Ablation catheter with an inflatable element and bipolar electrodes for treating venous aneurysms

Abstract

At least some embodiments of the present disclosure relate to a catheter for use in the treatment of aneurysms, comprising a handle, an elongate shaft connected to the handle, and a heating element disposed in the vicinity of the distal end of the shaft. In some embodiments, the heating element has a proximal end and an opposite distal end, and includes an inflatable balloon that defines a longitudinal dimension between the proximal end and the distal end, and a plurality of electrode sets each including an elongate electrode extending along a majority of the longitudinal dimension of the balloon, the electrodes of each electrode set being configured to form an anode-cathode pair for bipolar delivery of high frequency ablation energy to the target tissue.

Description

Technical Field

[0001] The present disclosure relates to medical devices, systems, and methods for providing therapeutic heat treatment. More specifically, the present disclosure relates to medical devices, systems, and methods for providing therapeutic heat treatment for venous diseases.

Background Art

[0002] Therapeutic heat treatment can be used to treat a variety of medical conditions such as tumors, fungal growths, etc. Heat treatment can be used to treat medical conditions in parallel with other treatment methods or as a standalone treatment method. Since heat treatment performs local heating, it does not cause cumulative toxicity, in contrast to other treatment methods such as drug-based treatments.

[0003] One exemplary clinical application of therapeutic heat treatment is the treatment of chronic venous diseases such as venous aneurysms that can expand and / or serpentine due to one or more pathological conditions. By applying sufficient thermal energy through an intravascular device, the venous aneurysm can be treated by contracting or occluding the target vein.

[0004] There is a continuing need for improved devices and methods for delivering intensively controlled thermal energy while minimizing or eliminating the impact on surrounding healthy tissue for thermally treating chronic venous conditions such as venous aneurysms.

Summary of the Invention

[0005] In Example 1, the device for treating an aneurysm includes a catheter, the catheter including an elongate shaft having a proximal end and a distal end sized and configured such that the distal end can be inserted into a target blood vessel, and a heating element disposed near the distal end of the elongate shaft. The heating element includes an inflatable balloon having a proximal end and an opposite distal end and defining a longitudinal dimension therebetween, and a plurality of electrode sets circumferentially disposed around the balloon, each electrode set including first and second elongate electrodes extending along a majority of the longitudinal dimension of the balloon, the electrodes of each electrode set being configured to form an anode-cathode pair for bipolar delivery of radiofrequency ablation energy to target tissue of a target blood vessel.

[0006] In Example 2, in the device of Example 1, the inflatable balloon has a length greater than 3 centimeters. In Example 3, in the device of Example 2, the inflatable balloon has a length less than 10 centimeters.

[0007] In Example 4, in the device of Example 1, the inflatable balloon has a diameter greater than 5 millimeters when inflated. In Example 5, in the device of Example 1, the inflatable balloon has a diameter greater than 12 millimeters when inflated.

[0008] In Example 6, in the device of Example 1, the inflatable balloon has a diameter greater than the diameter of the target blood vessel when inflated. In Example 7, in the device of Example 1, the inflatable balloon has a length and a diameter such that when inflated, its length is at least twice its diameter.

[0009] In Example 8, in the device of Example 1, at least one electrode of the plurality of electrode sets includes a flexible circuit. In Example 9, in the device of Example 1, the distance between the anode-cathode pair is smaller than the distance between two adjacent electrode sets.

[0010] In Example 10, in the device of Example 9, the distance between two adjacent electrode sets is at least twice the distance between the anode-cathode pair. In Example 11, a system for treating an aneurysm includes a device according to any one of Examples 1 to 10, an energy generator connected to a catheter and configured to generate an electrical signal, and a controller operably connected to the energy generator and configured to control the generation of the electrical signal.

[0011] In Example 12, in the system of Example 11, the plurality of electrode sets are operably coupled to the energy generator. In Example 13, in the system of Example 11, the inflatable balloon inflates to a first diameter in a first operating mode, and the inflatable balloon inflates to a second diameter in a second operating mode, and the first diameter is different from the second diameter.

[0012] In Example 14, in the system of Example 13, the inflatable balloon inflates to a diameter such that the inflatable membrane of the inflatable balloon is pressed against the wall of the target blood vessel. In Example 15, in the system of Example 14, the controller is configured to receive the measured impedance between the plurality of electrode sets and determine whether the inflatable balloon is in contact with the wall of the target blood vessel.

[0013] Although multiple embodiments are disclosed, further other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description showing and describing exemplary embodiments of the present invention. Therefore, the drawings and the detailed description should be regarded as being essentially exemplary and not restrictive.

Brief Description of the Drawings

[0014]

Figure 1

Figure 2A

Figure 2B

Figure 2C

Figure 3

Figure 4A

Figure 4B

DETAILED DESCRIPTION OF THE INVENTION

[0015] The present invention is capable of following various modified forms and alternative forms. However, specific embodiments are shown in the drawings as examples and will be described in detail below. However, the intention is not to limit the present invention to the specific embodiments described. On the contrary, the present invention is intended to embrace all modified forms, equivalents, and alternative forms included within the scope of the present invention as defined by the appended claims.

[0016] The following detailed description is merely exemplary in nature and is not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the following description provides some practical illustrations for implementing exemplary embodiments of the invention. Examples of configurations, materials, and / or dimensions are provided for the selected elements. Those skilled in the art will recognize that there are various suitable alternative means for many of the described examples.

[0017] Therapeutic heat treatment can be used to treat a variety of medical conditions, including chronic venous diseases such as varicose veins that can expand and / or serpentine due to one or more pathological conditions. By applying sufficient thermal energy through an intravascular device, the varicose veins can be treated by contracting or occluding the target vein.

[0018] An exemplary catheter for use in treating varicose veins can include a handle, a long shaft connected to the handle, and a heating element disposed near the distal end of the shaft. In some embodiments, the heating element can receive an electric current (e.g., alternating current, direct current) supplied by an energy generator and generate and supply thermal ablation energy. In certain embodiments, the heating element can receive an electrical signal (e.g., high-frequency alternating current) generated by an energy generator and generate and supply high-frequency ablation energy.

[0019] As described above, there is a continuing need for improved devices and methods for delivering intensively controlled thermal energy while minimizing or eliminating the impact on surrounding healthy tissue in order to thermally treat chronic venous conditions such as varicose veins. For example, the diameter of the varicose vein to be treated may vary depending on the patient, i.e., the location of the treatment (e.g., the diameter of the great saphenous vein can range from about 2.5 mm to about 14.0 mm at the groin, from about 1.5 mm to about 12.0 mm in the thigh, and from about 1.0 mm to about 8.0 mm in the calf. The diameter of the small saphenous vein can range from about 1.5 mm to about 3.0 mm). If the same size catheter is used to treat veins of different diameters, the heat treatment may not be performed efficiently or effectively. In certain situations, it may be desirable for the heating element to completely occlude the target vein during treatment. In addition, catheters used to treat the target blood vessel are desired to have improved flexibility in order to minimize potential undesirable damage to the vessel wall during treatment.

[0020] Some embodiments of the present disclosure will describe a catheter comprising an elongate shaft and a heating element disposed in the vicinity of the distal end of the elongate shaft. In some embodiments, the heating element has a proximal end and an opposite distal end, and an inflatable balloon defining a longitudinal dimension between the proximal end and the distal end, and a plurality of electrode sets circumferentially spaced around the inflatable balloon and operably coupled to an energy generator. In some embodiments, each electrode set includes first and second elongate electrodes extending along a majority (e.g., at least one-half, at least three-quarters, at least five-eighths) of the longitudinal dimension of the inflatable balloon, and the electrodes of each electrode set are configured to form an anode-cathode pair for bipolar delivery of radiofrequency ablation energy to the target tissue. In some embodiments, the inflatable balloon may comprise a flexible material, and the balloon may inflate to different diameters (e.g., two different diameters in two different operating modes) during the procedure. In certain embodiments, the inflatable balloon can inflate to a first diameter in a first operating mode, a second diameter in a second operating mode, and a third diameter in a third operating mode, the first diameter being different from the second diameter, the first diameter being different from the third diameter, and the second diameter being different from the third diameter. In some examples, the second diameter is larger than the first diameter, and the third diameter is larger than the second diameter.

[0021] FIG. 1 is a schematic view of an exemplary ablation device 100 for treating chronic venous diseases, such as venous aneurysms, according to an embodiment of the present disclosure. The ablation device 100 includes an ablation catheter 102 including a handle 104, an elongate shaft 106 having a distal end portion 110 terminating at a proximal end 108 and a distal end 112, and a heating element 114 disposed in the vicinity of the distal end 112 of the elongate shaft 106. The shaft 106 is sized and configured such that the distal end 112 can be inserted into the target blood vessel. The heating element 114 is configured to supply ablation energy (e.g., radiofrequency energy, thermal energy) to the wall of the target blood vessel.

[0022] The ablation device 100 may include an energy generator 116 that is electrically coupled to the handle 104 via a connector 118 and is configured to generate energy by supplying an electrical signal (e.g., current, high-frequency alternating current). The controller 120 is operably connected to the energy generator 116 and controls the generation of the electrical signal. The controller 120 may be implemented using firmware, integrated circuits, and / or software modules that interact with each other or are combined together. For example, the controller 120 may include a memory 122 that stores computer-readable instructions / code 124 for execution by a processor 126 (e.g., a microprocessor) to implement aspects of the method embodiments described herein.

[0023] In certain embodiments, the heating element 114 employs structural features and / or components to improve the clinical performance of the ablation catheter 102 and enhance manufacturability. In some embodiments, as described in more detail below, the heating element 114 has a proximal end and an opposite distal end and includes an inflatable component 115, also referred to as an inflatable balloon, that defines a longitudinal dimension (e.g., 3 centimeters, 7 centimeters) between the proximal end and the distal end, and a plurality of electrode sets that are circumferentially spaced around the inflatable component 115 and are operably coupled to the energy generator 116. In some embodiments, each electrode set includes first and second elongate electrodes that extend along a majority of the longitudinal dimension of the inflatable component 115, and the electrodes of each electrode set are configured to form an anode-cathode pair for bipolar delivery of high-frequency ablation energy to the target tissue. In a particular example, the first and second elongate electrodes have the same length. In some examples, the length of the first elongate electrode is greater than half the length of the inflatable component 115. In a particular example, the length of the first elongate electrode is greater than three-quarters the length of the inflatable component 115.

[0024] According to some embodiments, the ablation device 100 includes a fluid source 130 fluidly connected to an expandable component 115. In certain embodiments, the expandable component 115 contracts when the ablation device is in a first state and expands by fluid (e.g., saline, gas, etc.) from the fluid source 130 when in a second state. In some embodiments, the expandable component 115 has an elongated shape. For example, the length of the expandable component 115 is at least twice the diameter of the expandable component 115. In some examples, the length of the expandable component 115 is at least three times the diameter of the expandable component 115.

[0025] In some embodiments, the controller 120 can be configured to communicate with various components of the device 100 and generate a graphical user interface (GUI) that is displayed via the display 128. The controller 120 can include any type of computing device suitable for implementing the embodiments of the present disclosure. Examples of computing devices include workstations, servers, laptops, portable devices, desktops, tablet computers, handheld devices, and dedicated computing devices or general-purpose computing devices such as general-purpose graphics processing units (GPGPUs), all of which are contemplated within the scope of FIG. 1 with reference to the various components of the device 100.

[0026] In some embodiments, the controller 120 includes a bus that directly and / or indirectly couples devices such as a processor, a memory, input / output (I / O) ports, I / O components, and a power supply. Any number of additional components, different components, and / or combinations of components may also be included in the computing device. The bus represents one or more buses (such as an address bus, a data bus, or a combination thereof). Similarly, in some embodiments, the computing device may include multiple processors, multiple memory components, multiple I / O ports, multiple I / O components, and / or multiple power supplies. Additionally, any number of these components, or combinations thereof, may be distributed and / or replicated across multiple computing devices.

[0027] In some embodiments, the memory 122 includes computer-readable media in the form of volatile and / or non-volatile memory, a temporary storage medium and / or a non-temporary storage medium, and can be removable, non-removable, or a combination thereof. Examples of the media include random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory, optical media or holographic media, magnetic cassettes, magnetic tapes, magnetic disk storage devices or other magnetic storage devices, data transmission, and / or any other media that can be used to store information and can be accessed by a computing device such as, for example, quantum state memory, and / or the like. In some embodiments, the memory 122 stores computer-executable instructions for causing a processor (such as the controller 120) to implement aspects of the embodiments of the system components described herein and / or to execute aspects of the embodiments of the methods and procedures described herein.

[0028] Computer-executable instructions 124 can include, for example, computer code, machine-usable instructions, and program components executable by one or more processors associated with a computing device, such as, for example. Program components can be programmed using any number of different programming environments, including various languages, development kits, frameworks, and / or the like. Some or all of the functionality contemplated herein can also or alternatively be implemented in hardware and / or firmware.

[0029] In some embodiments, memory 122 can include a data repository implemented using any one of the configurations described below. The data repository can include random access memory, flat files, XML files, and / or one or more database management systems (DBMSs) running on one or more database servers or data centers. The database management system can be a relational (RDBMS), hierarchical (HDBMS), multidimensional (MDBMS), object-oriented (ODBMS or OODBMS), or object-relational (ORDBMS) database management system, for example. The data repository can be, for example, a single relational database. In some cases, the data repository can include multiple databases that can exchange and aggregate data by means of a data integration process or software application. In an exemplary embodiment, at least a portion of the data repository can be hosted in a cloud data center. In some cases, the data repository can be hosted on a single computer, server, storage device, cloud server, or the like. In some other cases, the data repository can be hosted on a series of network-connected computers, servers, or devices. In some cases, the data repository can be hosted on a tiered data storage device including local, regional, and central.

[0030] The various components of device 100 can communicate via a communication interface, such as a wired interface or a wireless interface, or can be coupled to the communication interface. The communication interface includes, but is not limited to, wired or wireless short - and long - distance communication interfaces. For the wired interface, cables, umbilicals, and the like can be used. The short - distance communication interface can be, for example, an interface compliant with known communication standards such as a local area network (LAN), the Bluetooth® standard, the IEEE 702 standard (e.g., IEEE 702.11), ZigBee® or a similar specification (e.g., based on the IEEE 702.15.4 standard), or other public or proprietary wireless protocols. The long - distance communication interface can be, for example, a wide area network (WAN), a cellular network interface, a satellite communication interface, etc. The communication interface can be within a private computer network such as an intranet or on a public computer network such as the Internet.

[0031] FIG. 2A is a schematic diagram of an exemplary ablation catheter 200 that includes a connector 218 (similar to connector 118 as shown in FIG. 1) for treating chronic venous diseases, such as varicose veins. FIG. 2B is a schematic cross - sectional view of the connector 218 of the exemplary ablation catheter 200 along the cross - section indication line 2B - 2B of FIG. 2A. FIG. 2C is a schematic cross - sectional view of the handle 204 of the exemplary ablation catheter of FIG. 2A according to an embodiment of the present disclosure.

[0032] As shown, ablation catheter 200 includes a handle 204, a elongate shaft 206 having a distal end portion 210 terminating at a proximal end 208 and a distal end 212, and a heating element 214 disposed in the vicinity of the distal end 212 of the elongate shaft 206. The shaft 206 is sized and configured such that the distal end 212 can be inserted into a target blood vessel. The heating element 214 is configured to supply ablation energy (e.g., high frequency energy, thermal energy) to the wall of the target blood vessel.

[0033] In some embodiments, as described in more detail below, the heating element 214 has a proximal end and an opposite distal end, and includes an inflatable balloon 216 that defines a longitudinal dimension between the proximal end and the distal end, and a plurality of electrode sets 217 that are circumferentially spaced around the balloon 216 and are operatively coupled to an energy generator (e.g., energy generator 116 of FIG. 1). In some embodiments, each electrode set 217 includes first and second elongate electrodes that extend along a majority of the longitudinal dimension of the balloon, and the electrodes of each electrode set are configured to form an anode-cathode pair for bipolar delivery of high frequency ablation energy to the target tissue. During the procedure, the inflatable balloon 216 can be inflated and / or deflated via a fluid source 230. The fluid source 230 can be attached to a pump or syringe (not shown). In an embodiment, the fluid source 230 can include a valve to prevent the inflatable balloon 216 from deflating during the procedure. In some embodiments, for example, as shown in FIG. 2A, the fluid source 230 can be connected to the inflatable balloon 216 via the handle 204 and the elongate shaft 206. In some embodiments, the fluid source 230 can be connected directly to the inflatable balloon 216 (not shown).

[0034] In some embodiments, the connector 218 includes pins 242 of different sizes (e.g., including pins 242a, 242b) and pins 244 (e.g., including pins 244a, 244b). The pins 242 are relatively smaller than the pins 244 and are configured to transmit electrical signals (e.g., the electrical signals generated by the energy generator 116 of FIG. 1). Exemplary electrical signals may include thermocouple signals or pressure signals. The pins 244 are relatively larger compared to the pins 242 and may be configured to pass a current from an energy generator (e.g., the energy generator 116 of FIG. 1) to generate heat in the heating element 214. One of the pins 244 may be used as a pin connected to ground (i.e., a ground pin). In some embodiments where the heating element includes a plurality of heating segments (e.g., coil segments), the ground pin may be used as a common ground pin by the plurality of heating segments.

[0035] As shown in FIG. 2C, an electrode set (e.g., the electrode set 217 as shown in FIG. 2A) may be connected to a printed circuit board ("PCB") 246 disposed within the handle 204 via one or more wires 248 within the elongate shaft 206. In some embodiments, the one or more wires 248 may be copper wires. The PCB 246 may be connected to a generator (e.g., the energy generator 116 of FIG. 1) via one or more cables 250.

[0036] FIG. 3 is a schematic partial enlarged view of a distal end portion 300 of an ablation catheter in an extended state, according to an embodiment of the present disclosure. As shown, the distal end portion 300 includes a portion of an elongate shaft 302 terminating at a distal end 304 that defines a longitudinal axis 303, and a heating element 306 disposed in the vicinity of the distal end 304 of the elongate shaft 302. The shaft 302 and the heating element 306 are sized and configured such that the distal end 304 can be inserted into a target blood vessel.

[0037] The heating element 306 has a proximal end 310 and an opposite distal end 312, and includes an inflatable balloon 308 that defines a longitudinal dimension portion 314 between the proximal end 310 and the distal end 312, and a plurality of electrode sets 316 that are circumferentially spaced around the balloon 308 and are operably coupled to an energy generator (e.g., the energy generator 116 of FIG. 1). Since veins can meander due to chronic venous disease, it is not easy for an operator to insert the distal end portion 300 of the ablation catheter into the target vein. If the catheter is too rigid, it may become increasingly difficult to place the heating element 306 on the distal end portion 300 at a specific treatment site. By using the inflatable balloon 308 as part of the heating element 306, the flexibility of the catheter is increased, the distal end portion 300 can more easily pass through the tortuous vein and reach the target treatment site, and the surgical time can also be shortened.

[0038] In some embodiments, each electrode set 316 includes first and second elongate electrodes (e.g., 318 and 320, or 322 and 324 as shown in the figures) that extend along a majority of the longitudinal dimension portion 314 of the balloon 308, and the electrodes 318 - 324 of each electrode set 316 are configured to form an anode - cathode pair for bipolar delivery of radiofrequency ablation energy to the target tissue. In an exemplary embodiment as shown in FIG. 3, the electrode 318 of the electrode set 316a is a positively charged anode, and the electrode 320 of the electrode set 316b is a negatively charged cathode. Similarly, the electrode set 316b includes an anode electrode 322 and a cathode electrode 324. In some embodiments, at least one electrode of the plurality of electrode sets 316 includes a flexible circuit. In some embodiments, the electrodes in the plurality of electrode sets 316 include a flexible circuit.

[0039] The plurality of electrode sets 316 can be formed by electroplating or metal spraying processes, or can be manufactured using any method commonly used to manufacture flexible circuits as understood by those skilled in the art. In some examples, the flexible circuit can be disposed on the inflatable balloon 308 using an adhesive. In some embodiments, the plurality of electrode sets 316 includes materials similar to those typical of materials used for flexible circuits. In some embodiments, the plurality of electrode sets 316 includes materials having a relatively low electrical resistance.

[0040] In some embodiments, the distance d1 between the anode-cathode pair (i.e., the distance between the anode electrode 318 and the cathode electrode 320) is less than the distance d2 between two adjacent electrode sets (i.e., the distance between the electrode sets 316a and 316b as measured by the distance between the cathode electrode 320 and the anode electrode 322, and the distance between two adjacent electrode sets is the distance between two adjacent electrodes at each electrode of each electrode set). In some examples, the distance between two adjacent electrodes is at least twice the distance between the anode-cathode pair. In an embodiment, the distance d1 between each of the anode-cathode pairs (i.e., the distance between the anode electrode 318 and the cathode electrode 320, or the distance between the anode electrode 322 and the cathode electrode 324) can be the same. In a particular example, the first and second elongate electrodes have the same length L e In some examples, the length L of the first elongate electrode e is greater than half the length L of the inflatable balloon 308 b In a particular example, the length L of the first elongate electrode e is greater than three-quarters of the length L of the inflatable balloon 308 b

[0041] According to some embodiments, the inflatable balloon 308 is fluidly connected to a fluid source (e.g., fluid source 130 of FIG. 1). In certain embodiments, the inflatable balloon 308 is in a first state and contracts, and in a second state, it inflates via a fluid source (e.g., by saline, gas, etc.). In some embodiments, the inflatable balloon 308 has an elongated shape. For example, the length L b of the inflatable balloon 308 b is at least twice the diameter d b of the inflatable balloon 308. b In some examples, the length L

[0042] of the inflatable balloon 308 is about 3 centimeters to about 10 centimeters. b In some embodiments, the inflatable balloon 308 has a diameter d b of about 3 millimeters to about 12 millimeters when inflated. In some embodiments, the inflatable balloon 308 has a diameter d b of about 5 millimeters to about 10 millimeters when inflated. In some examples, the balloon 308, when inflated, has a length L b that can be at least twice the diameter d b of the balloon 308. In some embodiments, during the procedure, the inflatable balloon 308 can have a diameter d b that is larger than the diameter of the target vessel when inflated.

[0043] During the procedure, the inflatable balloon 308 can inflate to press against the target vein wall. The controller (e.g., controller 120 of FIG. 1) can be configured to measure the impedance between the electrode sets 316. The controller can be configured to determine whether the balloon 308 is in contact with the target vessel wall in response to a change in the measured impedance, without the need for an additional pressure sensor.

[0044] As described above, the diameter of the aneurysm to be treated may vary depending on the patient, i.e., the location of the treatment (e.g., the diameter of the great saphenous vein can range from about 2.5 mm to about 14.0 mm at the thigh joint, from about 1.5 mm to about 12.0 mm in the thigh, and from about 1.0 mm to about 8.0 mm in the calf. The diameter of the small saphenous vein can range from about 1.5 mm to about 3.0 mm). Having an expandable balloon 308 with an adjustable width can enable a physician to adapt the same catheter to treat blood vessels with different diameters or different sections within a particular vasculature, conform it perfectly to the vessel wall, and thus help achieve a better therapeutic effect.

[0045] During treatment, the expandable balloon 308 can expand to occlude the target vasculature, thereby avoiding blood flow through the vasculature and enhancing the thermal efficiency of the treatment. In an embodiment, the balloon can expand to different sizes according to the diameter of the target vasculature such that one or more of the electrode sets 316 press against the wall of the target vasculature. In some embodiments, a controller (e.g., controller 120 of FIG. 1) can be configured to measure the impedance between the electrode sets 316 to determine whether the balloon 308 is in contact with the vessel wall, and thus it is possible for an operator to estimate the degree of ablation based on the impedance information measured by the controller.

[0046] In some cases, the expandable balloon 308 is inflated by a fluid. In some cases, the fluid is saline. In one example, the fluid is a gas. In one example, the fluid is nitrous oxide (N2O). In some cases, the expandable balloon 308 is semi-compliant. In another case, the expandable balloon 308 comprises a non-compliant material. When the balloon material is non-compliant, the distance from the electrode to the tissue can be determined. When the balloon material is semi-compliant, the distance from the electrode to the tissue can be determined, for example, using a known pressure within the balloon.

[0047] In an embodiment, the inflatable balloon 308 may include materials such as, for example, polyvinyl chloride (PVC), polyethylene (PE), cross-linked polyethylene, polyolefin, polyolefin copolymer (POC), polyethylene terephthalate (PET), nylon, polymer blend, polyester, polyimide, polyamide, polyurethane, silicone, polydimethylsiloxane (PDMS), and / or equivalents. The inflatable balloon 308 may include a relatively non-elastic polymer such as a PE, POC, PET, polyimide, or nylon material. The membrane of the inflatable balloon 308 may be composed of a relatively flexible elastomeric material including, but not limited to, silicone, latex, urethane, or Mylar® elastomer. The inflatable balloon 308 can be surrounded by other materials such as, for example, metal, nylon fiber, and / or equivalents. The inflatable balloon 308 can be constructed from a thin inextensible polymer film such as, for example, polyester, flexible thermoplastic polymer film, thermosetting polymer film, and / or equivalents.

[0048] In an embodiment, the membrane of the inflatable balloon 308 can have a thickness of about 5 - 50 micrometers to provide sufficient burst strength and enable foldability. In one embodiment, the membrane of the inflatable balloon 308 can have a thickness in the range of 25 - 250 micrometers. In one embodiment, the membrane of the inflatable balloon 308 can have a tensile strength of 30,000 - 60,000 psi (207 - 414 MPa).

[0049] In one embodiment, the balloon includes an insulating material. In some implementations, the electrodes 318 - 324 may include a thin film of conductive ink or optical ink. The ink may be polymer-based. The ink may further include materials such as carbon and / or graphite in combination with a conductive material. The electrodes may additionally include biocompatible low-resistance metals such as silver, silver flakes, gold, and platinum that are radiopaque.

[0050] In some embodiments, the shaft 302 can be made from polyether ether ketone (“PEEK”), polycarbonate (“PC”), Pebax®, high density polyethylene (“HDPE”), polyimide (“PI”), or any suitable polymeric material known to those skilled in the art for manufacturing catheter shafts. In some embodiments, the inflatable balloon 308 can be made from Pebax®, polyethylene terephthalate (“PET”), thermoplastic polyurethane (“TPU”), nylon, polyamide (“PA” or “nylon plastic”), or any suitable polymeric or synthetic thermoplastic polymeric material known to those skilled in the art.

[0051] FIGS. 4A and 4B are schematic diagrams of a portion of an ablation catheter for use within a patient's target vessel for the treatment of a venous aneurysm, according to an embodiment of the present disclosure. In some embodiments, during an endovenous thermal ablation procedure, an introducer sheath can be placed within the patient's target vein using ultrasonic guidance and standard vascular techniques. The ablation catheter (e.g., ablation catheter 102 in FIG. 1) can then be inserted through the introducer sheath into the target vein. In some situations, under ultrasonic guidance, an infiltration anesthetic solution or saline can be injected into the target vein segment to function as a heat sink to protect the tissue from thermal damage and to improve the thermal conductivity between the wall of the target vein and the ablation catheter.

[0052] As shown in FIG. 4A, the distal end portion 400 of the ablation catheter (e.g., ablation catheter 102 of FIG. 1) is disposed within the target vessel 402a. The ablation catheter can be introduced and positioned by an introducer sheath using ultrasonic guidance. As will be understood by those skilled in the art, any standard vascular technique may be used here to introduce and position the distal end portion 400 of the ablation catheter within the target vein segment. The distal end portion 400 may include a heat generating element 408 having an inflatable balloon 406a and a plurality of electrode sets 410 that are circumferentially spaced around the balloon and operably connected to an energy generator (e.g., energy generator 116 of FIG. 1).

[0053] During the procedure, the inflatable balloon 408a can be inflated (e.g., via fluid source 130 of FIG. 1) to press against the target vein wall, e.g., as shown in FIG. 4A, when the ablation catheter is in a first state (e.g., an expanded state). The controller (e.g., controller 120 of FIG. 1) can be configured to measure the impedance between the electrode sets 410. The impedance can change before and after the inflatable balloon 408a contacts the target vein wall (e.g., the impedance is high without contact, decreases at the first contact between the inflatable balloon 408a and the target vein wall, and then may increase again as the procedure progresses). The controller can be configured to determine whether the balloon 408a in the first state is in contact with the target vessel wall without the need for an additional pressure sensor, in response to the measured change in impedance. Having an inflatable balloon can help the physician adapt the same catheter to treat vessels of different diameters, conform it completely to the vessel wall, and achieve a better therapeutic effect.

[0054] In some embodiments, during the procedure, a current can be applied by a generator (e.g., energy generator 116 of FIG. 1) to a plurality of electrode sets 410. The generator can include a high-frequency generator that generates a high-frequency current to heat the plurality of electrode sets 410. In some implementations, the ablation catheter can include a temperature sensor disposed along the length of the catheter shaft, and the power supply to the electrode sets 410 can be automatically adjusted by a controller (e.g., controller 120 of FIG. 1) based on the temperature measured by the temperature sensor or a signal indicative of the temperature. In some embodiments, the temperature sensor can be disposed along the length of the distal end portion 400. In some embodiments, the temperature sensor can be disposed on the inflatable balloon 408a and can contact one of the plurality of electrode sets 410. In some embodiments, one of the plurality of electrode sets 410 can be a thermocouple electrode set.

[0055] The segment of the target vessel 402a to be treated adjacent to the plurality of electrode sets 410 will close (e.g., constrict, decrease in diameter) as energy is supplied to the plurality of electrode sets 410, as shown as 402b in FIG. 4B. During the procedure, external pressure can be applied as needed. After a particular section has been treated (i.e., the section of the vein has been closed), the catheter can be moved toward the vein access, and this process is repeated until the entire vein is occluded. The catheter and introducer sheath can then be removed, and the inflated balloon 408b can be deflated (e.g., via fluid source 130 of FIG. 1) and then removed after the procedure is complete. In some use cases, the diameter of the heating element 406 and / or the balloon 408b is smaller than the diameter of the vessel 402a, and the heating element 406 can be moved close to the vessel wall during the procedure.

[0056] As used herein, the terms “about” and “approximately” are used with respect to measured values (e.g., dimensions, characteristics, attributes, components, etc.) and ranges thereof, specifically with respect to tangible things (e.g., products, inventories, etc.) and / or intangible things (e.g., data, electronic currency representations, accounts, information, ratios of things (e.g., percentages, fractions), calculations, data models, dynamic system models, algorithms, parameters, etc.), and may be used interchangeably. These “about” and “approximately” include the recited measured values and also measured values that are reasonably close to the recited measured values, including measurement errors, differences in calibration of measurement or manufacturing equipment, human error in reading and / or setting measured values, adjustments for optimization of performance and structural parameters considering other measured values (e.g., measured values related to other things), specific implementation scenarios, human, computing device, mechanical operation, setting, inaccurate adjustment and / or operation of measured values, system tolerances, control loops, machine learning, predictable variations (e.g., statistically negligible variations, chaotic variations, system and / or model instabilities, etc.), preferences, and / or the like, and also include minor differences that can be readily judged as such.

[0057] Exemplary methods may be represented by one or more drawings (e.g., flowcharts, communication flows, etc.), but the drawings should not be construed as implying requirements for the various steps disclosed herein or a particular order between steps. However, some specific embodiments may require a particular step and / or a particular order between particular steps, as may be explicitly described herein and / or understood from the nature of the steps themselves (e.g., the execution of some steps may depend on the result of a previous step). Further, a “set,” “subset,” or “group” of items (e.g., inputs, algorithms, data values, etc.) may include one or more items, and similarly, a subset or subgroup of items may include one or more items. “Plurality” means two or more.

[0058] Without departing from the scope of the present invention, various modifications and additions can be made to the exemplary embodiments described. For example, although the above-described embodiments refer to specific features, the scope of the present invention also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Accordingly, the scope of the present invention is intended to embrace all such alternative, modified, and variant forms, together with all of their equivalents, that are included in the claims.

Claims

1. A device for treating a venous aneurysm, comprising a catheter, the catheter comprising a long shaft having a proximal end and a distal end, the distal end sized and configured to be insertable into a target blood vessel, the long shaft; and a heating element disposed near the distal end of the long shaft, the heating element comprising an inflatable balloon having a proximal end and an opposite distal end, defining a longitudinal dimension therebetween; and a plurality of electrode sets circumferentially disposed around the balloon, each electrode set comprising first and second elongate electrodes extending along a majority of the longitudinal dimension of the balloon, the electrodes of each electrode set configured to form an anode-cathode pair for bipolar delivery of radiofrequency ablation energy to target tissue of a target blood vessel, the plurality of electrode sets.

2. The device of claim 1, wherein the inflatable balloon has a length greater than 3 centimeters.

3. The device of claim 2, wherein the inflatable balloon has a length less than 10 centimeters.

4. The device of claim 1, wherein the inflatable balloon has a diameter greater than 5 millimeters when inflated.

5. The device of claim 1, wherein the inflatable balloon has a diameter greater than 12 millimeters when inflated.

6. The device of claim 1, wherein the inflatable balloon has a diameter greater than the diameter of the target blood vessel when inflated.

7. The device of claim 1, wherein the inflatable balloon has a length and a diameter, and when inflated, the length is at least twice the diameter.

8. The device of claim 1, wherein at least one electrode in the plurality of electrode sets comprises a flexible circuit.

9. The device of claim 1, wherein the distance between the anode-cathode pair is less than the distance between two adjacent electrode sets.

10. The device of claim 9, wherein the distance between two adjacent electrode sets is at least twice the distance between the anode-cathode pair.

11. A system for treating a venous aneurysm, comprising the device of any one of claims 1 to 10; and An energy generator connected to the catheter and configured to generate an electrical signal, A system comprising a controller operably connected to the energy generator and configured to control the generation of the electrical signal. **Claim 12** The system according to claim 11, wherein the plurality of electrode sets are operably coupled to the energy generator. **Claim 13** The system according to claim 11, wherein the inflatable balloon inflates to a first diameter in a first operating mode and the inflatable balloon inflates to a second diameter in a second operating mode, and the first diameter is different from the second diameter. **Claim 14** The system according to claim 13, wherein the inflatable balloon inflates to a size diameter such that an expandable membrane of the inflatable balloon is pressed against the wall of the target blood vessel. **Claim 15** The system according to claim 14, wherein the controller is configured to receive a measured impedance between the plurality of electrode sets and determine whether the inflatable balloon is in contact with the wall of the target blood vessel.

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