Prospective evaluation of tension-reducing closure with intentional muscle-layer grasping for large colorectal post-ESD defects using an anchor-pronged clip (MANTIS study).

BACKGROUND AND AIMS: Complete mucosal defect closure after colorectal endoscopic submucosal dissection (ESD) may reduce delayed adverse events. However, the durable closure of large defects remains technically challenging. We prospectively evaluated the feasibility, efficacy, and durability of a novel anchor-pronged clip (MANTIS Clip; Boston Scientific Co., Massachusetts, United States) for defect closure after colorectal ESD. METHODS: This single-center prospective study evaluated defect closure using the MANTIS Clip after colorectal ESD for lesions measuring 30-50 mm. The clip was used to approximate the defect by grasping the mucosal and muscular layers to achieve deeper plication and tension reduction. The primary endpoint was the complete closure rate. The secondary endpoints included closure times, number of clips used, sustained closure, and adverse events. RESULTS: Complete closure was achieved in 95.2% (20/21) of cases during a median closure time of 17 min using a median of eight clips. Closure was successful in all defects with a specimen size ≤59 mm in size and in 75% of those ≥60 mm in size. Sustained complete closure was observed in 76.2% (16/21) of cases at 3-5 days and partial or complete dislodgement at ≥2 weeks after ESD in 95.2%. Delayed bleeding, delayed perforation, and post-ESD coagulation syndrome occurred in 0%, 0%, and 14.3% of cases, respectively. CONCLUSIONS: The MANTIS Clip achieved a high complete closure rate with acceptable short-term durability for mucosal defects after colorectal ESD of lesions measuring 30-50 mm.