Submucosal tunneling endoscopic resection for rectal gastrointestinal stromal tumor.

Abstract

A 60-year-old man was referred for evaluation of a rectal submucosal tumor located 5 cm proximal to the anus ([Video 1, ] [Fig. 1]). Endoscopic ultrasonography revealed a 3-cm hypoechoic lesion originating from the muscular layer. The patient underwent submucosal tunneling endoscopic resection (STER) under sedation with propofol for diagnosis and treatment ([Fig. 2]). A small horizontal incision was made at the anus and a submucosal pocket was created with injection of a mixture of hydroxyethyl starch and indigo carmine into the submucosal layer (GIF 190TH1; Olympus, Tokyo, Japan; and Flush Knife BTs 1.5 mm, FujiFilm, Tokyo, Japan). The tip of the tumor was enucleated ([Fig. 3]), and then the intramuscular portion of the tumor was dissected with a square-tip knife (Square Knife; Endoaccess, Garbsen, Germany) using spray coagulation (VIO 3; Erbe, Tübingen, Germany). Dissection was advanced up to the level of the perirectal fat, while paying attention to avoid damage to the tumor capsule. The tumor was removed en bloc ([Fig. 4]) and the mucosal entrance was closed with two clips. The procedure lasted for 1 hour. The patient was hospitalized for 1 night, received oral amoxicillin/clavulanic acid for 5 days, and had an uneventful recovery. Histology showed a benign gastrointestinal stromal tumor ([Fig. 4]). STER is mainly applied in the stomach and esophagus [1]. This case report demonstrates the feasibility of this technique in the rectum.