Cold snare polypectomy: does snare type influence outcomes?

Abstract

Cold snare techniques are widely used for the removal of small and diminutive polyps. The influence of snare type on the effectiveness of cold snare polypectomy is unknown. Cold snare polypectomy of 3-7-mm polyps was undertaken using either a thin wire mini-snare (0.30 mm) or a thick wire mini-snare (0.47 mm). Primary outcome was endoscopic completeness of excision. Consensus regarding endoscopic assessment of completeness of excision was standardized and aided by chromoendoscopy. Secondary outcomes included: completeness of histological excision, polyp 'fly away', polyp retrieval rate, early or delayed bleeding and perforation. One hundred and fifty-seven polyps were removed ranging from 3 to 7 mm, 62% were situated in the left side of the colon and 89.4% were sessile. Endoscopic completeness of excision was significantly higher with the thin wire snare compared to the thick wire snare (90.2% vs 73.3%, P < 0.05). There was a numerical trend towards a higher complete histological excision rate with the thin wire snare, but this did not reach statistical significance (73.3% vs 65.2%, P = 0.4). There was a fair level of agreement (kappa = 0.36) between endoscopic and histological completeness of excision. Polyp 'fly away' occurred less often with the thin wire snare (14.6% vs 35.3%, P = 0.002), but there was no significant difference in polyp retrieval rate (84.3% vs 83.8%, P = 0.94). There were no complications with either snare. Snare type appears to be an important determinant of completeness of excision when removing small polyps by the cold snare technique.