Surgical Snare with Electrosurgical Tip and Method of Use

Abstract

A medical device includes a tissue dissector and a snare loop on a common shaft. At least the distal tip of the snare loop is energizable to function as an electrosurgical element for tissue dissection. In use the snare loop is partially extended from the shaft to expose the electrosurgical element for electrosurgical dissection, and the snare loop is fully extended from the shaft to deploy the snare loop for retrieval and positioning of an implant such as a gastric banding device. The snare loop may be deployed through a pair of jaws also mounted on the shaft for use in tissue dissection.

1 . A medical instrument comprising:
 a shaft having a distal portion;   a pair of jaws on the distal portion of the shaft; and   a snare extendable from the distal portion of the shaft.   
     
     
         2 . The medical instrument of  claim 1 , wherein the snare is extendable to an extended position in which a portion of the snare extends distal to the jaws. 
     
     
         3 . The medical instrument of  claim 2  wherein when the snare is in the extended position a portion of the snare extends longitudinally through the jaws. 
     
     
         4 . The medical instrument of  claim 2  wherein when the snare is in the extended position a portion of the snare extends between the jaws. 
     
     
         5 . The medical instrument of  claim 4 , wherein the jaws are moveable between an open position and a closed positions and wherein the jaws in the closed position define a passage, and wherein a portion of the snare extends through the passage to a position distal to the jaws when the snare is in the extended position and the jaws are in the closed position. 
     
     
         6 . The medical instrument of  claim 1 , wherein the snare includes a snare loop and a distal tip on the snare loop, and wherein the snare includes a first extended position in which the distal tip is positioned distal to the jaws, and a second extended position in which the snare loop is positioned distal to the jaws. 
     
     
         7 . The medical instrument of  claim 6 , wherein the distal tip includes an electrically conductive element electrically connectable to a source of radiofrequency energy. 
     
     
         8 . The medical instrument of  claim 5 , wherein:
 the shaft includes a lumen;   the medical instrument further includes a guide tube extending through the lumen, the guide tube including a distal portion disposed between the jaws and a spreading element on the distal portion;   the guide tube is longitudinally slidable relative to the shaft between a distal position and a proximal position, wherein when the guide tube in the proximal position positions the spreading element into contact with opposed contact surfaces on the jaws, and thereby positions the jaws in the opened position.   
     
     
         9 . The medical instrument of  claim 1 , wherein the medical instrument includes an electrically conductive element electrically connectable to a source of radiofrequency energy, the element extendable from the distal portion of the shaft. 
     
     
         10 . The medical instrument of  claim 9 , wherein the electrically conductive element is extendable through the jaws. 
     
     
         11 . The medical instrument of  claim 9  wherein the electrically conductive element is a distal portion of the snare. 
     
     
         12 . A medical instrument comprising:
 an elongate tube having a lumen;   a snare comprising a loop and a distal tip on the loop, wherein the snare is extendable from the distal portion of the tube from a retracted position in which the loop is contained within the tube, to a first extended position in which the distal tip extends distally from the tube, and a second extended position in which the loop extends distally from the tube;   wherein at least a portion of the loop has an electrically conductive portion electrically connectable to a source of radiofrequency energy.   
     
     
         13 . The medical instrument of  claim 12  wherein the electrically conductive portion includes the distal tip. 
     
     
         14 . The medical instrument of  claim 13 , wherein the portion of the loop proximal to the distal tip has a non-conductive surface. 
     
     
         15 . The medical instrument of  claim 13 , wherein the snare comprise a wire, and wherein at the distal tip the wire is formed into a generally v-shaped element.