Use Of Forward-Viewing Echoendoscope For Evaluation Of Suspected Subepithelial Colonic Lesions

INTRODUCTION: Evaluation of suspected subepithelial (SEL) colonic lesions proximal to the rectosigmoid using oblique-viewing echoendoscope is technically challenging. Forward-viewing echoendoscope offers safe advancement of the scope into the colon as well as ultrasound evaluation with fine needle aspiration/biopsy. METHODS: We reviewed outcomes of using of forward-viewing echoendoscope (Olympus TGF-UC180J) for colonic SEL proximal to the rectosigmoid between November 2016 and December 2019. The following data were collected: Patient demographics, clinical indication, EUS findings, EUS-FNA yield, technical success, and procedural complications. RESULTS: A total of 18 patients with either cecum (10), ascending (3), transverse (3), or descending colon (2) lesions detected during routine colonoscopy underwent lower EUS using the forward-viewing echoendoscope. There were 11 patients who were male and 7 who were female with an average age of 61 years. The average length of the procedure was 22 minutes for lesions in right colon, 29 minutes for transverse colon, and 21 minutes for left colon. The lesion was reached in all but one patient due to significant looping in the colon. FNA was performed on 4 patients and was diagnostic in 2. The EUS and pathologic findings based on location are summarized as follows: in the cecum, there was 1 lymphoid aggregate, 1 non-malignant leiomyoma, 1 inflammatory polyp, and 2 extrinsic compressions (one unspecified pelvic mass and one large right ovarian cyst); in the ascending colon, there was 1 lymphoid aggregate and 1 villous adenoma; in the transverse colon, there was 1 gastrointestinal stromal tumor and 2 lipomas; and in the descending colon, there was 1 MALT lymphoma and 1 lipoma. There were 3 patients with a normal appearing colon on EUS, with 1 inverted appendix near the cecum, and 2 patients with non-diagnostic lesions. The only complication noted was bleeding in one patient after FNA of a transverse colonic lesion that resolved with epinephrine injection. CONCLUSION: The forward-viewing echoendoscope is a safe and effective tool for the evaluation and sampling of suspected SEL colonic lesions proximal to the rectosigmoid that would otherwise be difficult/impossible to reach using an oblique-viewing echoendoscope.