A Study of Physical Efficacy of Different Snares for Endoscopic Mucosal Resection

Abstract

There are various types of snares for endoscopic mucosal resection (EMR). Some endoscopists may choose the snare according to their feeling, but we supposed that there were some physical reasons behind each choice. In this paper, we raise the questions, ‘What is the best snare chosen for EMR?’, and ‘Why do we have to do it?’. From the theory of dynamics, we thought that the most important element was vertical force, which we could add against mucosa through the snare. First, we made two situations; one was keeping horizontal faced position of loop of snare (we defined it as HPW; horizontal faced position weight), and the other was rising up position of it (we defined it as RPW). We inspected these forces for the representative and different seven snares, and calculated the ‘Effective Range’, which was a RPW minus a HPW in average. The results demonstrated that both the spiral snare and the smaller ‘Snare Master’ showed higher than other snares in HPW, RPW, and the Effective Range. Based on our study, we judged them as the most adequate snares for EMR in physics and logicality.

Dynamics of endoscopic snares: a new approach towards more practical and objective performance evaluation

“…Each snare should be evaluated objectively before applying it in vivo. "Static" evaluation via bench testing and usability in animal models have been assessed previously [8]; however, these tests were insufficient to fully evaluate the snares. Each snare's performance would change during snaring; thus, "static" data may change according to the measured points, even if each snare is evaluated similarly.…”

“…For example, sustainable hold-down force is desirable if a polyp is located at the colonic flexure, and sharp cutting force is desirable for cold snare polypectomy [7]. In the real world, however, endoscopists must choose each snare according to personal preference, primarily because few methods exist to objectively compare each device's performance [8]. The previously reported methodology only evaluated the "static" performance in a purely experimental setting [8], although fold-down and tightening forces can change dynamically during snaring.…”

“…In the real world, however, endoscopists must choose each snare according to personal preference, primarily because few methods exist to objectively compare each device's performance [8]. The previously reported methodology only evaluated the "static" performance in a purely experimental setting [8], although fold-down and tightening forces can change dynamically during snaring. A more practical method for better understanding the "dynamic" performance of polypectomy snares may facilitate their logical choice and right use.…”

Submucosal injection solution for gastrointestinal tract endoscopic mucosal resection and endoscopic submucosal dissection

“…Various recently developed endoscopic techniques, submucosal injection solutions, and devices such as the electrosurgical snare, submucosal injection catheter, and endo-clip have made EMR safer, easier, and more effective (Yamano et al 2004; Taku et al 2007). The use of submucosal injection is essential for a successful EMR, as injection of fluid into the submucosa cushions and isolates the tissue just before capture of the target lesion with a snare, thereby reducing thermal injury and the risk of perforation and hemorrhage while also facilitating an en-bloc resection.…”

Update on Techniques of Colonic Endoscopic Mucosal Resection

“…For submucosal injection, epinephrine‐saline solution is commonly used, but various solutions, such as sodium hyaluronate, were recently developed in order to enhance formation of a good, long‐lasting bleb 10 . Futhermore, various snares, such as the spike snare or the spiral snare, which can make it easy to grip the tumor without slipping, were also developed 11 …”