Underwater polypectomy without submucosal injection for colorectal lesions ≤ 20 mm in size—a multicenter retrospective observational study
Underwater polypectomy (UWP) of large (≥ 20 mm) colorectal lesions is well described, but reports of UWP for lesions ≤ 20 mm in size, which account for > 95% of polyps encountered in routine clinical practice, are limited. We assessed the feasibility of UWP in routine practice across various sites for colorectal lesions ≤ 20 mm in size.
A multicenter retrospective study was performed on pooled data from nine colonoscopists at 3 U.S., 1 Taiwanese and 2 Italian sites. Outcomes related to UWP on lesions ≤ 20 mm in size were analyzed.
In 117 patients, UWP netted 169 lesions. Polypectomy by hot (HSP, 54%) or cold (CSP, 41%) snare, and cold forceps (CFP, 5%) were performed successfully without endoscopic evidence of residual neoplasia or immediate clinically significant adverse events. The majority (74.6%) were tubular adenomas; 60.9% were from the proximal colon. Histopathologic margins were positive in 4 and unavailable in 26 CSP and 24 HSP specimens. The remainder had negative resection margins on pathologic reports.
UWP for colorectal lesions ≤ 20 mm in routine practice across multiple sites confirms the feasibility and acceptability of this technique. Improvement of resection outcomes by UWP in routine practice deserves further evaluation in a randomized controlled trial.
KeywordsPolypectomy Underwater Water exchange colonoscopy
Hot snare polypectomy
Cold snare polypectomy
Cold forceps polypectomy
Randomized controlled trial
The project described was supported by the National Center for Advancing Translational Sciences, National Institutes of Health, through Grant Number UL1 TR001860. (AWY). The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH. This material is the result of work that was supported by resources from the VA Northern California Health Care System, Sacramento, California, Palo Alto VA, Palo Alto, California, and VA Greater Los Angeles Health System, Los Angeles, California. The contents reported/presented within do not represent the views of the Department of Veterans Affairs or the United States Government.
Compliance with ethical standards
Drs. Yen, Amato, Cadoni, Friedland, Hsieh, J. Leung, Liggi, Sul and F. Leung have no conflicts of interest or financial ties to disclose.
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