Systems and methods for electroporation devices including basket and balloon configurations

Abstract

To provide systems and methods for electroporation catheters.SOLUTION: An electroporation catheter 1000 includes a shaft, and a plurality of splines 1004 forming a basket around a distal portion of the shaft, each spline extending between a proximal end that is coupled to the shaft and a distal end that is coupled to the shaft, where each spline of the plurality of splines comprises at least one energizable electrode. The electroporation catheter further includes a balloon 1008 positioned within the basket formed by the plurality of splines, the balloon being selectively inflatable to facilitate securing a position of the plurality of splines.SELECTED DRAWING: Figure 10A

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to Provisional Application No. 63 / 192,723, filed May 25, 2021, which is incorporated herein by reference in its entirety.

[0002] The present disclosure relates generally to tissue ablation systems. In particular, the present disclosure relates to electroporation catheters that include catheter assemblies having baskets and / or balloons. [Background technology]

[0003] It is generally known that ablation therapy may be used to treat a variety of conditions afflicting the human anatomy. For example, ablation therapy may be used to treat atrial arrhythmias. When tissue is ablated, or at least exposed to ablation energy produced by an ablation generator and delivered by an ablation catheter, lesions are formed in the tissue. Electrodes attached to or within the ablation catheter are used to induce tissue apoptosis in cardiac tissue to ameliorate conditions such as atrial arrhythmias (including, but not limited to, ectopic atrial tachycardia, atrial fibrillation, atrial flutter, etc.).

[0004] Cardiac arrhythmias (i.e., irregular heart rhythms) can lead to a variety of dangerous conditions, such as loss of synchronization between atrioventricular contractions and stasis of blood flow, and can even result in various illnesses and death. The primary cause of atrial arrhythmias is thought to be stray electrical signals within the left or right atrium of the heart. Ablation catheters apply ablation energy (e.g., radiofrequency energy, cryoablation, laser, chemical agents, high-intensity focused ultrasound, etc.) to cardiac tissue, creating lesions in the cardiac tissue. This lesion disrupts undesirable electrical pathways, thereby limiting or preventing the stray electrical signals that lead to arrhythmias.

[0005] Electroporation is a non-thermal ablation technique that applies a strong electric field to induce pore formation in cell membranes. The electric field can be induced by applying relatively short pulses, which can last, for example, from nanoseconds to a few milliseconds. Such pulses may be repeated to form a pulse train. When such an electric field is applied to tissue in vivo, cells within the tissue experience a transmembrane potential, causing pores in the cell wall to open. Electroporation can be reversible (i.e., the temporarily opened pores reclose) or irreversible (i.e., the pores remain open). For example, in the field of gene therapy, reversible electroporation (i.e., temporary pore opening) is used to introduce high-molecular-weight therapeutic vectors into cells. In other therapeutic applications, cell destruction can be induced using only appropriately configured pulse trains, for example, by inducing irreversible electroporation. Summary of the Invention [Problem to be solved by the invention]

[0006] For catheters used to deliver bipolar energy using irreversible electroporation (IRE) or pulsed field ablation (PFA), it is important to ensure that the catheter electrodes are close to or in contact with the vessel wall. In general, the closer the electrode is to the vessel wall, the larger the lesion size. Therefore, catheter configurations that place the electrodes close to or in contact with the vessel wall are desirable. [Means for solving the problem]

[0007] In one aspect, an electroporation catheter is provided. The electroporation catheter includes a shaft and a plurality of splines forming a basket around a distal portion of the shaft, each spline extending between a proximal end coupled to the shaft and a distal end coupled to the shaft, each spline of the plurality of splines including at least one energizable electrode. The electroporation catheter further includes a balloon disposed within the basket formed by the plurality of splines, the balloon being selectively inflatable to facilitate fixation of the position of the plurality of splines.

[0008] In another aspect, an electroporation system is provided. The system includes a generator and a catheter coupled to the generator. The catheter includes a handle, a shaft extending distally from the handle, and a plurality of splines forming a basket around a distal portion of the shaft, each spline extending between a proximal end coupled to the shaft and a distal end coupled to the shaft, each spline of the plurality of splines including at least one energizable electrode. The catheter further includes a balloon disposed within the basket formed by the plurality of splines, the balloon being selectively inflatable to facilitate fixation of the position of the plurality of splines.

[0009] In yet another aspect, a method of assembling an electroporation catheter is provided, the method including the steps of providing a shaft, coupling a plurality of splines to the shaft to form a basket about a distal portion of the shaft, each spline extending between a proximal end coupled to the shaft and a distal end coupled to the shaft, each spline of the plurality of splines including at least one energizable electrode, and disposing a balloon within the basket formed by the plurality of splines, the balloon being selectively inflatable to facilitate securing the position of the plurality of splines.

[0010] The foregoing and other aspects, features, details, utilities, and advantages of the present disclosure will become apparent from a reading of the following description and claims, and from a reference to the accompanying drawings. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a schematic block diagram of an electroporation treatment system.

[0012] [Figure 2] FIG. 2 is a diagram of one embodiment of a handle that can be used with the system shown in FIG. 1.

[0013] [Figure 3] FIG. 2 is a side schematic view of one embodiment of a catheter assembly that can be used with the system shown in FIG. 1.

[0014] [Figure 4] FIG. 2 is a side schematic view of an alternative embodiment of a catheter assembly that may be used with the system shown in FIG. 1.

[0015] [Figure 5] FIG. 2 is a side schematic view of an alternative embodiment of a catheter assembly that may be used with the system shown in FIG. 1.

[0016] [Figure 6] FIG. 2 is a side schematic view of an alternative embodiment of a catheter assembly that may be used with the system shown in FIG. 1.

[0017] [Figure 7] FIG. 7 is a side schematic view of an inner lumen that may be used with the catheter assembly shown in FIG. 6.

[0018] [Figure 8] FIG. 8 is a perspective schematic view showing the splines deployed from the inner lumen shown in FIG. 7.

[0019] [Figure 9A]FIG. 1 is a perspective view of an alternative embodiment of a catheter assembly.

[0020] [Figure 9B] FIG. 9B is a side schematic view of the catheter assembly shown in FIG. 9A.

[0021] [Figure 10A] FIG. 1 is a perspective view of an alternative embodiment of a catheter assembly.

[0022] [Figure 10B] FIG. 10B is a side schematic view of the catheter assembly shown in FIG. 10A.

[0023] [Figure 10C] FIG. 10B is a schematic diagram showing the catheter assembly of FIG. 10A in a first configuration.

[0024] [Figure 10D] FIG. 10B is a schematic diagram showing the catheter assembly of FIG. 10A in a second configuration.

[0025] [Figure 10E] FIG. 10B is a side cross-sectional view of the catheter assembly shown in FIG. 10A.

[0026] [Figure 10F] 10F-10J are schematic cross-sectional side views of the catheter assembly shown in FIG. 10A illustrating the transition of the catheter assembly between different states. [Figure 10G] 10F-10J are schematic cross-sectional side views of the catheter assembly shown in FIG. 10A illustrating the transition of the catheter assembly between different states. [Figure 10H] 10F-10J are schematic cross-sectional side views of the catheter assembly shown in FIG. 10A illustrating the transition of the catheter assembly between different states. [Figure 10I] 10F-10J are schematic cross-sectional side views of the catheter assembly shown in FIG. 10A illustrating the transition of the catheter assembly between different states. [Figure 10J] 10F-10J are schematic cross-sectional side views of the catheter assembly shown in FIG. 10A illustrating the transition of the catheter assembly between different states.

[0027] [Figure 10K] 10B is a side cross-sectional view of a portion of a handle that can be used with the catheter assembly shown in FIG. 10A.

[0028] [Figure 10L] FIG. 10C is a perspective view of a compression valve component, pin, and ring that may be used with the handle shown in FIG. 10K.

[0029] [Figure 10M] FIG. 10D is a perspective exploded view of the compression valve components, pin, and ring shown in FIG. 10L.

[0030] [Figure 11] FIG. 1 is a perspective view of an alternative embodiment of a catheter assembly.

[0031] [Figure 12] FIG. 1 is a perspective view of an alternative embodiment of a catheter assembly.

[0032] [Figure 13] FIG. 1 is a perspective view of an alternative embodiment of a catheter assembly.

[0033] [Figure 14] FIG. 1 is a perspective view of an alternative embodiment of a catheter assembly.

[0034] [Figure 15] FIG. 1 is a perspective view of an alternative embodiment of a catheter assembly.

[0035] [Figure 16] FIG. 1 is a perspective view of an alternative embodiment of a catheter assembly.

[0036] [Figure 17]FIG. 1 is a perspective view of an alternative embodiment of a catheter assembly.

[0037] [Figure 18] FIG. 1 is a perspective view of an alternative embodiment of a catheter assembly.

[0038] [Figure 19] FIG. 1 is a perspective view of an alternative embodiment of a catheter assembly. DETAILED DESCRIPTION OF THE INVENTION

[0039] Systems and methods for electroporation catheters are described herein. An exemplary electroporation catheter includes a shaft and a plurality of splines forming a basket around a distal portion of the shaft, each spline extending between a proximal end coupled to the shaft and a distal end coupled to the shaft, each spline of the plurality of splines including at least one energizable electrode. The electroporation catheter further includes a balloon disposed within the basket formed by the plurality of splines, the balloon being selectively inflatable to facilitate fixation of the position of the plurality of splines.

[0040] Although exemplary embodiments of the present disclosure are described with respect to pulmonary vein isolation (PVI), it is contemplated that the described features and methods of the present disclosure may be incorporated into any number of systems and any number of applications, as would be understood by one of ordinary skill in the art based on the disclosure herein.

[0041] FIG. 1 is a block diagram of a system 10 for electroporation therapy. Generally, the system 10 includes a catheter electrode assembly 12 disposed at the distal end 48 of a catheter 14. As used herein, "proximal" refers to the direction toward the end of the catheter closest to the clinician, and "distal" refers to the direction away from the clinician and (generally) within the patient's body. The electrode assembly includes one or more individual, electrically isolated electrode elements. Each electrode element, also referred to herein as a catheter electrode, is individually wired so that it can be selectively paired or combined with other electrode elements to function as a bipolar or multipolar electrode.

[0042] System 10 can be used for irreversible electroporation (IRE) to destroy tissue. In particular, system 10 can be used for electroporation-induced primary apoptosis treatment, which refers to the application of electrical current in a manner that directly causes irreversible loss of cell membrane (cell wall) integrity, resulting in its destruction and cell apoptosis. This cell death mechanism can be considered an "outside-in" process, meaning that destruction of the cell's outer wall has a detrimental effect on the cell's interior. Typically, in classical cell membrane electroporation, electrical current is provided as a pulsed electric field in the form of brief pulses (e.g., having a duration of 0.1 to 20 milliseconds (ms)) between closely spaced electrodes, capable of providing a field strength of approximately 0.1 to 1.0 kilovolts per centimeter (kV / cm). System 10 can be used, for example, with basket and / or balloon catheter assemblies for high-power (e.g., high voltage and / or high current) electroporation procedures. In certain embodiments, system 10 is configured to provide electroporation pulse signals with relatively high voltages and short pulse durations.

[0043] In one embodiment, all electrodes on the catheter deliver current simultaneously. Alternatively, in another embodiment, stimulation is delivered between a pair of electrodes on the catheter. Delivering current simultaneously using multiple electrodes can facilitate creating lesions deep enough for electroporation. To facilitate simultaneous electrode activation, the electrodes may be switchable between connection to a 3D mapping system and an EP amplifier.

[0044] Irreversible electroporation using the catheter described herein may enable pulmonary vein isolation with as little as one shock per vein, significantly reducing procedure time compared to sequential placement of radiofrequency (RF) ablation tips around the vein.

[0045] Although the energization method is described with respect to DC pulses, it should be understood that embodiments may use variations and remain within the spirit and scope of the present disclosure. For example, exponentially decaying pulses, exponentially increasing pulses, and combinations thereof may be used. Additionally, in some embodiments, AC pulses may be used.

[0046] Furthermore, it should be understood that the mechanism of cell destruction in electroporation is not primarily due to a heating effect, but rather to the disruption of cell membranes by the application of a high-voltage electric field. Thus, electroporation may avoid some of the thermal effects that can occur when using radio frequency (RF) energy. This "cold therapy" is a desirable feature.

[0047] With this background and referring again to Figure 1, system 10 includes a catheter electrode assembly 12 including at least one catheter electrode. Electrode assembly 12 is incorporated as part of a medical device, such as a catheter 14, for electroporation treatment of tissue 16 within a patient's body 17. In the exemplary embodiment, tissue 16 includes a heart or cardiac tissue. However, it should be understood that embodiments may be used to perform electroporation treatment on a variety of other body tissues.

[0048] FIG. 1 also illustrates multiple return electrodes 18, 20, and 21, which are diagrams of body connections that may be used by various subsystems included in the overall system 10, such as an electroporation generator 26, an electrophysiology (EP) monitor such as an ECG monitor 28, and a localization and navigation system 30 for visualization, mapping, and navigation of internal body structures. In the illustrated embodiment, the return electrodes 18, 20, and 21 are patch electrodes. The illustration of a single patch electrode is schematic (for clarity), and it should be understood that the subsystems to which these patch electrodes are connected may include more than one patch (body surface) electrode, typically more than one patch (body surface) electrode, and may include a split patch electrode (as described herein). In other embodiments, the return electrodes 18, 20, and 21 may be other types of electrodes suitable for use as return electrodes, including, for example, one or more catheter electrodes. A catheter return electrode may be part of the electrode assembly 12 or a separate catheter or device (not shown). System 10 may further include a main computer system 32 (including an electronic control unit 50 and a data storage memory 52), which may, in certain embodiments, be integrated with location and navigation system 30. System 32 may further include conventional interface components such as various user input / output mechanisms 34A and a display 34B, among other components.

[0049] The electroporation generator 26 is configured to energize the electrode elements according to an electroporation energization regimen, which may be predetermined or user-selectable. For electroporation-induced primary apoptosis therapy, the generator 26 may be configured to generate current delivered through the electrode assembly 12 as a pulsed electric field in the form of short-duration DC pulses (e.g., nanoseconds to milliseconds in duration, 0.1 to 20 milliseconds in duration, or any duration suitable for electroporation) between closely spaced electrodes, capable of providing a field strength (i.e., at the tissue site) of approximately 0.1 to 1.0 kV / cm. The amplitude and pulse duration required for irreversible electroporation are inversely proportional. As the pulse duration decreases, the amplitude must increase to achieve electroporation.

[0050] The electroporation generator 26, sometimes referred to herein as a DC energy source, is a monophasic electroporation generator 26 configured to generate a series of DC energy pulses that all generate current in the same direction. In other embodiments, the electroporation generator is a biphasic or polyphasic electroporation generator configured to generate DC energy pulses that do not all generate current in the same direction. In some embodiments, the electroporation generator 26 is configured to output DC pulses of energy at selectable energy levels, such as 50 joules, 100 joules, 200 joules, etc. Other embodiments may have more or fewer energy settings, and the available settings may be the same or different. For successful electroporation, some embodiments utilize a power level of 200 joules. For example, the electroporation generator 26 may output DC pulses having a peak magnitude of about 300 volts (V) to about 3,200 V at a power level of 200 joules. In some embodiments, the peak magnitude may be even greater (e.g., about 10,000 V). Other embodiments may output any other suitable positive or negative voltage. For example, in some embodiments, the systems and methods described herein can include pulses having amplitudes of about 500V to about 4,000V with pulse widths of about 200 nanoseconds to about 20 microseconds.

[0051] In some embodiments, variable impedance 27 can vary the impedance of system 10 to limit arcing. Additionally, variable impedance 27 can be used to change one or more characteristics of the output of electroporation generator 26, such as the amplitude, duration, pulse shape, etc. Although illustrated as a separate component, variable impedance 27 may be incorporated into catheter 14 or generator 26.

[0052] 1, as noted above, catheter 14 may include functionality for electroporation and, in certain embodiments, may also include functionality for other types of ablation (e.g., RF ablation). However, it should be understood that in those embodiments, variations are possible as to the type of ablation energy provided (e.g., cryoablation, ultrasound, etc.).

[0053] In the illustrated embodiment, the catheter 14 includes a cable connector or interface 40, a handle 42, and a shaft 44 having a proximal end 46 and a distal end 48. The catheter 14 may also include other conventional components not shown herein, such as a temperature sensor, additional electrodes, and corresponding electrical conductors or leads. The connector 40 provides a mechanical and electrical connection for a cable 56 extending from the generator 26. The connector 40 may include conventional components known in the art and is located at the proximal end of the catheter 14, as shown.

[0054] The handle 42 provides a location for the clinician to hold the catheter 14 and may also provide a means for steering or guiding the shaft 44 within the body 17. For example, the handle 42 may include a means for changing the length of a guidewire extending through the catheter 14 to the distal end 48 of the shaft 44 or a means for steering the shaft 44. Furthermore, in some embodiments, the handle 42 may be configured to change the shape, size, and / or orientation of a portion of the catheter, and it will be understood that the configuration of the handle 42 may vary. In another embodiment, the catheter 14 may be robotically driven or controlled. Thus, rather than a clinician manipulating the handle to advance / retreat and / or guide or guide the catheter 14 (and particularly its shaft 44), a robot is used to manipulate the catheter 14. The shaft 44 is an elongated, tubular, flexible member configured to move within the body 17. The shaft 44 is configured to support the electrode assembly 12 and contain associated conductors and, possibly, additional electronics used for signal processing or conditioning. Shaft 44 may also allow for the transport, delivery, and / or removal of fluids (including irrigation fluids and bodily fluids), medications, and / or surgical tools or instruments. Shaft 44 may be made from conventional materials, such as polyurethane, and defines one or more lumens configured to accommodate and / or transport electrical conductors, fluids, or surgical instruments, as described herein. Shaft 44 may be introduced into a blood vessel or other structure within body 17 via a conventional introducer. Shaft 44 may then be advanced / retracted and / or guided or guided through body 17 to a desired location, such as a site in tissue 16, including through the use of a guidewire or other means known in the art.

[0055] In some embodiments, the catheter 14 includes a basket catheter assembly having a catheter electrode (not shown in FIG. 1) disposed at the distal end of the shaft 44 within the basket structure. Additionally, as described herein, an inflatable balloon may be housed within the basket structure.

[0056] A localization and navigation system 30 can be provided for visualization, mapping, and navigation of internal body structures. The localization and navigation system 30 may include conventional devices commonly known in the art (e.g., the ENSITE PRECISION™ system, commercially available from ABBOTT LABORATORIES, Inc., and generally described with reference to commonly assigned U.S. Patent No. 7,263,397, entitled "Method and Apparatus for Catheter Navigation and Location and Mapping in the Heart," which is incorporated herein by reference in its entirety). However, it should be understood that this system is exemplary and not limiting in nature. Other techniques for localizing / navigating (and visualizing) a catheter in space are known, including, for example, Biosense Webster's CARTO navigation and localization system, Boston Scientific SciMed's RHYTHMIA® system, KONINKLIJKE PHILIPS NV's KODEX® system, Northern Digital's AURORA® system, commercially available fluoroscopy systems, or magnetic location systems such as Mediguide's gMPS system. In this regard, some localization, navigation, and / or visualization systems involve the provision of sensors to generate signals indicative of the catheter's location, such as one or more electrodes in the case of impedance-based localization systems, or one or more coils (i.e., wire windings) configured to detect one or more characteristics of a magnetic field in the case of magnetic field-based localization systems. As yet another example, system 10 may utilize a combined electric field-based and magnetic field-based system, such as is generally described with reference to U.S. Pat. No. 7,536,218, entitled "Hybrid Magnetic-Based and Impedance Based Position Sensing," which is incorporated herein by reference in its entirety.

[0057] Pulsed field ablation (PFA) has been shown to be an effective form of ablation for the treatment of cardiac arrhythmias, particularly for momentary pulmonary vein isolation (PVI). PFA involves the delivery of high-voltage pulses from electrodes positioned on a catheter (including, for example, the basket catheters and / or balloon catheters described herein). In PFA, for example, the voltage amplitude may range from about 300 V to at least 3,200 V (or even as much as about 10,000 V), and the pulse width may range from hundreds of nanoseconds to tens of milliseconds.

[0058] These electric fields can be applied between adjacent electrodes (in a bipolar approach) or between one or more electrodes and a return patch (in a monopolar approach), each of which has advantages and disadvantages (e.g., when using basket and / or balloon catheters as described herein).

[0059] For example, with regard to lesion spread, a monopolar approach can leave gaps (called dead zones) in the lesion area between electrodes where the field strength is low or zero, whereas the field strength of a bipolar approach generally prevents dead zones between electrodes.

[0060] In terms of lesion size and proximity, monopolar approaches have a wider effective range and may be able to create deeper lesions with the same applied voltage. Furthermore, monopolar approaches can create lesions from a greater distance (e.g., generally in close proximity, but not necessarily in contact with tissue). Bipolar approaches can create smaller lesions, requiring tissue proximity and contact to create transmural lesions. However, monopolar approaches may create larger lesions than necessary, and bipolar approaches may result in more localized lesions.

[0061] A unipolar approach has a wider area of ​​effect and may undesirably activate skeletal muscle and nerves, whereas a bipolar approach has a more limited area of ​​effect proportional to the electrode spacing on the lead and is less likely to depolarize cardiomyocytes and nerve fibers.

[0062] In a monopolar approach, only a single potential is applied to the catheter wire and electrodes. Furthermore, because all electrodes are of the same polarity, this configuration is less susceptible to arcing (e.g., when using basket catheters and / or balloon catheters as described herein). In contrast, in a bipolar approach, the various electrodes are at different potentials, and the internal structure of the catheter must be constructed to prevent arcing.

[0063] To monitor the operation of system 10, one or more impedances between the catheter electrodes and / or return electrodes 18, 20, 21 may be measured. For example, for system 10, impedance may be measured as described in U.S. Patent Application Publication No. 2019 / 0117113, filed October 23, 2018, U.S. Patent Application Publication No. 2019 / 0183378, filed December 19, 2018, and U.S. Patent Application No. 63 / 027,660, filed May 20, 2020, all of which are incorporated by reference in their entireties.

[0064] FIG. 2 is a diagram of one embodiment of a handle 200 that can be used with the system 10 and the catheter 14. The handle 200 includes a first actuator 222 and a second actuator 224. The first actuator 222 may be rotatable, for example, about an axis of rotation substantially perpendicular to the longitudinal axis of the handle 200 to selectively deflect at least a portion of the catheter 14. The second actuator 224 may be rotatable, for example, about the same axis as the first actuator 222 to selectively fix the deflected orientation of the catheter 14. That is, the first actuator 222 can be operated to deflect at least a portion of the catheter 14 to a desired orientation, and the second actuator 224 can then be operated to lock the catheter 14 in that orientation. Accordingly, the first actuator 222 and the second actuator 224 can be connected to one or more actuation wires extending through the catheter 14.

[0065] 2, a number of connectors 230 are coupled to the handle 200 by cables 232. The connectors 230 may be used to connect the catheter 14 to a generator, such as the generator 26 (shown in FIG. 1). Additionally, the connectors 230 may provide an interface between a positioning and navigation system, such as the positioning and navigation system 30 (shown in FIG. 1), and one or more magnetic sensors included in the catheter 14, as described in more detail below.

[0066] Those skilled in the art will appreciate that handle 200 is merely exemplary and that any suitable handle and / or actuator arrangement may be utilized to implement the systems and methods described herein.

[0067] 3 is a side schematic view of one embodiment of a catheter assembly 300 that may be used with system 10 (shown in FIG. 1 ). Catheter assembly 300 includes a shaft 302 and a balloon 304 coupled to a distal end 305 of shaft 302. In this embodiment, catheter assembly 300 includes a first electrode 308 at a proximal end 310 of balloon 304 and a second electrode 312 at a distal end 314 of balloon 304. Catheter assembly 300 is shown positioned within a pulmonary vein 320.

[0068] 4 is a side schematic view of an alternative embodiment of a catheter assembly 402 that may be used with system 10 (shown in FIG. 1 ). Catheter assembly 400 includes a shaft 400 and a balloon 404 coupled to a distal end 406 of shaft 402. In this embodiment, catheter 400 includes multiple electrodes 412 proximate a distal end 414 of balloon 404. The electrodes 412, unlike the second electrode 312 shown in FIG. 3 , extend outward from balloon 404 to be proximate the wall of pulmonary vein 320. In this embodiment, catheter assembly 400 includes eight electrodes 412 (only five are shown for clarity). Alternatively, catheter assembly 400 may include any suitable number of electrodes 412.

[0069] In this embodiment, each electrode 412 is coupled to a corresponding spline (not shown). The spline and electrodes 412 fit into the inner lumen of the catheter assembly 400 during delivery. Upon deployment of the catheter assembly 400, the spline flares outward (e.g., like an umbrella) so that the electrodes 412 are close to or in contact with the wall of the pulmonary vein 320. Using the catheter assembly 400, an applied voltage of 1,400 V to 2,500 V can produce sufficient damage even in a pulmonary vein with a diameter of 25 mm.

[0070] 5 is a side schematic view of an alternative embodiment of a catheter assembly 500 that may be used with system 10 (shown in FIG. 1 ). Catheter assembly 500 includes a shaft 502 and a balloon 504 coupled to a distal end 506 of shaft 502. In this embodiment, catheter assembly 500 includes multiple electrodes 512 proximate a distal end 514 of balloon 504. Electrode 512, unlike second electrode 312 shown in FIG. 3 , is positioned on a loop 516 so as to be proximate to the wall of pulmonary vein 320. Loop 516 and electrode 512 fit within the inner lumen of catheter assembly 500 during delivery. Upon deployment of catheter assembly 500, loop 516 deploys so that electrodes 512 are proximate to or in contact with the wall of pulmonary vein 320.

[0071] In this embodiment, the catheter assembly 500 includes 14 electrodes 512 (for clarity, only half of the loops 514 and eight electrodes 512 are shown). Alternatively, the catheter assembly 500 may include any suitable number of electrodes 512. Using the catheter assembly 500, an applied voltage of 2,000 V or 2,500 V can produce sufficient lesions in even a 25 mm diameter pulmonary vein.

[0072] 6 is a side schematic view of an alternative embodiment of a catheter assembly 600 that may be used with system 10 (shown in FIG. 1 ). Catheter assembly 600 includes a shaft 602 and a balloon 604 coupled to a distal end 606 of shaft 602. In this embodiment, catheter assembly 600 includes a plurality of preformed splines 612 that function as electrodes. Splines 612 may fit into an inner lumen of catheter assembly 600 or may surround balloon 604 during delivery. In embodiments where splines 612 fit into an inner lumen, splines 612 may expand radially outward when deployed such that splines 612 are adjacent to or in contact with the wall of pulmonary vein 320.

[0073] In the illustrated embodiment, the catheter assembly 600 includes 12 splines 612 (although only seven splines 612 are shown). Alternatively, the catheter assembly 600 can include any suitable number of splines 612. For example, the catheter assembly 600 can include 10 to 16 splines 612 in some embodiments.

[0074] The splines 612 may be made from nitinol, stainless steel, and / or other superalloys. Furthermore, the entirety of each spline 612 may function as an electrode, or a portion of each spline 612 may be covered with an insulating material (e.g., polyethylene terephthalate (PET) heat shrink material or polyether block amide (PEBA) material) so that only the uninsulated portion of each spline 612 functions as an electrode. Furthermore, in some embodiments, multiple independently energizable electrodes are attached to each spline 612. Using the catheter assembly 600, an applied voltage of 2,000 V or 2,500 V can be applied to produce sufficient damage, even in a 25 mm diameter pulmonary vein.

[0075] The splines 612 can be formed, for example, by laser cutting a tube (e.g., made of nitinol, stainless steel, and / or other superalloy) into strips and heat treating the strips to form a shape that conforms to the balloon 604.

[0076] Figure 7 is a side schematic view of the inner lumen 630 of the catheter assembly 600 with the splines 612 housed within the inner lumen 630 (e.g., during delivery of the catheter assembly 600 and prior to deployment of the splines 612). Figure 8 is a perspective schematic view showing the splines 612 deployed from the inner lumen 630.

[0077] The splines 612 may all be electrically connected to each other as a single electrode, or each may be an individual electrode. If the splines 612 are individual electrodes, each spline 612 may be selectively energizable to form different energization sequences and / or patterns. Generally, each spline 612 has the same polarity to avoid arcing problems.

[0078] The splines 612 may all be the same length, or at least some of the splines 612 may be different lengths. Additionally, the splines 612 may include insulation covering at least a portion of each spline 612. The insulation for each spline 612 may be the same length, or at least some of the splines 612 may have different lengths of insulation. Additionally, in some embodiments, the catheter assembly 600 includes a distal electrode (not shown) disposed distal to the splines 612. The distal electrode may be used to perform point ablation (e.g., by forming a bipole between the distal electrode and one of the splines 612) and / or may be used for visualization / mapping (e.g., by using the distal electrode in combination with an electrode on the shaft 602).

[0079] Figure 9A is a perspective view of an alternative embodiment of a catheter assembly 900, and Figure 9B is a side schematic view of the catheter assembly 900. The catheter assembly 900 includes a shaft 902 and a plurality of splines 904 that surround a distal portion 906 of the shaft 902. Each spline 904 includes a proximal end 910 that is coupled to the shaft 902 and a distal end 912 that is also coupled to the shaft 902. The splines 904 extend radially outward from the proximal end 910 to an inflection point 914 and then extend radially inward to the distal end 912. Figure 9B shows the catheter assembly 900 positioned within a pulmonary vein 320.

[0080] The body of each spline 904 is made of a resilient material (e.g., nitinol) and functions as a relatively large electrode. In this embodiment, alternating splines 904 alternate polarity; that is, each positive spline 904 is positioned between two negative splines 904, and vice versa. Alternatively, any suitable polarization scheme may be used.

[0081] To control the ablation zone of each spline 904, a portion of each spline 904 may be covered with an insulating material 920 (e.g., heat shrink (e.g., PET) or polymer tubing, or a spray or dip coat with polyimide or PEBA), with the exposed portion of the spline 904 functioning as an electrode. In the embodiment shown in FIGS. 9A and 9B, the inflection point 914 and the portion of the spline 904 between the inflection point 914 and the distal end 912 are generally exposed, while the portion of the spline 904 between the inflection point 914 and the proximal end 910 is generally insulated. This results in the portion of the spline 904 that contacts the pulmonary vein 320 being exposed (see FIG. 9B). Alternatively, any suitable insulating configuration may be used.

[0082] During delivery, the splines 904 may collapse and be oriented substantially parallel to the shaft 902 (i.e., with the inflection points 914 proximate to the shaft 902). To perform the ablation, the splines 904 are then deployed with the inflection points 914 flared radially outward.

[0083] Notably, compared to the catheter assemblies 300, 400, 500, and 600 shown in FIGS. 3-6, the catheter assembly 900 facilitates ablation of a more proximal and wider portion of the pulmonary vein 320.

[0084] The splines 904 may all be the same length, or at least some of the splines 904 may be different lengths. Further, the insulating material 920 of each spline 904 may be the same length, or at least some of the splines 904 may have different lengths of insulating material 920. Furthermore, in some embodiments, the catheter assembly 900 includes a distal electrode (not shown) disposed distal to the splines 904. The distal electrode may be used to perform point ablation (e.g., by forming a bipole between the distal electrode and one of the splines 904) and / or may be used for visualization / mapping (e.g., by using the distal electrode in combination with an electrode on the shaft 902).

[0085] Figure 10A is a perspective view of an alternative embodiment catheter assembly 1000, and Figure 10B is a side schematic view of the catheter assembly 1000. Similar to the catheter assembly 900 shown in Figure 9, the catheter assembly 1000 includes a shaft 1002 and a plurality of splines 1004 surrounding a distal portion 1006 of the shaft 1002. However, in contrast to the catheter assembly 900, the catheter assembly 1000 includes a balloon 1008 surrounded by the splines 1004. The balloon 1008 may be selectively inflated to occupy the spaces between the splines 1004. Notably, the balloon 1008 acts as an insulator and generally reduces energy loss compared to the catheter assembly 900, potentially increasing the size of the lesion.

[0086] Each spline 1004 includes a proximal end 1010 coupled to the shaft 1002 and a distal end 1012 coupled to the shaft 1002. The splines 1004 extend radially outward from the proximal end 1010 to an inflection point 1014 and then extend radially inward to the distal end 1012. Figure 10B shows the catheter assembly 1000 positioned within the pulmonary vein 320.

[0087] During delivery, the splines 1004 and balloon 1008 may collapse. To perform ablation, the splines 1004 are deployed with the inflection points 1014 flaring radially outward, and the balloon 1008 is selectively inflated to occupy the spaces between the splines 1004.

[0088] In some embodiments, the shape of the balloon 1008 can be selectively altered to improve ablation. For example, Figure 10C is a schematic diagram showing the catheter assembly 100 in a first configuration 1030, and Figure 10D is a schematic diagram showing the catheter assembly 100 in a second configuration 1032. In the second configuration 1032, the splines 1004 are axially compressed compared to the first configuration 1030 such that the effective diameter of the splines 1004 is increased.

[0089] To facilitate selective transition of the balloon catheter assembly 100 between the first configuration 1030 and the second configuration 1032, an inner shaft member (not shown in FIGS. 10A-10D ) can be slidably disposed within the shaft 1002, with the distal end of the inner shaft member coupled to the distal end 1034 of the balloon 1008 and the splines 1004. When the inner shaft member is pulled proximally relative to the shaft 1002, the distal end 1034 of the balloon 1008 and the splines 1004 are also pulled proximally relative to the proximal end 1036 of the balloon 1008 and the splines 1004, axially compressing the balloon 1008 and the splines 1004. The position of the inner shaft member relative to the shaft 1002 can be held in place using a suitable locking mechanism (e.g., a Tuohy Borst compression valve), as described in detail herein.

[0090] FIG. 10E is a side cross-sectional view of the catheter assembly 1000. As shown in FIG. 10E, the catheter assembly 1000 can include one or more magnetic sensors (e.g., to facilitate determining the position and / or orientation of the catheter assembly 1000 within a patient). In this embodiment, a hollow-core magnetic sensor 1050 is positioned proximate the distal end 1034 of the balloon 1008. The hollow-core magnetic sensor 1050 allows a central lumen 1052 of the shaft 1002 to extend therethrough. The hollow-core magnetic sensor 1050 can have sensing capabilities across five degrees of freedom (enabling position detection in the X, Y, and Z directions), for example. The central lumen 1052 can be used, for example, to accommodate a guidewire, a small-diameter mapping catheter, and / or to inject contrast into the patient (e.g., to facilitate determining the position of the catheter assembly 1000). Additionally, in some embodiments, two or more electrodes (not shown) are coupled to the shaft 1002 to facilitate impedance-based localization.

[0091] The catheter assembly 1000 also includes two solid-core magnetic sensors 1060 positioned adjacent the proximal end 1036 of the balloon 1008. The solid-core magnetic sensors 1060 may, for example, be embedded in the shaft 1002, but positioned outside of the central lumen 1052. The solid-core magnetic sensors 1060 individually have five or more degrees of freedom sensing capabilities, but combined have six or more degrees of freedom sensing capabilities (enabling position sensing in X, Y, and Z directions, and roll detection of the catheter assembly 1000).

[0092] In this embodiment, the central lumen 1052 facilitates the delivery of fluid to the interior of the balloon 1008 to selectively inflate the balloon 1008. The fluid may include saline or a mixture of saline and contrast media. In some embodiments, the shaft 1002 may include irrigation holes (not shown) that provide fluid communication between the central lumen 1052 and the interior of the balloon 1008. Additionally, in some embodiments, the central lumen 1052 may allow for the injection of contrast media distal to the catheter assembly 1000, which may assist the user in assessing blood flow through the pulmonary vein 320 and the extent to which the catheter assembly 1000 is occluding the pulmonary vein 320.

[0093] 10F-10J are schematic side cross-sectional views of the catheter assembly 1000 illustrating the transition of the catheter assembly 1000 between different states. As shown in FIG. 10F, in this embodiment, the shaft 1002 includes an outer shaft element 1062 and an inner shaft element 1064, both of which are tubular members. The inner shaft element 1064 is axially slidable within the outer shaft element 1062 and defines a central lumen 1052 therethrough. The outer shaft element 1062 can have a French size of, for example, 11.5 French. Alternatively, the outer shaft element 1062 can have any suitable dimensions.

[0094] A valve 1066 at the distal end of the inner shaft element 1064 controls access to the central lumen 1052. For example, as described above, contrast may be flowed into the patient through the central lumen 1052 to identify pulmonary vein obstruction. As another example, a mapping catheter (e.g., a 3 French mapping catheter) may extend into the patient through the central lumen 1052. As yet another example, a guidewire may extend through the central lumen 1052. Those skilled in the art will appreciate that obstruction can be monitored using any suitable technique. For example, pressure monitoring may be used to assess venous obstruction, contrast injection may be used to assess venous obstruction using fluoroscopy, and / or ultrasound (e.g., Doppler) may be used to assess obstruction.

[0095] 10F, in this embodiment, a channel 1070 is defined between the outer shaft element 1062 and the inner shaft element 1064. The channel is in fluid communication with the interior of the balloon 1008. Additionally, a stopcock valve 1072 (e.g., a three-way stopcock valve) controls the flow of fluid into the interior of the balloon 1008, thereby allowing the balloon to be inflated and deflated as desired.

[0096] In some embodiments, shape sensing fibers may extend through the central lumen 1052 and / or the channel 1070. The shape sensing fibers may be optical fibers that allow a user to precisely determine the position and orientation of the shape sensing fibers, and thus the position and orientation of the shaft 1002.

[0097] In this embodiment, the catheter assembly 1000 further includes a compression valve 1080 that facilitates fixing the position of the outer shaft element 1062 relative to the inner shaft element 1064. Specifically, when the compression valve 1080 is open, the inner shaft element 1064 is slidable relative to the outer shaft element 1062. Once the inner shaft element 1064 is in a desired position, the compression valve 1080 may be closed to prevent the inner shaft element 1064 from sliding relative to the outer shaft element 1062. The compression valve 1080 also seals the proximal end of the channel 1070.

[0098] 10F, each spline 1004 extends between a distal end 1084 of the outer shaft element 1026 and a distal end 1086 of the inner shaft element 1064. Thus, by sliding the inner shaft element distal end 1086 relative to the outer shaft element distal end 1084, the shape of the spline 1004 is adjustable.

[0099] Figure 10F shows the splines 1004 in a neutral position with the balloon 1008 deflated. Specifically, in this embodiment, the splines 1004 are made from a shape memory material (e.g., nitinol) such that when not subjected to an external force or bias, the splines 1004 assume the shape shown in Figure 10F.

[0100] To compress the catheter assembly 1000 (e.g., for delivery of the catheter assembly 1000), the inner shaft element 1064 is slid distally relative to the outer shaft element 1062. This causes the splines 1004 to collapse inward toward the inner shaft element, transitioning the catheter assembly 1000 to the collapsed position, as shown in FIG. 10G, in which the balloon 1008 is deflated. The catheter assembly 1000 can be locked in the collapsed position using the compression valve 1080.

[0101] 10H, during treatment, the balloon 1008 expands to fill the space between the splines 1004. Specifically, as shown in FIG. 10H, with the balloon 1008 inflated, the balloon 1008 generally conforms to the shape of the basket formed by the splines 1004.

[0102] 10C and 10D, the basket formed by the splines 1004 may be compressed to increase the outer diameter of the catheter assembly 1000. Specifically, as shown in FIG. 10I, when the inner shaft element 1064 is slid proximally relative to the outer shaft element 1062, this causes the splines 1004 to flex outward and moves the catheter assembly 1000 to a compressed position. In FIG. 10I, the balloon 1008 is deflated. The catheter assembly 1000 can be locked in the compressed position using the compression valve 1080.

[0103] 10J, in the compressed position, the balloon 1008 can be inflated to fill the spaces between the splines 1004. Specifically, as shown in FIG. 10J, with the balloon 1008 inflated, the balloon 1008 generally conforms to the shape of the basket formed by the splines 1004 in the compressed position.

[0104] 10K is a side cross-sectional view of a portion of a handle 1090 that can be used with the catheter assembly 1000. The handle 1090 includes a housing 1091 and a compression valve component 1092 (e.g., including the compression valve 1080) disposed within the housing 1091. The handle 1090 further includes a rotatable knob 1093 coupled to the compression valve component 1092 at the distal end of the housing 1091. By rotating the knob 1093, a user can selectively open or close the compression valve 1080 and secure the position of the inner shaft element 1064 as desired.

[0105] Additionally, as shown in FIG. 10K, a positioning piece 1094 is coupled to the distal end of the inner shaft element 1064. With the compression valve 1080 open, the positioning piece 1094 can slide axially relative to the housing 1091 to allow the inner shaft element 1064 to slide relative to the outer shaft element 1062, as described above. A first fluid supply line 1095 (i.e., for supplying fluid to the central lumen 1052) and a second fluid supply line 1096 (i.e., for supplying fluid to the channel 1070) are also shown in FIG. 10K.

[0106] A pin 1097 non-rotatably couples the positioning component 1094 to the compression valve component 1092 to prevent rotation of the positioning component 1094 and first fluid supply line 1095 relative to the housing 1091. Specifically, as shown in the perspective view of FIG. 10L and the exploded view of FIG. 10M, a ring 1098 couples the pin 1097 to the compression valve component 1092. The ring 1098 has protrusions 1099 that engage slots defined in the compression valve component 1092 and the pin 1097 such that the pin 1097 (and thus the positioning component 1094) cannot rotate relative to the compression valve component 1092.

[0107] In some embodiments, one or more lumens are defined within the outer shaft element 1062 (e.g., between the inner and outer surfaces of the outer shaft element 1062). The lumens can be used to route electrical wires (i.e., for powering the splines 1004) and / or actuation wires (i.e., for controlling the orientation of the catheter assembly 1000) through the catheter assembly 1000. For example, in one embodiment, all positive electrical wires that energize the positive splines 1004 are routed through a first lumen, and all negative electrical wires that energize the negative splines are routed through a second, separate lumen. This effectively separates the positive electrical wires from the negative electrical wires.

[0108] Each electrical wire may be coupled to an associated spline 1004, for example, via a weld, with the proximal end of the weld and spline disposed on a proximal coupler piece (not shown). Additionally, in some embodiments, a strain relief piece (not shown) is coupled to the outside of the inner shaft element 1064 distal to the outer shaft element 1062 to prevent the inner shaft element 1064 from bending excessively.

[0109] The catheter assembly 1000 has several advantages. For example, the combination of the balloon 1008 and splines 1004 facilitates straight delivery and deployment of the catheter assembly 1000. Additionally, the balloon 1008 delivers more energy to the ablated tissue and stabilizes the splines 1004 to prevent lateral migration. Furthermore, the use of the splines 1004 as electrodes instead of individual small electrodes helps reduce costs and improve the reliability of the catheter assembly 1000.

[0110] The splines 1004 may all be the same length, or at least some of the splines 1004 may be different lengths. Furthermore, the insulating material (e.g., PET or PEBA material) on each spline 1004 may be the same length, or at least some of the splines 1004 may have different lengths of insulating material. Furthermore, in some embodiments, the catheter assembly 1000 includes a distal electrode (not shown) disposed distal to the splines 1004. The distal electrode may be used to perform point ablation (e.g., by forming a bipole between the distal electrode and one of the splines 1004) and / or may be used for visualization / mapping purposes (e.g., by using the distal electrode in combination with an electrode on the shaft 1002).

[0111] 11 is a perspective view of an alternative embodiment catheter assembly 1100. The catheter assembly 1100 includes a shaft 1102 and a plurality of splines 1104 that surround a distal portion 1106 of the shaft 1102. Each spline 1104 includes a proximal end 1110 that is coupled to the shaft 1102 and a distal end 1112 that is also coupled to the shaft 1102. From the proximal end 1110 to the distal end 1112, the splines 1104 have an arcuate shape that extends radially outward.

[0112] In this embodiment, each spline 1104 includes a plurality of individual electrodes 1120. For example, each spline 1104 can include a resilient material (e.g., nitinol) covered with a polymer tube 1122, with the individual electrodes 1120 attached to the outside of the polymer tube 1122. In the illustrated embodiment, each spline 1104 includes two electrodes 1120. Furthermore, as shown in FIG. 11 , the electrodes 1120 are generally positioned closer to the distal end 1112 than to the proximal end 1110 to correspond to the portion of the spline 1104 that contacts the pulmonary vein 320.

[0113] Alternatively, each spline 1104 may include any suitable number and arrangement of electrodes 1120. For example, in some embodiments, each spline 1104 includes four electrodes 1120.

[0114] In this embodiment, the alternating splines 1104 alternate polarity. That is, the electrodes 1120 on a particular spline 1104 have the same polarity, but the electrodes 1120 on a particular spline 1104 have a different polarity than the electrodes 1120 on adjacent splines 1104. Alternatively, any suitable polarization scheme may be used. During delivery, the splines 1104 may collapse toward the shaft 1102. Thereafter, the splines 1104 are deployed to spread radially outward to perform ablation.

[0115] Including multiple electrodes 1120 on each spline 1104, instead of the elastic material of the spline 1104 itself being the electrode 1120, allows each electrode 1120 to be used as an individual sensor for acquiring mapping data, thereby improving the ability of the catheter assembly 1100 to perform various mapping routines.

[0116] The splines 1104 may all be the same length, or at least some of the splines 1104 may be different lengths. Additionally, the insulating material (e.g., PET or PEBA material) on each spline 1104 may be the same length, or at least some of the splines 1104 may have different lengths of insulating material. Additionally, in some embodiments, the catheter assembly 1100 includes a distal electrode (not shown) disposed distal to the splines 1104. The distal electrode may be used to perform point ablation (e.g., by forming a bipole between the distal electrode and one of the splines 1104) and / or may be used for visualization / mapping purposes (e.g., by using the distal electrode in combination with an electrode on the shaft 1102).

[0117] Figure 12 is a perspective view of an alternative embodiment catheter assembly 1200. Similar to catheter assembly 1100 (shown in Figure 11), catheter assembly 1200 includes a shaft 1202 and a plurality of splines 1204 surrounding a distal portion 1206 of shaft 1202. However, in contrast to catheter assembly 1100, catheter assembly 1200 includes a balloon 1208 surrounded by splines 1204. Balloon 1208 can be selectively inflated to fill the spaces between splines 1204. Notably, balloon 1208 acts as an insulator and generally allows for less energy loss and, consequently, larger lesion sizes compared to catheter assembly 1200.

[0118] Each spline 1204 includes a proximal end 1210 coupled to the shaft 1202 and a distal end 1212 coupled to the shaft 1202. From the proximal end 1210 to the distal end 1212, the spline 1204 has an arcuate shape that extends radially outward.

[0119] In this embodiment, each spline 1204 includes a plurality of individual electrodes 1220. For example, each spline 1204 can include a resilient material (e.g., nitinol) covered with a polymer tube 1222, with the individual electrodes 1220 attached to the outside of the polymer tube 1222. In the illustrated embodiment, each spline 1204 includes two electrodes 1220. Furthermore, as shown in FIG. 12 , the electrodes 1220 are generally positioned closer to the distal end 1212 than to the proximal end 1210 to correspond to the portion of the spline 1204 that contacts the pulmonary vein 320.

[0120] Alternatively, each spline 1204 may include any suitable number and arrangement of electrodes 1220. For example, in some embodiments, each spline 1204 includes four electrodes 1220.

[0121] In this embodiment, the alternating splines 1204 alternate polarity. That is, the electrodes 1220 on a particular spline 1204 have the same polarity, but the electrodes 1220 on a particular spline 1204 have a different polarity than the electrodes 1220 on adjacent splines 1204. Alternatively, any suitable polarization scheme may be used. During delivery, the splines 1204 may collapse toward the shaft 1202. Thereafter, to perform ablation, the splines 1204 are deployed to spread radially outward.

[0122] The splines 1204 may all be the same length, or at least some of the splines 1204 may be different lengths. Furthermore, the insulating material (e.g., PET or PEBA material) on each spline 1204 may be the same length, or at least some of the splines 1204 may have different lengths of insulating material. Furthermore, in some embodiments, the catheter assembly 1200 includes a distal electrode (not shown) disposed distal to the splines 1204. The distal electrode may be used to perform point ablation (e.g., by forming a bipole between the distal electrode and one of the splines 1204) and / or may be used for visualization / mapping purposes (e.g., by using the distal electrode in combination with an electrode on the shaft 1202).

[0123] 13 is a perspective view of an alternative embodiment catheter assembly 1300. The catheter assembly 1300 includes a shaft 1302 and a plurality of splines 1304 that surround a distal portion 1306 of the shaft 1302. Each spline 1304 includes a proximal end 1310 that is coupled to the shaft 1302 and a distal end 1312 that is also coupled to the shaft 1302. The splines 1304 extend radially outward from the proximal end 1310 to an inflection point 1314 and then extend radially inward to the distal end 1312.

[0124] The splines 1304 are made of a resilient material (e.g., nitinol) and function as relatively large electrodes. In this embodiment, alternating splines 1304 alternate polarity; that is, each positive spline 1304 is located between two negative splines 1304, and vice versa. Alternatively, any suitable polarization scheme may be used.

[0125] To control the ablation zone of each spline 1304, a portion of each spline 1304 may be covered with an insulating material 1320 (e.g., heat shrink or polymer tubing such as PET or PEBA), with the exposed portion of the spline 1304 functioning as an electrode. In the embodiment shown in FIG. 13 , the inflection point 1314 and the portion of the spline 1304 between the inflection point 1314 and the distal end 1312 are generally exposed, while the portion of the spline 1304 between the inflection point 1314 and the proximal end 1310 is generally insulated. This results in the portion of the spline 1304 that contacts the pulmonary vein 320 being exposed. Alternatively, any suitable insulating configuration may be used.

[0126] 13, each spline 1304 includes a diverging member 1330. The diverging member 1330 includes a first end 1332, a second end 1334, a first branch 1336, and a second branch 1338. The first branch 1336 and the second branch 1338 extend away from each other from the first end 1332 and then extend back toward each other before reuniting at the second end 1334.

[0127] The spreading member 1330 can be fabricated, for example, using laser cutting. In this embodiment, all of the spreading member 1330 is exposed (i.e., not covered with insulating material). Alternatively, only a portion of the spreading member 1330 can be covered with insulating material.

[0128] The inclusion of the spreader members 1330 on the splines 1304 reduces the extent of circumferential clearance between the splines 1304, facilitating an increase in the lesion volume. Additionally, additional splines 1304 may be included to further reduce the extent of circumferential clearance.

[0129] In some embodiments, at least one of the splines 1304 includes multiple spreading members 1330 instead of a single spreading member 1330. Furthermore, as shown in Figure 13, the spreading members 1330 are longitudinally aligned with one another in the catheter assembly 1300. However, in some embodiments, at least some of the spreading members 1330 are longitudinally offset with respect to one another.

[0130] Additionally, although the spreader member 1330 is shown as having two branches 1336 and 1338 of substantially equal length, the spreader member 1330 may have a varying number of branches and / or branches of non-uniform lengths. Additionally, in some embodiments, the spreader member 1330 may be formed from two separate splines 1304 instead of a single spline 1304 forming the spreader member 1330.

[0131] During delivery, the splines 1304 may collapse inward toward the shaft 1302. Furthermore, as the splines 1304 collapse, the first and second branches 1336, 1338 of each spreading member 1330 also collapse inward toward each other, reducing the overall profile of the catheter assembly 1300. Thereafter, to perform ablation, the splines 1304 are deployed such that the inflection points 1314 extend radially outward.

[0132] The splines 1304 may all be the same length, or at least some of the splines 1304 may have different lengths. Furthermore, the insulating material on each spline 1304 may be the same length, or at least some of the splines 1304 may have different lengths of insulating material. Furthermore, in some embodiments, the catheter assembly 1300 includes a distal electrode (not shown) disposed distal to the splines 1304. The distal electrode may be used to perform point ablation (e.g., by forming a bipole between the distal electrode and one of the splines 1304) and / or may be used for visualization / mapping purposes (e.g., by using the distal electrode in combination with an electrode on the shaft 1302).

[0133] Figure 14 is a perspective view of an alternative embodiment catheter assembly 1400. The catheter assembly 1400 includes a shaft 1402 and a plurality of splines 1404 surrounding a distal portion 1406 of the shaft 1402. However, in contrast to the catheter assembly 1300 (shown in Figure 13), the catheter assembly 1400 includes a balloon 1408 surrounded by the splines 1404. The balloon 1408 can be selectively inflated to fill the spaces between the splines 1404. Notably, the balloon 1408 acts as an insulator and generally reduces energy loss compared to the catheter assembly 1300, which may result in increased lesion size.

[0134] Each spline 1404 includes a proximal end 1410 coupled to the shaft 1402 and a distal end 1412 coupled to the shaft 1402. The splines 1404 extend radially outward from the proximal end 1410 to an inflection point 1414 and then extend radially inward to the distal end 1412.

[0135] The splines 1404 are made of a resilient material (e.g., nitinol) and function as relatively large electrodes. In this embodiment, alternating splines 1404 alternate polarity; that is, each positive spline 1404 is located between two negative splines 1404, and vice versa. Alternatively, any suitable polarization scheme may be used.

[0136] To control the ablation zone of each spline 1404, a portion of each spline 1404 may be covered with an insulating material 1420 (e.g., heat shrink or polymer tubing such as PET or PEBA), with the exposed portion of the spline 1404 functioning as an electrode. In the embodiment shown in FIG. 14 , the inflection point 1414 and the portion of the spline 1404 between the inflection point 1414 and the distal end 1412 are generally exposed, while the portion of the spline 1404 between the inflection point 1414 and the proximal end 1410 is generally insulated. This results in the portion of the spline 1404 that contacts the pulmonary vein 320 being exposed. Alternatively, any suitable insulating configuration may be used.

[0137] 14, each spline 1404 includes a flaring member 1430. The flaring member 1430 includes a first end 1432, a second end 1434, a first branch 1436, and a second branch 1438. The first branch 1436 and the second branch 1438 extend away from each other from the first end 1432 and then extend back toward each other before reuniting at the second end 1434.

[0138] The spreading member 1430 can be fabricated using, for example, laser cutting. In this embodiment, all of the spreading member 1430 is exposed (i.e., not covered with insulating material). Alternatively, only a portion of the spreading member 1430 can be covered with insulating material.

[0139] The inclusion of the spreader members 1430 on the splines 1404 reduces the extent of circumferential clearance between the splines 1404, facilitating an increase in lesion volume. Additionally, additional splines 1404 may be included to further reduce the extent of circumferential clearance.

[0140] In some embodiments, at least one of the splines 1404 includes multiple spreading members 1430 instead of a single spreading member 1430. Furthermore, as shown in Figure 14, the spreading members 1430 are longitudinally aligned with one another in the catheter assembly 1400. However, in some embodiments, at least some of the spreading members 1430 are longitudinally offset with respect to one another.

[0141] During delivery, the splines 1404 may collapse inward toward the shaft 1402. Furthermore, as the splines 1404 collapse, the first and second branches 1436, 1438 of each spreading member 1430 also collapse inward toward each other, reducing the overall profile of the catheter assembly 1400. Thereafter, to perform the ablation, the splines 1404 are deployed such that the inflection points 1414 extend radially outward.

[0142] The splines 1404 may all be the same length, or at least some of the splines 1404 may be different lengths. Further, the insulating material on each spline 1404 may be the same length, or at least some of the splines 1404 may have different lengths of insulating material. Furthermore, in some embodiments, the catheter assembly 1400 includes a distal electrode (not shown) disposed distal to the splines 1404. The distal electrode may be used to perform point ablation (e.g., by forming a bipole between the distal electrode and one of the splines 1404) and / or may be used for visualization / mapping purposes (e.g., by using the distal electrode in combination with an electrode on the shaft 1402).

[0143] 15 is a perspective view of an alternative embodiment catheter assembly 1500. The catheter assembly 1500 includes a shaft 1502 and a plurality of splines 1504 that surround a distal portion 1506 of the shaft 1502. Each spline 1504 includes a proximal end 1510 that is coupled to the shaft 1502 and a distal end 1512 that is also coupled to the shaft 1502. The splines 1504 extend radially outward from the proximal end 1510 to an inflection point 1514, and then extend radially inward to the distal end 1512.

[0144] The splines 1504 are made of a resilient material (e.g., nitinol) and function as relatively large electrodes. In this embodiment, alternating splines 1504 alternate polarity; that is, each positive spline 1504 is located between two negative splines 1504, and vice versa. Alternatively, any suitable polarization scheme may be used.

[0145] To control the ablation zone of each spline 1504, a portion of each spline 1504 may be covered with an insulating material 1520 (e.g., heat shrink or polymer tubing such as PET or PEBA), with the exposed portion of the spline 1504 functioning as an electrode. In the embodiment shown in FIG. 15 , the inflection point 1514 and the portion of the spline 1504 between the inflection point 1514 and the distal end 1512 are generally exposed, while the portion of the spline 1504 between the inflection point 1514 and the proximal end 1510 is generally insulated. This results in the portion of the spline 1504 that contacts the pulmonary vein 320 being exposed. Alternatively, any suitable insulating configuration may be used.

[0146] 15, each spline 1504 includes a tapered member 1530. The tapered member 1530 includes a first end 1532 and a second end 1534. The width of the tapered member 1530 tapers outward from the first end 1532 along a first tapered section 1540, the width is substantially constant along an intermediate portion 1542, and the width tapers inward toward the second end 1534 along a second tapered section 1544. In some embodiments, the tapered member 1530 includes only a single tapered section.

[0147] The tapered member 1530 can be fabricated using, for example, laser cutting. In this embodiment, all of the tapered member 1530 is exposed (i.e., not covered with insulating material). Alternatively, a portion of the tapered member 1530 can be covered with insulating material. Further, in this embodiment, the tapered member 1530 functions as a single electrode. Alternatively, the tapered member 1530 can be divided into multiple separate electrodes (e.g., including insulating material and ring electrodes, if desired).

[0148] The inclusion of tapered members 1530 in splines 1504 reduces the extent of circumferential clearance between splines 1504, facilitating an increase in damage volume. Additionally, additional splines 1504 may be included to further reduce the extent of circumferential clearance.

[0149] In some embodiments, at least one of the splines 1504 includes multiple tapered members 1530 instead of a single tapered member 1530. Furthermore, as shown in FIGURE 15, the tapered members 1530 are longitudinally aligned with one another in the catheter assembly 1500. However, in some embodiments, at least some of the tapered members 1530 are longitudinally offset with respect to one another.

[0150] During delivery, the splines 1504 may collapse inward toward the shaft 1502. Then, to perform the ablation, the splines 1504 are deployed so that the inflection points 1514 extend radially outward.

[0151] The splines 1504 may all be the same length, or at least some of the splines 1504 may have different lengths. Further, the insulating material on each spline 1504 may be the same length, or at least some of the splines 1504 may have different lengths of insulating material. Furthermore, in some embodiments, the catheter assembly 1500 includes a distal electrode (not shown) disposed distal to the splines 1504. The distal electrode may be used to perform point ablation (e.g., by forming a bipole between the distal electrode and one of the splines 1504) and / or may be used for visualization / mapping purposes (e.g., by using the distal electrode in combination with an electrode on the shaft 1502).

[0152] Figure 16 is a perspective view of an alternative embodiment catheter assembly 1600. The catheter assembly 1600 includes a shaft 1602 and a plurality of splines 1604 surrounding a distal portion 1606 of the shaft 1602. However, in contrast to the catheter assembly 1500 shown in Figure 15, the catheter assembly 1600 includes a balloon 1608 surrounded by the splines 1604. The balloon 1608 can be selectively inflated to fill the spaces between the splines 1604. Notably, the balloon 1608 acts as an insulator and generally reduces energy loss compared to the catheter assembly 1500, which may result in increased lesion size.

[0153] Each spline 1604 includes a proximal end 1610 coupled to the shaft 1602 and a distal end 1612 coupled to the shaft 1602. The splines 1604 extend radially outward from the proximal end 1610 to an inflection point 1614 and then extend radially inward to the distal end 1612.

[0154] The splines 1604 are made of a resilient material (e.g., nitinol) and function as relatively large electrodes. In this embodiment, alternating splines 1604 alternate polarity; that is, each positive spline 1604 is located between two negative splines 1604, and vice versa. Alternatively, any suitable polarization scheme may be used.

[0155] To control the ablation zone of each spline 1604, a portion of each spline 1604 may be covered with an insulating material 1620 (e.g., heat shrink or polymer tubing such as PET or PEBA), with the exposed portion of the spline 1604 functioning as an electrode. In the embodiment shown in FIG. 16 , the inflection point 1614 and the portion of the spline 1604 between the inflection point 1614 and the distal end 1612 are generally exposed, while the portion of the spline 1604 between the inflection point 1614 and the proximal end 1610 is generally insulated. This results in the portion of the spline 1604 contacting the pulmonary vein 320 being exposed. Alternatively, any suitable insulating configuration may be used.

[0156] 16, each spline 1604 includes a tapered member 1630. The tapered member 1630 includes a first end 1632 and a second end 1634. The width of the tapered member 1630 tapers outward from the first end 1632 along a first tapered section 1640, the width is substantially constant along an intermediate portion 1642, and the width tapers back inward along a second tapered section 1644 toward the second end 1634. In some embodiments, the tapered member 1630 includes only a single tapered section.

[0157] The tapered member 1630 can be fabricated using, for example, laser cutting. In this embodiment, all of the tapered member 1630 is exposed (i.e., not covered with insulating material). Alternatively, portions of the tapered member 1630 can be covered with insulating material. Furthermore, in this embodiment, the tapered member 1630 functions as a single electrode. Alternatively, the tapered member 1630 can be divided into multiple separate electrodes (e.g., including insulating material and ring electrodes, if desired).

[0158] The inclusion of tapered members 1630 on the splines 1604 facilitates reducing the extent of circumferential clearance between the splines 1604 and increasing the damage volume. Additionally, additional splines 1604 may be included to further reduce the extent of circumferential clearance.

[0159] In some embodiments, at least one of the splines 1604 includes multiple tapered members 1630 instead of a single tapered member 1630. Furthermore, as shown in FIGURE 16, the tapered members 1630 are longitudinally aligned with one another in the catheter assembly 1600. However, in some embodiments, at least some of the tapered members 1630 are longitudinally offset with respect to one another.

[0160] During delivery, the splines 1604 may collapse inward toward the shaft 1602. Then, to perform the ablation, the splines 1604 are deployed so that the inflection points 1614 extend radially outward.

[0161] The splines 1604 may all be the same length, or at least some of the splines 1604 may have different lengths. Further, the insulating material on each spline 1604 may be the same length, or at least some of the splines 1604 may have different lengths of insulating material. Furthermore, in some embodiments, the catheter assembly 1600 includes a distal electrode (not shown) disposed distal to the splines 1604. The distal electrode may be used to perform point ablation (e.g., by forming a bipole between the distal electrode and one of the splines 1604) and / or may be used for visualization / mapping purposes (e.g., by using the distal electrode in combination with an electrode on the shaft 1602).

[0162] Due at least in part to the length of the exposed spline, the catheter assemblies described herein, in some embodiments, can create lesions having lengths ranging from approximately 1.0 to 1.5 cm. This results in a wider lesion streak, helping to prevent breakthrough, as opposed to lesions in at least some known systems (which may have lengths of approximately 4 or 5 mm). This is important because lesions are often non-uniform. Furthermore, a longer lesion length results in ablation of a larger area of ​​the pulmonary vein, which is advantageous because pulmonary veins contain many transitional tissue fibers that can induce arrhythmias.

[0163] In the embodiments described herein, the splines are generally straight. However, the splines may have any suitable shape. For example, in some embodiments, the splines may have an S-shape, which may facilitate stress relief as the splines expand and contract.

[0164] Additionally, although the embodiments described herein are shown with a particular number of splines, one skilled in the art will appreciate that any suitable number of splines may be included. For example, a catheter assembly may include 4, 6, 8, 10, 12, 14, 16, 18, or 20 splines in some embodiments.

[0165] As mentioned above, catheter assemblies that include a balloon surrounded by splines (and corresponding electrodes) generally result in reduced energy loss because the balloon acts as an insulator and allows the electrodes to primarily transfer energy outward from the balloon, thereby transferring energy primarily to the target tissue rather than to the blood pool.

[0166] During PFA therapy, at least some known systems may generate microbubbles, which may be undesirable. However, it has been observed that increasing the current density at the electrode increases microbubble formation. Therefore, reducing the current density generally reduces microbubble formation. In at least some of the embodiments described herein, the electrode has a relatively large surface area (e.g., in embodiments in which a relatively long exposed portion of the spline serves as the electrode). This larger surface area allows for lower current density and therefore reduces microbubble formation (in addition to more efficient energy delivery to the target tissue, as discussed above).

[0167] Those skilled in the art will appreciate that the various embodiments of the catheter assembly may be implemented independently of one another or in any suitable combination.

[0168] Additionally, the catheter assemblies described herein can have any suitable dimensions. For example, in some embodiments, with the splines in the expanded configuration, the catheter assemblies described herein have a diameter in the range of about 28-35 mm. Alternatively, the catheter assemblies described herein can have a smaller diameter (e.g., in the range of about 8-10 mm).

[0169] For example, Figure 17 is a perspective view of an alternative embodiment catheter assembly 1700. The catheter assembly 1700 includes a shaft 1702 and a plurality of splines 1704 that surround a distal portion 1706 of the shaft 1702. The catheter assembly 1700 also includes a balloon 1708 that is surrounded by the splines 1704. The balloon 1708 can be selectively inflated to fill the spaces between the splines 1704. Notably, the balloon 1708 acts as an insulator and generally reduces energy loss, which can result in increased lesion size.

[0170] Compared to catheter assemblies 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, and 1600, catheter assembly 1700 may have a more simplified design and be smaller, potentially resulting in reduced manufacturing costs. For example, in some embodiments, catheter assemblies 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, and 1600 may have a diameter in the range of approximately 28 to 35 mm with the splines unfolded to facilitate PVI. In contrast, with splines 1704 unfolded, catheter assembly 1700 may have a diameter in the range of approximately 8 to 10 mm (e.g., a 9 mm diameter). Furthermore, in the collapsed state, catheter assembly 1700 may be deliverable using a 7.5 French shaft.

[0171] Because of its small diameter, catheter assembly 1700 can generate smaller, more focused lesions. For example, catheter assembly 1700 can be used to treat gaps remaining after PVI using any of catheter assemblies 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, and 1600. Thus, catheter assembly 1700 can be used to complement procedures performed using catheter assemblies 300, 400, 500, 600, 900, 1000, 1100, 1200, 1300, 1400, 1500, and 1600. As another example, catheter assembly 1700 can be used to treat other targets, such as the posterior wall.

[0172] Simulations revealed that the catheter assembly 1700 produced lesions substantially consistently regardless of the orientation of the catheter assembly 1700 relative to the target tissue. For example, in simulations, lesions having a depth of at least 4 mm were achieved with the shaft 1702 at angles of approximately 10°, 45°, and 90° relative to the surface of the target tissue.

[0173] In the illustrated embodiment, each spline 1704 includes an exposed portion 1710 that functions as an electrode and an insulated portion 1712 proximal to the exposed portion 1710. In some embodiments, another insulated portion 1712 is included distal to the exposed portion 1710. Alternatively, this distal insulated portion 1712 may be omitted. Although the splines 1704 are shown as having a constant width, one skilled in the art will understand that other spline shapes (e.g., tapered, segmented, etc.) may be used.

[0174] To perform ablation, a voltage (e.g., 1500 V) is applied to the catheter assembly 1700. Specifically, the voltage may be applied between the splines 1704 according to a bipolar approach. Alternatively, the voltage may be applied between one or more splines 1704 and a separate electrode (e.g., a body patch electrode) according to a monopolar approach. Furthermore, the voltage may be applied to the splines 1704 simultaneously or sequentially (e.g., via multiplexing).

[0175] Catheter assembly 1700 includes two splines 1704. Alternatively, more splines may be included. For example, Figure 18 is a perspective view of an alternative embodiment catheter assembly 1800 including four splines 1804, and Figure 19 is a perspective view of an alternative embodiment catheter assembly 1900 including six splines 1904. Except for the number of splines, catheter assemblies 1800 and 1900 are substantially similar to catheter assembly 1700.

[0176]

[0003] Embodiments described herein provide systems and methods for electroporation catheters. An exemplary electroporation catheter includes a shaft and a plurality of splines forming a basket around a distal portion of the shaft, each spline extending between a proximal end coupled to the shaft and a distal end coupled to the shaft, each spline of the plurality of splines including at least one energizable electrode. The electroporation catheter further includes a balloon disposed within the basket formed by the plurality of splines, the balloon being selectively inflatable to help secure the position of the plurality of splines.

[0177] While certain embodiments of the present disclosure have been described in some detail above, those skilled in the art may make numerous modifications to the disclosed embodiments without departing from the spirit or scope of the present disclosure. All directional references (e.g., top, bottom, upward, downward, left, right, left, right, upper, lower, upward, downward, vertical, horizontal, clockwise, and counterclockwise) are used solely for identification purposes to aid the reader's understanding of the present disclosure and are not intended to impose any limitations on the location, orientation, or use of the present disclosure. References to connections (e.g., attached, connected, coupled, etc.) should be interpreted broadly and may include intermediate members between connections of elements and relative movement between elements. As such, references to connections do not necessarily imply that two elements are directly connected and in a fixed relationship to each other. All matter contained in the above description or shown in the accompanying drawings is intended to be interpreted as illustrative only and not limiting. Changes in detail or structure may be made without departing from the spirit of the present disclosure, as defined by the appended claims.

[0178] When introducing elements of the disclosure or preferred embodiments thereof, the articles "a," "an," "the," and "said" are intended to mean that there are one or more of the elements. The terms "comprising," "including," and "having" are intended to be inclusive and mean that there may be additional elements other than the listed elements.

[0179] Since various changes may be made to the above configurations without departing from the scope of the present disclosure, it is intended that all matter contained in the above description or shown in the accompanying drawings be interpreted as illustrative and not in a limiting sense.

Claims

1. 1. An electroporation catheter, comprising: A shaft and a plurality of splines forming a basket around a distal portion of the shaft, each spline of the plurality of splines extends between a proximal end coupled to the shaft and a distal end coupled to the shaft; the plurality of splines, each spline including at least one energizable electrode; a balloon disposed within the basket formed by the plurality of splines, the balloon being selectively inflatable to facilitate fixing the position of the plurality of splines; and An electroporation catheter comprising:

2. Each spline is a body comprising a resilient conductive material; an insulating material covering a portion of the body; at least one exposed portion of the body corresponds to the at least one selectively energizable electrode; The electroporation catheter of claim 1 .

3. each spline includes at least one flaring member corresponding to the at least one energizable electrode; The at least one spreading member is a first end; a second end; and a first branch extending from the first end to the second end; a second branch extending from the first end to the second end, the first branch and the second branch being spaced apart from each other; The electroporation catheter of claim 1 , comprising:

4. each spline including at least one tapered member corresponding to the at least one energizable electrode; The at least one tapered member comprises: a first end; a second end; and at least one tapered portion disposed between the first end and the second end; The electroporation catheter of claim 1 , comprising:

5. the at least one tapered portion comprises a first tapered portion and a second tapered portion; 5. The electroporation catheter of claim 4, wherein the at least one tapered member further comprises an intermediate portion extending between the first tapered portion and the second tapered portion, the intermediate portion having a constant width.

6. The shaft an outer shaft element; an inner shaft element extending through the outer shaft element, the distal end of each spline is operably connected to the distal end of the inner shaft element; the proximal end of each spline is connected to the distal end of the outer shaft element; the inner shaft element being slidable relative to the outer shaft element to adjust an effective diameter of the basket formed by the plurality of splines; The electroporation catheter of claim 1 , comprising:

7. Sliding the inner shaft element distally relative to the shaft element reduces the effective diameter; The electroporation catheter of claim 6 , wherein the effective diameter increases when the inner shaft element is slid proximally relative to the shaft element.

8. the inner shaft element defining a central lumen; the central lumen is configured to receive at least one of a contrast agent, a mapping catheter, a guidewire, and a shape-sensing fiber; 7. The electroporation catheter of claim 6.

9. a channel defined between the inner shaft element and the outer shaft element; 7. The electroporation catheter of claim 6, wherein the channel is in fluid communication with the interior of the balloon to facilitate selective inflation of the balloon with fluid.

10. 10. The electroporation catheter of claim 1, wherein alternating splines have electrodes with alternating polarities.

11. 1. An electroporation system comprising: A generator; a catheter coupled to the generator; The catheter comprises: The handle and a shaft extending distally from the handle; a plurality of splines forming a basket around a distal portion of the shaft, each spline of the plurality of splines extending between a proximal end coupled to the shaft and a distal end coupled to the shaft; the plurality of splines, each spline including at least one energizable electrode; a balloon disposed within the basket formed by the plurality of splines, the balloon being selectively inflatable to facilitate fixing the position of the plurality of splines; and An electroporation system comprising:

12. Each spline is a body comprising a resilient conductive material; an insulating material covering a portion of the body; at least one exposed portion of the body corresponds to the at least one selectively energizable electrode; 12. The electroporation system of claim 11.

13. each spline comprising at least one flaring member corresponding to said at least one energizable electrode; The at least one spreading member is a first end; a second end; and a first branch extending from the first end to the second end; a second branch extending from the first end to the second end, the first branch and the second branch being spaced apart from each other; The electroporation system of claim 11 , comprising:

14. each spline including at least one tapered member corresponding to the at least one energizable electrode; The at least one tapered member comprises: a first end; a second end; and at least one tapered portion disposed between the first end and the second end; 12. The electroporation catheter of claim 11, comprising:

15. the at least one tapered portion comprises a first tapered portion and a second tapered portion; 15. The electroporation system of claim 14, wherein the at least one tapered member further comprises an intermediate portion extending between the first tapered portion and the second tapered portion, the intermediate portion having a constant width.

16. The shaft an outer shaft element; an inner shaft element extending through the outer shaft element, the distal end of each spline is operably connected to the distal end of the inner shaft element; the proximal end of each spline is connected to the distal end of the outer shaft element; the inner shaft element being slidable relative to the outer shaft element to adjust an effective diameter of the basket formed by the plurality of splines; The electroporation system of claim 11 , comprising:

17. Sliding the inner shaft element distally relative to the shaft element reduces the effective diameter; 17. The electroporation system of claim 16, wherein the effective diameter increases when the inner shaft element is slid proximally relative to the shaft element.

18. the inner shaft element defining a central lumen; the central lumen is configured to receive at least one of a contrast agent, a mapping catheter, a guidewire, and a shape-sensing fiber; 17. The electroporation system of claim 16.

19. a channel defined between the inner shaft element and the outer shaft element; 17. The electroporation catheter of claim 16, wherein the channel is in fluid communication with the interior of the balloon to facilitate selective inflation of the balloon with fluid.

20. 1. A method of assembling an electroporation catheter, comprising: providing a shaft; coupling a plurality of splines to the shaft to form a basket around a distal portion of the shaft; each spline of the plurality of splines extends between a proximal end coupled to the shaft and a distal end coupled to the shaft; each spline including at least one energizable electrode; placing a balloon within the basket formed by the plurality of splines, the balloon being selectively inflatable to facilitate fixing the position of the plurality of splines; A method comprising:

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