Abstract: A surgical apparatus for removing a portion of tissue comprising an elongated body having a distal edge, a collapsible cutting member mounted to the elongated body, having an opening therethrough and extending distally of the distal edge of the elongated body. The cutting member has a closed loop conductive surface and is movable from a first loop configuration to a second smaller loop configuration, the exposed conductive distal edge forming an electrosurgical cutting surface for applying electrical energy to tissue. The cutting member resects a tubular region of tissue as the apparatus is advanced through tissue and the resected tissue extends through an opening in the cutting ring for containment within the elongated body.

Abstract: This invention relates broadly to surgical instruments. More particularly, this invention relates to a surgical snare instrument for excising polyps. Preferably, the instrument includes a coupling member that may increase ability to actuate the snare. According to a preferred embodiment, the present invention comprises a surgical instrument for insertion through an endoscope having a handle and a working channel, said surgical instrument including an elongate flexible tubular sheath having proximal and distal ends; a flexible shaft extending through and axially movable relative to the sheath, said shaft having proximal and distal ends; an end effector coupled to or formed at said distal end of said shaft; and a coupling member disposed at said distal end of said shaft.

Abstract: An ablation instrument having a flexible portion at or near the distal portion of the instrument, is provided. The instrument includes an elongated tubular member having a steerable distal end configured to deflect, or otherwise direct, and properly position at least a portion of the distal portion, comprising an ablation device, during an ablation procedure. The instrument further includes a deflectable member which cooperates with the steering system allowing for the proper placement of the ablation device adjacent or proximate to the target tissue surface. The steering system may alternatively be incorporated into a separate guiding catheter as part of the catheter system.

Abstract: A device for cutting and retrieving tissue, including a handle having a tube, a first set of wires positioned within the tube and extending from the handle to distal ends, and a control tip secured to the distal ends. A second set of wires are positioned within the tube and extend from the handle, through a slot in the control tip, to coupled distal ends. A retaining pin is secured to the control tip, extends between at least two of the second set of wires, allows the second set of wires to be extended from the tube and through the control tip, and prevents the second set of wires from being withdrawn from the control tip and into the tube. The retaining pin also extends the second set of wires from the tube upon the first set of wires being extended from the tube.

Abstract: Ablation systems and methods for treating atrial fibrillation utilizing RF energy are provided. The system generally includes a first conductive member having a shape which defines a desired lesion pattern or a portion of a desired lesion pattern, and a second conductive member effective to transmit ablative radiation to the first conductive member. The first conductive member is adapted to be positioned on a first tissue surface, and the second conductive member is adapted to be positioned on a second, opposed tissue surface. In use, ablative radiation is transmitted from the second conductive member through the tissue to the first conductive member to form a lesion having the desired lesion pattern.

Abstract: A surgical instrument and method for facilitating the capture of objects during surgery are provided. The surgical instrument comprises a flexible tube having a proximal tube end and a distal tube end, the flexible tube defining a cable passageway and being configured for insertion of at least a distal portion of the flexible tube into a body cavity of a patient. The surgical instrument further comprises a flexible cable having a proximal cable end and a distal cable end. At least a portion of the flexible cable is slidably disposed in the cable passageway. A snare loop having a loop member is attached to the distal cable end. The snare loop and the cable are adapted so that the snare loop can be selectively retracted within the cable passageway by sliding the flexible cable proximally within the cable passageway.

Abstract: An electrically activated surgical device includes a probe body, an active element and a structure for selectively electrically insulating and/or physically isolating the active element from the patient's tissue when the device is in use. The probe body defines an outer surface, a proximal end, a distal end and a window defined within the outer surface near or at the distal end. The active element is electrically connected to a power source and is configured to selectively assume a non-deployed configuration and a variable deployed configuration in which the active element at least partially emerges from the window out of the probe body. The insulating structure selectively insulates the active element from the patient's tissue when the device is inserted therein.

Abstract: An electrosurgical instrument is provided for the treatment of tissue in the presence of an electrically-conductive fluid medium. The instrument comprises an instrument shaft (10), and a tissue treatment electrode (12) at the distal end of the shaft for electrosurgically excising tissue pieces at an operation site. The tissue treatment electrode (12) is cyclically movable relative to the distal end of the shaft (10). Threshold control means are provided for controlling the power threshold for vaporisation of the electrically-conductive fluid medium at the tissue treatment electrode (12).

Abstract: A system for recanalizing an occluded blood vessel including a centering catheter employed to center an ablative guide wire within the blood vessel as the guide wire traverses the occlusion. The centering catheter includes a catheter body with an operative lumen through which the ablative guide wire is slidingly disposed. The centering catheter further includes a distally disposed centering mechanism that, when activated, centers the ablative guide wire within the blood vessel as it traverses the occlusion. The centering mechanism can comprise various embodiments including a single inflatable balloon or segmented inflatable balloon, which is in fluid communication with an inflation lumen. An airless preparation lumen may be disposed within the inflation lumen for ease of centering catheter preparation. The ablative guide wire includes insulation that is preferably formed of heat shrink tubing, which is stretched prior or concurrently with the heating process.

Abstract: A suction assisted ablation device having a support surface, suction elements disposed adjacent the support surface, at least one electrode and at least one suction conduit is provided. The device may further include fluid openings, which allow fluid to irrigate target tissue and aid in ablation. A method for ablating tissue using suction is also provided.

Abstract: An electrosurgical instrument having a working end that utilizes a coagulation surface and a cutting surface that can be moved relative to each other and wherein only one of the two surfaces is electrically enabled depending on their relative positions. The user can then depress a switch to activate the electrically enabled surface.

Abstract: An ablation catheter including a probe, an electrode mounted on the probe so as to be movable relative thereto, a remote-operated actuator means for moving the electrode, an elongate conductor connected to the electrode and insulation provided around the conductor. The insulation can include a sleeve axially slidable on the probe, the elongate conductor extending longitudinally between the probe and the insulation sleeve and the insulation sleeve being retractable at least in part into a recess formed in a rearward portion of the probe.

Abstract: The invention provides a device and method for reducing or segmenting a large tissue mass in a body cavity during a minimally invasive surgery. This is accomplished with using a device that uses both mechanical and electro-surgical mechanisms by creating an electrical path between two electrodes through the tissue mass. The invention uses an isolation bag to insulate the electrical path created from the body cavity.

Abstract: A device for cutting and retrieving tissue, including a handle having a tube, a first set of wires positioned within the tube and extending from the handle to distal ends, and a control tip secured to the distal ends. A second set of wires are positioned within the tube and extend from the handle, through a slot in the control tip, to coupled distal ends. A retaining pin is secured to the control tip, extends between at least two of the second set of wires, allows the second set of wires to be extended from the tube and through the control tip, and prevents the second set of wires from being withdrawn from the control tip and into the tube. The retaining pin also extends the second set of wires from the tube upon the first set of wires being extended from the tube.

Abstract: A medical apparatus assembly (10) comprises a medical device (11) that includes a side port assembly 13 adapted to combine a first pathway (37) for infusion of fluids with a second pathway (38) for wire guide (12) into a first passageway (26) while the second passageway (27) includes the third pathway (39), which comprises a control member (24), such as an electrical wire. The side port assembly is configured such that the first passageway communicates with both a first port (16), such as a fitting for connecting to a syringe, and a second port (15) which includes a sealing mechanism (32), such as a Tuohy-Borst fitting, thereby allowing the wire guide to be preloaded, instead of requiring it to be removed prior to infusing fluids. Optionally, a third port (43) may be included when external communication with the second passageway, is desired, such as balloons or baskets.

Abstract: A surgical apparatus for removing a portion of tissue comprising an elongated body having a distal edge, a collapsible cutting member mounted to the elongated body, having an opening therethrough and extending distally of the distal edge of the elongated body. The cutting member has a closed loop conductive surface and is movable from a first loop configuration to a second smaller loop configuration, the exposed conductive distal edge forming an electrosurgical cutting surface for applying electrical energy to tissue. The cutting member resects a tubular region of tissue as the apparatus is advanced through tissue and the resected tissue extends through an opening in the cutting ring for containment within the elongated body.

Abstract: The present invention relates to a tissue ablation device assembly which is adapted to form a conduction block along a length of tissue between two predetermined locations along the left atrial wall. The assembly comprises an ablation element on an elongated ablation member that is coupled to each of two delivery members, wherein the delivery members are adapted to controllably position and secure the ablation element along the length of tissue between the predetermined locations. A linear lesion in the tissue between the predetermined locations is then formed by actuation of the ablation element. The invention further provides that the ablation member may slideably engage one or two delivery members such that an adjustable length of the ablation element along the ablation member may be extended externally from the engaged delivery member and along a length of tissue.

Abstract: The invention provides surgical systems and methods for ablating heart tissue within the interior and/or exterior of the heart. A plurality of probes is provided with each probe configured for introduction into the chest for engaging the heart. Each probe includes an elongated shaft having an elongated ablating surface of a predetermined shape. The elongated shaft and the elongated ablating surface of each probe are configured to ablate a portion of the heart. A sealing device affixed to the heart tissue forms a hemostatic seal between the probe and the penetration in the heart to inhibit blood loss therethrough.

Abstract: A device and procedure for performing resections and ablations, and more particularly for performing a partial ablation of the endometrium to treat uterine bleeding (menorrhagia), by which complications caused by “total” endometrial ablation or resection are avoided. The device includes a support member, a first conductor member supported with the support member and reciprocable relative to the support member, the first conductor member having an end that extends beyond the support member, a nonconducting member interconnecting the end of the first conductor member with the support member, and at least one flexible conductor member supported with the support member and interconnected with the end of the first conductor member. Retraction of the first conductor member relative to the support member causes the nonconducting member and the flexible conductor member to expand outward from the first conductor member in substantially opposite directions.

Abstract: An apparatus, method and kit are provided for removal of polyps, especially pursuant to colonoscopic surgery. The apparatus includes an endoscopic guide tube, a heating element, a power transmitting element traversing through the guide tube and communicating with the heating element, at least one temperature sensor for measuring temperature near the polyp, and optionally an external monitor for receiving temperature data from the sensor and then activating a power source for adjusting the temperature of the heating element in a controlled manner. An operator/physician can manually set the temperature range and temperature increase rate, but preferentially this is achieved automatically through a pre-programmed computer schedule.

Abstract: This invention relates broadly to surgical instruments. More particularly, this invention relates to a surgical snare instrument for excising polyps. Preferably, the instrument includes a coupling member that may increase ability to actuate the snare. According to a preferred embodiment, the present invention comprises a surgical instrument for insertion through an endoscope having a handle and a working channel, said surgical instrument including an elongate flexible tubular sheath having proximal and distal ends; a flexible shaft extending through and axially movable relative to the sheath, said shaft having proximal and distal ends; an end effector coupled to or formed at said distal end of said shaft; and a coupling member disposed at said distal end of said shaft.

Abstract: The invention provides surgical systems and methods for ablating heart tissue within the interior and/or exterior of the heart. A plurality of probes is provided with each probe configured for introduction into the chest for engaging the heart. Each probe includes an elongated shaft having an elongated ablating surface of a predetermined shape. The elongated shaft and the elongated ablating surface of each probe are configured to ablate a portion of the heart. A sealing device affixed to the heart tissue forms a hemostatic seal between the probe and the penetration in the heart to inhibit blood loss therethrough.

Abstract: A deflectable interstitial ablation device includes an elongated housing, an electrode mounted within the elongated housing, a driver coupled to the electrode, an imaging device integrally mounted within the elongated housing and a deflection system disposed within the elongated housing. The elongated housing has a proximal end, a distal end, and a deflectable segment. The electrode is deployable from a first position within the elongated housing to a second position a predetermined distance beyond the distal end of the elongated housing. The electrode further has a flexible portion capable of deflecting with the deflectable segment of the elongated housing, and can be deployed by the driver with a sufficient force such that penetration of the urethral wall occurs in a single motion. The imaging device further has a flexible portion capable of deflecting with the deflectable segment of the elongated housing.

Abstract: Method, system and apparatus for carrying out accurate electrosurgical cutting. A thin resilient electrode is utilized at the forward end region of an instrument which is deployable from a longitudinally disposed slot positioned rearwardly of the tip of the instrument. Lateral sides of the slot extend between a forward location adjacent the tip and a rearward location. The electrode is deployed by urging it forwardly in compression to form an arch profile supported by the abutting slot sides adjacent the forward and rearward locations. Electrosurgically excitable with a cutting output, the electrode may carry out a cutting action both during its deployment and retraction into the noted slot. This permits a pivoting maneuver effective for circumscribing a volume of targeted tissue.

Abstract: A transurethral needle ablation device for use by a human hand to treat the prostate of a human male. The device includes a cartridge assembly having an elongate probe member and a stylet. The elongate probe member has proximal and distal extremities and is provided with a passageway extending from the proximal extremity to the distal extremity. The stylet is slidably mounted in the passageway of the elongate probe member. A housing is included in the device. The cartridge assembly is removably mountable on the housing. An assembly adapted for actuation by the human hand is carried by the housing and coupled to the proximal extremity of the stylet for causing the distal extremity of the stylet to extend into the tissue of the prostate.

Abstract: A process for the treatment of atrial arrhythmia by use of ablation procedures comprising circumferential ablation of vessels, particularly pulmonary veins associated with the left atrium of the heart. Also disclosed are medical devices used for formation of the circumferential ablation lesions in vessels associated with the heart.

Abstract: An orthopedic apparatus, for effecting a change in ligaments, joint capsules and connective tissue through the controlled contraction of collagen fibers, includes a trocar. The trocar has a trocar elongated body with a trocar longitudinal axis, a trocar distal end that is laterally deflectable relative to the trocar longitudinal axis, and a trocar proximal end. An electrode is positioned at the trocar distal end. The electrode delivers substantially uniform energy across an energy delivery surface of the electrode. The energy delivery surface is positioned next to an area of collagen fibers to cause a controlled amount of contraction of the collagen fibers while minimizing dissociation and breakdown of the collagen fibers. A handle is positioned at the proximal end of the trocar. The handle includes an actuating member and a locking member.

Abstract: A device for ablating tissue is provided. The device comprises a conductive element with a channel for irrigating fluid formed therein, which is in contact with a non-conductive microporous interface. All or a portion of the interface may be removable. When the interface is removed, a portion of the conductive element is exposed for use in ablating tissue. Methods of using the device and of removing the interface are also provided.

Abstract: A catheter system and methods for repairing a valvular annulus or an annular organ structure of a patient comprising sandwiching and compressing the annulus and applying heat sufficient to shrink or tighten tissue surrounding the annulus defect.

Abstract: A multifilar flexible rotary shaft includes a plurality of individual filaments which are not wound around each other or around a central core, a loose ensemble of filaments. The input ends of each filament are coupled to each other and the output ends of each filament are coupled to each other. Preferably all of the filaments are identical. A loose ensemble of N filaments can transmit N times the torque of a single filament, and will have N times the torsional stiffness of a single filament, while retaining the minimum radius of operation of a single filament. Since a loose ensemble of filaments does not have any appreciable contact forces among the filaments (because they are not forcibly twisted together), there is no appreciable internal friction or hysteresis. In order to appreciably eliminate all the hysteresis in such an ensemble of filaments, the filaments should be no more than loosely twisted together, if at all.

Abstract: An endoscopic high-frequency knife is provided in which, on the external wall of a sheath, two grooves for exposing a knife wire to the external wall surface are formed along the longitudinal axis and are punched to be spaced from each other. In addition, a knife chip fixed along the longitudinal axis of the sheath is provided at the tip end portion of the knife wire. The knife wire has a guide arm section formed by bending a portion adjacent to the knife chip. The guide arm section is disposed at the tip end groove. The tip end of an exposed portion exposed to the external wall side is overhung laterally of the sheath longitudinal central plane passing through the two grooves and the knife chip.

Abstract: A tissue ablation device creates long linear lesions along a body space wall of an animal, and primarily between adjacent pulmonary vein ostia in a left atrial wall. An ablation element includes first and second ends that are bordered by first and second anchors. The anchors are adapted to secure the ablation element ends at predetermined first and second locations along the body space wall such that the ablation element is adapted to ablate an elongate region of tissue between those locations. The anchors may be guidewire tracking members, each including a bore adapted to receive and track over a guidewire, and may anchor within adjacent pulmonary vein ostia when the engaged guidewires are positioned within the respective veins. Stop members may be provided on the guidewires and may be adapted for positioning the relative anchors or for forcing the anchors to fit snugly within the vein ostia.

Abstract: A probe that facilitates the creation of circumferential lesions in bodily tissue. The probe includes a relatively short shaft and a loop-like structure that supports electrodes or other operative elements against the bodily tissue.

Abstract: An energy delivery system for performing myocardial revascularization on a heart of a patient including an energy pulse source that produces energy pulses sufficient to create channels in a wall of a heart, and an energy pulse delivery system connected to receive the energy pulses and deliver the energy pulses to desired locations for channels in the wall of the heart. Also disclosed are a sensor that senses a cyclical event related to the contraction and expansion of the beating heart; a controller responsive to the sensor for automatically firing the energy pulse system to provide energy to strike the beating heart only within a safe time period during a heart beat cycle; RF electrical or laser energy pulses; a temperature sensor to avoid damage caused by overheating adjacent heart tissue; a thermal conductivity cooling system; and programmably adjusting duty cycle, duration and amplitude of energy pulses.

Abstract: The transurethral dissection electrode has a shank and an electrode head located at the distal shank end. The electrode head essentially consists of at least one distally tapering truncated cone body with two oppositely lying flattenings.

Abstract: An apparatus and method for the thermal treatment of tissue, e.g., prostatic tissue, with RF energy is disclosed. The apparatus includes a handle dimensioned to be grasped with a single hand of a surgeon, an elongated portion extending distally from the handle and defining a longitudinal axis, at least one electrode extending within the elongated portion and movable between a non-deployed position and a fully deployed position, and a trigger mechanism associated with the handle and having a trigger operatively connected to the one electrode. The trigger is movable to selectively and incrementally move the one electrode between the non-deployed position and the fully deployed position. A ratchet mechanism permits movement of the trigger in one direction corresponding to movement of the one electrode toward the fully deployed position while preventing movement of the trigger in a second direction.

Abstract: A multifilar flexible rotary shaft includes a plurality of individual filaments which are not wound around each other or around a central core, a loose ensemble of filaments. The input ends of each filament are coupled to each other and the output ends of each filament are coupled to each other. Preferably all of the filaments are identical. A loose ensemble of N filaments can transmit N times the torque of a single filament, and will have N times the torsional stiffness of a single filament, while retaining the minimum radius of operation of a single filament. Since a loose ensemble of filaments does not have any appreciable contact forces among the filaments (because they are not forcibly twisted together), there is no appreciable internal friction or hysteresis. In order to appreciably eliminate all the hysteresis in such an ensemble of filaments, the filaments should be no more than loosely twisted together, if at all.

Abstract: Apparatuses and methods for removing solid tissue from beneath a tissue surface are described. The methods rely on positioning an energy conductive element at a target site beneath the tissue surface and energizing the element so that it can vaporize tissue. The element is then moved in a pattern which provides the desired tissue removal geometry, such as spherical, ovoid, or cylindrical. Usually, the shaft is moved, typically rotated or reciprocated, and the energy conductive element is moved relative to the shaft, typically by pivoting a rigid element or bowing a flexible element.

Abstract: An electrically activated surgical device includes a probe body, an active element and a structure for selectively electrically insulating and/or physically isolating the active element from the patient's tissue when the device is in use. The probe body defines an outer surface, a proximal end, a distal end and a window defined within the outer surface near or at the distal end. The active element is electrically connected to a power source and is configured to selectively assume a non-deployed configuration and a variable deployed configuration in which the active element at least partially emerges from the window out of the probe body. The insulating structure selectively insulates the active element from the patient's tissue when the device is inserted therein.

Abstract: The invention concerns a surgical instrument preferably for high-frequency surgery, which is designed for simple operation. For this purpose, by means of an operating device consisting of a movable handle and a grip handle, the housing 8 of the instruments of the electrode 5 moves longitudinally, through the motion of the thumb, so that the electrode 6 can be brought into working position or an APC mode can be selected. Through spring force, for instance, upon activation of a catch button or by setting aside the instrument, the electrode can automatically be retracted into the housing 8 or the housing 8 can be brought to a position surrounding the electrode 5.

Abstract: A cervical biopsy instrument comprises a shaft defining a longitudinal axis and having a proximal end and a distal end; an arm extending laterally from the shaft; a cutting portion of cutting wire being supported at an outer end by the arm and being inclined relative to the longitudinal axis; and means for adjusting and setting the inclination and/or length of the cutting portion. This enables a single instrument to deal effectively with differently-sized, shaped and positioned cervical lesions, while tailoring the profile of the excision to the lesion concerned.

Abstract: The invention provides surgical systems and methods for ablating heart tissue within the interior and/or exterior of the heart. A plurality of probes is provided with each probe configured for introduction into the chest for engaging the heart. Each probe includes an elongated shaft having an elongated ablating surface of a predetermined shape. The elongated shaft and the elongated ablating surface of each probe are configured to ablate a portion of the heart. A sealing device affixed to the heart tissue forms a hemostatic seal between the probe and the penetration in the heart to inhibit blood loss therethrough.

Abstract: A surgical instrument includes a body, a snare electrode, a spool and an electrical connector. A distal part of the body includes a passageway extending axially therethrough. The snare electrode is adapted to telescope in the passageway. The distal part of the body has an outward surface electrically insulated from the snare electrode. A second portion of the snare electrode is extendable from a second port of the passageway for forming a loop sized to be placed over tissue (e.g., portion(s) of the uterus and/or kidney(s), spleen, pancreas, gallbladder, remnant from the liver, and/or vascular aneurysm) to be removed from a patient. The spool is rotatably supported in a proximal part of the body. A first portion of the snare electrode is windable about the spool. A rotation of the spool in a winding direction causes retraction of the first portion of the snare electrode from a first port of the passageway, thereby closing the loop to engage the tissue.

Abstract: This is a tool used during open heart or open chest surgery for creating lesions or lines of ablation in tissue to treat atrial fibrillation. It is a relatively short device having a rigid or semi-rigid shaft connected on one end to a handle and on the other end to a more flexible distal tip having one or more electrodes. The distal end of the shaft is angled so to define a first plane of deflection. A deflection mechanism consisting of a pull wire and flat spring housed in a lumen of the tool is manipulable via the handle for deflecting the distal tip in a plane different than the first plane of deflection, allowing direct contact with the curved surface of the tissue, either epicardial or endocardial, to be ablated. The tool may contain fiber optic or other data lines for transmitting data relevant to the patient, and it may be irrigated to cool the tool and the electrodes or to deliver therapeutic fluids to tissue.

Abstract: A hood for an endoscope has a cap part detachably mounted on the end portion of the insertion part of an endoscope. An opening communicates with the inside of the cap part, at the end of a flexible tube connected to the opening. Into the flexible tube, such an endoscopic treating instrument as a high frequency snare is inserted.

Abstract: A medical device is disclosed which includes a deformable electrode device. In one illustrative embodiment, the deformable electrode is in the form of a braided member, at least a portion of which is electrically conductive. The braided member is extended over an elongated inner member, such as a guide wire, catheter shaft, or the like. A proximal sheath is slidably extended over the inner member and is connected to the braided, electrically conductive member. The proximal sheath may be advanced distally to deform the braided member so that it defines a distally facing, ablative ring, and is operative to form an annular lesion.

Abstract: The invention provides apparatus and methods for mapping conduction pathways and creating lesions in the heart wall for the treatment of atrial fibrillation. The apparatus may include at least one epicardial ablation probe having a plurality of electrodes for creating a lesion. The apparatus and method facilitate the formation of a lesion which electrically isolates the pulmonary veins from the surrounding myocardium.

Abstract: The invention provides apparatus and methods for mapping conduction pathways and creating lesions in the heart wall for the treatment of atrial fibrillation. The apparatus may include at least one epicardial ablation probe having a plurality of electrodes for creating a lesion. The apparatus and method facilitate the formation of a lesion which electrically isolates the pulmonary veins from the surrounding myocardium.

Abstract: A device and method for treatment of a tissue specimen disposed in surrounding tissue has a tissue specimen isolating tool and a tissue specimen damager. The tissue specimen isolating tool isolates the tissue specimen from the surrounding tissue. The tissue specimen damager damages the tissue, with a possible end result being necrosis. The severing tool may have a cutting member that is extendable to an outwardly radially bowed position about device. The tissue specimen is isolated by rotating the cutting member about the tissue specimen. The cutting member may be functionally connected to a cutting member radio frequency generation source. The tissue specimen damager may damage the tissue specimen using ionizing radiation, cutting devices, thermal treatment devices, chemical treatment devices, or sealing an outer boundary of the tissue specimen.

Abstract: A device for localizing a target tissue mass in a body includes a tubular trocar portion having a distal end and a proximal end portion that is removably attachable to a handle portion. The trocar portion contains at least a first plurality of locator wires that are movable between a retracted position within the trocar and a deployed position extending radially from the trocar. In a preferred embodiment, the trocar portion has an electrosurgical cutting element at its distal end, and first and second pluralities of locator wires that, when deployed, respectively define first and second locating perimeters. The first plurality of locator wires is connected to a first wire carrying member longitudinally mounted for axial movement within the trocar portion between a proximal position corresponding to the retracted position of the first plurality of locator wires, and a distal position corresponding to the deployed position of the first plurality of locator wires.