Underwater endoscopic resection: an alternative for difficult colorectal polyps.

BACKGROUND AND AIMS: Underwater endoscopic resection can be an alternative to standard resection techniques to remove difficult colorectal polyps. This video shows 4 cases of underwater resection of large colorectal polyps.
METHODS: Underwater resection consists of complete filling of the lumen through the accessory channel, using an infusion pump followed by snare resection of the polyp. We present 4 cases: a 3-cm pseudodepressed laterally spreading tumor (LST) in the sigmoid colon, a 6-cm pedunculated polyp with a thick stalk in the sigmoid, a 7-cm sessile lesion in the midrectum, and a 4-cm LST in the distal rectum close to the dentate line, resected with a monofilament snare or a multifilament snare.
RESULTS: All tumors were successfully resected without any adverse events or residual lesions during follow-up.
CONCLUSIONS: The underwater technique is a good alternative to standard resection techniques to remove difficult colorectal lesions.

Underwater endoscopic resection is an alternative technique to standard polypectomy in the management of difficult polyps. This video (Video 1, available online at www.VideoGIE.org) shows 4 cases of underwater resection of large colorectal polyps: a 3-cm pseudodepressed laterally spreading tumor (LST) in the sigmoid colon that could not be resected with standard mucosectomy (Fig. 1A); a 6-cm pedunculated polyp with a thick stalk in the sigmoid colon (Fig. 2A), in which the loop application was possible only under water; a 7-cm sessile lesion in the midrectum (Fig. 3A); and a 4-cm LST in the distal rectum, close to the dentate line (Fig. 4A). One endoscopist performed all procedures while the patients were under conscious sedation. The technique consisted of infusion of water through the accessory channel, using an infusion pump until complete filling of the lumen was achieved, followed by snare resection without prior submucosal injection. A monofilament snare was used to resect the LST lesions in the sigmoid colon and rectum, and a multifilament snare was used for the other 2 lesions. The Erbe (Erbe Elektromedizin GmbH, Tuebingen, Germany) electrosurgical setting was endocut mode effect 2, cut interval 6, and cut duration 1 for all lesions. All lesions would have been difficult to resect by conventional mucosectomy or polypectomy, and in 2 of them previous attempted resections had failed. There were no adverse events, and no residual lesions were seen at follow-up colonoscopy. The underwater technique is a good alternative to standard techniques to resect difficult colorectal lesions, including those in which conventional resection techniques have failed.

Figure 1

A, Pseudodepressed laterally spreading tumor in the sigmoid colon. B, After resection.

Figure 2

A, Giant pedunculated polyp in the sigmoid colon. B, After resection.

Figure 3

A, Giant sessile lesion in the midrectum. B, After resection.

Figure 4

A, Laterally spreading tumor in the distal rectum. B, After resection.