Abstract: Devices, systems, and methods for maintaining cryoballoon size, cryoballoon pressure, and/or coolant flow rate based on physical characteristics of the tissue to be ablated. In one embodiment, a cryoablation system comprises: a cryoablation device, the cryoablation device including: an expandable treatment element defining an interior chamber; and a pressure sensing system at least partially within the interior chamber; a fluid flow path including at least one valve that is in communication with at least one PID device; and a control unit including processing circuitry in communication with the pressure sensing system and the at least one PID device, the processing circuitry being configured to: determine a target pressure of the expandable treatment element based on a target size of the expandable treatment element; and determine a target flow rate of coolant through the fluid flow path based on the target pressure of the expandable treatment element.

Abstract: A device, system, and method for mapping myocardial tissue, such as epicardial tissue on the right ventricle. A system for mapping myocardial tissue may include a mapping device having a distal portion that includes a distal assembly sized and configured to be positioned within the pericardial space. The distal assembly may include an expandable shell, at least one inflatable or expandable element within the expandable shell, and a mapping electrode assembly. Inflation or expansion of the at least one inflatable or expandable element, and therefore expansion of the expandable shell, within the pericardial space may provide sufficient force of the mapping electrodes against the myocardial tissue being mapped. The system may also include a delivery sheath with a retention element for controllably retracting the device within the sheath during delivery and removal of the device from the pericardial space.

Abstract: A medical device including an outer tube, an expandable chamber coupled to the outer tube, and an injection tubular member in fluid communication with an interior of the expandable chamber. The injection tubular member is coupled to a source of fluid and a distal end within the expandable chamber and a fluid nozzle is located in a distalmost end face of the distal end of the injection tubular member. A fluid dispersion unit is coupled to the injection tubular member with a longitudinal axis, the fluid nozzle being within the fluid dispersion unit and configured to direct a flow of fluid into the fluid dispersion unit. The fluid dispersion unit has an opening to direct a flow path of the flow of fluid expelled by the fluid nozzle within the fluid dispersion unit and into an interior surface of the expandable chamber from the opening at the distalmost end face.

Abstract: An epicardial device, system, and method for stabilizing the left atrial appendage during a left atrial appendage ligation/occlusion procedure. A cryoadhesion device including a stabilization element is positioned within the pericardial space proximate the left atrial appendage through subxiphoid access. Once the stabilization element is in contact with the left atrial appendage, the stabilization element is cooled to a temperature that is sufficient to cryoadhere the stabilization element to the left atrial appendage. In this way, the cryoadhesion device stabilizes the left atrial appendage in order to perform left atrial appendage ligation/occlusion with a secondary medical device.

Abstract: A device, system, and method for identifying an area of ablated tissue. Specifically, the device, system, and method may include a device having one or more fiber sensors and a processing unit for receiving emitted and/or reflected light from tissue and making one or more determinations based on the received light regarding ablated tissue, tissue contact, and/or occlusion. Each of the fiber sensors may include at least one multimode waveguide segment and at least one singlemode waveguide segment, or each of the fiber sensors may be singlemode waveguide. Further, each fiber sensor may have a core with long-period grating for optically coupling light from tissue to the fiber sensor. The processing unit may include a beam processing apparatus and a hyperspectral imaging and analysis apparatus, and may optionally include a light source.

Abstract: A device and system for thermally affecting tissue that includes a balloon catheter with a reduced distal length for ease of navigation and that also includes a balloon that is more resistant to bursting and delamination. The balloon may include a proximal neck generally attached to an elongate body and a distal neck generally attached to a shaft disposed within the elongate body. The distal neck is turned inward to extend within the balloon chamber and the proximal neck may either extend within the chamber or extend proximally away from the balloon chamber. Alternatively, the device may include an inner balloon and an outer balloon, the distal necks of both being turned inward and extending within the inner balloon chamber. The proximal necks may both also be turned inward to extend within the chamber or the proximal neck of the outer balloon may extend away from the balloon chamber.

Abstract: A system and device for cryoablation of tissue that is suitable for use within an MRI environment. The device may include an elongate body, a treatment element at the distal portion of the elongate body, and one or more pull fibers. The pull fibers may be composed of a non-ferromagnetic material, such as a polymer. Likewise, none of the other device components may be composed of a ferromagnetic material. The device may also include at least one fiber optic sensor. The elongate body distal portion may include a distal tip to which the pull fibers are directly coupled. Additionally or alternatively, the elongate body may include one or more pull fiber lumens configured to allow the pull fibers to deflect the distal portion when a pull force is exerted on the pull fibers.

Abstract: An intravascular ablation device, including a flexible elongate body; an expandable element positioned on the elongate body; a radiofrequency or electroporation treatment segment located distally of the expandable element; a cryogenic coolant source in fluid communication with an interior of the expandable element; and a radiofrequency or electroporation energy source in communication with the radiofrequency or electroporation treatment segment.

Abstract: An intravascular catheter is provided, including a flexible elongate body; an expandable element positioned on the elongate body; a substantially linear thermal segment located proximally of the expandable element, the thermal segment defining a first flexibility, where the thermal segment is positioned between two portions of the catheter body each including a flexibility less than that of the thermal segment; a first fluid flow path in fluid communication with the expandable element; and a second fluid flow path in fluid communication with the thermal segment.

Abstract: A system and method for providing greater control over the temperature of a thermal treatment element of a medical device, enabling an operator to extend a thawing period of a cryoablation procedure. The system may include a fluid flow path that bypasses a subcooler, giving the operator selective control over the temperature of refrigerant delivered to the treatment element and, therefore, treatment element temperature. Additionally or alternatively, the system may include a fluid delivery conduit that is in communication with a liquid refrigerant and a gaseous refrigerant. Adjustment of the ratio of liquid to gaseous refrigerant also offers control over the treatment element temperature. Additionally or alternatively, the system may include one or more valves and/or heating elements in the fluid delivery and recovery conduits to control the treatment element temperature.

Abstract: A method, system and device for securing conductive material on catheter elements for tissue sensing and cryogenic ablation. This may be used to deposit or embed conductive material onto or within polymeric materials. The method of manufacturing a balloon with conductive material may include extruding a polymeric material where the polymeric material includes embedded electrically conductive material. At least a portion of the polymeric material may be removed to expose at least a portion of the embedded electrically conductive material. The benefits may include allowing local bipolar recordings, contact assessment and ice thickness, and compatibility with 3-dimensional electroanatomical mapping systems.

Abstract: A system and kit for using a source of low-pressure refrigerant for a cryotherapy procedure and for subcooling a cryotherapy refrigerant. The system may generally include a fluid reservoir and a fluid flow path in thermal exchange with the fluid reservoir, the fluid flow path including a first thermal exchange device in thermal exchange with the fluid reservoir, a compressor in fluid communication with the first thermal exchange device, a condenser, a reversing valve located between the compressor and the condenser, a second thermal exchange device located between the reversing valve and the compressor, and an expansion valve located between the condenser and the thermal exchange device. The third thermal exchange device may be configured to be in fluid communication with the cryotherapy console and configured to place a secondary refrigerant within the first fluid flow path in thermal communication with a secondary refrigerant of the cryotherapy system.

Abstract: A device, system and method for temperature-based lesion formation assessment and mapping functionality using an accessory usable with an over-the-wire balloon catheter. The device may include a first annular element, a plurality of wires coupled to the first annular element, and a second annular element, the plurality of wires passing from the first annular element through the second annular element and into an elongate wire conduit coupled to the second annular element. At least one of the plurality of wires may include at least one temperature sensor and/or at least one mapping electrode. The first annular element coupled to an outer surface of a sheath. As a balloon catheter is advanced out of the sheath lumen, the distal tip of the catheter engages the second annular element and pushes the wires out of the sheath lumen, everting them over the balloon of the catheter.

Abstract: The present invention provides a medical device that may include a catheter body having proximal and distal portions, a fluid injection lumen disposed within elongate body, and a guidewire lumen disposed within the elongate body. A tip portion defining a cavity in fluid communication with the fluid injection lumen may be coupled to the distal end of the guidewire lumen, and an expandable element may be coupled to the distal portion of the catheter body and to the tip portion, such that the expandable element is in fluid communication with the fluid injection lumen. A shaping element may at least partially surround the expandable element, where the shaping element is configurable in a first geometric configuration and a second geometric configuration.

Abstract: A system and method of using a source of low-pressure refrigerant for a cryotherapy procedure. The system may generally include a fluid reservoir and a fluid flow path in thermal exchange with the fluid reservoir, the fluid flow path including a thermal exchange device in thermal exchange with the fluid reservoir, a compressor in fluid communication with the thermal exchange device, a condenser, a reversing valve located between the compressor and the condenser, and an expansion valve located between the condenser and the thermal exchange device. The method may include transferring a low-pressure refrigerant to a first fluid reservoir, reducing the temperature of the refrigerant within the first fluid reservoir, increasing the temperature of the refrigerant within the first fluid reservoir, and transferring the pressurized refrigerant from the first fluid reservoir to a second fluid reservoir.

Abstract: A device, system, and method for treating an area of tissue and evaluating lesion formation and quality. The system may include a medical device having a plurality of mapping electrodes on a treatment element, the plurality of mapping electrodes being configured to record from the area of tissue at least one of unipolar impedance measurements, bipolar impedance measurements, local electrical activity, and pace threshold measurements before, during, and after circulation of the cryogenic fluid within the treatment element. These measurements may be transmitted to a control unit having processing circuitry configured to compare pre-treatment measurements, in-treatment measurements, and/or post-treatment measurements to each other and/or to threshold values to determine occlusion and/or lesion quality, such as lesion transmurality.

Abstract: A method, system, and device for predicting lesion quality. Specifically, lesion quality may be predicted based on an assessment of pulmonary vein occlusion using injection of an impedance-modifying agent and evaluation of changes in impedance measurements recorded by an electrode located distal to an occlusion element of the treatment device used to inject the impedance-modifying agent. The quality of the occlusion may be rated based on the changes in impedance over time within the pulmonary vein. For example, the quality of the occlusion may be rated as being good, fair, or poor. This assessment may be quickly and easily communicated to an operator.

Abstract: Systems and methods for controllably variable fluid flow are disclosed that provide the ability to modify the effective cross-sectional area of the fluid delivery conduit available for fluid flow. Accordingly, selective control of these configurations allows fluid flow to be regulated as desired while the fluid delivery pressure remains the same. Additional configurations provided herein allow for the selective manipulation of a footprint or therapeutic pattern achievable with the medical device during a single procedure, negating the need for the removal and insertion of multiple devices to achieve the same variations in treatment geometry or characteristics.

Abstract: A method and system for creating permanent lesions in an area of target tissue, such as tissue at or proximate a junction between a pulmonary vein and the left atrium. The method may generally include positioning a medical device in contact with a pulmonary vein ostium, ablating the tissue, and recording a plurality of temperature measurements from one or more of three temperature sensors. The device may include an occlusion element in communication with a coolant source, a first sensor located distal of the occlusion element, a second sensor located proximal of the occlusion element, and a third sensor located in the occlusion element. One or more temperature measurements may be compared with each other to assess occlusion of the pulmonary vein, and/or may be compared with a set of reference temperatures to predict a real-time temperature within the target tissue.

Abstract: A device, system, and method for performing a variety of treatment procedures safely with a single treatment device. For example, a system is provided that includes a treatment device with a highly conformable balloon that is inflated at a constant pressure and that remains “soft” during use, which enhances balloon-tissue contact, treatment efficacy, and patient safety. In one embodiment, a system for ablating tissue comprises: a treatment device including a highly conformable balloon; a control unit including a fluid supply reservoir in fluid communication with the highly conformable balloon, the control unit being configured to deliver fluid from the fluid supply reservoir to the highly conformable balloon such that the highly conformable balloon is maintained at a balloon pressure of between 0.2 psig and 3.0 psig.