Mechanisms of cutting soft tissues using snare-type tools

Cold snare polypectomy (CSP) is the predominant method for removing colonic polyps under 6 mm, utilizing snare-type tools as cutting tools. However, complete resection rates often decrease due to occasional cutting failure. Understanding the cutting mechanisms of snare-type tools is thus crucial for optimizing both the tool and procedure. Research on CSP has primarily focused on surgical case studies, with limited focus on the snare tools. This study investigates the cutting mechanisms of snare-type tools, examining the effects of cutting speed and snare properties on cutting force. The results show that the internal tissue fractures first during CSP, followed by the external tissue. High cutting speeds and thin wire ropes reduce the cutting force required and produce flatter cut cross-sections. Cold snare defect protrusions are primarily due to the high toughness and strength of the submucosa layer tissue, which impedes internal tissue fracture. These findings enhance the understanding of the internal fracture mechanism of soft tissue and provide valuable insights for optimizing snare-type tools, potentially improving the efficacy and safety of polyp resection procedures.