Pulmonary vein isolation balloon catheter

Abstract

The present invention relates to electrophysiology catheters for intramyocardial tissue ablation. In particular, the present invention relates to electrophysiology ablation balloon catheters having conductive and non-conductive surfaces for focusing ablation energy on desired portions of pulmonary vein tissue.

Description

[0001] This application is a divisional application of the PCT application PCT / US2017 / 064532 with application number 2017800763974, application date December 4, 2017, invention name “Pulmonary Vein Isolation Balloon Catheter” and priority date December 15, 2016 entering the Chinese national phase.

[0002] CROSS-REFERENCE TO RELATED APPLICATIONS

[0003] This application claims the benefit of U.S. Provisional Patent Application No. 62 / 434,828, filed on December 15, 2016. Technical Field

[0004] The present invention relates to catheters, and more particularly to catheters for performing ablation therapy within the heart. In one embodiment, the present invention relates to a catheter for treating arrhythmias by ablating near pulmonary vein tissue. Background Art

[0005] The human heart regularly experiences an electrical current passing through its myocardial tissue. After each cardiac contraction, the heart repolarizes, causing the electrical current to spread through the myocardial tissue. In a healthy heart, the cardiac tissue will experience an orderly progression of depolarization waves. In unhealthy hearts, such as those experiencing atrial arrhythmias (including, for example, ectopic atrial tachycardia, atrial fibrillation, and atrial flutter), the progression of the depolarization waves becomes chaotic. Arrhythmias may persist due to scar tissue or other obstructions to accelerated and uniform depolarization. These obstructions may cause the depolarization waves to cycle through certain parts of the heart more than once. Atrial arrhythmias can produce a variety of dangerous conditions, including irregular heart rate, loss of orderly atrial and ventricular contraction, and blood stasis. All of these conditions are associated with a variety of diseases, including death.

[0006] Catheters are used in a variety of diagnostic and / or therapeutic medical procedures to correct conditions such as atrial arrhythmias, including, for example, ectopic atrial tachycardia, atrial fibrillation, and atrial flutter.

[0007] Typically in an endovascular procedure, a catheter is manipulated through a patient's vasculature to, for example, the patient's heart, and carries one or more electrodes that can be used for mapping, ablation, diagnosis, or other treatments. In cases where ablation therapy is required to relieve symptoms including atrial arrhythmias, the ablation catheter imparts ablative energy to the myocardial tissue to produce damage. The damaged tissue is less able to conduct electrical signals, thereby disrupting undesirable electrical pathways and limiting or preventing discrete electrical signals that cause arrhythmias. The ablation catheter can utilize ablative energies, including, for example, radiofrequency (RF), cryoablation, laser, chemical ablation, and high-intensity focused ultrasound. Obviously, such ablation therapy requires precise positioning of the ablation catheter to obtain optimal results.

[0008] The foregoing discussion is intended merely to illustrate the art and should not be construed as a disclaimer of the scope of the claims. Summary of the invention

[0009] The present invention relates to electrophysiology catheters for intracardiac tissue ablation. In particular, the present invention relates to electrophysiology ablation balloon catheters having a conductive surface and a non-conductive surface for focusing ablation energy at a desired tissue portion.

[0010] In one embodiment of the present invention, an ablation balloon device is disclosed. The ablation balloon device includes a catheter shaft and an ablation balloon, wherein the proximal end of the ablation balloon is connected to the distal end of the catheter shaft. The ablation balloon includes a conductive portion and a non-conductive portion. The conductive portion can promote energy transfer between the ablation balloon and tissue in contact with the conductive portion, while the non-conductive portion reduces energy transfer between the ablation balloon and tissue in contact with the non-conductive portion.

[0011] In another embodiment of the present invention, a system for treating atrial fibrillation is disclosed. The system includes an elongated shaft, a balloon delivery catheter, and an ablation balloon. The elongated shaft includes an inner cavity extending through the elongated shaft, wherein the balloon delivery catheter extends through the inner cavity. The ablation balloon includes a conductive portion and a non-conductive portion and is coupled to the distal end of the balloon delivery catheter. The ablation balloon can engage with the tissue wall of the pulmonary vein along the conductive portion of the ablation balloon and provide ablation therapy along the tissue wall of the pulmonary vein engaged by the conductive portion of the balloon.

[0012] Other embodiments herein relate to a balloon catheter for pulmonary vein isolation. In such an embodiment, the balloon catheter includes a steerable balloon delivery catheter shaft, an ablation balloon, and a tissue ablation mechanism. The steerable balloon delivery catheter shaft deploys the ablation balloon into the pulmonary vein, and the ablation balloon includes a conductive region at the distal end of the balloon delivery catheter. The deployed ablation balloon can engage the tissue wall of the pulmonary vein along the conductive portion of the ablation balloon. The tissue ablation mechanism together with the ablation balloon will provide ablation therapy to the tissue wall of the pulmonary vein along the conductive portion of the ablation balloon.

[0013] The foregoing and other aspects, features, details, utilities and advantages of this document will become apparent from a reading of the following description and claims, and from a reading of the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Various embodiments may be more fully understood considering the following detailed description taken in conjunction with the accompanying drawings.

[0015] Figure 1 is a schematic illustration of a catheter system for performing a therapeutic medical procedure consistent with various aspects herein.

[0016] Figure 2is a cross-sectional anterior view of the left atrium with an ablation balloon catheter positioned in a pulmonary vein consistent with various aspects herein.

[0017] Figure 3 is a cross-sectional anterior view of the left atrium having the pulmonary veins positioned within the pulmonary veins consistent with various aspects of the present invention Figure 2 ablation balloon catheter.

[0018] Figure 4 is a cross-sectional front view of a pulmonary vein having an ablation balloon positioned therein prior to deployment of the ablation balloon consistent with various aspects of the present disclosure. Figure 2 ablation balloon catheter.

[0019] Figure 5 is a cross-sectional front view of a pulmonary vein having a pulmonary vein extending therethrough consistent with various aspects of the present invention. Figure 2 ablation balloon catheter.

[0020] Figure 6 is an isometric side view of a deployed ablation balloon catheter and an electrophysiology loop catheter extending through a central lumen of the ablation balloon catheter consistent with various aspects herein.

[0021] Figure 7 is an isometric side view of a deployed ablation balloon catheter and an electrophysiology loop catheter extending through a central lumen of the ablation balloon catheter consistent with various aspects herein.

[0022] Figure 8 is an isometric side view of a deployed ablation balloon catheter and an electrophysiology loop catheter extending through a central lumen of the ablation balloon catheter consistent with various aspects herein.

[0023] Although the various embodiments discussed herein are suitable for modification and alternative forms, various aspects thereof have been shown by way of example in the accompanying drawings and will be described in detail. However, it should be understood that it is not intended to limit the scope to the specific embodiments described. On the contrary, it is intended to cover all modifications, equivalents and substitutions falling within the scope of this document (including aspects defined in the claims). In addition, the term "example" used throughout this application is intended to be illustrative and not limiting. DETAILED DESCRIPTION

[0024] The present invention relates to an electrophysiology catheter, for example, for ablation of tissue within the heart. In particular, the present invention relates to an electrophysiology ablation balloon catheter having a conductive surface and a non-conductive surface for focusing ablation energy on a desired portion of tissue (e.g., pulmonary vein tissue). The details of various embodiments of the present invention are described below with specific reference to the accompanying drawings.

[0025] Typically, ablation therapy is provided by performing multiple individual ablations in a controlled manner to form a lesion line. Such a lesion line is typically desired to be formed around / between the pulmonary veins in the left atrium of the heart, which is associated with the introduction point of unstable electrical signals into the heart. Devices being developed or commercialized attempt to achieve adequate lesion lines with minimal energy application. Existing designs vary from diagnostic catheters with loops to balloon-mounted designs with energy application features. Existing designs lack the ability to focus ablative energy on a target circumference and length of the pulmonary veins during treatment delivery, resulting in energy loss to the blood pool and inadvertent ablation of non-target tissue. In addition, the resulting energy loss may reduce the efficacy of target tissue ablation and result in inconsistent lesion lines and incomplete electrical signal blockage.

[0026] Referring now to the drawings, in which like reference numerals are used to identify similar parts throughout the various views, Figure 1 1 is a schematic diagram of a catheter ablation system 100 for performing a tissue ablation procedure. In one embodiment, tissue 120 includes cardiac tissue within a human body 140. However, it should be understood that the system can be applied to various other tissues in the human body and non-human body, and therefore, the content of this article is not meant to be limited to the use of the system only in relation to cardiac tissue and / or the human body.

[0027] The catheter ablation system 100 may include a catheter 160 and an ablation subsystem 180 for controlling ablation therapy performed by an ablation balloon 130 at a distal end 128 of the catheter 160. The ablation subsystem 180 may control the application and / or generation of ablative energy, including, for example, radiofrequency (RF), cryoablation, laser, chemical ablation, and high-intensity focused ultrasound.

[0028] exist Figure 1 In an embodiment, a catheter 160 is provided for examining, diagnosing and / or treating internal body tissue such as cardiac tissue 120. The catheter may include a cable connector or interface 121, a handle 122, a shaft 124 having a proximal end 126 and a distal end 128 (as used herein, "proximal" refers to a direction toward the end of the catheter 160 near the handle 122, and "distal" refers to a direction away from the handle 122), and an ablation balloon 130 coupled to the distal end 128 of the catheter shaft 124.

[0029] Using handle 122, ablation balloon 130 can be steered through the vasculature of patient 140 to steer one or more portions of shaft 124 and position the ablation balloon at a desired location (e.g., within the myocardium). In various embodiments, the ablation balloon includes an ablation element (e.g., an ablation electrode, a high-intensity focused ultrasound ablation element, supercooled / heated fluid, etc.) that, when operated by ablation subsystem 180, ablates tissue 120 that contacts ablation balloon 130 (and in some cases, tissue near ablation balloon 130 can be ablated by conduction energy transfer through the blood pool and to proximal tissue).

[0030] In various specific embodiments herein, the catheter 160 may include electrodes and one or more position sensors (e.g., electrodes and / or magnetic sensors) at the distal end 128 of the catheter shaft 124. In such embodiments, the electrodes acquire EP data related to the cardiac tissue 120, and the position sensors generate position data representing the 3-D position of the ablation balloon 130. In further embodiments, the catheter 160 may also include other conventional catheter components, such as, but not limited to, steering wires and actuators, irrigation lumens and ports, pressure sensors, contact sensors, temperature sensors, additional electrodes and corresponding conductors or wires.

[0031] The connector 121 provides mechanical and electrical connections for one or more cables 132, which extend, for example, from the ablation subsystem 180 to the ablation balloon 130. In other embodiments, the connector can also provide mechanical, electrical, and / or fluid connections for cables extending from other components in the catheter system 100, such as a fluid source (when the catheter 160 includes an irrigation catheter) and contact / pressure sensing circuits. The connector 121 is conventional in the art and is disposed at the proximal end 126 of the catheter 160.

[0032] The handle 122 provides a position for the user to hold the catheter 160, and can also steer or guide the shaft 124 within the body 140. For example, the handle 122 may include a mechanism for manipulating one or more steering wires extending through the catheter 160 to the distal end 128 of the shaft 124, thereby steering the shaft. The handle 122 is conventional in the art, and it should be understood that the structure of the handle can vary. In other embodiments, the control of the catheter 160 can be automated by mechanically driving or controlling the catheter shaft 124, or using a magnetic-based guidance system to drive and control the catheter shaft 124.

[0033] The catheter shaft 124 is an elongated tubular flexible member configured to move within the patient's body 140. The shaft supports the ablation balloon 130 at the distal end 128 of the catheter 160. The shaft 124 may also allow for the transport, delivery and / or removal of fluids (including irrigation fluids, cryogenic ablation fluids and body fluids), drugs and / or surgical tools or instruments. The shaft 124 may be made of conventional materials used for catheters, such as polyurethane, which defines one or more lumens that are configured to accommodate and / or transport electrical conductors, fluids and / or surgical instruments. The catheter may be introduced into a blood vessel or other structure within the body 140 through a conventional guide sheath.

[0034] In an exemplary cardiac ablation treatment, in order to correct atrial arrhythmias, a guide sheath is introduced through a peripheral vein (usually the femoral vein) and into the right atrium, which is called a transseptal puncture. The guide sheath then forms an incision in the fossa ovalis (the tissue wall between the left and right atria) and extends through the incision in the fossa ovalis to secure the guide sheath therein. The ablation catheter 160 can then extend through the lumen of the guide sheath into the left atrium. The catheter shaft 124 of the ablation catheter 160 can then be diverted or guided through the left atrium to position the ablation balloon 130 to a desired location in the left atrium, such as the pulmonary veins.

[0035] In order to achieve effective and efficient ablation of the target myocardial tissue in contact with the ablation balloon 130, the energy delivered by the ablation balloon must be concentrated to limit energy transmission through the portion of the balloon that is not in contact with the target myocardial tissue. When using a cryoablation balloon, the cryogenic fluid injected into the balloon not only cools the portion of the balloon in contact with the target tissue, but also acts as a heat sink together with the blood pool and non-target tissue to cool other portions of the balloon; this undesirable energy loss hinders the effectiveness of tissue ablation treatment because the precise energy applied to the target tissue is unknown, and the efficiency of the cryogenic fluid is greatly hindered due to various non-target heat sinks. Therefore, various aspects of the present invention focus energy transmission through the ablation balloon by having conductive and non-conductive regions on the surface of the balloon (or within the balloon itself). The non-conductive portions can be placed in areas where the target tissue is unlikely to contact the surface of the ablation balloon, and isolate these portions to prevent unwanted energy transmission. The conductive portion can be placed in an area where target tissue may contact the surface of the ablation balloon and transfer energy between the ablation balloon and tissue in contact with the conductive portion, thereby focusing energy usage to the target tissue area and reducing the overall cryogenic fluid required for a given treatment.

[0036] In applications where tissue ablation therapy is performed using direct current electroporation pulses and / or radio frequency, the conductive region can help facilitate the flow of radio waves and / or electrical pulses. In such applications, the non-conductive region can be used to shield non-target tissue from the effects of radio waves and / or electrical pulses originating from the ablation balloon. In some specific embodiments, the electrical shielding within the non-conductive portion of the ablation balloon can reflect radio waves and / or electrical pulses transmitted from the ablation balloon and increase the intensity / strength of the resulting radio waves and / or electrical pulses transmitted from the conductive portion of the ablation balloon.

[0037] Figure 2 2 is a cross-sectional front view of a portion of myocardium 210 with an ablation balloon catheter 231 positioned within a pulmonary vein (e.g., 214, 216, 218, and 220) for ablation therapy therein. Ablation therapy can minimize symptoms associated with, for example, atrial fibrillation. Figure 2 As shown, the myocardium 210 includes two upper chambers, referred to as the left atrium 212L and the right atrium 212R, and two lower chambers, referred to as the left ventricle and the right ventricle (partially visible).

[0038] Aspects herein relate to ablation therapy in which tissue in (or adjacent to) the pulmonary veins 214, 216, 218, and 220 that forms a conductive pathway for electrical signals through the tissue is destroyed in order to electrically isolate a source of unwanted electrical impulses (e.g., an arrhythmogenic foci) located in the pulmonary veins. By destroying the arrhythmogenic foci or electrically isolating them from the left atrium 212L, the cause of atrial symptoms may be reduced or eliminated.

[0039] like Figure 2 As shown, an ablation balloon catheter 231 can be introduced into the left atrium 212L through the guide sheath 230. Once introduced into the left atrium 212L by the guide sheath 230, the guide wire 232 and the catheter shaft 234 can guide the ablation balloon 236. Optionally, the ablation balloon catheter 231 can include mapping electrodes at the proximal and distal ends of the ablation balloons 240 and 238, respectively. In operation, the distal end of the guide sheath 230 is located in the left atrium 212L. As shown in FIG. Figure 2 As shown, a transseptal approach can be used, wherein an introducer sheath 230 is introduced through a peripheral vein (usually the femoral vein) and advanced to the right atrium 212R. The introducer sheath 230 forms a small incision in the fossa ovalis 224, which allows the distal end of the introducer sheath 230 to enter the left atrium 212L (through the atrial septum 226) and anchor itself to the wall of the fossa ovalis 224.

[0040] The ablation balloon catheter 231 can also be introduced into the left atrium 212L through the arterial system. In that case, the guide sheath 230 is introduced into an artery (e.g., the femoral artery) and advanced retrogradely through the artery to the aorta, the aortic arch, and into the left ventricle. The ablation balloon catheter 231 is then extended from the lumen of the guide sheath 230 to pass through the mitral valve 222 and into the left atrium 212L.

[0041] Once the guide sheath 230 is in place within the left atrium 212L, the steerable ablation balloon catheter 231 is advanced from the distal end of the guide sheath 230 and toward one of the pulmonary veins (e.g., 214, 216, 218, and 220). Figure 2 In FIG. 2 , the target pulmonary vein is the right superior pulmonary vein 214 . The guidewire 232 and the catheter shaft 234 of the ablation balloon catheter 231 are operated until the distal end of the ablation balloon catheter is directed toward the target pulmonary vein, and then the ablation balloon is extended into the pulmonary vein 214 .

[0042] Near the distal end of the ablation balloon catheter 231, the ablation balloon 236 is maintained in a deflated state so that it can be passed through the introducer sheath 230 and into the target pulmonary vein 214. Once in place, the ablation balloon 236 is expanded so that it engages and secures the ablation balloon catheter 231 within the target pulmonary vein 214.

[0043] Optionally, Figure 2 Embodiments may include mapping electrodes 238 and 240. The mapping electrodes 238 and 240 may be ring electrodes that allow a clinician to perform pre-deployment electrical mapping of the conduction potential of the pulmonary veins 214. Although shown as being carried on the ablation balloon catheter 231, the mapping electrodes may alternatively be carried on a separate electrophysiology catheter (e.g., on a loop catheter). In various other embodiments, the electrodes may also be positioned on the outer surface of the ablation balloon 236. After the ablation treatment is completed, the clinician may again utilize the mapping electrodes 238 and 240 to map the conduction potential of the pulmonary veins to determine the efficacy of the ablation therapy.

[0044] To ablate tissue, once deployed, the ablation balloon 236 can electrically conduct a DC energy current into the target tissue of the pulmonary vein 214 (also known as electroporation). In other embodiments, the ablation balloon 236 can transmit radiofrequency energy to ablate the target tissue. In other embodiments, the ablation balloon 236 can deliver one or more of the following energies to the target tissue: cryoablation, laser, chemical ablation, and high-intensity focused ultrasound, among others.

[0045] In various embodiments consistent with the above-described embodiments, the ablation balloon 236 may also include a non-conductive portion of the ablation balloon 236 that isolates, shields, resists, limits, or otherwise attenuates the ablation energy flowing therethrough. In a specific embodiment, the non-conductive portion is aligned with tissue that is not a target of ablation therapy; and the conductive region of the ablation balloon 236 is positioned to contact the target tissue portion for ablation therapy. Therefore, various ablation balloon embodiments are contemplated, including an ablation balloon for ablating the pulmonary vein vestibule. In such an embodiment, the distal portion of the ablation balloon may include a conductive portion that allows ablation energy to be transferred between the conductive portion of the ablation balloon and the pulmonary vein vestibule. In such an embodiment, the proximal portion of the ablation balloon may also be composed of a non-conductive portion to prevent the ablation energy from being directed away from the pulmonary vein vestibule, for example, by a blood pool heat sink and / or non-target tissue. Other ablation balloon embodiments consistent with this document relate to ablating pulmonary vein openings. In such an embodiment, the middle circumferential portion of the ablation balloon is composed of a conductive portion to affect ablation therapy of the target portion of the pulmonary vein opening. In such an embodiment, the proximal and distal portions of the ablation balloon may also include non-conductive portions to prevent ablation energy from being directed away from the pulmonary vein opening by the blood pool heat sink and / or non-target tissue (e.g., the pulmonary vein vestibule).

[0046] Figure 3 An ablation balloon catheter 331 is shown, which includes an ablation balloon 336, which is advanced into the vestibule of the pulmonary vein 314 (by extending out of the introducer sheath 330). As the ablation balloon catheter 331 enters the pulmonary vein 314, mapping can be performed using electrodes 338 (hidden from view) and 340 to verify the correct position before deploying the ablation balloon 336.

[0047] It has been discovered that an enhanced ablation balloon 336 having a conductive portion and a non-conductive portion can more effectively transfer energy into / out of the ablation balloon 336. In various embodiments herein, the conductive portion and the non-conductive portion can be integral to the expandable ablation balloon (e.g., a material additive such as metal dust) and connected to the interior and / or exterior surface of the ablation balloon, include an additional / separate layer within the ablation balloon 336, or include a double-layer balloon arrangement in which the conductive / non-conductive balloon is positioned within the outer ablation balloon (or vice versa). In more specific embodiments, each of the conductive portion and the non-conductive portion can include its own balloon segment that is self-supporting relative to the other layer and the expandable ablation balloon itself. In such embodiments, the conductive portion and the non-conductive portion can be adjusted by a pull wire or other adjustment mechanism to change the position of the conductive portion and the non-conductive portion. By dynamically adjusting the position of the conductive portion and the non-conductive portion, the focus point of the energy transfer system of the ablation balloon 336 can be adjusted to various portions of the pulmonary vein that are in contact with the balloon.

[0048] In one particular application, where treatment is being performed to treat a patient suffering from symptoms of atrial fibrillation, an ablation balloon 336 (consistent with the present invention) engages the inner wall of a target pulmonary vein 314. Once in place, conductive and non-conductive baffles within the ablation balloon can be positioned to focus energy delivery using pull wires and / or steering wires that extend the length of the catheter shaft 334. For the first treatment, the conductive and non-conductive baffles can be positioned to minimize energy delivery therethrough by positioning the non-conductive portions near the distal and proximal portions of the ablation balloon; accordingly, the conductive baffle can be positioned near the middle portion of the ablation balloon. This configuration can be implemented to ablate a pulmonary vein opening. In some embodiments, a conductive baffle may not be required where the ablation balloon material is conductive. Using one or more of the energy delivery systems discussed above, the ablation balloon focuses energy delivery at the tissue of the pulmonary vein opening while minimizing energy delivered to other areas of the pulmonary vein tissue by shielding, isolating, reflecting, or otherwise attenuating energy flow through the non-conductive baffle. The treatment creates a circumferential ablation zone around the inner wall of the pulmonary vein opening. The ablation zone electrically isolates the target pulmonary vein 314 from the left atrium 312L. To the extent that the arrhythmic foci are within the ablation zone, the arrhythmic foci are destroyed. To the extent that the arrhythmic foci are in the target pulmonary vein on the side opposite to the ablation zone from the left atrium, the electrical pulses generated by these foci are blocked or substantially suppressed by the ablation zone.

[0049] After completing ablation treatment of the pulmonary vein opening, the ablation balloon can be deflated to be removed from the myocardium 310, or the ablation balloon can be repositioned and / or reconfigured to perform additional ablation treatment on other pulmonary veins (e.g., 316, 318, and 320) and / or other portions of the target pulmonary vein 314 (e.g., the pulmonary vein vestibule). For example, the conductive and non-conductive baffles can be reconfigured, and the ablation balloon 336 can be repositioned to perform ablation treatment on the vestibule of the target pulmonary vein 314. In this application, the distal portion of the ablation balloon is positioned to contact the vestibule portion of the target pulmonary vein, and the non-conductive baffle is repositioned to the proximal portion of the ablation balloon via a guidewire. Using one or more of the energy delivery systems discussed above, the ablation balloon concentrates energy delivery at the tissue of the vestibule portion of the pulmonary vein while minimizing energy delivered to the blood pool and other areas of the pulmonary vein tissue by shielding, isolating, reflecting, or otherwise mitigating energy flow through the non-conductive baffle. The treatment creates a circumferential ablation zone around the vestibular portion of the pulmonary veins, which electrically isolates the target pulmonary vein 314 from the left atrium 312L.

[0050] Figure 4 An ablation balloon catheter 431 is shown with an ablation balloon 436 positioned near a target pulmonary vein 414 prior to balloon deployment. Figure 4As shown, the ablation balloon catheter 431 is guided to a position near the vestibule 416 of the target pulmonary vein 414. Before reaching the vestibule 416, the ablation balloon catheter 431 must make the ablation balloon 436 pass through the left atrium 412L and be located near the target pulmonary vein 414. In this embodiment, the ablation balloon catheter 431 is positioned to perform ablation treatment at the vestibule 416 of the target pulmonary vein 414. In such a process, once the ablation balloon is inflated to contact the vestibule 416, the ablation treatment can be started, which ablates the circumferential ablation area around the vestibule 416. The circumferential ablation area electrically isolates the left atrium 412L from the electrical pulses generated by the arrhythmia lesion opposite to the ablation area. In some embodiments herein, accurate positioning of the ablation balloon catheter 431 can greatly affect the efficacy of the ablation treatment; therefore, some embodiments herein use mapping using electrodes at the proximal and distal ends of the ablation balloon 436 before deploying the ablation balloon to correctly position the ablation balloon within the target pulmonary vein 414 (e.g., Figure 2 and Figure 3 shown).

[0051] Figure 5An ablation balloon catheter 531 is shown having an inflated ablation balloon 536 engaged within the vestibule 516 of a target pulmonary vein 514. The shaft 534 of the ablation balloon catheter 531 extends out of the vestibule 516 of the target pulmonary vein 514 and into the left atrium 512L. The inflated shape of the ablation balloon 536 is designed to conform to at least the length and circumference of the vestibule 516 of the pulmonary vein 514. Various aspects of the present invention relate to an ablation balloon 536, which includes conductive and non-conductive portions 538 and 537, respectively. In one embodiment, the ablation balloon is a cryoablation balloon that can be filled with a cryogenic fluid to fill and cool the ablation balloon to ablate tissue in contact therewith (and in some cases, tissue near the ablation balloon). The conductive portion 538 can be located around the middle circumference of the ablation balloon 536, and facilitates ablation of tissue in contact with the conductive portion 538 by transferring energy heat from the vestibule 516 of the pulmonary vein 514 in contact with the conductive portion 538 to the ablation balloon 536. The ablation balloon may also include non-conductive portions 537 on the proximal and distal ends of the balloon that isolate these portions of the ablation balloon to prevent energy transfer from the pulmonary veins (e.g., the opening 515 of the pulmonary vein 514) and the blood pool therein. Such an embodiment improves the efficiency of the cryogenic fluid because its specific heat capacity is used to absorb energy from the vestibule 516 rather than from non-target tissue areas and the blood pool. Therefore, less cryogenic fluid (e.g., nitrous oxide) and ablation treatment time are required to achieve the same ablation area and depth, also referred to as the ablation zone 550. In addition, in applications using other ablation methods such as radiofrequency or direct current electroporation pulses, the non-conductive portion 537 can radiate the generated energy back to the ablation balloon 536 to achieve energy concentration and / or amplification through the conductive portion 538. With regard to irreversible electroporation ablation using direct current energy, the energy pulses can be delivered to the target tissue in various forms, such as one or more monophasic pulses, one or more biphasic pulses, etc.

[0052] exist Figure 5 In the inflated state shown, the ablation balloon 536 engages the inner wall of the target pulmonary vein 514. Through one or more ablation processes described above, the ablation balloon creates a circumferential ablation zone 550 along the inner wall of the pulmonary vein at the vestibule 516. The ablation zone electrically isolates the target pulmonary vein 514 from the left atrium 512L. To the extent that arrhythmic foci are located within the ablation zone, the arrhythmic foci are destroyed. To the extent that arrhythmic foci are located in the target pulmonary vein on the side opposite the ablation zone from the left atrium, the electrical pulses generated by these foci are blocked or suppressed by the ablation zone.

[0053] In a typical ablation treatment, pulmonary veins are treated based on their likelihood of having arrhythmic lesions. Typically, all pulmonary veins are treated. For each of the other three pulmonary veins, the process described herein for the right superior pulmonary vein can be similarly reproduced.

[0054] Once the ablation treatment is complete, the ablation balloon 536 can be deflated and the ablation balloon catheter 534 can be retracted into the guide sheath 330 (see, e.g., Figure 3 ). Electrodes proximal and distal to the electrophysiology catheter or ablation balloon may be used to verify the efficacy of the treatment prior to removal of the ablation balloon catheter 531. In various embodiments herein, additional electrodes may also be provided alone or in combination with electrodes 238 and 240 (e.g., Figure 2 512L).

[0055] Ablation balloons have been developed for a variety of different applications and have taken many different forms. Aspects of the present invention may utilize various types of ablation balloons and mechanical configurations. The ablation balloon may be self-standing or mechanically standing, such as by using an internal balloon. In one embodiment, a lumen extending through the length of the shaft of the ablation balloon catheter 534 may inject a fluid into the ablation balloon, which exerts a radial force on the ablation balloon, thereby expanding the balloon into a standing configuration (such as Figure 5 ). In addition, the conductive and non-conductive portions (538 and 537, respectively) of the balloon 536 can be positioned in various patterns, arrangements, and configurations on the surface of the ablation balloon as desired for a given application. Some embodiments may not require a conductive portion, where the material of the balloon allows for the transmission of ablation energy, and likewise, embodiments may not require a non-conductive portion, where the balloon material isolates the transmission of energy through the balloon. It should also be understood that aspects of the present invention relate to various embodiments in which the conductive and non-conductive portions (538 and 537, respectively) are integral to the expandable ablation balloon 536, are coupled to the inner and / or outer surfaces of the ablation balloon 536, and / or are positioned within a gap between the expanded ablation balloon 536 and the shaft 534.

[0056] Figure 66 is an isometric side view of an electrophysiology system 600 consistent with various aspects of the present invention, which includes a deployed ablation balloon catheter 631 and an electrophysiology loop catheter 632 extending through a central lumen 641 of the ablation balloon catheter. The deployed ablation balloon catheter 631 of this embodiment includes a cryoablation balloon 601 having a fluid lumen that delivers a cryogenic fluid along the length of the shaft to a shunt 642 that distributes the cryogenic fluid circumferentially within the chamber of the ablation balloon 601. In various embodiments consistent with the present invention, the shunt 642 (or the holes therein) can be positioned to distribute the cryogenic fluid in a manner that concentrates the cryogenic fluid in a specific area of ​​the ablation balloon 601 (e.g., the distal, proximal, or middle portion of the balloon 601). In more specific embodiments, the shunt 642 and / or the holes therein can be adjustable, allowing the clinician to optimize treatment given various conditions and the position of the ablation balloon 601 relative to the pulmonary veins.

[0057] Aspects of the electrophysiology system 600 can be directed to ablation treatment of a pulmonary vein opening, wherein the conductive portion 638 of the ablation balloon 601 contacts the tissue of the pulmonary vein opening and transfers heat from the tissue into the ablation balloon 601 in response to the ablation balloon being filled with a cryogenic fluid. The cryogenic fluid undergoes a phase change from liquid to gas in response to the rapid pressure change as it enters the ablation balloon, which requires a large amount of energy, thereby absorbing energy from the pulmonary vein opening with which it is thermally connected, which ablates the tissue of the opening.

[0058] To help focus energy absorption by the ablation balloon 601, non-conductive portions 637 of the ablation balloon 601 adjacent to either side of the conductive portion 638 thermally insulate tissue and blood pools in their vicinity to prevent heat transfer that could result in undesirable / excessive ablation of pulmonary vein tissue. The non-conductive regions 637 also focus energy absorption from cryogenic fluid phase changes to the desired tissue for ablation to help mitigate heat transfer variations that could affect the overall efficacy of the ablation treatment, as well as reduce the amount of cryogenic fluid used for a given ablation treatment.

[0059] In various embodiments herein, the loop catheter 632 can extend through the central lumen 641 of the ablation balloon catheter 631 to measure the electrophysiological properties of the target pulmonary vein. Once the loop catheter 632 extends out of the central lumen 641, it can be expanded into a loop, wherein the contact electrodes contact the inner surface of the pulmonary vein along the loop catheter.

[0060] Figure 7is an isometric side view of an ablation balloon catheter 731 consistent with various aspects herein, comprising an expanded ablation balloon 701 and an electrophysiology loop catheter 732 extending through a central lumen 741 of the ablation balloon catheter. The expanded ablation balloon 701 of the present embodiment is a cryoablation balloon having a fluid lumen that delivers cryogenic fluid along the length of the shaft to a shunt 742 that distributes the cryogenic fluid circumferentially within the chamber of the ablation balloon 701. In various embodiments consistent with the present invention, the shunt 742 can be positioned in a manner that concentrates the cryogenic fluid in a specific area of ​​the ablation balloon 701, for example, in the present embodiment, the shunt 742 can direct the cryogenic fluid toward the distal end of the ablation balloon 701.

[0061] Aspects of the electrophysiology system 700 can target the pulmonary vein vestibule for ablation therapy, and the conductive portion 738 of the ablation balloon 701 can be placed in contact with the pulmonary vein vestibule and transfer heat from the tissue into the ablation balloon 701 in response to the ablation balloon being filled with a cryogenic fluid. To help focus the energy absorption of the ablation balloon 701, a non-conductive portion 737 at the proximal end of the ablation balloon separates the blood pool from the distal end of the ablation balloon 701. Therefore, the non-conductive region 737 concentrates the ablation energy of the cryogenic fluid to the target pulmonary vein tissue in contact with the conductive portion 738. In a more specific embodiment, the non-conductive portion 737 can also include a parabolic reflective surface on the interior of the ablation balloon 701 that enhances energy transfer from the pulmonary vein vestibule to the ablation balloon 701. As described with reference to Figure 6 As discussed, the loop catheter 732 may be extended through the central lumen 741 of the ablation balloon catheter 731 to measure electrophysiological properties near the vestibule of the target pulmonary vein.

[0062] In with Figure 5-7 In various alternative embodiments, the ablation balloons 501, 601, and 701 can be deployed by filling the cavity within the balloon with a conductive fluid (e.g., saline). In such embodiments, the n electrodes 642, 742 within the ablation balloon can be powered to transmit radiofrequency waves, one or more direct current pulses, and other forms of energy through the conductive fluid and the conductive regions 538, 638, and 738 of the ablation balloon to ablate tissue in contact with the conductive regions. As described above, the non-conductive regions 537, 637, and 737 block or minimize the transmission of such energy to non-target tissue in contact therewith.

[0063] Figure 883 is an isometric side view of an electrophysiology system 800 consistent with various aspects of the present invention, which includes an expanded ablation balloon catheter 831 and an electrophysiology loop catheter 832 extending through a central lumen 841 of the ablation balloon catheter 831. Various aspects of the present invention relate to an electroporation ablation balloon 801, which utilizes direct current applied to target pulmonary vein tissue to ablate tissue. In addition, various aspects of the present invention may further relate to ablation therapy for pulmonary vein openings. In such an embodiment, the distal and proximal portions of the ablation balloon 801 include electrically insulated non-conductive portions 837. Between the non-conductive portions 837, a conductive portion 838 extends around the middle circumference portion of the ablation balloon 801. The conductive portion 838 has a low resistance, which helps the current flow from the ablation balloon to the tissue in contact therewith. In this embodiment, direct current (via a signal generator) is generated at the distal end of the catheter (outside the patient's body) and is transmitted along two electrical conductors 845 passing through the catheter shaft and the ablation balloon 801. A-B In some embodiments herein, the ablation balloon 801 may include a solder pad that facilitates soldering the electrical conductor 845 to the conductive portion 838. A-B Electrical connection to ablation balloon 801. Various other electrical connection methods are also apparent, including, for example, flexible circuits and electrical connectors.

[0064] In with Figure 8 In some specific embodiments consistent with the disclosure of the present invention, the ablation balloon 801 may be composed of a conventional catheter balloon polymer, wherein the conductive portion 838 is attached to the outer surface of the ablation balloon 801 and includes a corrugated structure of electrodes that are coupled to the outer surface and can expand and contract with the ablation balloon. The electrodes are electrically connected to the electrical conductors 845 via electrical terminals extending through the polymer balloon. A-B In some specific embodiments, ablation balloon 801 may be a stretchable circuit with electrodes printed on and extending over its surface.

[0065] In with Figure 8 In other embodiments, the fluid used to inflate the ablation balloon 801 can be a conductive fluid, such as a saline solution. An electroporation pulse generated at the proximal end of the catheter shaft (e.g., by a signal generator) can be transmitted upward through the fluid column within the electrically insulating fluid lumen of the shaft, through the ablation balloon 801, and into contact with the conductive portion 838. In some embodiments, the electroporation pulse can be a direct current pulse.

[0066] In various electroporation-based ablation balloon catheter embodiments as disclosed herein, the ablation balloon 801 may include one or more layers with holes located therebetween. For example, the inner layer of the balloon may be electrically insulating to prevent current from a volume of saline fluid used to expand the balloon 801. The outer layer of the balloon may be conductive. The balloon may include one or more hole regions that extend circumferentially around the longitudinal axis of the balloon. Therefore, in the case where the clinician wishes to ablate tissue in contact with the distal portion of the ablation balloon 801, a saline solution may be pumped into the distal hole to form a conductive path to the target tissue. An electroporation pulse may be generated and transmitted upward through a fluid column connected to the distal hole filled with saline and in contact with the target tissue (through the conductive outer layer of the ablation balloon). In order to perform subsequent ablation treatments at other tissue sites, the saline in the distal hole may be evacuated, and another hole region (e.g., an intermediate hole region) in contact with the tissue subsequently used for ablation may be filled with a saline solution and an electroporation pulse may be delivered thereto.

[0067] In various embodiments herein, the ablation balloon can be integrated onto the shaft of an electrophysiology cuff catheter (also referred to as a loop catheter). In other embodiments, the ablation balloon catheter can include a central lumen that allows the electrophysiology cuff catheter to extend through the length of the ablation balloon catheter.

[0068] Embodiments consistent with the present invention may include an ablation balloon utilizing radiofrequency ablation technology. In such embodiments, a radiofrequency transmitter may be located within the ablation balloon, such as in contact with a catheter shaft. The radiofrequency waves emitted by the transmitter pass through the fluid within the ablation balloon and the conductive portion of the ablation balloon and contact tissue adjacent to the conductive portion. In some embodiments, the conductive portion is only a polymer that allows radio waves to be transmitted. In various embodiments where it is desired to selectively irradiate tissue with radio waves, a portion of the surface of the ablation balloon may be or include a radiowave shielding material that prevents radio waves from being transmitted through non-conductive portions, thereby facilitating selective radiation and tissue ablation.

[0069] In some embodiments herein, the conductive portion of the ablation balloon may include electrodes (eg, contoured electrodes) along the surface of the conductive portion of the ablation balloon to facilitate electrical delivery of ablation energy to tissue.

[0070] Various ablation balloon embodiments utilizing electroporation and consistent with this disclosure may require 200 joules of energy, with a maximum power of 5 kilowatts. In embodiments where the electroporation pulse travels up the fluid column in the catheter shaft, the requirements may be higher based on the electrical insulating properties of the fluid lumen.

[0071] In various embodiments herein, the conductive portion of the ablation balloon may include a polymer with nickel or other metal dust contained therein. The conductive portion may also be a conductive polymer that is formed using at least some conductive material and is conductive even in its static state, so that the polymer can conduct enough energy to ablate tissue. Aspects of this article are applicable to various conductive polymer materials. For example, U.S. Patent 6,999,821 discloses intrinsically conductive and conductor-filled polymers that can be used in the present invention, and the patent is incorporated herein by reference as if fully set forth herein. As disclosed therein, intrinsically conductive polymers include polyacetylene, polypyrrole, and polyaniline, among others. Conductor-filled polymers may include materials currently available for implantation, such as silicone rubber with metal, carbon, or graphite particles or powder contained therein. Silver-filled silicone rubber manufactured by NuSil or SpecialtySilicone Products that has been modified to allow implantation has potential utility. An example is silver-plated nickel-filled silicone rubber sold as NuSil R2637.

[0072] The substrate of the conductive portion of the ablation balloon need not be silicone, for example other insulating or weakly conductive materials (e.g. non-conductive elastomers) are contemplated, which may contain conductive materials, conductive alloys and / or reduced metal oxides (e.g., using gold, silver, platinum, iridium, titanium, tantalum, zirconium, vanadium, niobium, hafnium, aluminum, silicon, tin, chromium, molybdenum, tungsten, lead, manganese, beryllium, iron, cobalt nickel, palladium, osmium, rhenium, technetium, rhodium, ruthenium, cadmium, copper, zinc, germanium, arsenic, antimony, bismuth, boron, scandium and one or more of the lanthanide and actinium metals, if appropriate, and at least one conductive agent). The conductive material may be in the form of a powder, granules, fibers or other shapes. The oxide may be a mixture of sintered powders containing oxygen compounds. The alloy may be conventional, such as titanium boride.

[0073] Other examples of conductive polymers useful in the present invention include those described and disclosed in US Patents 6,646,540, 6,495,069, and 6,291,568, all of which are incorporated herein by reference as if fully set forth herein.

[0074] Conductive polymers can be pressure sensitive in that the resistance of the electrode can vary inversely with the pressure applied thereto. However, it should be understood that the flexible conductive polymer electrodes disclosed herein are conductive even in their resting state (i.e., when not under stress), and are therefore different from, for example, pressure-sensitive conductive composite ("PSCC") electrodes disclosed in U.S. Pat. No. 7,955,326, which are non-conductive in the resting state. Preferably, the conductive polymer material will also meet cytotoxicity, hemolysis, systemic toxicity, and intradermal injection criteria.

[0075] Other examples of conductive polymers useful in the present invention include those described and disclosed in U.S. Patent No. 8,500,731, which is hereby incorporated by reference as if fully set forth herein. The insulating sheath of the catheter shaft may preferably be made of a biocompatible electrically insulating material, including, for example, a polymeric material such as an extruded polytetrafluoroethylene (PTFE) tube (e.g., card management).

[0076] Based on the above discussion and explanation, it will be readily appreciated by those skilled in the art that various modifications and changes may be made to various embodiments without strictly following the embodiments and applications shown and described herein. These modifications do not depart from the true spirit and scope of various aspects of this document, including those set forth in the claims.

[0077] Although several embodiments have been described above with a certain degree of particularity to facilitate understanding of at least some ways in which this document may be practiced, a person skilled in the art may make various changes to the disclosed embodiments without departing from the scope of this document and the appended claims. It is intended that all contents contained in the above description or shown in the accompanying drawings be interpreted as merely illustrative and not restrictive. Therefore, the examples and embodiments herein should not be interpreted as limiting the scope of this document. Changes in detail or structure may be made without departing from this teaching. The foregoing description and the appended claims are intended to cover all such modifications and changes.

[0078] The embodiments described herein have various devices, systems and / or methods. Many specific details are stated to provide a thorough understanding of the overall structure, function, manufacture, and the use of the embodiments described in the specification and shown in the drawings. However, it should be understood by those skilled in the art that these embodiments can also be practiced without these specific details. In other cases, well-known operations, parts and elements have not been described in detail to avoid blurring the embodiments described in the specification. It will be understood by those skilled in the art that the embodiments described and shown herein are non-limiting examples, and it is therefore understood that the specific structural and functional details disclosed herein may be representative without having to limit the scope of all embodiments, and its scope is limited only by the appended claims.

[0079] Unless otherwise stated, the terms "include", "comprising" and variations thereof as used herein mean "including but not limited to". Unless otherwise expressly stated, the terms "a", "an" and "the" as used herein mean "one or more".

[0080] References throughout this specification to "various embodiments," "some embodiments," "one embodiment," or "an embodiment," etc., mean that a particular feature, structure, or characteristic described in conjunction with the embodiment(s) is included in at least one embodiment. Therefore, phrases such as "in various embodiments," "in some embodiments," "in one embodiment," or "in an embodiment," etc., that appear throughout this specification do not necessarily refer to the same embodiment. In addition, particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. Therefore, particular features, structures, or characteristics shown or described with reference to one embodiment may be combined in whole or in part with features, structures, or characteristics of one or more other embodiments without limitation.

[0081] Although process steps, method steps, algorithms, etc. can be described in chronological order, such processes, methods, and algorithms can be configured to work in alternative sequences. In other words, any sequence or sequence of steps that can be described does not necessarily represent a requirement to perform the steps in that sequence. The steps of the processes, methods, and algorithms described herein can be performed in any practical order. In addition, some steps can be performed simultaneously.

[0082] When a single device or article is described herein, it is apparent that more than one device or article may be used in place of a single device or article. Similarly, where more than one device or article is described herein, it is apparent that a single device or article may be used in place of more than one device or article. The functions or features of a device may alternatively be performed by one or more other devices that are not explicitly described as having such functions or features.

[0083] It should be understood that the terms "near" and "far" can be used throughout the specification by referring to an end of an instrument operated by a clinician for treating a patient. The term "near" refers to the instrument portion closest to the clinician, and the term "far" refers to the part farthest from the clinician. However, surgical instruments can be used in many orientations and positions, and these terms are not restrictive and absolute. All other directions or spatial references (such as upper, lower, upward, downward, left, right, left, right, top, bottom, above, below, vertical, horizontal, clockwise and counterclockwise) are only used for specified purposes to help readers understand this article without generating restrictions, particularly with respect to the position, orientation or use of this article. Connection references (such as, attachment, connection, connection, etc.) are all broadly interpreted, and can include intermediate members between connecting elements and movement between each element. Similarly, connection references do not necessarily infer that two elements are directly connected and are in a fixed relationship to each other.

[0084] Any patent, publication, or other public material incorporated herein by reference (in whole or in part) is said to be incorporated herein only to the extent that the incorporated material does not conflict with existing definitions, statements, or other public materials clearly set forth herein. Likewise, to the extent the disclosure clearly set forth herein supersedes any conflicting material incorporated herein by reference. Any material or portion thereof incorporated herein by reference (which conflicts with existing definitions, statements, or other public materials clearly set forth herein) is said to be incorporated herein only to the extent that no conflict exists between the incorporated material and the existing public material.

Claims

1. An ablation balloon device, comprising: a catheter shaft comprising a proximal end and a distal end; and An ablation balloon, comprising a proximal end and a distal end, wherein the proximal end of the ablation balloon is coupled to the distal end of the catheter shaft, and the ablation balloon comprises: Balloon surface; an ablation portion configured to facilitate energy transfer between the ablation balloon and tissue in contact with the ablation portion, wherein the ablation portion is self-supporting relative to the balloon surface, and wherein the position of the ablation portion is dynamically adjustable between a middle portion of the balloon surface and a distal portion of the balloon surface by an adjustment mechanism, and A non-ablative portion is configured to reduce energy transfer between the ablation balloon and tissue in contact with the non-ablative portion.

2. The ablation balloon device of claim 1, wherein the ablation portion extends circumferentially around the ablation balloon.

3. The ablation balloon device according to claim 1, wherein the ablation portion is further configured as Engage the circumference of the pulmonary veins, and Tissue in contact with the ablation portion is ablated along a circumference of the pulmonary vein. 4 . The ablation balloon device of claim 1 , further comprising a signal generator configured to transmit one or more direct current pulses to the ablation portion of the ablation balloon.

5. The ablation balloon device according to claim 1, further comprising a plurality of electrical conductors extending from the proximal end of the catheter shaft, through the length of the catheter shaft, and electrically connected to the ablation portion; and A signal generator is electrically connected to the proximal ends of the plurality of electrical conductors and is configured to delivering one or more electroporation pulses to the ablation portion of the ablation balloon via the electrical lead, and Tissue in contact with the ablation portion is ablated.

6. The ablation balloon device of claim 5, wherein one or more of the electroporation pulses comprises an irreversible electroporation pulse.

7. The ablation balloon device of claim 5, wherein one or more of the electroporation pulses comprises a bidirectional pulse.

8. The ablation balloon device of claim 5, wherein one or more of the electroporation pulses comprises a unidirectional pulse.

9. The ablation balloon device of claim 5, wherein one or more of the electroporation pulses deliver 200 joules of energy with a maximum power of 5 kilowatts to the tissue.

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