Snare devices with thinner loop wire may provide higher performance for cold snare polypectomy in an experimental model

Abstract

Background and study aims Snare devices play an important role in treatment of intestinal polyps. However, there are no objective measurements for the characteristics of the various types of snare devices. Materials and methods Seven types of snare devices from four manufacturers were evaluated based on original measurements. The evaluated factors were stiffness, cutting quality, and change in force required for cutting depending on sheath shape. The latter two factors were evaluated by measuring the force required to cut 20 % gelatin cylinders, which simulated intestinal polyps. The cutting sharpness was evaluated by observing the sectional surface of cut gelatin cylinders using a stereomicroscope. The correlations between these measurements and characteristics of the snare devices were investigated. Results A strong positive correlation, with an R2 value of 0.863, was shown between the force required to cut gelatin cylinders and loop wire diameter. Loop wire diameter also had a strong correlation, with an R2 value of 0.7997, with the change in force required for cutting gelatin cylinders depending on sheath shape. No correlations were detected between loop stiffness and characteristics of snare devices. The edge-enhanced image revealed that the rougher surfaces of the gelatin cylinders were cut by snares with a thicker diameter. Conclusions Thinner loop wire may provide higher performance in cold snare polypectomy in an experimental model.

Colorectal cold snare polypectomy: Current standard technique and future perspectives

“…showed that when performing CSP on colorectal polyps measuring 3–7 mm, a snare with a thin 0.30 mm wire showed higher CRR than a thicker 0.42 mm wire. In an experimental model, the thinness of the loop wire and diameter of the snare positively correlated with the force at the time of lesion excision, but not with the stiffness of the loop or the characteristics of the snare device 22 . Contrarily, an international multicenter RCT that compared the efficacy of thin wire snares (0.30 mm) versus thick wire snares (0.47 mm) for colorectal polyps smaller than 10 mm found no statistically significant difference in the IRR between both groups 23 .…”

“…In an experimental model, the thinness of the loop wire and diameter of the snare positively correlated with the force at the time of lesion excision, but not with the stiffness of the loop or the characteristics of the snare device. 22 Contrarily, an international multicenter RCT that compared the efficacy of thin wire snares (0.30 mm) versus thick wire snares (0.47 mm) for colorectal polyps smaller than 10 mm found no statistically significant difference in the IRR between both groups. 23 The report concluded that standardization of the operator's skill level was more important than snare performance.…”

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

“…1,2,14,15 However, no model can accurately and objectively evaluate and compare the resection ability of these snares, and only preliminary resection evaluations using substitutes, such as gelatin, have been conducted. 16 Since differences in resection targets will alter the results of resection ability evaluation, the human colonic mucosa should be used as the resection target to accurately evaluate snare resection ability. However, it is difficult to procure sufficient human colonic mucosa for evaluation.…”