Electrosurgical snare

Abstract

The disclosure relates to three enhancements for a surgical snare: an electrosurgical snare in which the loop of snare wire extends from an energy transfer surface which can act both as a physical reaction surface for mechanical cutting using the snare and as a region for emitting electromagnetic energy; a surgical snare having a snare wire having a first end connected to a movable boss that is slidably mounted on a coaxial cable; and a surgical snare having an end cap with a distally facing reaction surface and a pair of channels for guiding a snare wire, where the distally facing reaction surface is arranged to contact the retractable loop when fully retracted

1 . A surgical snare comprising:
 a distal head assembly; and   a snare wire slidably mounted in the distal head assembly,   wherein the distal head assembly comprises an end cap having:   a distally facing reaction surface, and   a pair of channels, each of the pair of channels extending axially between an outlet on the distally facing reaction surface and an inlet on a proximal surface of the end cap,   wherein the snare wire is disposed within the pair of channels to form a retractable loop beyond the distally facing conductive surface, and   wherein the distally facing reaction surface is arranged to contact the retractable loop when fully retracted.   
     
     
         2 . A surgical snare according to  claim 1 , wherein the distally facing reaction surface includes a groove for receiving the retractable loop. 
     
     
         3 . A surgical snare according to  claim 1 , wherein the distally facing reaction surface is rounded. 
     
     
         4 . A surgical snare according to  claim 3 , wherein the distally facing reaction surface is a dome, wherein the outlets of the pair of channels are located on the dome.