Abstract: A closed loop high pressure generating cryoablation system circulates a working fluid through a catheter to freeze a target tissue. The system includes a plurality of functional cycles or circuits. A freeze circuit is operable to pressurize, cool and drive fluid through the catheter. A refill circuit replenishes fluid from a main reservoir. A pressure overflow circuit prevents over pressurization. Related methods are also described.

Abstract: An ablation apparatus for creating a lesion in target tissue has a handle, an elongate shaft extending from the handle and a distal ablation portion. The distal ablation portion includes a cryogen flow manifold defining a plurality of fluid pathways between an insert body and a sleeve. Cryogen is circulated through the plurality of fluid pathways to create the lesion in the target tissue.

Abstract: A method of reducing visceral fat in the body of a patient comprises thermally treating the visceral fat sufficient to form a liquid-fat mixture or emulsion. The liquid-fat emulsion is then aspirated. Thermally treating can be performed by cooling according to a temperature profile causing the cell membranes to be disrupted. The visceral fat cells are warmed with a warming liquid immediately following cooling. The warming liquid, along with the contents of the fat cells that mix with the warming liquid, are withdrawn by aspiration.

Abstract: A surgical method for reducing insulin resistance comprises cryolipolysis of mesenteric fat in a controlled manner to avoid tissue ablative temperatures. Cryolipolysis is carried out in stages based on evaluating reduction in volumes of mesenteric fat and fasting glucose levels.

Abstract: An endovascular near critical fluid based cryoablation catheter for creating an elongated lengthwise-continuous lesion in tissue can comprise an elongated shaft, a flexible distal tissue treatment section, and a distal tip. A plurality of flexible tubes can extend through the distal treatment section to transport a near critical fluid to and from the distal tip. The distal treatment section can also include a flexible fluid-sealed cover or barrier layer surrounding the delivery tubes. The cover and tubes can collectively define a space which is filled with a fluidic thermally conductive media. The thermally conductive media, fluid delivery tubes, and the cover can be arranged such that a flow of the near critical fluid through the tube bundle transfers heat between a target tissue and the distal treatment section of the catheter thereby creating the elongated lengthwise-continuous lesion in the tissue.

Abstract: A multimodality or hybrid ablation system includes an ablation apparatus for creating a lesion in target tissue. The ablation apparatus has an ablation shaft including a handle, a first portion, an ablation portion, distal tip, at least one ablation energy delivery lumen, at least one ablation energy return lumen, and a stylet lumen that extends substantially along a length of the ablation shaft from the handle to at least the ablation portion. The ablation apparatus also includes a stylet that is capable of being inserted into the stylet lumen where the stylet is made of a shape-memory material. A plurality of electrodes are arranged on the ablation portion for measuring or verifying tissue contact with the tissue and applying a pulsed electric field. Optionally, the pulsed electric field may be applied after or in parallel with freezing the target tissue.

Abstract: An endovascular near critical fluid based cryoablation catheter for creating an elongated lengthwise-continuous lesion in tissue can comprise an elongated shaft, a flexible distal tissue treatment section, and a distal tip. A plurality of flexible tubes can extend through the distal treatment section to transport a near critical fluid to and from the distal tip. The distal treatment section can also include a flexible fluid-sealed cover or barrier layer surrounding the delivery tubes. The cover and tubes can collectively define a space which is filled with a fluidic thermally conductive media. The thermally conductive media, fluid delivery tubes, and the cover can be arranged such that a flow of the near critical fluid through the tube bundle transfers heat between a target tissue and the distal treatment section of the catheter thereby creating the elongated lengthwise-continuous lesion in the tissue.

Abstract: An ablation apparatus for creating a lesion in target tissue, the ablation apparatus including a handle, an elongate shaft extending from the handle to a distal tip, where the shaft includes a first portion, an ablation portion distal to the first portion and having an outer sheath, and at least one ablation energy element disposed within the outer sheath, where a space is formed between the at least one ablation energy element and the outer sheath. The ablation apparatus further includes a thermally conductive liner disposed within the space.

Abstract: Embodiments described herein are directed to a system for providing alternating freeze and thaw cycles. The system includes a controller, a vessel for holding a working fluid, a pressure generator, a cooler, a cooler heat exchanger, a heater, a heater heat exchanger, a check valve, and a treatment instrument. In some embodiments, the treatment instrument includes a distal end, a proximal end, a connecting portion adjacent to the proximal end, a needle element adjacent the distal end, a handle portion disposed between the proximal and distal end, and a depth-limiting element to limit an injection depth of the needle element.

Abstract: Embodiments described herein are directed to a system for providing alternating freeze and thaw cycles. The system includes a controller, a vessel for holding a working fluid, a pressure generator, a cooler, a cooler heat exchanger, a heater, a heater heat exchanger, a check valve, and a treatment instrument. In some embodiments, the treatment instrument includes a distal end, a proximal end, a connecting portion adjacent to the proximal end, a needle element adjacent the distal end, a handle portion disposed between the proximal and distal end, and a depth-limiting element to limit an injection depth of the needle element.

Abstract: An endovascular near critical fluid based cryoablation catheter for creating an elongated lengthwise-continuous lesion in tissue can comprise an elongated shaft, a flexible distal tissue treatment section, and a distal tip. A plurality of flexible tubes can extend through the distal treatment section to transport a near critical fluid to and from the distal tip. The distal treatment section can also include a flexible fluid-sealed cover or barrier layer surrounding the delivery tubes. The cover and tubes can collectively define a space which is filled with a fluidic thermally conductive media. The thermally conductive media, fluid delivery tubes, and the cover can be arranged such that a flow of the near critical fluid through the tube bundle transfers heat between a target tissue and the distal treatment section of the catheter thereby creating the elongated lengthwise-continuous lesion in the tissue.

Abstract: An ablation apparatus for creating a lesion in target tissue has a handle, an elongate shaft extending from the handle and a distal ablation portion. The distal ablation portion includes a cryogen flow manifold defining a plurality of fluid pathways between an insert body and a sleeve. Cryogen is circulated through the plurality of fluid pathways to create the lesion in the target tissue.

Abstract: A multimodality or hybrid ablation system includes an ablation apparatus for creating a lesion in target tissue. The ablation apparatus has an ablation shaft including a handle, a first portion, an ablation portion, distal tip, at least one ablation energy delivery lumen, at least one ablation energy return lumen, and a stylet lumen that extends substantially along a length of the ablation shaft from the handle to at least the ablation portion. The ablation apparatus also includes a stylet that is capable of being inserted into the stylet lumen where the stylet is made of a shape-memory material. A plurality of electrodes are arranged on the ablation portion for measuring or verifying tissue contact with the tissue and applying a pulsed electric field. Optionally, the pulsed electric field may be applied after, contemporaneously, or for only a portion that the cryo-modality is applied to the target tissue.

Abstract: A method of cooling a material including the steps of (i) providing a cryotherapy instrument, (ii) positioning a portion of the cryotherapy instrument adjacent the material to be cooled, and (iii) circulating a cryogenic fluid through the cryotherapy instrument under physical conditions near a critical point of a liquid-vapor system for the cryogenic fluid. The critical point defines a point in a phase diagram of the liquid-vapor system where molar volumes are substantially equivalent for liquid and gas, whereby vapor lock associated with cooling of the cryotherapy instrument is avoided.

Abstract: An endovascular near critical fluid based cryoablation catheter for creating an elongated lengthwise-continuous lesion in tissue can comprise an elongated shaft, a flexible distal tissue treatment section, and a distal tip. A plurality of flexible tubes can extend through the distal treatment section to transport a near critical fluid to and from the distal tip. The distal treatment section can also include a flexible fluid-sealed cover or barrier layer surrounding the delivery tubes. The cover and tubes can collectively define a space which is filled with a fluidic thermally conductive media. The thermally conductive media, fluid delivery tubes, and the cover can be arranged such that a flow of the near critical fluid through the tube bundle transfers heat between a target tissue and the distal treatment section of the catheter thereby creating the elongated lengthwise-continuous lesion in the tissue.

Abstract: A cryoablation apparatus for creating a lesion in a target tissue includes an expandable energy transfer region formed of a plurality of independent spline ablation members. Manipulation of a control member extending from a handle to the energy transfer region controllably adjusts the shape of the energy transfer region to contact complex anatomies. A service lumen extending through the length of apparatus can slidably receive an ancillary catheter such as a guide catheter or diagnostic catheter. The catheter has particular application to treating conditions of the heart. Related methods and systems are also described.

Abstract: An endoesophageal balloon and catheter for operation with a transesophageal echocardiography (TEE) probe includes an inflatable balloon body disposed over the ultrasound element of the TEE probe, a liquid inflow lumen in fluid communication with the balloon, and a liquid outflow lumen in fluid communication with the balloon. The balloon is inflated with an acoustically transmitting liquid.

Abstract: An ablation apparatus for creating a lesion in target tissue, the ablation apparatus including a handle, an elongate shaft extending from the handle to a distal tip, where the shaft includes a first portion, an ablation portion distal to the first portion and having an outer sheath, and at least one ablation energy element disposed within the outer sheath, where a space is formed between the at least one ablation energy element and the outer sheath. The ablation apparatus further includes a thermally conductive liner disposed within the space.

Abstract: An endovascular near critical fluid based cryoablation catheter for creating an elongated lengthwise-continuous lesion in tissue can comprise an elongated shaft, a flexible distal tissue treatment section, and a distal tip. A plurality of flexible tubes can extend through the distal treatment section to transport a near critical fluid to and from the distal tip. The distal treatment section can also include a flexible fluid-sealed cover or barrier layer surrounding the delivery tubes. The cover and tubes can collectively define a space which is filled with a fluidic thermally conductive media. The thermally conductive media, fluid delivery tubes, and the cover can be arranged such that a flow of the near critical fluid through the tube bundle transfers heat between a target tissue and the distal treatment section of the catheter thereby creating the elongated lengthwise-continuous lesion in the tissue.

Abstract: An endovascular near critical fluid based cryoablation catheter for creating an elongated lengthwise-continuous lesion in tissue can comprise an elongated shaft, a flexible distal tissue treatment section, and a distal tip. A plurality of flexible tubes can extend through the distal treatment section to transport a near critical fluid to and from the distal tip. The distal treatment section can also include a flexible fluid-sealed cover or barrier layer surrounding the delivery tubes. The cover and tubes can collectively define a space which is filled with a fluidic thermally conductive media. The thermally conductive media, fluid delivery tubes, and the cover can be arranged such that a flow of the near critical fluid through the tube bundle transfers heat between a target tissue and the distal treatment section of the catheter thereby creating the elongated lengthwise-continuous lesion in the tissue.