Sessile serrated adenoma invading a diverticulum in the right colon: tips and tricks for a safe complete endoscopic resection

Abstract

Large sessile serrated adenomas are at high risk of incomplete resection because of difficulty visualizing their margins [1]. Moreover, cases involving invasion of a diverticulum are technically challenging and carry a high risk of perforation. Here, we report on a 3.5-cm sessile serrated adenoma in the right colon with invasion of the diverticulum (▶ Fig. 1 a, ▶ Video 1). To identify the margin, acid acetic spraying [2] was combined with blue-laser imaging virtual chromoendoscopy to produce a clear whitish area with excellent contrast between the lesion and normal mucosae (▶ Fig. 1 b). Then, endoscopic submucosal dissection was performed using our double-clip traction (DCT) technique [3,4] (▶ Fig. 2 a). After injecting the margin far from the diverticulum with a glycerol mixture, a circumferential incision was made. Countertraction using the DCT technique enabled us to identify a good submucosal dissection plane, even in the diverticulum area. After rapid en bloc resection of the 3.5-cm sessile serrated adenoma, we decided to close the area because of the high risk of delayed perforation secondary to diverticulum involvement. Small incisions were made in the mucosa all around the scar (▶ Fig. 2 b) using a dissection knife, which enabled hemoclips to grasp the tissue and facilitated closure of the large scar within 2 minutes (▶ Fig. 2 c). Pathological analysis revealed a nondysplastic sessile serrated adenoma, and the patient was discharged on the day of the procedure. Many simple, inexpensive techniques have been described for the removal of lesions that, until recently, were considered too difficult for an endoscopic approach. Physicians should be aware of these techniques. Endoscopy_UCTN_Code_TTT_1AQ_2ADCompeting interests J. Jacques, R. Legros and M. Pioche are consultants for Olympus. E-Videos ▶ Fig. 1 Sessile serrated adenoma invading a diverticulum. a No clear margins were visible.b Clear margins after acetic acid spraying.