Endoscopic Ligation with O-Ring Closure for Mucosal Defects after Rectal Endoscopic Submucosal Dissection: A Feasibility Study (with Video).

Introduction: Mucosal defect closure after colorectal endoscopic submucosal dissection (ESD) may prevent post-ESD adverse events. Delayed bleeding is a particular concern in the rectum due to the presence of numerous blood vessels. However, rectal defect closure often fails due to the thick rectal wall. This study aimed to examine the feasibility of our newly developed endoscopic ligation with O-ring closure (E-LOC) for defects after rectal ESD.

Methods: This was a prospective observational study conducted at a single institution. After excluding 2 patients with tumors mostly extending into the anal canal, the study cohort comprised 30 consecutive patients who underwent ESD of rectal neoplasms between July 2020 and July 2021. E-LOC using an endoscopic variceal ligation device was performed for closing mucosal defects after rectal ESD. The primary outcome was the complete closure rate. The secondary outcomes were the delayed bleeding rate, E-LOC procedure time, sustained closure rates on postoperative day (POD) 3, and E-LOC-associated complications.

Results: Complete closure of the defect (median defect size 29.0 mm) was successfully achieved in 24 cases (80%). Delayed bleeding occurred in one case with incomplete closure (3.3%). The median E-LOC procedure time was 25.5 min (interquartile range, 20.0-30.0 min). The sustained closure rates were 83.3% (20/24) on POD 3 in the 24 cases with complete closure. No E-LOC-associated complications occurred.

Discussion/conclusions: E-LOC was feasible for defect closure after rectal ESD, and probably led to a decreased incidence of delayed bleeding.