A novel low-power pure-cut hot snare polypectomy for 10-14 mm colorectal adenomas: An ex vivo and a clinical prospective feasibility study (SHARP trial).

BACKGROUND AND AIM: Hot snare polypectomy using blend or coagulation current is widely used; however, it causes deeper tissue heat injury, leading to adverse events. We hypothesized that hot polypectomy using low-power pure cut current (PureCut, effect 1 10 W) could reduce deeper tissue heat injury. We conducted animal experiments to evaluate the deeper tissue heat injury and conducted a prospective clinical study to examine its cutting ability.

METHODS: In a porcine rectum, hot polypectomy using Blend current (EndoCut, effect 3 40 W) and low-power pure cut current was performed. The deepest part of heat destruction and thickness of the non-burned submucosal layer were evaluated histologically. Based on the results, we performed low-power pure cut current hot polypectomy for 10-14 mm adenoma. The primary endpoint was complete resection defined as one-piece resection with negative for adenoma in quadrant biopsies from the defect margin.

RESULTS: In experiments, all low-power pure-cut resections were limited within the submucosal layer whereas blend current resections coagulated the muscular layer in 13% (3/23). The remaining submucosal layer was thicker in low-power pure cut current than in blend current resections. In the clinical study, low-power pure-cut hot polypectomy removed all 100 enrolled polyps. For 98 pathologically neoplastic polyps, complete resection was achieved in 84 (85.7%, 95% confidence interval, 77-92%). The lower limit of the 95% confidence interval was not more than 15% below the pre-defined threshold of 86.6%. No severe adverse events occurred.

CONCLUSIONS: A novel low-power pure-cut hot polypectomy may be feasible for adenoma measuring 10-14 mm. (UMIN000037678).