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: 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 ablation apparatus for creating a lesion in target tissue, the ablation apparatus having 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.

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: A system for monitoring electrical activity at an ablation site where the system includes an ablation device having an elongate, flexible shaft and a distal treatment section for delivering ablation energy to target tissue, a first electrode mounted on the distal treatment section, a second electrode mounted on the distal treatment section where the second electrode is spaced from the first electrode a distance (D1), a plurality of conducting elements extending along the distal treatment section and being connected to the first electrode and the second electrode, the plurality of conducting elements for connecting the first electrode and the second electrode to an electrophysiological recording system, a processing device programmed to receive the electrical information from the ablation site from the first electrode and the second electrode, and an electrophysiological recording system.

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: A method of creating a lesion in cardiac tissue where the method includes deploying a distal treatment section of an ablation catheter into a heart chamber and manipulating the distal treatment section against the cardiac tissue and into a curved shape that encloses a plurality of vessel entries in the heart chamber. The method further includes commencing a first application of ablation energy from the distal treatment section to the cardiac tissue and halting the first application of ablation energy to the cardiac tissue. The first application of ablation energy causes formation of a first continuous lesion in the cardiac tissue that encloses the plurality of vessel entries.

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.

Abstract: An endovascular near critical fluid based cryoablation catheter for creating an elongate lengthwise-continuous lesion in tissue comprises an elongate shaft, a flexible distal tissue treatment section, and a distal tip. A plurality of flexible tubes extend through the distal treatment section to transport a near critical fluid to and from the distal tip. The distal treatment section is controllably deployed to match the contour of an anatomical region to be treated. In embodiments the distal treatment section includes a superelastic material and can assume a plurality of different shapes based on the distance ejected from an outer sleeve member. When the catheter is activated, heat is transferred between a target tissue and the distal treatment section of the catheter thereby creating the elongate lengthwise-continuous lesion in the tissue.

Abstract: A near critical fluid based cryoablation system comprises a cryoablation catheter for creating a lesion in tissue. A cryogenic fluid is transported under pressure through the catheter. A controller adjusts the pressure from a relatively high (e.g., near critical) pressure to a substantially lower pressure based on a condition during the catheter activation. In one configuration, the pressure is modulated based on the temperature of the catheter. When the temperature of the catheter reaches a target temperature, the pressure is reduced.

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: A device for freezing body tissue, the device having a main driving system capable of generating nitrogen under physical conditions near a critical point of a liquid-vapor system for the nitrogen. 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 and the physical conditions include a pressure of about 33.5 atm.

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: A device for freezing body tissue, the device having a main driving system capable of generating nitrogen under physical conditions near a critical point of a liquid-vapor system for the nitrogen. 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 and the physical conditions include a pressure of about 33.5 atm.