LAUSR

VARIOUS ENDOSCOPIC SUBMUCOSAL dissection (ESD) devices have been used for colorectal ESD. Stag-Beetle Knife Jr. (SB Knife Jr.; Sumitomo Bakelite, Tokyo, Japan) is a scissor-type knife. Both blades of the knife are insulated and allow grasping of tissue, thereby facilitating controlled dissection and potentially preventing unexpected injury to the muscular layer (Fig. 1a). When it is used for large lesions during ESD, there are limitations regarding its incision ability, because the frequency of switching/energization increases. Recently, a novel monopolar scissor-type knife (SB Knife Jr.2; Sumitomo Bakelite) was developed (Fig. 1b). Its durable coating improves insulation and incision ability. In this video, we present two procedures of colorectal ESD using SB Knife Jr.2. In both cases, a high-frequency generator was used (ESG-100, Olympus Medical Systems, Tokyo, Japan). The pulse cut fast mode setting (30 W) was used for mucosal incision and submucosal dissection. The soft coagulation mode setting (40 W) was used for endoscopic hemostasis. The first case involved a 60-mm elevated lesion (0-IIa+Is; LST-G) in the cecum of a 69-year-old man. The second involved a 35-mm elevated lesion (0-Is) in the ascending colon of a 70-year-old woman (Fig. 2a). After injecting 0.4% sodium hyaluronate into the submucosal layer, a circumferential incision was initiated from the anal side with SB Knife Jr.2. SB Knife Jr.2 was used as hemostatic forceps to stop any bleeding. The circumferential incision was extended and was followed by submucosal dissection repetitively until the entire lesion was resected. The procedure was completed without adverse events (Fig. 2b–f). Histological findings revealed a horizontal margin-negative tubulovillous adenoma (case 1) and adenocarcinoma in situ (case 2; Videos S1 and S2). Therefore, colorectal ESD using SB Knife Jr.2 is technically efficient and safe for treating early colorectal neoplasms.