Use of the front-view forward-array echoendoscope to evaluate right colonic subepithelial lesions

Abstract

Background: Endosonographic evaluation and sampling of right colonic subepithelial lesions is technically difficult.

Objective: To evaluate the feasibility, safety, and tissue yield of a prototype front-view, forward-array, curved linear array echoendoscope in the evaluation and sampling of right colonic subepithelial lesions.

Setting: Tertiary referral center.

Design: Procedural and outcome data on all patients undergoing EUS evaluation of right-sided colonic and pericolonic lesions were collected during a 1-year study period.

Main outcome measurements: Patient demographics, clinical indication, EUS findings, EUS-FNA yield, technical success, and procedural complications.

Results: A total of 15 patients underwent EUS examination of right-sided colonic lesions with the prototype echoendoscope. The lesions were located in the cecum (n = 12) and the ascending colon (n = 3). The cecum was reached in all examinations within 10 minutes. Twelve patients had subepithelial lesions detected during colonoscopy. Findings included 6 extrinsic compressions from an adjacent normal structure, 1 calcified lymph node, 1 ovarian cyst, 1 prolapsed appendiceal orifice, 1 GI stromal tumor, 1 appendiceal mucocele, and 1 lymphoma. Two patients were evaluated for a pericolonic lesion seen on CT; findings included focal diverticulitis and a metastatic lymph node. In the patient evaluated for an infiltrative mass with previous nondiagnostic biopsies, colonic histoplasmosis was diagnosed. FNA was performed in 6 patients and provided diagnostic samples in 5 (83%). No procedure- or FNA-related complications were reported.

Conclusions: Endosonographic evaluation and sampling of right-sided colonic subepithelial lesions with the prototype front-view, forward-array, curved linear array echoendoscope is feasible and safe. The yield of FNA is high, consistent with applications in the upper GI tract.