Clipping closure length is a crucial factor for delayed bleeding after endoscopic papillectomy: a retrospective multicenter cohort study.

Background: Bleeding is a serious and frequent adverse event that occurs during and after endoscopic papillectomy (EP). Previous studies have highlighted the effectiveness of preventive clipping closure of the resection site in preventing post-EP bleeding. However, the optimal length of closure remained unclear.

Objectives: We aimed to clarify the optimal clipping length at the post-EP resection site to prevent delayed bleeding.

Design: This study was a multicenter retrospective cohort study.

Methods: We retrospectively analyzed patients who were consecutively admitted to nine high-volume centers for EP between November 2003 and October 2023. The primary outcome was the frequency of delayed bleeding based on the closure length. The optimal closure length rate of the resected site to prevent delayed bleeding was determined using a receiver operating characteristic curve. Secondary outcomes were the incidence, treatment outcomes, and risk factors for post-EP delayed bleeding.

Results: A total of 130 patients who underwent EP were analyzed. Delayed bleeding was observed in 22 (17%) patients, occurring more frequently in cases without clipping closure than in those with clipping closure (28% (13/47) vs 11% (9/83); p = 0.014). Among 83 patients who underwent clipping closure, delayed bleeding occurred more frequently with a closure length rate <65% than in those with a closure rate ⩾65% (25% (5/20) vs 6% (4/63); p = 0.019). Multivariate analysis showed that a closure rate <65% was the risk factor for delayed bleeding (odds ratio, 6.3; 95% confidence interval, 1.2-33; p = 0.030) in cases with clipping.

Conclusion: Clipping closure was effective in preventing delayed bleeding, and closure length rate ⩾65% of the resected site significantly reduced post-EP delayed bleeding.