UNDERWATER ENDOSCOPIC MUCOSAL RESECTION SHOWS COMPARABLE OUTCOMES THAN TRADITIONAL EMR WITH LESS ADVERSE EVENTS

Aims:

Underwater endoscopic mucosal resection (UEMR) is an emerging resection technique, which is performed plunging the lesions in water without submucosal cushion. Somehow, the floating effect makes a feasible cutting line, and allows a safe resection. We aimed to evaluate the experience of two tertiary hospital using UEMR compared with traditional resection method for the treatment of non pedunculated colorectal polyps, focusing on the indication of both techniques.

Methods:

This was a retrospective study performed in four tertiary hospitals, in which endoscopic resection with UEMR and EMR were included and compared during the last 12 months. All the resections were performed by two experienced endocopists (JRS & HU) using from 13 to 30 mm size snares. Indications, outcomes and complications were assessed with both approaches.

Results:

A total of 174 resections (118 EMR and 56 UEMR) performed in 164 patients were included (70,7% males; mean age 67 y.o). En bloq resection rate was similar with Both procedures (69% vs. 65%; p = 0.44). However, Lesions resected by EMR were larger than those resected by UEMR (31 mm vs. 19 mm; p < 0.001). On the other hand, UEMR was usually chosen for the treatment of challenging lesions: Ileocecal valv involvement (11.5% vs. 2.5%; p = 0.01), recurrences (23.1% vs. 11.3%; p = 0.01) and Non lifting sign (25% vs. 5.9%; p < 0.001). Procedural bleeding rate was slightly higher in EMR group than UEMR group (9.3% vs. 3.2%; p = ns). Only one perforation was registered in EMR group, neither in UEMR group.

Conclusions:

UEMR shows as effective as EMR despite of been performed in worse scenarios. Therefore, UEMR might be a feasible approach as elective treatment in these challenging polyps. Besides, UEMR could help to decrease the risk of complications, especially bleeding.