LAUSR

The local recurrence rate after endoscopic piecemeal resection of superficial duodenal epithelial tumors (SDETs) is high, regardless of the technique used [1], which makes it difficult to perform endoscopic salvage treatment. The ideal situation would be to achieve an en bloc resection to avoid local recurrence. Underwater endoscopic mucosal resection (UEMR) can be performed safely for small SDETs [2]; however, the snare tip, without being fixed, may move from the initially planned area during snaring. Resected specimens may include excessive amounts of normal tissue or insufficient amounts of the target neoplasm. It is particularly difficult to achieve en bloc resection for SDETs of > 15mm in size [3], because such lesions straddle at least two folds and cannot be precisely grasped by the snare. Anchoring the snare tip to the duodenal mucosa to fix it in place has been tried [4]; however, there may be problems achieving an en bloc resection with this method. We previously reported that saline injection into a duodenal fold promotes a protruded form of the mucosa [5]. We suggest that mucosal protrusion has a role to play in anchoring and allows the snare tip to be fixed during UEMR. We devised a novel UEMR method that creates a new type of anchor by protruding the distal fold by the injection of saline. We used rotatable snares (Medi-Globe; Germany) to grasp the target lesions. In the novel technique, saline is first injected into the distal normal fold, so that it protrudes (▶Fig. 1 a). After water-immersion, the snare tip is fixed to the protruding fold, meaning it will not easily move after opening the snare because the protruding mucosa provides a cushioned anchor for the tip (▶Fig. 1 b). The direction and the lateral position of the snare can be repeatedly adjusted to grasp the entire lesion more precisely (▶Fig. 1 c; ▶Video 1). We suggest that this method will enable complete resection with free lateral margins, which are uncertain when performing conventional UEMR.