Effective Retrograde Dissection by the Floating Tongue-Like Flap Method for Gastric Neoplasm Involving the Pyloric Channel.

Background/Aims: Endoscopic submucosal dissection (ESD) of gastric neoplasm involving the pyloric channel (GNPC) is technically challenging due to difficulty in precise assessment of resection margin and inadequate visualization. The aim of this study was to evaluate the effectiveness and long-term outcome of ESD for GNPC and introduce a noble technique for resection of GNPC. Methods: A total of 97 patients with GNPC underwent ESD from January 2007 to October 2017. We divided them into a conventional anterograde resection group and a retrograde resection group according to the method of procedure. We compared their clinical outcomes and investigated risk factors for postprocedural complications. Results: The en bloc resection rate was 87.6%, and complete resection rate was 83.5%. Postprocedure stenosis occurred in 16 cases (16.5%). GNPCs of the retrograde resection group were more frequently located from antrum to bulb, were significantly larger, were related to ≥75% resection of the circumference, and involved significantly longer procedure times than those in the anterograde resection group. Multivariate analysis showed that resection ≥75% of the circumference was the only significant risk factor for postprocedure stenosis. Conclusions: ESD by retrograde resection method is a novel technique to make the procedure easier, depending on the size, location, and circumference of resection.