Abstract: A tissue protective system and method having particular application in thermoablative surgical therapies where heat or cold is used to create a kill zone for treating cancer cells as well as malignant or benign tumors in a targeted internal tissue area (e.g., the prostate) of a patient while sparing an adjacent benign internal tissue area (e.g., a neurovascular bundle). One of a hollow sheath or a balloon that is carried by a balloon catheter is located within an access opening that is made by a needle trocar inserted between the targeted tissue area in need of treatment and the benign tissue area to be protected in order to hold the protected tissue area off the targeted tissue area and away from the lethal temperature of the kill zone. The balloon of the balloon catheter is inflated in the access opening via a balloon channel which runs longitudinally through the catheter. At least one temperature sensor is mounted on the balloon and responsive to the temperature near the benign tissue area to be protected.

Abstract: A closed loop heat exchange catheter can be placed in a patient suffering from cardiac arrest or myocardial infarction to cool the patient. Or, a heat exchange pad can be placed against the patient's skin to cool the patient. Magnesium sulfate is infused into the patient.

Abstract: Embodiments of the invention provide a system for temperature control of the human body. The system includes an indwelling catheter with a tip-mounted heat transfer element. The catheter is fluidically coupled to a console that provides a heated or cooled heat transfer working fluid to exchange heat with the heat transfer element, thereby heating or cooling blood. The heated or cooled blood then heats or cools the patient's body or a selected portion thereof. In particular, strategies for providing cooling while reducing shivering are disclosed, including administration of various drugs and drug combinations.

Abstract: Systems for phase-change particulate slurry cooling equipment and methods to induce hypothermia in a patient through internal and external cooling are provided. Subcutaneous, intravascular, intraperitoneal, gastrointestinal, and lung methods of cooling are carried out using saline ice slurries or other phase-change slurries compatible with human tissue. Perfluorocarbon slurries or other slurry types compatible with human tissue are used for pulmonary cooling. And traditional external cooling methods are improved by utilizing phase-change slurry materials in cooling caps and torso blankets.

Abstract: An ablation catheter having a catheter shaft and a virtual electrode, the virtual electrode comprising portholes through an outer peripheral wall of the catheter shaft and a metal electrode, the catheter being used for treatment of cardiac arrhythmia, for example, atrial fibrillation, by electrically isolating a vessel, such as a pulmonary vein, from a chamber, such as the left atrium. The catheter shaft includes a proximal portion and a distal portion. The distal portion includes an active region, which is either a looped structure transverse to the longitudinal axis of the catheter shaft, or a linear structure that extends parallel to the longitudinal axis of the catheter shaft. During use, the active region is directed into contact with, for example, the wall of a pulmonary vein. Upon energization, the virtual electrode creates a continuous lesion on an inner wall of the pulmonary vein, thereby electrically isolating the pulmonary vein from the left atrium.

Abstract: An apparatus and method for causing necrosis of tissue and specifically intended for thermal ablation of the uterine cavity to cauterizing the endometrial tissue. The apparatus includes a liquid-tight, liquid filled system having a distal flexible member; a proximal flexible member; and a catheter joining and providing a liquid path between these distal and proximal members. The apparatus further includes a pressurizable pneumatic chamber into which the proximal flexible member is inserted and a means to controllably heat the contents of the pneumatic chamber. The system operates to: first withdraw substantially all of the liquid into the proximal flexible member contained within the pressurizable pneumatic chamber; second to heat this liquid to a temperature such that it can cause tissue necrosis; and third to force the heated liquid from the proximal flexible member into the distal flexible member where it is maintained for a predetermined time and at a predetermined pressure.

Abstract: Multipolar, multi-lumen, virtual-electrode catheters having at least one surface electrode, and methods for treatment (e.g., treatment of cardiac arrhythmias) with such catheters are disclosed. The catheters have at least two internal lumens, and at least one internal, flexible electrode rides in each internal lumen. The flexible electrodes carry treatment energy (e.g., radiofrequency energy). The energy exits the catheters via at least one exit feature (e.g., slots, portholes, or micro-pores). The methods for treatment include operating the catheters in different modes depending upon location and type of treatment to be performed. The treatment energy delivered by one of the internal, flexible electrodes may be directed to the other internal, flexible electrode; or the energy delivered by one or both of the internal, flexible electrodes may be directed to one or more surface electrodes. The delivered energy establishes at least one electric field, and possibly one or more lesions, in the tissue.

Abstract: A method of warming a patient during a surgical procedure under operating room conditions. The patient's bladder is catheterized to allow simultaneous filling and draining of the bladder. A pump and a fluid warmer are provided. The warmed fluid and urine are drained out of the bladder under passive gravity-flow conditions.

Abstract: An electrode catheter is introduced into a hollow anatomical structure, such as a vein, and is positioned at a treatment site within the structure. Tumescent fluid is injected into the tissue surrounding the treatment site to produce tumescence of the surrounding tissue which then compresses the vein. The solution may include an anesthetic, and may further include a vasoconstrictive drug that shrinks blood vessels. The tumescent swelling in the surrounding tissue causes the hollow anatomical structure to become compressed, thereby exsanguinating the treatment site. Energy is applied by an electrode catheter in apposition with the vein wall to create a heating effect. The heating effect causes the hollow anatomical structure to become molded and durably assume the compressed dimensions caused by the tumescent technique. The electrode catheter can be moved within the structure so as to apply energy to a large section of the hollow anatomic structure.

Abstract: The present disclosure is directed towards methods, systems, and apparatus for protecting esophageal tissue during ablation. An ablation system can include an esophageal catheter having a heat sink and an ablation catheter having at least one ablation element to deliver ablation energy, where heat generated by the ablation energy is absorbed by the heat sink.

Abstract: Apparatus and methods for treating an inter-vertebral disc by ablation, coagulation, shrinking, stiffening, or other treatment of disc tissue. A method of the invention includes positioning at least one active electrode within the inter-vertebral disc, and applying at least a first high frequency voltage between the active electrode(s) and one or more return electrode(s), wherein the volume of the nucleus pulposus is decreased, pressure exerted by the nucleus pulposus on the annulus fibrosus is reduced, and discogenic pain of a patient is alleviated. An apparatus of the invention includes an electrosurgical probe, an introducer needle adapted for passing the distal end of the probe therethrough, and a positioning unit for monitoring a position of the probe in relation to the introducer needle.

Abstract: A method for treating viral infections in vivo in subjects in need of such treatment by applying heat to affected body tissue, use of an apparatus to provide heated moist gas or heated liquids to affected body tissue that is infected with a virus and apparatuses capable of providing heat to a body part that is infected with a virus.

Abstract: A catheter used for diagnosing and treating, for example, atrial fibrillation. The catheter includes a catheter shaft that has a proximal portion and a distal portion. The distal portion is adapted to be inserted into a body cavity having tissue to be diagnosed or treated and is disposed remotely from the proximal portion. The distal portion, which may be curved or straight, comprises an outer peripheral wall having an active region, and the distal portion has a cross-sectional configuration along the active region. The cross-sectional configuration is adapted to bias the active region against the tissue to be diagnosed or treated.

Abstract: Apparatus and methods for treating a target tissue by delivering a fluid at a defined temperature to a patient's body. An apparatus of the invention includes a fluid delivery unit for delivering fluid in at least close proximity to the target tissue, an aspiration unit for withdrawing the fluid, and a fluid source unit for providing the fluid at the defined temperature. A method of the invention includes forming a void in at least close proximity to the target tissue, and circulating a preheated fluid through the void, wherein the target tissue undergoes adjustment from body temperature to a treatment temperature due to heat exchange between the fluid and the target tissue.

Abstract: A system and method for cooling and warming the central nervous system of a patient comprises a delivery tube with one of the ends couplable to a supply of fluid. A head structure is coupled to the other end of the delivery tube and cooling or warming fluid is directed through the tube to the head structure. The head structure is configured to be placed within the rectal cavity of a patient such that either a contact surface on the head structure or the fluid itself directly contacts a portion of the rectal mucosal membrane. A means for reversing the vertebral venous flow of blood through Batson's plexus supplies cooled or warmed blood directly to the vertebral structures. Unique methods of utilizing the system to selectively cool and warm the central nervous system structures of a patient are set forth herein.

Abstract: A system for ablating tissue includes a reusable control unit including a processor monitoring and controlling ablation and a control interface receiving input to and output from the processor in combination with a disposable procedure set releasably connectable to the control unit to couple to the control interface for communication with the processor.

Abstract: The present invention provides a system for chemohyperthermia treatment.

Abstract: The threaded cryostat for a cryosurgical probe system includes an outer tube and a hollow elongated threaded element positioned within the outer tube. The threaded element has integral, external threads that extend from on an outer surface thereof. During operation a working fluid is transported in a first direction between a fluid supply line and a distal end of a cryosurgical probe within a first space defined within the threaded element. Working fluid is transported in a second direction between the distal end of the cryosurgical probe and the fluid supply line within a second space defined between the outer tube and the threaded element.

Abstract: A brain cooling apparatus includes a tube body 2 which can maintain an airway in the respiratory tract of living body; a pharyngeal cuff 5 which is provided in the peripheral part of this tube body 2 and can store a cooled fluid; and an injection and discharge portion 6 which can inject and discharge a fluid into and from this pharyngeal cuff 5, in which the pharyngeal cuff 5 is flexible enough to inflate and deflate when a fluid is injected and discharged, and when a fluid is injected in a state where an airway in the respiratory tract of living body is maintained by the tube body 2, the inflated pharyngeal cuff adheres closely to the pharyngeal part T of the living body.

Abstract: Embodiments of the invention provide a system for temperature control of the human body. The system includes an indwelling catheter with a tip-mounted heat transfer element. The catheter is fluidically coupled to a console that provides a heated or cooled heat transfer working fluid to exchange heat with the heat transfer element, thereby heating or cooling blood. The heated or cooled blood then heats or cools the patient's body or a selected portion thereof. In particular, strategies for optimizing the rewarming of patients for various medical procedures are provided, including stroke, neurosurgery, and myocardial infarction.

Abstract: An arrangement for influencing magnetic particles in a region of action with the help of an arrangement for generating magnetic fields, by which there is generated a spatially inhomogeneous magnetic field having at least one zone in which the magnetization of the particles is in a state of non-saturation, whereas it is in a state of saturation in the remaining zone. By moving the zone within the region of action, a change in magnetization is produced that can be detected from outside in a first mode of operation and gives information on the spatial distribution of the magnetic particles in the region of action. In a second mode of operation, the movement is repeated so frequently that the region of action heats up.

Abstract: A method for exchanging heat with a patient's spinal column incident to spinal surgery or to relieve a patient for a hypoxia condition of the spine. A closed loop heat exchange catheter is percutaneously advanced into the retroperitoneal space of the patient, and then heat exchange fluid is circulated through the catheter to cool the spinal column.

Abstract: A system, ablation probe, and method is provided for treating tissue, e.g., tissue having tumors. The treatment system is configured to automatically deliver infusaid to tissue when needed and comprises an ablation probe having an ablative element and at least one perfusion exit port. The system further comprises an ablation source operably coupled to the ablative element, and a pump assembly operably coupled to the perfusion exit port(s). The pump assembly is configured for pumping infusaid out through the perfusion exit port(s), preferably during the ablation process. The system further comprises a feedback device configured for controlling the amount of infusaid displaced by the pump assembly based on a sensed tissue parameter, e.g., tissue temperature or tissue impedance.

Abstract: A method and apparatus for carrying our thermal ablation of target tissue is disclosed. The apparatus includes an RF ablation device having a multi-electrode electrode assembly designed to be deployed in target tissue, defining a selected-volume tissue region to be ablated, and having infusion channels for infusing a liquid into the target tissue during the ablation process. A control unit in the apparatus is operably connected to an RF energy source, for controlling the RF power level supplied to the electrodes, and to an infusion device, for controlling the rate of infusion of a liquid through the device into the tissue. During both electrode deployment and tissue ablation, impedance and or temperature measurements made within the tissue are used to control the RF source and infusion device, for optimizing the time and extent of tissue ablation.

Abstract: An installation for delivering calories to all or part of human or animal cell tissue via a liquid comprises: a heating unit heating the liquid; an injection unit injecting the liquid into the heating unit; a dispenser for dispensing the heated liquid; and a transporter for transporting the liquid from the heating unit to the dispenser. The installation allows the heated liquid to be dispensed from the dispensing means in a pulsed operation.

Abstract: Electrosurgical methods and apparatus for treating tissue at a target site of a patient. An electrosurgical instrument includes a shaft, having a shaft distal end and a shaft proximal end, and an electrode assembly disposed at the shaft distal end. The electrode assembly includes at least one active electrode disposed on an electrode support. The instrument is adapted for coupling to a high frequency power supply or electrosurgical generator. Each active electrode is adapted for removing tissue from a target site and/or for localized coagulation of the target tissue. In one embodiment, the instrument is adapted for laparoscopic procedures.

Abstract: By present invention it has been found that hypothermia decreases adhesion formation more specifically pneumoperitoneum-enhanced adhesion formation. A cooling system has been designed to reduce the peritoneal cavity temperature during surgery, while maintaining at all times a 100% relative humidity in order to prevent desiccation, and a regulatory unit designed to condition the insufflated gas to achieve this while minimalising the necessary cooling. This is a new method for more effectively preventing adhesion though cooling while preventing desiccation. In mice it was demonstrated that factors such as environmental temperature, anaesthesia, ventilation and pneumoperitoneum can be used to influence body temperature in order to prevent adhesion formation.

Abstract: Systems and related methods for treating postpartum hemorrhage through insertion of a flexible and expandable cryoballoon into the intrauterine cavity, inflating it to conform to the size and shape of the cavity, pressurizing it to apply pressure on damaged tissue and/or blood vessels that are bleeding, and filling it with a chilled fluid to provide numbing and blood coagulation. The cryoballoon can be coated with a drug or hormone to promote blood coagulation and/or uterine contractions to expedite the cessation of bleeding. In addition, cryoballoon can be coated with a topical anesthetic and/or antiseptic agent to numb and clean the damaged areas. Further, the cryoballoon can be fabricated of a biodegradable, bioerodeable or other biocompatible material so that it can be left in the intrauterine cavity for an extended period of time after insertion.

Abstract: The invention relates to a method for hypothermia and rewarming of the cerebrospinal fluid in the brain. In one embodiment, cooling and rewarming of the cerebrospinal fluid is accomplished by applying cooling and rewarming elements externally placed in contact with the skin overlying the cerebrospinal fluid cisterns at the back of the head and spine regions of a patient. In another embodiment, hypothermia and rewarming is accomplished using a double barrel ventricular catheter placed within the lateral ventricles with one catheter used for heat exchange and the other for drainage of excess cerebrospinal fluid. In yet another embodiment of the invention, hypothermia and rewarming is accomplished using a loop catheter with fluid running through the loop placed in the lateral ventricles.

Abstract: Apparatus and methods for treating an intervertebral disc by ablation of disc tissue. A method of the invention includes positioning at least one active electrode within the intervertebral disc, and applying at least a first high frequency voltage between the active electrode(s) and one or more return electrode(s), wherein the volume of the nucleus pulposus is decreased, pressure exerted by the nucleus pulposus on the annulus fibrosus is reduced, and discogenic pain of a patient is alleviated. In other embodiments, a curved or steerable probe is guided to a specific target site within a disc to be treated, and the disc tissue at the target site is ablated by application of at least a first high frequency voltage between the active electrode(s) and one or more return electrode(s). A method of making an electrosurgical probe is also disclosed.

Abstract: The present invention provides a method and apparatus for controlling the internal body temperature of a patient. According to the present invention, a catheter is inserted through an incision into a large blood vessel of a patient. By selectively heating or cooling a portion of the catheter lying within the blood vessel, heat may be transferred to or from blood flowing within the vessel and the patient's body temperature may thereby be increased or decreased as desired. The invention will find use in treating undesirable conditions of hypothermia and hyperthermia, or for inducing a condition of artificial hypothermia when desired.

Abstract: A device and method for providing body cooling. The cooling device applies cooling to blood flowing in a vena cavae that is then distributed throughout the body. The cooling can be assisted by use of thermoregulatory drugs or warming devices to prevent shivering and vasoconstriction.

Abstract: Apparatus and methods for insulating tissue during therapeutic procedures.

Abstract: The invention relates to a method as well as to a system for the local heating of a target region of an object by varying the magnetization of magnetic or magnetizable substances. A magnetic field is then generated whose magnetic field strength varies in space in such a manner that a first sub-region (301) of low magnetic field strength and a second sub-region (302) which encloses the first sub-region and has a higher magnetic field strength are formed in the target region. Subsequently, the position in space of the two sub-regions in the target region is varied with a given frequency for so long that the particles are heated to a desired temperature due to frequent variation of the magnetization.

Abstract: A catheter and method for heating or cooling a surrounding fluid in a feeding vessel in a vasculature of a patient. The catheter includes a heat transfer element shaped and arranged to create turbulence in a surrounding fluid. A guidewire tube runs substantially parallel to the axis of the catheter to receive a guidewire. The catheter may further have a temperature-monitoring device disposed at the distal tip of the guidewire. Feedback may further be provided to control the temperature of a source of working fluid. A method is also provided for selectively controlling the temperature of a selected volume of blood in a patient.

Abstract: Methods for delivering precise amounts of fluid into cardiac tissue for the purpose of facilitating ablation of the tissue along a desired lesion line. One method injects fluid through a hollow needle. The injected fluid can be a highly conductive fluid injected in conjunction with radiofrequency ablation to create an ablative virtual electrode. The injected conductive fluid can provide deeper and narrower conduction paths and resulting lesions. Radiofrequency ablation can be performed at the same time as the fluid injection, using the injection device as an electrode, or subsequent to the fluid injection, using a separate device. In some methods, the injected fluid is a protective fluid, injected to protect tissue adjacent to the desired lesion line. Fluid delivery can be endocardial, epicardial, and epicardial on a beating heart. The present methods find one use in performing maze procedures to treat atrial fibrillation.

Abstract: A cooling system for an indwelling heat exchange catheter includes a heat exchange bath that is configured to receive a conduit that carries saline to and from the catheter. A heating/cooling fluid is in the bath and exchanges heat with the saline. The heating/cooling fluid flows through a heat exchanger that includes a refrigerant and two variable speed DC compressor for removing heat from the refrigerant. A gear pump circulates the working fluid to and from the catheter and is removably engaged with a pump support platform.

Abstract: An intravascular heat transfer device is provided with a mixing-inducing surface formed by an easily manufacturable process. The device can have a plurality of elongated, articulated segments, each having a mixing-inducing exterior surface. A flexible joint connects adjacent elongated, articulated segments. The device may be conveniently formed, e.g., by vapor deposition or molding, and further lacks undercuts so that the same may be conveniently removed from, e.g., a two-part mold.

Abstract: Ablation probes are provided for perfusing the tissue, while the tissue is ablated. The ablation probe comprises an elongated shaft and an ablative element, such as a needle electrode. The ablation probe further comprises a lumen that extends through the probe shaft, which will be used to deliver a fluid to the distal end of the probe shaft for perfusion into the surrounding tissue. The ablation probe further comprises a porous structure that is associated with the distal end of the shaft in fluid communication with the lumen. For example, the distal end of the shaft, or the entirety of the shaft, can be composed of the porous structure. Or, if the ablative element is an electrode, the electrode can be composed of the porous structure. Because the pores within the porous structure are pervasive, the fluid will freely flow out into the tissue notwithstanding that some of the pores may become clogged.

Abstract: Apparatus and methods for cooling and/or heating selected regions within a body are described herein. An implantable system is used to cool or heat nerve bodies down to about 15° C. to diminish nerve impulses. In one embodiment, the system can include an implantable unit containing a pumping mechanism and/or various control electronics. The system has a cooling element. The cooling element can be a Peltier junction or a catheter through which hot or cold fluid flows. The heated portion of the Peltier junction can be cooled by a liquid heat transfer medium which absorbs the heat from the junction and dissipates the heat elsewhere.

Abstract: Systems, apparatus, and methods for treating spinal tissue and other body structures in open and endoscopic spine surgery to relieve symptoms, such as neck or back pain. In particular, the present invention provides methods for the controlled heating of various tissues in or around the vertebral column, including various interspinous tissues, such that spinal ligaments and cartilage surrounding the vertebrae and the facet joints are shrunk or tightened to stabilize the vertebral column of a patient. Thermal energy is applied to the target tissue in a subablation mode of an electrosurgical system to cause shrinkage of the tissue, thereby stiffening the interspinous tissue and stabilizing the vertebral column. In an exemplary embodiment, a high frequency RF voltage can be applied between one or more active electrode(s) and one or more return electrode(s) to heat a target interspinous tissue to within a temperature range at which irreversible shrinkage of the tissue occurs.

Abstract: An RF device includes a support structure. An RF electrode is coupled to the support structure and includes conductive and dielectric portions. A thermo-electric cooler is coupled to the support structure and is configured to cool a back surface of the RF electrode.

Abstract: A method and apparatus for creating a virtual electrode to ablate bodily tissue. The apparatus includes an outer tube, a first electrode, an inner tube and a second electrode. The outer tube is fluidly connected to a source of conductive fluid and defines a proximal end and a distal end. The distal end includes an opening for delivering conductive fluid from the outer tube. The first electrode is disposed at the distal end of the outer tube for applying a current to conductive fluid delivered from the outer tube. The inner tube is coaxially received within the outer tube and is connected to a source of conductive fluid. The inner tube defines a proximal end and a distal end, with the distal end forming an opening for delivering conductive fluid from the inner tube. Finally, the second electrode is disposed at the distal end of the inner tube for applying a current to conductive fluid delivered from the inner tube.

Abstract: Methods and apparatuses for temperature modification of a patient, or selected regions thereof, including an induced state of hypothermia. The temperature modification is accomplished using an in-dwelling heat exchange catheter within which a fluid heat exchange medium circulates. A heat exchange cassette of any one of several disclosed variations is attached to the circulatory flow lines of the catheter, the heat exchange cassette being sized to engage a cavity within one of various described re-usable control units. The control units include a heater/cooler device, a user input device, and a processor connected to receive input from various sensors around the body and the system. The heater/cooler device may be thermoelectric to enable both heating and cooling based on polarity. A temperature control scheme for ramping the body temperature up or down without overshoot is provided.

Abstract: An indwelling heat exchange catheter with integrated temperature sensor includes a catheter tube. A closed loop heat exchanger extends from the catheter tube. A temperature sensor can be integrally formed with the catheter tube such that it is insulated from the closed loop heat exchanger. The indwelling heat exchange catheter can further include a guide-wire tube that extends from the catheter tube and in such a case, the temperature sensor can be affixed to the guide-wire tube. Alternatively, a wire can extend through the catheter tube and the temperature sensor can be affixed to the wire.

Abstract: The present invention provides an apparatus and a method for producing a virtual electrode within or upon a tissue to be treated with radio frequency alternating electric current, such tissues including but not limited to liver, lung, cardiac, prostate, breast, and vascular tissues and neoplasms. An apparatus in accord with the present invention includes a supply of a conductive or electrolytic fluid to be provided to the patient, an alternating current generator, and a processor for creating, maintaining, and controlling the ablation process by the interstitial or surficial delivery of the fluid to a tissue and the delivery of electric power to the tissue via the virtual electrode.

Abstract: Electrosurgical methods and apparatus for the controlled ablation of tissue from a target site of a patient. The instrument includes a shaft having proximal and distal end portion and an active screen electrode on the distal end portion; a return electrode arranged on the shaft spaced from the screen electrode; at least one electrical connector extending through the shaft that connects the active electrode with a high frequency power supply; at least one electrical coupling member (such as a ball wire) adapted to secure the active screen electrode to the shaft and to electrically couple the screen electrode to the at least one electrical connector; and an aspiration lumen within the shaft having a distal opening coupled to the single active electrode wherein the screen electrode inhibits clogging of the aspiration lumen.

Abstract: A fluid transfer assembly includes a fluid carrier and a heat exchange assembly coupled to the fluid carrier. The heat exchange assembly includes a heat exchange conduit, a heat exchanger in thermal communication with the heat exchange conduit, and a pump. The pump defines a stroke volume that is greater than a fluid carrier volume defined by the fluid carrier. The configuration of the stroke volume of the pump and the fluid carrier volume of the fluid carrier limits the length of the fluid carrier. In such a configuration, the heat exchange assembly orients in proximity to the body during operation to create a relatively short ex vivo flow path between a body and the heat exchange assembly. During operation, as the fluid flows along the ex vivo flow path, the relatively short ex vivo flow path minimizes thermal change in the fluid caused by a heat exchange between the walls of the fluid carrier and the atmosphere.

Abstract: An ablation catheter employing one or more manifold arrangements to convey a conductive fluid medium to a target tissue. The manifold includes at least one inlet port in fluid communication with a fluid supply lumen running along at least a portion of the catheter. The inlet port or ports are in fluid communication with a larger outlet port. The outlet ports provide an outlet for the fluid to flow out of the catheter and against the target tissue. As such, the combination of at least the inlet port with the outlet port provides a flow path for fluid within the fluid lumen to flow through the manifold and to outside of the catheter. An electrode is arranged in the flow path of fluid within or adjacent the manifolds. As such, fluid may be energized and conduct ablation energy to the target tissue to ablate the tissue.

Abstract: Apparatus and methods for treating an intervertebral disc by ablation of disc tissue. A method of the invention includes positioning at least one active electrode within the intervertebral disc, and applying at least a first high frequency voltage between the active electrode(s) and one or more return electrode(s), wherein the volume of the nucleus pulposus is decreased, pressure exerted by the nucleus pulposus on the annulus fibrosus is reduced, and discogenic pain of a patient is alleviated. In other embodiments, a curved or steerable probe is guided to a specific target site within a disc to be treated, and the disc tissue at the target site is ablated by application of at least a first high frequency voltage between the active electrode(s) and one or more return electrode(s). A method of making an electrosurgical probe is also disclosed.