Comparison of complete resection rates in cold snare polypectomy using two different wire diameter snares: A randomized controlled study

Abstract

Background and Aim: Cold snare polypectomy (CSP) is a standard treatment for small colorectal polyps. This study examined the effect of different snare wire diameters on complete histological resection rate, resection depth, and CSP safety. Methods: This randomized controlled trial was conducted at two institutions between June 2019 and March 2021. Eligible colorectal polyps (≤10 mm) were randomly assigned in a 1:1 ratio to receive either CSP with a conventional snare made of normal-diameter wire (0.40 mm) or CSP with a dedicated snare made of thin wire (0.23 mm). The primary endpoint was the complete resection rate determined on histological assessment of the resected specimen. Results: In total, 254 lesions in 152 patients were included, with 128 and 126 lesions assigned to the normal-diameter wire snare group and the thin-wire snare group, respectively. No significant differences were observed in patient characteristics between the two groups. The histological complete resection rate was significantly higher in the thin-wire snare group than in the normal-diameter wire snare group (70.0% vs 81.0%, P = 0.04). The normal-diameter wire snare group had significantly more cases of unclear horizontal margin evaluation than the thin-wire snare group (28.1% vs 15.9%, P = 0.02). No significant differences were observed between the two groups in the muscularis mucosa and submucosa of the resected specimens or the thickness of the submucosa in the resected specimens. Conclusions: CSP with a dedicated thin-wire snare provides more specimens that can be evaluated at the horizontal end and increases the histological complete resection rate. maceutical Co. T.G. received honoraria for his lectures from FUJIFILM Co., FUJIFILM Medical Co., Olympus Co. AstraZeneca K. K., Daiichi Sankyo Co., MC Medical, Inc., and AMCO Co. Author contributions: S.S. and T.H. proposed the study. S.S., T.H., and C.K. performed the research. A.S. and M.Y. performed the pathological examination. T.H. conducted the statistical analysis. T.H. and S.S. wrote the first draft. H.I. and T.G. critically revised the manuscript for important intellectual content. Ethics statement:The study protocol was approved by the institutional review board at Yuri Kumiai General Hospital on May 28, 2019, and was approved by each participating institution. Written informed consent was obtained from all patients before enrolment. Funding sources: None.

Effectiveness and safety of thin vs. thick cold snare polypectomy of small colorectal polyps: Systematic review and meta-analysis

“…underwent thin-wire CSP (Table 2). For thick-wire snares, 3 studies used a 0.47 mm snare [9,20,22], 1 study used 0.40 mm and 0.47 mm snares [21], 1 study used a 0.43 mm snare [30], and 1 study used a 0.40 mm snare [29]. For thin-wire snares, 5 studies used a 0.30 mm snare [9,[20][21][22]30] and 1 study used 0.23 mm snare [29].…”

“…Endoscopists were explicitly instructed to position the polyp near the bottom of the screen (approximately 5-8 o'clock) in 5 studies [9,[20][21][22]29], to capture a rim of normal tissue in 5 studies [9,[20][21][22]29], and to inspect the resection bed after CSP to ensure removal of any endoscopically visible residual tissue in 4 studies [9,[20][21][22]. Complete resection was assessed based on histological examination of the resected polyp sample in three RCTs [20,29,30], and based on histological examination of biopsies from polyp resection sites in one RCT and two observational studies [9,21,22]. The pooled estimates from included RCTs showed no significant differences between the CR rate for thin-and thick-wire snares, at 92.1% versus 87.7%, respectively (RR 1.05, 95% CI 0.94-1.16).…”

“…Of the six included studies, four were randomized controlled trials (RCTs) [20,22,29,30] and two were observational (cohort) studies [9,21]. Three randomized trials were published in full manuscript form [20,22,29].…”

Does the wire diameter really determine the outcomes in cold snare polypectomy?

“…We read with great interest the recently published randomized controlled trial (RCT) by Horii et al 1 comparing the outcome of different snare wire diameters for cold snare polypectomy (CSP) of small colorectal polyps (≤ 10 mm). Compared with the conventional thick-wire snare, the dedicated thin-wire snare was associated with a significantly higher histological complete resection rate (CRR) (70.0% vs 81.0%, P = 0.04).…”

Editorial: Optimizing the success of cold snare polypectomy in colonoscopy practice

“…In this issue of Journal of Gastroenterology and Hepatology , Horii et al performed a randomized controlled study and reported that CSP using a thinner diameter of snare wire could achieve a significantly higher histological complete resection rate compared with that using a normal‐diameter snare (70% vs 81%, P = 0.04) 9 . In a subanalysis of results based on level of experience, it is noteworthy that more experienced endoscopists appeared to have a higher complete resection rate than trainees.…”