Cold Snare Polypectomy Without Submucosal Injection Is Safe and Effective for Large Sessile Serrated Lesions

colon polyp
colon polyp
Investigators of the prospective trial studied the safety and efficacy of cold snare polypectomy (CSP) and piecemeal CSP for sessile serrated lesions 10 mm in size or larger.

Cold snare polypectomy (CSP) without submucosal injection is safe and effective for patients with sessile serrated lesions (SSLs) 10 mm in size or larger, according to study data published in Clinical Gastroenterology and Hepatology.

The prospective study (University Hospital Medical Information Network Identifier: UMIN000034763) enrolled 300 consecutive patients (median age, 62 years [range, 26 to 84 years]; 162 [54%] male) who underwent CSP for 474 SSLs (≥10 mm) from November 2018 to January 2020. Patients were required to have SSLs greater than or equal to 10 mm in size and were excluded if cytological dysplasia was detected.

The investigators performed indigo carmine chromoendoscopy and/or image-enhanced endoscopy to delineate SSL borders; piecemeal CSP (pCSP) was performed for patients for whom en-bloc resection was difficult. Biopsy specimens from the margins of the post-polypectomy defect were collected to confirm complete resection and screened for local recurrence via surveillance colonoscopy.

“We used narrow band imaging, blue light imaging, or optical enhancement as well as white light imaging to observe the border, supplemented by indigo carmine for difficult cases,” the researchers stated. “This obviated the need for submucosal injection in all cases. One advantage of avoiding submucosal injection is that it can enlarge the lesion and consequently widen the resection field. Our high rate of successful en-bloc resection could thus be partly explained by the lack of submucosal injection.”

All lesions were successfully resected with the use of CSP without submucosal injection. The median diameter of the resected lesions was 14 mm (range, 10 mm to 40 mm); pCSP was used to resect 106 (22%) lesions. About 70% of the SSLs were located in the proximal colon. Morphologically, 86% of the lesions were type 0 to typeII. The remaining 14% were type 0 to type I. Post-polypectomy biopsies revealed residual serrated tissue in 1 case.

CSP was “associated with a lower risk of bleeding,” according to the investigators, who observed immediate post-polypectomy bleeding in 8 patients (3%). No delayed post-polypectomy bleeding was seen. At a median follow-up of 7 months, surveillance colonoscopy was performed for 384 lesions (81%), at which point no local recurrences were observed.

The researchers noted several study limitations. For example, because comparison patients who underwent endoscopic mucosal resection (EMR) or polypectomy were not included, the investigators could not definitively confirm that CSP decreased the risk of adverse events (AEs). Secondly, the study was conducted at a single Japanese endoscopy center; therefore, CSP’s efficacy needs to be further evaluated in multicenter studies. The investigators also cited the short median follow-up period (7 months) and the resection of multiple lesions during a single procedure, which can increase the risk for post-procedural AEs, as other limitations.

“We have demonstrated the safety and efficacy of CSP for the treatment of large SSLs [greater than or equal to] 10 mm,” the study authors concluded. “Because no injection needles or solutions are required, our method is more economical and requires less time than pCS-EMR.”

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Kimoto Y, Sakai E, Inamoto R, et al. Safety and efficacy of cold snare polypectomy without submucosal injection for large sessile serrated lesions: a prospective study. Clin Gastroenterol Hepatol. Published online November 2, 2020. doi: 10.1016/j.cgh.2020.10.053