Abstract: Blood loss during solid organ surgery where diseased tissue is removed from the solid organ by delivery of thermal energy by one or more probes. The blood loss is stemmed by effecting coagulative necrosis of solid organ in the zone adjacent the probe(s). The or each probe can have means for cooling tissue in the vicinity of the tip of the probe. The method can be applied, inter alia, to liver and spleen surgery.

Abstract: An enhanced method and device are provided to treat atrial fibrillation or inhibit or reduce restenosis following angioplasty or stent placement. A balloon-tipped catheter is disposed in the area treated or opened through balloon angioplasty immediately following angioplasty. The balloon, which can have a dual balloon structure, may be delivered through a guiding catheter and over a guidewire already in place. A fluid such as a perfluorocarbon flows into the balloon to freeze the tissue adjacent the balloon, this cooling being associated with reduction of restenosis. A similar catheter may be used to reduce atrial fibrillation by inserting and inflating the balloon such that an exterior surface of the balloon contacts at least a partial circumference of the portion of the pulmonary vein adjacent the left atrium. In another embodiment, blood perfusion is performed simultaneously.

Abstract: Techniques and devices for treating atherosclerotic disease use controlled cryogenic cooling, often in combination with angioplasty and/or stenting. A combination cryogenic/angioplasty catheter may cool the diseased blood vessel before, during, and/or after dilation. Controlled cooling of the vessel wall reduces actual/observed hyperplasia as compared to conventional uncooled angioplasty. Similar reductions in restenosis may be provided for other primary treatments of the blood vessel, including directional arthrectomy, rotational arthrectomy, laser angioplasty, stenting, and the like. Cooling of vessel wall tissues will often be performed through plaque, and the cooling process will preferably take the thermodynamic effects of the plaque into account.

Abstract: A volumetric tissue ablation apparatus includes a probe having a plurality of wires journaled through a catheter with a proximal end connected to the active terminal of a generator and a distal end projecting from a distal end of the catheter. The probe wire distal ends are arranged in an array with the distal ends located generally radially and uniformly spaced-apart from the catheter distal end. A conductor connected to the return terminal of the generator is located relative to the probe wire array to form a closed electrical circuit through tissue to be ablated. Preferably, the probe wire array includes 10 wires, each formed in an arch from the catheter distal end. The conductor can be either a conventional ground plate upon which the tissue is supported, or a conductor wire extending through the probe and electrically insulated from the probe wires.

Abstract: A system for treating a target region in tissue beneath a tissue surface comprises a probe for deploying an electrode array within the tissue and a surface electrode for engaging the tissue surface above the treatment site. Preferably, surface electrode includes a plurality of tissue-penetrating elements which advance into the tissue, and the surface electrode is removably attachable to the probe. The tissue may be treated in a monopolar fashion where the electrode array and surface electrode are attached to a common pole on an electrode surgical power supply and powered simultaneously or successively, or in a bipolar fashion where the electrode array and surface electrode are attached to opposite poles of the power supply. The systems are particularly useful for treating tumors and other tissue treatment regions which lie near the surface.

Abstract: The present invention provides systems and methods for selectively applying electrical energy to a fissure or tear location within an invertebral disc. The present invention applies high frequency (RF) electrical energy to one or more active electrodes in the presence of electrically conductive fluid to heat and seal a fissure on an annulus fibrosus. In one aspect of the invention, a method is provided for treating the fissure by applying sufficient electrical energy to the disc tissue to seal the fissure. In one embodiment, the RF energy is directed through the conductive fluid to heat the tissue immediately surrounding the fissure. The RF energy is sufficient to vaporize at least a portion of the fluid in contact with the active electrode. In another embodiment, the electrical current is directed through the tissue to directly heat the annulus tissue. This causes the annulus tissue to contract and seal the fissure. In a specific configuration, a sealant is added to the fissure to enhance the seal.

Abstract: The invention provides a method for substantially reducing the size of a thrombus in a blood vessel in which blood is flowing. The method includes delivering a heat transfer element to a blood vessel in fluid communication with a thrombosed blood vessel. The temperature of the heat transfer element is adjusted such that the same is sufficient to remove heat from the flowing blood. Heat is transferred from a volume including the thrombus to the heat transfer element. In a separate embodiment, heat may be delivered to the volume including the thrombus from the heat transfer element. The resultant temperature of the volume may be sufficient to substantially reduce the size of a thrombus. For example, the resultant temperature of the volume may be sufficiently high to substantially enhance plasminogen activation near the thrombus.

Abstract: Systems, apparatus and methods for ablation, resection, aspiration, collagen shrinkage and/or hemostasis of tissue and other body structures in open and endoscopic spine surgery. In particular, the present invention includes a channeling technique in which small holes or channels are formed within spinal discs, and thermal energy is applied to the tissue surface immediately surrounding these holes or channels to cause thermal damage to the tissue surface, thereby stiffening the surrounding tissue structure and for reducing the volume of the disc to relieve pressure on the surrounding nerves. High frequency voltage is applied between one or more active electrode(s) and one or more return electrode(s) to volumetrically remove or ablate at least a portion of the disc tissue, and the active electrode(s) are advanced through the space left by the ablated tissue to form a channel, hole, divot or other space in the disc tissue.

Abstract: The present invention provides systems and methods for selectively applying electrical energy to a target location within a patient's body, particularly including tissue in the spine. The present invention applies high frequency (RF) electrical energy to one or more electrode terminals in the presence of electrically conductive fluid to contract collagen fibers within the tissue structures. In one aspect of the invention, a system and method is provided for treating herniated or swollen discs within a patient's spine by applying sufficient electrical energy to the disc tissue to contract or shrink the collagen fibers within the nucleus pulposis. This causes the pulposis to shrink and withdraw from its impingement on the spinal nerve.

Abstract: Systems, apparatus and methods for ablation, resection, aspiration, collagen shrinkage and/or hemostasis of tissue and other body structures in open and endoscopic spine surgery. In particular, the present invention includes a channeling technique in which small holes or channels are formed within spinal discs, and thermal energy is applied to the tissue surface immediately surrounding these holes or channels to cause thermal damage to the tissue surface, thereby stiffening the surrounding tissue structure and for reducing the volume of the disc to relieve pressure on the surrounding nerves. High frequency voltage is applied between one or more active electrode(s) and one or more return electrode(s) to volumetrically remove or ablate at least a portion of the disc tissue, and the active electrode(s) are advanced through the space left by the ablated tissue to form a channel, hole, divot or other space in the disc tissue.

Abstract: A catheter includes a plurality of primary leads to deliver energy for ligating a hollow anatomical structure. Each of the primary leads includes an electrode located at the working end of the catheter. Separation is maintained between the primary leads such that each primary lead can individually receive power of selected polarity. The primary leads are constructed to expand outwardly to place the electrodes into apposition with a hollow anatomical structure. High frequency energy can be applied from the leads to create a heating effect in the surrounding tissue of the anatomical structure. The diameter of the hollow anatomical structure is reduced by the heating effect, and the electrodes of the primary leads are moved closer to one another. Where the hollow anatomical structure is a vein, energy is applied until the diameter of the vein is reduced to the point where the vein is occluded. In one embodiment, a balloon is inflated to occlude the structure before the application of energy.

Abstract: Systems and methods are provided for removing adipose or fatty tissue underlying a patient's epidermis is disclosed (e.g., liposuction, abdominoplasty, and the like). The method includes positioning one or more active electrode(s) and one or more return electrode(s) in close proximity to a target region of fatty tissue. A high frequency voltage difference is applied between the active and return electrodes, and the fatty tissue or fragments of the fatty tissue are aspirated from the target region. The high frequency voltage either softens the fatty tissue or completely removes at least a portion of the tissue. In both embodiments, the remaining fatty tissue is more readily detached from the adjacent tissue in the absence of energy, and less mechanical force is required for removal. The bipolar configuration of the present invention controls the flow of current to the immediate region around the distal end of the probe, which minimizes tissue necrosis and the conduction of current through the patient.

Abstract: A catheter having an elongate shaft including a proximal and a distal end. The shaft includes a conductor. An electrode is disposed at the distal end of the shaft and is connected to the conductor. The electrode has a generally annular, cross-sectional shape. The annular shape defines an opening within the electrode. An insulator surrounds the conductor. In accordance with the method of the present invention, a crater wound can be formed through the endocardium and into the myocardium of a patient's heart. Collateral damage to the myocardium can be made by infusing pressurized fluid into the crater wound.

Abstract: A kit for establishing and maintaining hypothermia in a patient for neurotherapeutic purposes includes a high cooling capacity catheter that is advanced into the patient's central venous system to quickly cool the patient to, e.g., 32° C. or so. Once hypothermia has been established, the high capacity catheter is removed and replaced with a lower cooling capacity catheter which maintains a desired reduced temperature. The lower capacity catheter advantageously can be configured as a central venous catheter for permitting the catheter to be used for multiple functions. Alternatively, the high cooling capacity catheter can be used to attenuate a fever and lower the patient's body temperature to normal, with the lower capacity catheter being used to maintain normal body temperature.

Abstract: The invention relates generally to methods of treating cancer and other diseases by modulating body temperature. Heat may directed to the hypothalamus of a warm-blooded animal to cool the animal, utilizing the physiological mechanisms that regulate body temperature to effect a compensatory cooling response, thereby lowering body temperature (hypothermia), and rendering other methods of lowering body temperature more effective. Heat may be withdrawn from the hypothalamus of an animal, cooling the hypothalamus, inducing a compensatory increase in body temperature (hyperthermia), and rendering other methods of raising body temperature more effective. Body temperature may be directly modulated by heat-exchange catheter positioned within a blood vessel of a patient.

Abstract: A volumetric tissue ablation apparatus includes a probe having a plurality of wires journaled through a catheter with a proximal end connected to the active terminal of a generator and a distal end projecting from a distal end of the catheter. The probe wire distal ends are arranged in an array with the distal ends located generally radially and uniformly spaced-apart from the catheter distal end. A conductor connected to the return terminal of the generator is located relative to the probe wire array to form a closed electrical circuit through tissue to be ablated. Preferably, the probe wire array includes 10 wires, each formed in an arch from the catheter distal end. The conductor can be either a conventional ground plate upon which the tissue is supported, or a conductor wire extending through the probe and electrically insulated from the probe wires.

Abstract: A kit for establishing and maintaining hypothermia in a patient for neurotherapeutic purposes includes a high cooling capacity catheter that is advanced into the patient's central venous system to quickly cool the patient to, e.g., 32° C. or so. Once hypothermia has been established, the high capacity catheter is removed and replaced with a lower cooling capacity catheter which maintains a desired reduced temperature. The lower capacity catheter advantageously can be configured as a central venous catheter for permitting the catheter to be used for multiple functions. Alternatively, the high cooling capacity catheter can be used to attenuate a fever and lower the patient's body temperature to normal, with the lower capacity catheter being used to maintain normal body temperature.

Abstract: A method is disclosed for treating brain tissue with cryotreatment. A surgical tool, such as a catheter is disposed proximate to a target region of brain tissue. The tool or catheter provided includes a cryotreatment element. The cryotreatment element may be a cryochamber for enclosing the flow of a fluid refrigerant therein. The cryotreatment element is disposed at the situs of brain tissue to be treated, either through endovascular insertion, or via an opening in the cranium. A refrigerant flow within the cryochamber creates endothermic cooling with respect to the surrounding brain tissue, inducing hypothermia and forming iceballs proximate said tissue. The cooling may be reversible and non-permanent, or may be permanent leading to cell death, necrosis, apoptosis and/or surgical excision or ablation of tissue.

Abstract: A device and method for providing body cooling for treating fever. The cooling device applies cooling to blood flowing in a vein or artery, e.g., the vena cavae, that is then distributed throughout the body.

Abstract: Relief of urethral obstruction is achieved by heat ablation of prostatic tissue by an ablation instrument passed within the urethra to a position in the prostate near the point of urethral obstruction. An electrode is coupled to a high-frequency power supply to ablatively heat the urethra and the prostatic tissue near the urethra. Guidance of the electrode placement may be monitored by an imaging device. The instrument may consist of a catheter with an inflatable balloon structure for positioning the instrument. The temperature of the tissue may be sensed at the electrode to control the high-frequency heating energy and ablation process.

Abstract: An ablation system for ablating cardiac tissue within a chamber of the human heart including a guiding introducer system, a rail, one end of which is contained within the guiding introducer system, and an ablation catheter system which is supported by the guiding introducer system. The guiding introducer system may be a single or multiple guiding introducers. The ablation system may include a slotted sheath which passes over the rail which supports the ablation catheter. A process is disclosed for ablation of cardiac tissue to form a linear lesion utilizing a rail catheter ablation and mapping system which includes a guiding introducer, a rail and an ablation catheter system advanced over the rail.

Abstract: A device for thermally affecting tissue having a thermally transmissive contact member being in thermal communication with a thermal member and a surface area expansion element configured for contacting a tissue. The contact member and thermal member are disposed within a housing and the surface area expansion element is coupleable to the housing. The housing is configured to fit within an opening in a skull.

Abstract: Relief of urethral obstruction is achieved by heat ablation of prostatic tissue by an ablation electrode passed within the urethra to a position in the prostate near the point of urethral obstruction. The electrode is coupled to a high frequency power supply to ablatively heat the urethra and the prostatic tissue near the urethra. Image guidance of the electrode placement is monitored by an imaging device. The temperature of the tissue is sensed at the electrode to control the high frequency heating energy and ablation process. The electrode has a blunt tip to help prevent piercing of the wall of the urethra during insertion of the electrode into the urethra through the penis and the positioning of the electrode tip near to the point of urethral obstruction. Several forms of electrodes, apparatus, and methods accommodate the specific objectives.

Abstract: A heat exchange catheter has a catheter body with an inflow lumen, an outflow lumen, and an infusion lumen. A first heat exchange balloon helically wraps around at least a portion of the catheter body in fluid communication with the inflow lumen. A second heat exchange balloon helically wraps around at least a portion of the catheter body in fluid communication with the outflow lumen. The first and second balloons form a gap there between to facilitate infusion of fluid into the blood stream of the patient via an infusion port formed within the gap.

Abstract: The invention provides a single-use, disposable circulation set for a heat transfer catheter.

Abstract: A method and apparatus for lowering the body temperature of a patient while reducing shivering by using a heat exchange device in combination with an &agr;2-adrenoreceptor agonist, a non-opiod analgesic monoamine uptake inhibitor or neuropeptide that temporarily reduces shivering. The devices disclosed include a catheter having a heat exchange balloon thereon with heat exchange fluid circulating through the interior of the balloon. The heat exchange balloon is placed in the vasculature of a patient, and heat exchange fluid at a temperature other than the temperature of the blood in the vasculature is circulated through the interior of the balloon to add or remove heat from the blood of the patient. Various &agr;2-adrenoreceptor agonist&agr;2-adrenoreceptor agonists, non-opiod analgesic monoamine uptake inhibitors and neuropeptides are disclosed including dexmedetomidine, nepofam and neurotensin and pharmaceutically acceptable salts thereof.

Abstract: A catheter assembly for treatment of cardiac arrhythmia. The catheter assembly includes a catheter body and an ablative energy source. The catheter body includes a proximal portion, an intermediate portion, and a distal portion. The intermediate portion extends from the proximal portion and defines a longitudinal axis. The distal portion extends from the intermediate portion and includes an ablation section and a tip. The ablation section forms a loop defining a diameter greater than an outer dimension of a pulmonary vein ostium. The tip extends distally from the ablation section and is configured to locate a pulmonary vein. Finally, the ablative energy source is associated with the ablation section. With this configuration, upon activation of the energy source, the ablation section ablates a desired lesion pattern. In one preferred embodiment, the ablation section forms a distally decreasing radius helix, whereas the tip includes a relatively linear leader section.

Abstract: The present invention provides systems and methods for selectively applying electrical energy to a target location within the head and neck of a patient's body, particularly including tissue in the ear, nose and throat. The present invention includes a channeling technique in which small holes or channels are formed within tissue structures in the mouth, such as the tonsils, tongue, palate and uvula, and thermal energy is applied to the tissue surface immediately surrounding these holes or channels to cause thermal damage to the tissue surface, thereby stiffening the surrounding tissue structure. Applicant has discovered that such stiffening of certain tissue structures in the mouth and throat helps to prevent the tissue structure from obstructing the patient's upper airway during sleep.

Abstract: Electrode assemblies and associated systems employ a nonporous wall having an exterior for contacting tissue. The exterior peripherally surrounds an interior area. The wall is essentially free of electrically conductive material. The wall is adapted to assume an expanded geometry having a first maximum diameter and a collapsed geometry having a second maximum diameter less than the first maximum diameter. The assemblies and systems include a lumen that conveys a medium containing ions into the interior area. An element free of physical contact with the wall couples the medium within the interior area to a source of electrical energy to enable ionic transport of electrical energy from the source through the medium to the wall for capacitive coupling to tissue contacting the exterior of the wall.

Abstract: An apparatus to modify a stomach wall comprises an elongated member including at least one lumen. A deployable member is coupled to the elongated member. The deployable member is configured to be advanceable and removable from the stomach in a non-deployed state and sized to be positioned in the stomach in a deployed state to engage at least portions of the stomach wall. The deployable member is further configured to house a fluidic media and at least portions of the deployable member wall is configured to be cooled by the fluidic media. The deployable member has a contour in the deployed state approximating at least a portion of a stomach. A microwave antenna is movably positioned in the deployable member so as to control a microwave field strength vector in relation to the antenna.

Abstract: A dual mode transurethral warming apparatus particularly adapted to treat benign prostatic hyperplasia includes a urethral catheter dimensioned for insertia through the urethra. The catheter includes an elongated flexible tube having a plurality of longitudinal lumens extending between the ends of the tube. A coaxial cable extends along one of the lumens to an antenna in the form of a multi-turn helical winding wound around the outside of the tube. A first connector connects one of the cable conductors to one end of the winding and a second connector connects the other cable conductor to the other end of the winding so that the antenna formed by the winding is larger in diameter than the cable, and all of the lumens are located within the winding. The cable is connected to a control and display unit which includes a transmitter which provides electromagnetic energy via the cable to the antenna so that the antenna generates an electromagnetic field sufficient to treat tissue adjacent the antenna.

Abstract: A method of tumor ablation using injectable thermal-sensing balls. A catheter system (115) is used to inject a slurry (134) of thermal-sensing balls (136) into a tumor (122) located in, for example, a liver (120). The catheter system (115) comprises a catheter (128) and a specialized syringe (129) consisting of a housing (130) and a plunger (132). The housing (130) includes a cylindrical chamber having the slurry (134) of thermal-sensing balls (136). The catheter (128) is inserted retrograde into the femoral artery and passed to the site of the tumor (122). The hepatic artery (124) branches into smaller vessels, one of which is a tumor artery (126) which feeds the tumor (122). The tip of the catheter (128) is placed in the tumor artery (126) guided by conventional fluoroscopy. The injected balls (136) then receive energy from an external control system (110). The system (110) comprises a control panel (114) as an operator interface for controlling the system (110) and reading data therefrom.

Abstract: The present invention relates to devices and methods for altering the tissue in and around an intervertebral disc through localized hypothermia therapy to restore function of the disc and reduce pain. Hypothermia therapy is defined as the reduction of tissue temperature to below that of the equilibrium temperature. Target therapeutic temperatures and times are varied according to the desired treatment effect. Intended effects of hypothermia of the intervertebral disc include cellular disruption leading to cell death and or structural and chemical denaturation within the anulus fibrosus, nucleus pulposus, or nerve fibers, temporary or permanent deadening of the nerves within or surrounding the disc, induction of a healing response, angiogenesis, or accelerated degeneration and/or drying of the nucleus pulposus and/or anulus fibrosus. Various effects can be achieved by reaching different temperatures for differing periods of time or by the proximity of the hypothermia therapy device to the treatment target.

Abstract: An indwelling RF catheter achieves warming of patients by dielectric heating of blood or other bodily fluids. In one example, the catheter is deployed in a suitable blood vessel, such as the inferior vena cava. The catheter design includes an emitter structure electrically coupled to an RF generator, which provides a source of RF power. The emitter structure, distally located upon the catheter, administers electromagnetic radiation to the blood within the patient, thereby creating heat due to the dielectric qualities of blood. As blood heated by the indwelling RF catheter courses through the patient's body, the patient's body is systemically warmed, raising the body core temperature.

Abstract: A catheter system and method are provided which change the temperature of a fluid, such as blood, by heat transfer. Selective cooling or heating of an organ may be performed by changing the temperature of the blood feeding the organ. The catheter system includes an inlet lumen and an outlet lumen structured and arranged to carry a working fluid having a temperature different from the adjacent blood. The outlet lumen is configured to induce turbulence in the adjacent fluid passing adjacent the outlet lumen.

Abstract: A warming catheter for use during cryosurgical ablation of the prostate having a warming section with diffuser ports promoting even warming of the prostatic urethra; the warming catheter is also provided with a short monorail lumen, monorail tip lumen, or a full length monorail lumen.

Abstract: An apparatus is provided for ablating at least a portion of a nasal concha. By ablating at least a portion of a nasal concha, the size of the nasal concha is reduced. The three nasal concha in the body (inferior, middle and superior nasal concha) form at least a portion of the three nasal meatus (inferior, middle and superior nasal meatus) in the body. By reducing the size of a nasal concha, obstruction of a nasal meatus is reduced or eliminated. As a result, air flow through the nasal meatus is improved.

Abstract: The invention provides a method and device for selectively controlling the temperature of a selected organ of a patient for performance of a specified application. The method includes introducing a guide catheter into a blood vessel. The guide catheter may have a soft tip and a retaining flange, and may be used to provide treatments such as administration of thrombolytic drug therapies, stenting procedures, angiographic procedures, etc. A supply tube is provided having a heat transfer element attached to a distal end thereof. The heat transfer element having a plurality of exterior surface irregularities, these surface irregularities having a depth greater than the boundary layer thickness of flow in the feeding artery of the selected organ. The supply tube and heat transfer element may be inserted through the guide catheter to place the heat transfer element in the feeding artery of the selected organ.

Abstract: A catheter system and method are provided which change the temperature of a fluid, such as blood, by heat transfer. Selective cooling or heating of an organ may be performed by changing the temperature of the blood feeding the organ. The catheter system includes an inlet lumen and an outlet lumen structured and arranged to carry a working fluid having a temperature different from the adjacent blood. The outlet lumen is configured to induce turbulence in the adjacent fluid passing adjacent the outlet lumen.

Abstract: A method and expandable device for thermally affecting tissue in which there is a fluid conduit. An expandable element includes a wall defining an inner volume. The wall has a tissue contact region which is non-coaxial with the longitudinal axis of the fluid conduit. The tissue contact region is operable to have a first contact surface area and a second contact surface area in which the second contact surface area is larger than the first contact surface area. A port is formed through the wall and is in fluid communication with the fluid conduit.

Abstract: An electrosurgical probe (10) comprises a shaft (13) having an electrode array (58) at its distal end and a connector (19) at its proximal end for coupling the electrode array to a high frequency power supply (28). The shaft includes a return electrode (56) recessed from its distal end and enclosed within an insulating jacket (18). The return electrode defines an inner passage (83) electrically connected to both the return electrode and the electrode array for passage of an electrically conducting liquid (50). By applying high frequency voltage to the electrode array and the return electrode, the electrically conducting liquid generates a current flow path between the return electrode and the electrode array so that target tissue may be cut or ablated. The probe is particularly useful in dry environments, such as the mouth or abdominal cavity, because the electrically conducting liquid provides the necessary return current path between the active and return electrodes.

Abstract: A catheter is adapted to exchange heat with a body fluid, such as blood, flowing in a body conduit, such as a blood vessel. The catheter includes a shaft with a heat exchange region disposed at its distal end. This region may include at least one balloon which is adapted to receive a remotely cooled heat exchange fluid preferably flowing in a direction counter to that of the body fluid. Embodiments including multiple balloons enhance the surface area of contact, and the mixing of both the heat exchange and the body fluid. The catheter can be positioned to produce hypothermia in a selective area of the body without cooling the entire body system. It is of particular advantage in brain surgeries where stroke, trauma or cryogenic tumors can best be addressed under hypothermic conditions.

Abstract: A catheter having an elongate shaft including a proximal and a distal end. The shaft includes a conductor. An electrode is disposed at the distal end of the shaft and is connected to the conductor. The electrode has a generally annular, cross-sectional shape. The annular shape defines an opening within the electrode. An insulator surrounds the conductor. In accordance with the method of the present invention, a crater wound can be formed through the endocardium and into the myocardium of a patient's heart. Collateral damage to the myocardium can be made by infusing pressurized fluid into the crater wound.

Abstract: An electrosurgical probe (10) comprises a shaft (13) having an electrode array (58) at its distal end and a connector (19) at its proximal end for coupling the electrode array to a high frequency power supply (28). The shaft includes a return electrode (56) recessed from its distal end and enclosed within an insulating jacket (18). The return electrode defines an inner passage (83) electrically connected to both the return electrode and the electrode array for passage of an electrically conducting liquid (50). By applying high frequency voltage to the electrode array and the return electrode, the electrically conducting liquid generates a current flow path between the return electrode and the electrode array so that target tissue may be cut or ablated. The probe is particularly useful in dry environments, such as the mouth or abdominal cavity, because the electrically conducting liquid provides the necessary return current path between the active and return electrodes.

Abstract: Devices and methods are provided for creating lesions in endocardial tissues surrounding a vessel opening to thereby isolate focal arrhythmia substrates, including an invasive catheter assembly comprising an elongate body having a longitudinal axis and first and second lumens, a first catheter having a distally mounted expandable anchor body disposed in the first lumen, and a second catheter having a distally mounted electrode disposed in the second lumen, the elongate body having a first distal opening accessing the first lumen through which the first catheter may be extended axially relative to the longitudinal axis of the elongate body and a second distal opening accessing the second lumen through which the second catheter may be extended at an angle relative to the longitudinal axis of the elongate body.

Abstract: A catheter is adapted to exchange heat with a body fluid, such as blood, flowing in a body conduit, such as a blood vessel. The catheter includes a shaft with a heat exchange region disposed at its distal end. This region may include at least one balloon which is adapted to receive a remotely cooled heat exchange fluid preferably flowing in a direction counter to that of the body fluid. Embodiments including multiple balloons enhance the surface area of contact, and the mixing of both the heat exchange and the body fluid. The catheter can be positioned to produce hypothermia in a selective area of the body without cooling the entire body system. It is of particular advantage in brain surgeries where stroke, trauma or cryogenic tumors can best be addressed under hypothermic conditions.

Abstract: Methods and apparatus are provided for thermally affecting tissue via either a closed or open device. In each of the closed device embodiments, thermally transmissive fluid is circulated and distributed through into a device, an outer surface of which is in direct thermal contact with a region of tissue to thermally affect the tissue. In each of the open device embodiments, thermally transmissive fluid is circulated through a device and systematically deployed directly onto a region of tissue to irrigate, and, therefore, thermally affect the tissue.

Abstract: Electrode assemblies actively cool mucosal surface tissue at or near a sphincter while applying energy through an electrode to ohmically heat tissue beneath the surface. The applied energy creates one or more lesions, or a prescribed pattern of lesions, below the mucosal surface. Natural healing of the subsurface lesions leads to a physical tightening of the sphincter and/or adjoining tissue to treat sphincter dysfunction. The active surface cooling preserves and protects the mucosal surface against thermal damage. Furthermore, electrode assemblies can deliver a therapeutic material to the tissue region independent of or as an adjunct to lesion formation. The therapeutic material can comprise, e.g., a tissue ablating chemical; or a drug, such as a tissue growth factor, or a fibrosis inducer, or a fibroblast growth factor, or a sclerosant; or a tissue bulking agent; or an exotoxin.

Abstract: The invention provides a method and apparatus for producing reversible focal hypothermia of the nervous system to control chronic pain. Nerve conduction is blocked by mild cooling (0 to 25° C.), or hypothermia. At these temperatures, nerve tissue is not destroyed and recovers completely when cooling is terminated, such that the treatment is reversible. By blocking conduction in pain nerves, pain sensation is eliminated in a manner analogous to drugs such as lidocaine that also block nerve conduction to provide anesthesia. The invention can be applied to a variety of conditions such as urge incontinence, muscle spasticity, and epilepsy. Many of these disorders are mediated by nerve and nervous tissue that could be interrupted by cooling. In addition, neurologic dysfunction found in multiple sclerosis may improve by cooling of the nerves. The method and apparatus may be used to cool areas of the nervous system affected by multiple sclerosis to allow more normal functions.

Abstract: A central venous catheter includes coolant supply and return lumens which communicate coolant to and from first and second heat exchange membranes arranged along the distal segment of the catheter. The coolant in the heat exchange membranes removes heat from the patient. Additional lumens are provided for conventional central venous catheter uses.