Besides, there are applications with similar principle, such as gastrolith lithotripter, net which taking out foreign matter, accessory helping superfine endoscope enter biliary tract for observation and treatment operation, as well as ERCP net and urgent endoscope.

With a long history in TCRP, polyp snare is most widely used and classic. Through continuous development, the materials and technology of polyp snare continue to improve, combining with demands of endoscopy doctor, its kinds begin to boom.

Electric polyp snare is mainly composed of handle, snare core and outer sheathing canal. The function of polyp snare mainly focuses on snare core. According to different shapes of polyp snare cores, there are circle (rigid oval), oval (soft oval), spiral coil oval, semicircle, hexagon, and other shapes.

Polyp snare core uses steel wire material, for the ease of conduct electricity and with strong tension, which can realize good effect of tightening removal in the ESD polypectomy.

Besides, matters that need your attention are: the bigger the contact area of polyp snare for energizing, the better and steadier the cutting effect is, meanwhile, combining with anti-slip effect, steel wire uses spiral knitting, like a little girl's braid, so that polyp snare has enough contact with polyp and has anti-slip effect.

For special circumstances when some parts cannot be extracted, such as lesser curvature of gastric body, duodenal papilla and sigmoid colon lesion, half-moon polyp snare can be used for extracting, and generally combine with transparent cap for cutting.

Adenoma at duodenal papilla needs tip of polyp snare as fulcrum to fix snare and extract polyp for cutting after opening.

There are two kinds of polyp snare tip, one is tip bending (non-standard name) and the other is tip insulation.

Tip bending contributes to polyp snare' s good natural opening force when it unsheathes, meanwhile, contributes to complete extracting of target area when special lesion and part, which cannot be extracted, are fixed by tip and open snare.

Tip insulation is hardly used; however, we have to know that this kind polyp snare tip can avoid accidentally injure or punching, especially suitable for weak mucosa.

Pliable tip loses function of fixing polyp snare at certain degree, so it has small risk but also is not easy to control, which is the defect.