LAUSR

Recently, underwater endoscopic mucosal resection (U-EMR) has become established for treating duodenal adenomas. However, it is difficult to completely resect a large duodenal adenoma with en bloc resection [1]. An appropriate UEMR method is desirable because the resection margin on the oral side is sometimes positive [2]. We devised a method for en bloc resection of large duodenal adenomas, called clip-line-assisted underwater endoscopic mucosal resection (CLU-EMR). CLU-EMR is a U-EMR method that uses a clip (EZ Clip; Olympus Co., Tokyo, Japan) and line (nylon line, 0.22mm) (▶Fig. 1, ▶Video 1). First, we create a clip with a line. Second, the line is placed in the gap between the teeth at the base of the clip (locking-clip technique) [3], because it can be cut if it is strongly pulled. Third, the clip line is then inserted through the accessory channel and fixed at a distance from the most anal edge of the lesion. Finally, the tip of the snare is placed on the oral side of the clip line, and the snare is spread. A snare with a rotation function (Rotasnare 25mm; Medi-Globe GmbH, Achenmühle, Germany) is used to allow the snare to pass under the line. A clip line provides traction to pull the normal mucosa on the anal side toward the accessory channel, which fixes the snare tip and allows endoscopic en bloc resection of the tumor. A patient had a 20-mm duodenal adenoma at the superior duodenal angle (▶Fig. 2). Complete en bloc resection using CLU-EMR was performed. The lesion was resected underwater, and the specimen was removed. Hemorrhage occurred and was stopped using coagulation forceps. The lesion was completely closed using the reopenable-clip-overthe-line method [4, 5]. Snaring for duodenal adenoma using CLU-EMR is a useful method for fixing the snare tip to the anal normal mucosa. Endoscopy_UCTN_Code_TTT_1AO_2AG E-Videos