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

Factors determining the resection ability of snares in cold snare polypectomy: Construction of an ex vivo model for accurately evaluating resection ability

OBJECTIVES

Cold snare polypectomy (CSP)-dedicated snares (DSs) may have a higher resection ability than conventional snares. However, a model that can accurately and objectively evaluate and compare the resection ability of each snare has yet to be determined, and characteristics of snare parts that increase resection ability remain unknown. Therefore, we elucidated DSs' resection ability and all characteristics of the parts required for acquiring high resection ability.

METHODS

An ex vivo model for evaluating resection ability was generated using human colons obtained from forensic autopsy specimens. The force required to resect a 15 mm wide human colonic mucosa (FRR) was measured using this model; if the FRR is small, the resection ability is high. Next, after measuring the stiffness of each snare part, the correlation between the stiffness and resection ability was analyzed.

RESULTS

The force required to resect using SnareMaster Plus, Micro-Tech Cold Snare, Captivator Cold, Exacto Cold Snare, or Captivator II was 13.6 ± 1.0, 12.5 ± 1.2, 7.4 ± 1.2, 6.5 ± 1.0, and 28.7 ± 3.7 N, respectively. All DSs had significantly lower FRR than the conventional snare (Captivator II) and had higher resection ability (P < 0.001). A negative correlation was found between FRR and sheath or wire spindle stiffness, with correlation coefficients of 0.72 (P = 0.042) or 0.94 (P < 0.001), respectively. Moreover, 1 × 7 type wire rings had significantly higher friction coefficients than 1 × 3 type wire rings (P < 0.002).

CONCLUSION

Sheath and wire spindle stiffness should be increased to increase resection ability; 1 × 7 type wire rings may be suitable for CSP-snare parts.

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

Background and study aims Cold-snare polypectomy (CSP) is considered the standard of care for resection of colorectal polyps ≤10 mm. Data on the efficacy of CSP performed with thin-wire snares compared0 with thick-wire snares are conflicting. We performed a meta-analysis comparing complete resection (CR) and adverse event rates of CSP using thin-wire and thick-wire snares. Patients and methods Comparative studies of adult patients with ≧1 colorectal polyp(s) ≦10 mm who underwent CSP with thin-wire or thick-wire snares were included. We collected data on study, patient, polyp, and snare characteristics. The primary outcome was CR rate. Secondary outcomes were polyp retrieval rate, intraprocedural bleeding, delayed post-polypectomy bleeding, deep mural injury or perforation, patient discomfort, total sedation, and procedure time. We used random-effects models to calculate risk ratios for outcomes. We performed risk of bias assessments, rated the certainty of evidence, and assessed publication bias for all studies. Results We included four randomized controlled trials (RCTs) and two observational studies including 1316 patients with 1679 polyps (826 thin-wire CSPs and 853 thick-wire CSPs). There was no significant difference between thin-wire CSP (92.1%) and thick-wire CSP (87.7%) for RCTs (risk ratio [RR] 1.05, 95% confidence interval [CI] 0.94-1.16) or observational studies (78.1% versus 79.6%, RR 1.03, 95% CI 0.99-1.08). There were no significant differences in polyp retrieval rate or intraprocedural bleeding. There were no cases of delayed bleeding or perforation. Conclusions We found no differences in CR rates for CSP between thin-wire and thick-wire snares. CSP, regardless of snare type, is safe and effective for resection of small colorectal polyps.

Cold resection for colorectal polyps: where we are and where we are going?

INTRODUCTION

Endoscopic resection of colonic precancerous lesions has been demonstrated to significantly decrease colorectal cancer (CRC) incidence and mortality. Among resection techniques, cold snare polypectomy (CSP) has been shown as a highly feasible, effective and safe option and is widely used in clinical practice, being regarded as the first-line technique for removal of small and diminutive colorectal polyps. On the other hand, conventional hot snare polypectomy (HSP) and endoscopic mucosal resection (EMR), namely the gold standard treatments for larger polyps, may be occasionally associated to complications due to electrocautery injury.

AREAS COVERED

To overcome these shortcomings of electrocautery-based resection techniques, in the last few years CSP has been increasingly assessed as a treatment option for additional indications, with a focus on nonpedunculated colorectal polyps ≥10 mm.

EXPERT OPINION

This review aims to present current and widened indications of CSP discussing the latest findings from the most remarkable studies, with an insight into technical issues, novelties and potential advances in the near future.