Akira Dobashi, Christopher Gostout, Elizabeth Rajan, MD. Mayo Clinic
Background and Aims: Endoscopic full-thickness resection (EFTR) in the colon is challenging. Closure before resection is considered desirable for ideal EFTR and we previously reported on creating a pseudopolyp using the over-the-scope clip (OTSC) before resection. OTSC-assisted EFTR is reliable but the size of a resected lesion is limited, visibility during the procedure is suboptimal. And the margin of the target lesion is poorly visualized. The aim of this study was to evaluate EFTR of a large target lesion using a newly developed large overtube ligation system in an ex vivo porcine colon.
Methods: Four pig colons were used and EFTR was conducted at 7 sites (4 sigmoid colon and 3 rectum). A 30mm paper template was used to mark the margins of the target lesion using argon plasma coagulation. Endoclips were placed at the cephalad and caudal margins of the target lesion. A large overtube (inner diameter: 24mm) with a thick rubber band (inner diameter: 4.5mm) pre-loaded at the tip of overtube was inserted into the colon with guidance over diagnostic upper endoscope (GIF-H180; Olympus America, Center Valley, PA). The lesion was captured in a full-thickness manner using a snare (SnareMaster, SD-230U-20; Olympus America) and tri-pronged tissue retraction device (OTSC Anchor; Ovesco Endoscopy, Tübingen, Germany). The lesion was retracted into the overtube and the ligating rubber band was deployed creating a large pseudopolyp. The pseudopolyp was resected using the snare. An endoloop was used optionally to reinforce the closure. A leak test was done to evaluate the strength of closure.
Results: EFTR was successfully completed in all 7 colonic sites. The mean size of the resected lesion was 38 mm (IQR, 29-42). The rate of en bloc resection (contained all markings) was 57% (4/7). An endoloop was used in 3 sites after EFTR. The mean procedure time was 12.6 minutes (IQR, 11-14). The median maximum pressure for leak testing was 33 mmHg (IQR, 24-42). Luminal narrowing was noted after one resection.
Conclusion: This proof of concept study suggests that en bloc EFTR for large colonic lesions is feasible using a newly developed overtube ligation system.
Presented at the SAGES 2017 Annual Meeting in Houston, TX.
Abstract ID: 91051
Program Number: ETP888
Presentation Session: Emerging Technology iPoster Session (Non CME)
Presentation Type: Poster