl5fnot8xIYebqN4CHSGQR6nvD8_rxRTqUJVMGswTn66QSnQwqBG4OrbbaKt6fmEhhDOmrTAZBnPQ8yQJ8bQJhbSvQ52LW_EMgPPjeNJK6AaM69sYrHkelCizJf0ANDiLxfjXj-dYjXP2rvQ3tzEvhIyITZtdiEmAepSAg Download .mp4 (75.84 MB) Help with .mp4 files Video 1eyJraWQiOiI4ZjUxYWNhY2IzYjhiNjNlNzFlYmIzYWFmYTU5NmZmYyIsImFsZyI6IlJTMjU2In0.eyJzdWIiOiI3M2MzNzM3NmNhNmMwMGI4YTIwNWM2ZTZkMzQzZDBhMiIsImtpZCI6IjhmNTFhY2FjYjNiOGI2M2U3MWViYjNhYWZhNTk2ZmZjIiwiZXhwIjoxNjcwOTA2NjMyfQ.HbOFPuCIWcxxGCbp823ixGCEF76P7iXTS2rhwOlvACjHzUyL-rn6pTPgfQJXOltkKS3BG2-kyyfXhtAmK0iMpcXAxicrekUdGSJ551kNlvNg8qwN8C_89vanWYwXACXKRXAKlDliA564YE1PzRh4gS4o_mKTgmzadcb-OfAggU-wmTmegWQK-ovt2hfpVDGOGAXAkQWT1OHDAfiZSOtpyl9PVYkjpOYnhD08T4UeehVdyPXUA7oGrdfywvGa2N1fEakvscNio288G77Edn6rFM6l8idQRsD8b0iHD0HOVZTugUsgCE2uTbutGb5K0q5tkC9FGcY_B4FZihVaeWnnzQ Download .mp4 (77.44 MB) Help with .mp4 files Video 2