Polypectomy snare instrument

Abstract

A surgical snare instrument includes a tubular sheath having proximal and distal ends, a flexible shaft having proximal and distal ends extending through and axially movable relative to the sheath, a snare loop at the distal end of the shaft, and a handle assembly coupled to the proximal ends of the sheath and shaft for moving the shaft axially relative to the sheath. The handle assembly is provided with cautery capability to provide a cautery current to the snare loop. The snare loop is trained to have a proximal portion which extends along an angle or curve relative to the tubular member and a distal portion which is substantially parallel to the tubular member. As such, when the snare loop is axially moved beyond the distal end of the sheath, the distal portion of the snare loop; i.e., that portion which is adapted to engage a polyp, is oriented substantially parallel, yet non-axial, with the tubular member. According to one embodiment of the invention, the shaft is torqueable, preferably made from a multifilament twisted and drawn or swaged cable. The handle is preferably additionally adapted to axially rotate the sheath relative to the shaft and the snare loop to facilitate maneuvering the snare loop. According to another embodiment of the invention, the snare loop is provided with a net element adapted to capture a polyp severed by the snare loop.