How to manage pyloric tumours that are difficult to resect completely with endoscopic resection: Comparison of the retroflexion vs. forward view technique

Background: It is difficult to perform complete resection of prepyloric tumours, especially those involving pyloric channel due to incomplete visualisation and insufficient resection margin with forward view. Aim: To investigate outcomes of endoscopic submucosal dissection for pyloric tumours, we assess effectiveness of retroflexion view technique in comparison with forward view technique. Methods: We investigated 47 prepyloric tumours treated by endoscopic submucosal dissection and compared results of forward view technique with those of retroflexion view technique. Results: Of the 47 prepyloric tumours, 23 lesions had pyloric channel involvement (group 1) and 24 lesions did not (group 2). The en bloc resection, curative resection and complete resection rates for all endoscopic submucosal dissection cases were 80.9, 85.1 and 70.2%, respectively. The en bloc resection, curative resection and complete resection rates were significantly lower in group 1 than group 2. Of the tumours involving pyloric channel except 3 cases which were extended to duodenum, 12 lesions were resected with retroflexion and 8 lesions with forward. Curative resection rate was higher in retroflexion group than forward group (91.7% vs. 37.5%; p= 0.018). None of the patients experienced perforation or pyloric stenosis. Conclusions: Endoscopic submucosal dissection using retroflexion manoeuvre is a more effective method for the curative resection of gastric tumours involving pyloric channel.