-Original-

Novel Method of Sampling the Gastrointestinal Muscle Layer: Feasibility of Endoscopic Muscular Resection with a Ligation Device in an in Vivo Porcine Model

Osamu Goto, Kazutoshi Higuchi, Atsushi Tatsuguchi, Eriko Koizumi, Hiroto Noda, Takeshi Onda, Jun Omori, Mitsuru Kaise and Katsuhiko Iwakiri

Department of Gastroenterology and Hepatology, Nippon Medical School Hospital, Tokyo, Japan

Background: Gastrointestinal muscular sampling is useful in the histological assessment of functional gastrointestinal disorders. We devised a new sampling method to obtain a large volume of muscle tissues and then investigated the feasibility and safety of endoscopic muscular resection with a ligation device in an in vivo porcine model.
Methods: After establishing a submucosal tunnel, a rubber band was placed on the muscle tissue by sucking the exposed muscle layer. Thereafter, the established pseudopolyp was removed using an electrocautery snare, and the entry site of the submucosal tunnel was closed endoscopically. This procedure was performed at three sites in the esophagus and stomach of two pigs. The technical success, histology, and survival rate on postoperative day 7 were examined postoperatively.
Results: We successfully completed the mentioned procedure in 11 of the 12 sites (92%), without the occurrence of severe adverse events. The median diameters of obtained tissues from the esophagus and stomach, respectively, were 5 mm and 10 mm. Histologically, both the inner and outer muscle layers were included in all specimens. The postprocedural course was found uneventful in both pigs during the observatory period.
Conclusions: Endoscopic muscular resection using a ligation device enabled us to obtain large and thick muscle tissue samples. This approach may facilitate more precise histological assessments of functional gastrointestinal disorders.

J Nippon Med Sch 2021; 88: 441-447

Keywords
endoscopic muscle biopsy, submucosal endoscopy, functional disorder

Correspondence to
Osamu Goto, MD, PhD, Department of Gastroenterology and Hepatology, Nippon Medical School Hospital, 1-1-5 Sendagi, Bunkyo-ku, Tokyo 113-8603, Japan
o-goto@nms.ac.jp

Received, October 30, 2020
Accepted, December 11, 2020