Bipolar surgical snare and methods of use

Claim 1

A snare instrument for use in performing electrosurgery on protruding tissue, the instrument comprising: a support shaft having a proximal end, a distal end, and a bore; a strand of flexible electrically insulating material having first and second ends, the first and second ends of the strand engaged in the bore of the support shaft so that the strand forms a continuous snaring loop projecting from the distal end of the support shaft; first and second electrodes disposed on the strand; first and second electrical leads disposed from the proximal end of the support shaft, the first and second electrical leads connected to the first and second electrodes, respectively; and actuator means connected to the first and second ends of the strand for expanding and contracting the continuous snaring loop, the actuator means disposed from the proximal end of the support shaft, so that when the snaring loop is contracted around the protruding tissue, current may be selectively passed between the first and second electrodes to cause selective necrosis and hemostasis of the protruding tissue.

Claim 17

A method of performing surgery on a patient's protruding tissue using an instrument having a support shaft with a distal end and a proximal end for use with a snaring loop having first and second electrodes, the snaring loop to be disposed from the distal end of the support shaft, and an actuator means disposed from the proximal end of the support shaft for manipulating the instrument and for expanding and contracting the snaring loop, the method comprising the steps of: (a) providing a snaring loop comprising a strand of flexible electrically insulating material having first and second ends, the first and second ends disposed from the distal end of the support shaft, the strand forming a continuous snaring loop between the first and second ends; (b) connecting the first and second electrodes of the bipolar snare instrument to a power source for supplying alternating-current electrical power to the instrument; (c) using an opening in a patient's body to provide access to the patient's tissue; (d) inserting the working surface and support shaft of the instrument through the opening so that the snaring loop is disposed adjacent to the patient's protruding tissue; (e) selecting and maintaining a substantially constant voltage level output across the power source, the voltage level output independent of the impedance of the load connected across the power source; (f) placing the snaring loop around protruding tissue; (g) operating the actuator means to contract the snaring loop so that the first and second electrodes contact the protruding tissue; and (h) activating the first and second electrodes so that an alternating current passes between the first and second electrodes and the protruding tissue to cause selective necrosis and hemostasis of the tissue.

Claim 18

A method of performing surgery on a patient's protruding tissue using an instrument having a support shaft with a distal end and a proximal end for use with a snaring loop having first and second electrodes, the snaring loop to be disposed from the distal end of the support shaft, and an actuator means disposed from the proximal end of the support shaft for manipulating the instrument and for expanding and contracting the snaring loop, the method comprising the steps of: (a) providing a snaring loop comprising a strand of flexible electrically insulating material having first and second ends, the first and second ends disposed from the distal end of the support shaft, the strand forming a continuous snaring loop between the first and second ends; (b) connecting the first and second electrodes of the bipolar snare instrument to a power source for supplying alternating-current electrical power to the instrument; (c) using an opening in a patient's body to provide access to the patient's tissue; (d) inserting the working surface and support shaft of the instrument through the opening so that the snaring loop is disposed adjacent to the patient's protruding tissue; (e) selecting and maintaining a substantially constant voltage level output across the power source, the voltage level output independent of the impedance of the load connected across the power source; (f) placing the snaring loop around protruding tissue; (g) operating the actuator means to contract the snaring loop so that the first and second electrodes contact the protruding tissue; and (h) activating the first and second electrodes so that an alternating current passes between the first and second electrodes and the protruding tissue to cause selective necrosis and hemostasis of the tissue.

Claim 22

The method of claim-16 wherein the step of using an opening in a patient's body to provide access further comprises using a patient's natural body orifice.

Claim 24

A method of performing surgery on a patient's protruding tissue using an instrument having a support shaft with a distal end and a proximal end, for use with a snaring loop having first and second electrodes, the snaring loop to be disposed from the distal end of the support shaft, and an actuator means disposed from the proximal end of the support shaft for manipulating the instrument and for expanding and contracting the snaring loop, the method comprising the steps of: (a) providing the first electrode in the form of a continuous loop having first and second ends disposed from the distal end of the support shaft; (b) providing the second electrode in the form of a continuous loop having first and second ends disposed from the distal end of the support shaft; (c) connecting the first and second electrodes of the bipolar snare instrument to a power source for supplying alternating-current electrical power to the instrument; (d) using an opening in a patient's body to provide access to the patient's tissue; (e) inserting the working surface and support shaft of the instrument through the opening so that the snaring loop is disposed adjacent to the patient's protruding tissue; (f) selecting and maintaining a substantially constant voltage level output across the power source, the voltage level output independent of the impedance of the load connected across the power source; (g) placing the snaring loop around protruding tissue; (h) operating the actuator means to contract the snaring loop so that the first and second electrodes contact the protruding tissue; and (i) activating the first and second electrodes so that an alternating current passes between the first and second electrodes and the protruding tissue to cause selective necrosis and hemostasis of the tissue; and (j) maintaining a uniform spacing between the first and second electrodes during expansion and contraction of the snaring loop, so that the first and second electrodes do not contact each other.

Claim 25

A method of performing surgery on a patient's protruding tissue using an instrument having a support shaft with a distal end and a proximal end, for use with a snaring loop having first and second electrodes, the snaring loop to be disposed from the distal end of the support shaft, and an actuator means disposed from the proximal end of the support shaft for manipulating the instrument and for expanding and contracting the snaring loop, the method comprising the steps of: (a) providing the first electrode in the form of a continuous loop having first and second ends disposed from the distal end of the support shaft; (b) providing the second electrode in the form of a continuous loop having first and second ends disposed from the distal end of the support shaft; (c) connecting the first and second electrodes of the bipolar snare instrument to a power source for supplying alternating-current electrical power to the instrument; (d) using an opening in a patient's body to provide access to the patient's tissue; (e) inserting the working surface and support shaft of the instrument through the opening so that the snaring loop is disposed adjacent to the patient's protruding tissue; (f) selecting and maintaining a substantially constant voltage level output across the power source, the voltage level output independent of the impedance of the load connected across the power source; (g) placing the snaring loop around protruding tissue; (h) operating the actuator means to contract the snaring loop so that the first and second electrodes contact the protruding tissue; and (i) activating the first and second electrodes so that an alternating current passes between the first and second electrodes and the protruding tissue to cause selective necrosis and hemostasis of the tissue; and (j) maintaining a uniform spacing between the first and second electrodes during expansion and contraction of the snaring loop, so that the first and second electrodes do not contact each other.