Electroporation for reduced sensation

Abstract

A medical device includes an elongate structure. The elongate structure is configured to navigate from a point of entry of a patient to an implant site within the patient. At least one electrode is carried on a distal portion of the elongate structure. The at least one electrode is configured to be oriented relative to a heart of the patient when adjacent the implant site. The at least one electrode is configured to deliver electroporation energy to electroporate tissue adjacent to the thorax of the patient and in front of the heart.

Description

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 381,489, filed Oct. 28, 2022, the entire content of which is incorporated herein by reference. Technical Field

[0002] The present disclosure relates generally to implantable medical devices and, more particularly, to devices configured to deliver electroporation energy in the vicinity of the location of an implantable medical lead. Background Art

[0003] Medical device systems have been designed to provide electrostimulation therapy without placing an implantable medical lead within the heart or directly attaching an implantable medical lead to the heart. These medical device systems can provide, for example, bradycardia pacing, anti-tachyarrhythmia pacing (ATP), post-shock pacing, or other types of pacing to the heart from a non-transvenous or non-intracardiac location (such as from a location external to the heart). In some patients, a medical device system implanted within the patient can also provide cardioversion or defibrillation therapy to the patient's heart to terminate certain types of tachyarrhythmias (such as ventricular tachycardia (VT) or ventricular fibrillation (VF)) to prevent sudden cardiac death (SCD). Summary of the Invention

[0004] Medical device systems configured to provide electrostimulation therapy using electrodes external to the heart (such as implantable medical device systems or partially implantable medical device systems) can cause a patient to experience sensations (e.g., paresthesia, pain, etc.) during the delivered stimulation. In the case where an implantable medical device (IMD) system is configured to deliver pacing therapy (e.g., bradycardia pacing, anti-tachyarrhythmia pacing (ATP), post-shock pacing, pause-prevention pacing, or other types of pacing) to a patient's heart from an intrathoracic location, stimulation of skeletal muscle and intercostal nerves (and / or any other muscle tissue and nerve tissue) can occur adjacent to the electrodes of the lead or the device delivering the therapy.

[0005] According to the techniques of the present disclosure, an electroporation device can deliver electroporation energy to tissue capable of causing sensation during pacing to reduce or eliminate the sensation. For example, delivering electroporation energy to tissue can physiologically modify the cells of the tissue to which the energy is applied. The electroporation device can apply reversible electroporation energy or irreversible electroporation (IRE) energy. As a result of undergoing an electrical pulse, the sensation of the electroporated cells during pacing can be reduced or eliminated.

[0006] In some examples, a medical device includes: an elongate structure configured to navigate from an access point of a patient to an implantation site within the patient; and at least one electrode carried on a distal portion of the elongate structure, wherein the at least one electrode is configured to be oriented relative to the patient's heart when adjacent the implantation site, and wherein the at least one electrode is configured to deliver electroporation energy to electroporate tissue adjacent the patient's chest wall and in front of the heart.

[0007] In some examples, a medical system includes: a guide configured to define a lumen; an implantable medical lead configured to use the guide to navigate from an access point of a patient to an implantation site within the patient, wherein the lumen is sized to permit insertion of the implantable medical lead into the guide; and at least one electrode carried on a distal portion of the implantable medical lead, wherein the at least one electrode is configured to be oriented relative to the patient's heart when adjacent the implantation site, and wherein the at least one electrode is configured to deliver electroporation energy to electroporate tissue adjacent the patient's chest wall and in front of the heart.

[0008] In some examples, a method includes: delivering electroporation energy through at least one electrode carried on a distal portion of an elongate structure that navigates from an access point of a patient to an implantation site within the patient to electroporate tissue adjacent the patient's chest wall and in front of the heart, wherein the at least one electrode is oriented relative to the patient's heart.

[0009] Details of one or more examples are set forth in the accompanying drawings and the following description. Other features, objects, and advantages will be apparent from the description and drawings, and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 is a conceptual diagram illustrating an example implantable medical system in accordance with the techniques of the present disclosure.

[0011] Figure 2 is a conceptual diagram illustrating an example lead in accordance with the techniques of the present disclosure.

[0012] Figure 3 is a conceptual diagram illustrating an example lead carrying a shield in accordance with the techniques of the present disclosure.

[0013] Figures 4A to 4B is a conceptual diagram illustrating an example lead carrying a balloon in accordance with the techniques of the present disclosure.

[0014] Figure 5 is a conceptual diagram illustrating an example implantable medical system including a guide in accordance with the techniques of the present disclosure.

[0015] Figure 6Is a conceptual diagram illustrating an example implantable medical system including an external electrode according to the technology of the present disclosure.

[0016] Figure 7 Is a block diagram illustrating an exemplary configuration of an electroporation device according to the technology of the present disclosure.

[0017] Figure 8 Is a flowchart of an example technique for using an implantable medical system according to the technology of the present disclosure.

[0018] Figure 9 Is a flowchart of an example technique for using an implantable medical system according to the technology of the present disclosure.

[0019] Figure 10 Is a flowchart of an example technique for using an implantable medical system according to the technology of the present disclosure.

[0020] Figure 11 Is a flowchart of an example technique for using an implantable medical system according to the technology of the present disclosure. Detailed Description

[0021] As used herein, electroporation is the phenomenon of making cell membranes "leaky" (i.e., permeable to molecules that the cell membrane might otherwise be impermeable or semi-permeable to). Electroporation can also be referred to as electroosmosis, pulsed electric field treatment, non-thermal irreversible electroporation, irreversible electroporation, high-frequency irreversible electroporation, nanosecond electroporation or nanoelectroporation, which involves applying high-amplitude pulses to cause physiological modification (i.e., permeabilization) of the cells of the tissue to which the energy is applied. These pulses can be brief (e.g., nanosecond, microsecond or millisecond pulse widths, such as from about 100 nanoseconds to about 20 milliseconds) to allow the application of high voltages (e.g., from about 100 volts to 5000 volts), high currents (e.g., 20 amperes or more), without long-duration current flow that might otherwise cause significant tissue heating and muscle stimulation. In some examples, the number of pulses per second can range from about 1 to about 500. The pulsed electrical energy can induce the formation of microscopic defects, leading to hyperpermeabilization of the cell membrane. Depending on the characteristics of the electrical pulses, electroporated cells can survive after electroporation (referred to as "reversible electroporation") or die (referred to as "irreversible electroporation" (IRE)). Reversible electroporation can be used to transfer reagents (including genetic material and other large or small molecules) into target cells for various purposes, including altering the action potential of cardiomyocytes.

[0022] Electrical stimulation of body tissues and organs is commonly used as a method for treating various conditions. Such stimulation is typically delivered via electrical contact between an implantable medical device (IMD) and a target site through one or more implantable electrodes, such as stimulation electrodes disposed on a medical lead connected to the IMD. The lead typically includes one or more stimulation electrodes disposed near the distal portion of the lead, and the one or more stimulation electrodes are positioned and / or anchored near the target site.

[0023] As discussed above, in addition to anti-tachyarrhythmia shocks, implantable cardioverter defibrillators (ICDs), including extracorporeal implantable cardioverter defibrillators (EV-ICDs), can also deliver cardiac pacing. Generally, during pacing delivered by an EV-ICD, such as via a sub-sternal implanted electrode, a patient may experience sensations (e.g., paresthesia, discomfort, etc.). The sensations may be caused by stimulation of skeletal muscle and intercostal nerves (and / or any other muscle tissue and nerve tissue) of electrodes adjacent to the lead. According to the techniques of the present disclosure, an electroporation device can deliver electroporation energy to tissues capable of causing sensations during pacing to reduce or eliminate the sensations. For example, delivering electroporation energy to a tissue can at least temporarily physiologically modify the cells of the tissue to which the energy is applied. In some examples, depending on the characteristics of the electrical pulse, the electroporated cells can be irreversibly electroporated, such that the sensations during pacing are reduced or completely eliminated.

[0024] Figure 1 FIG. 7 is a conceptual diagram of an example medical system 10 (“system” 10) according to the techniques of the present disclosure. System 10 is primarily described herein as an extracorporeal and / or extracardiac medical system, such as an EV-ICD system having a lead placed between the sternum 11 and the pericardial surface. However, it should be understood that the techniques of the present disclosure can be applied, without limitation, to other medical device systems, such as intravascular and / or intracardiac medical systems. For example, the techniques of the present disclosure can be applied to a pacemaker configured to deliver pacing therapy but not defibrillation therapy. Additionally, it should be understood that the techniques of the present disclosure can be applied to non-cardiac devices (e.g., nerve stimulators, pelvic and gastric devices, etc.). Generally, the techniques of the present disclosure can be applied to any medical device or system that delivers an electrical therapy that may cause unintended sensations.

[0025] System 10 can include a medical device, such as IMD 12 (e.g., an ICD). IMD 12 can include a signal generator configured to provide cardiac pacing and / or defibrillation therapy. As Figure 1As shown, the IMD 12 can be subcutaneously implanted on the left mid-axilla of the patient 13, on the superficial surface of the patient's chest wall 15. The IMD 12 can communicate wirelessly with an external device 17 (e.g., a computing device for use by the patient, clinician, etc.) to transmit information to the external device 17, be programmed by the external device 17, and the like. The IMD 12 can be coupled to an elongate structure, such as an implantable medical lead 14 ("lead 14"). The lead 14 can be configured to navigate from an entry point of the patient 13 to an implantation site within the patient 13's body. The lead 14 can include a lead body 16 sized for extra-thoracic implantation (outside the chest wall and sternum, e.g., subcutaneously or submuscularly) or intra-thoracic implantation adjacent the patient 13's heart 19 (e.g., under the thoracic cavity or sternum, sometimes referred to as a "sub-sternal" location). For example, the lead 14 can extend subcutaneously toward the center of the patient 13's torso (e.g., toward the xiphoid process of the patient 13's sternum).

[0026] At least a portion of the body 16 of the lead 14 ("lead body 16") can have a generally wavy shape or pattern (e.g., serrated, zigzag, sinusoidal, serpentine, or other pattern). Additionally or alternatively, the lead body 16 can have a generally uniform shape along the length of the lead body 16. In another configuration, the lead body 16 can have a flat, ribbon-like, or paddle-like shape along at least a portion of the length of the lead body 16. Other lead body 16 designs can be used without departing from the scope of the present application. The lead body 16 of the lead 14 can be formed from a non-conductive material including silicone, polyurethane, fluoropolymer, mixtures thereof, and other suitable materials, and shaped to form one or more lumens (not shown), however, the technology is not limited to such configurations.

[0027] The lead body 16 can include a proximal portion 18 and a distal portion 20. The distal portion 20 can carry one or more electrodes configured to deliver electrical energy to the heart or sense electrical energy within the heart. The distal portion 20 can be anchored to a desired location within the patient's body, such as sub-sternal or subcutaneous, by, for example, suturing the distal portion 20 to the patient's muscle tissue, tissue, or bone at the xiphoid process entry site. Alternatively, the distal portion 20 can be anchored to the patient using fixation mechanisms such as rigid tines, forks, barbs, clamps, screws, flanges, etc. For example, the distal portion 20 can be anchored adjacent a target site within the patient 13's body.

[0028] In some examples, the distal portion 20 of the lead body 16 may be implanted within the anterior mediastinum. The anterior mediastinum may be considered to be bounded laterally by the pleura, posteriorly by the pericardium, and anteriorly by the sternum 11. In some cases, the anterior wall of the anterior mediastinum may also be formed by the transversus thoracis muscle and one or more costal cartilages. The anterior mediastinum includes a large amount of loose connective tissue (such as areolar tissue), some lymphatic vessels, lymph nodes, sub-sternal muscle tissue (e.g., the muscle that transects the chest), branches of the internal thoracic artery, and the internal thoracic vein. In one example, the distal portion 20 of the lead 16 may be substantially implanted within the loose connective tissue and / or sub-sternal muscle tissue of the anterior mediastinum.

[0029] In other examples, the distal portion 20 of the lead 16 may be implanted in other extra-thoracic, intra-thoracic locations, including extra-vascular, extra-cardiac, or extra-pericardial locations, including the spaces, tissues, or other anatomical features surrounding and adjacent to the perimeter of the pericardium or other parts of the heart, rather than above the sternum 11 or the thoracic cage 15. Thus, the lead 14 may be implanted anywhere within the sub-sternal space defined by the bottom surface between the sternum 11 and / or the thoracic cage 15 and the body cavity.

[0030] The distal portion 20 may include or otherwise support (e.g., carry) one or more electrodes, such as electrodes 22A through 22B (collectively referred to as "electrodes 22"). Examples of electrodes 22 may include segmented electrodes, circumferential electrodes, annular electrodes, strip electrodes, short coil electrodes, paddle electrodes, hemispherical electrodes, directional electrodes, defibrillation electrodes, etc., and may be positioned at any location along the distal portion 20.

[0031] The proximal portion 18 of the lead body 16 may include one or more connectors to electrically couple the lead 14 to the IMD 12. In some examples, each of the electrodes 22 on the distal portion 20 is electrically connected to a corresponding connector on the proximal portion 18. The IMD 12 may include a housing 24 that forms an airtight seal around the components that protect the IMD 12. The housing 24 of the IMD 12 may be formed of a conductive material such as titanium or a titanium alloy, which may act as a housing electrode for a particular therapy vector between the housing 24 and the distal portion 20. The IMD 12 may also include a connector assembly that includes electrical feedthroughs through which electrical connections are made between one or more connectors of the lead 14 and the electronic components included within the housing 24. The housing 24 may contain circuitry such as processing circuitry, memory circuitry, telemetry circuitry, sensing circuitry, therapy circuitry (which may include, for example, a pulse generator, transformer, capacitor, etc.), switching circuitry, power circuitry (capacitors and batteries), etc.

[0032] The IMD 12 can generate and deliver electrostimulation therapies via various electrode combinations or vectors, including traditional low-voltage stimulation therapies (e.g., antitachycardia pacing, post-shock pacing, bradycardia pacing, or pacing used in combination with VF induction) and (optionally) traditional high-voltage stimulation therapies (e.g., cardioversion or defibrillation shocks).

[0033] The IMD 12 can detect ventricular tachyarrhythmias (e.g., VT or VF) based on signals sensed using electrode 22. In response to detecting a tachyarrhythmia, the IMD 12 can generate low-voltage and / or high-voltage electrostimulation therapies and deliver the electrostimulation therapy via electrode 22. Additionally or alternatively, the IMD 12 can deliver pacing (e.g., ATP or post-shock pacing). If high-voltage therapy is necessary, the IMD 12 can deliver cardioversion / defibrillation shocks (or multiple shocks) using electrode 22 (and in some cases the housing 24). The IMD 12 can generate and deliver pacing pulses to provide antitachycardia pacing (ATP), bradycardia pacing, post-shock pacing, or other pacing therapies or combinations of pacing therapies. In this way, ATP therapy or post-shock pacing (or other pacing therapies) can be provided in the system 10 without entering the vasculature or pericardial space and without making close contact with the heart.

[0034] In some examples, the lead 14 can include a balloon 26 located at the distal portion 20. The balloon 26 can define an internal volume configured to receive an inflation medium (e.g., air, saline, or another medium), which in turn causes the balloon 26 to inflate. The lead 14 can define an inflation lumen fluidly coupled to the internal volume and configured such that a clinician can deliver the inflation medium to the internal volume defined by the balloon 26. The inflation lumen can extend from the proximal portion 18 of the lead body 16 to the distal portion 20. The outer surface of the proximal portion 18 can define an opening leading to the inflation lumen.

[0035] As described above, patients may experience sensations during pacing due to, for example, stimulation of skeletal muscle and intercostal nerves (and / or any other muscle tissue and nerve tissue) adjacent to the electrode 22 of the lead 14. According to the techniques of the present disclosure, the system 10 can include an electroporation device (not shown) configured to deliver electroporation energy (e.g., via the lead 14) to a target tissue to at least temporarily modify the physiological properties of the cells of the tissue, thereby preventing unwanted sensations while leaving other tissues (e.g., epicardial tissue) unharmed (e.g., not shocked, reversibly electroporated, etc.). In this way, the techniques of the present invention can safely reduce the discomfort experienced by the patient during treatment, thereby improving patient outcomes.

[0036] The electroporation device may be electrically connected to lead 14. Lead 14 may be navigated to an implantation site within patient 13 such that electrode 22 is adjacent to the implantation site. When adjacent to the implantation site, electrode 22 may be oriented relative to patient 13's heart 19. For example, in an example where electrode 22 is a segmented electrode (e.g., a directional electrode), electrode 22 may be oriented toward the posterior sternal surface such that the electric field generated by electrode 22 is simultaneously directed toward the target tissue for ablation and away from heart 19.

[0037] The electroporation device may include a signal generator configured to provide electrical pulses to electrode 22 to perform an electroporation protocol. For example, the signal generator may be configured and programmed to deliver a pulsed high-voltage electric field suitable for achieving a desired pulsed high-voltage ablation via reversible electroporation, IRE, pulsed radiofrequency (RF) ablation, etc.

[0038] In an example of reversible electroporation, the pulsed field energy may temporarily prevent electroporated cells from experiencing sensation. In this way, the clinician may confirm the target tissue before causing tissue death. After confirming the target tissue, the clinician may induce the death of the reversibly electroporated cells. For example, system 10 (such as lead 14) may deliver IRE or a therapeutic agent to cause cell death in the reversibly electroporated cells (such as tissue adjacent to the patient's chest wall). In some examples, the therapeutic agent may be preferentially placed on lead 14 to target the side of lead 14 closer to patient 13's chest wall 15. Additionally or alternatively, local or systemic injection of the therapeutic agent may cause cell death after reversible electroporation energy, thereby allowing the same ablation effect. In some examples, the therapeutic agent may include an anti-inflammatory agent, an analgesic, a neurotoxin, an antimicrobial agent, etc. For example, the therapeutic agent may be Bleomyocin.

[0039] In an example of IRE, the pulsed field energy may be sufficient to induce cell death for the purpose of disrupting the ability of the ablated tissue to propagate or conduct electrical signals associated with unwanted sensation. The target tissue may include tissue adjacent to patient 13's chest wall 15 and in front of heart 19, such as intercostal nerves, transected chest muscle tissue, etc.

[0040] Although the elongate structure has been described primarily with respect to Figure 1 an implantable medical lead, other examples of the elongate structure are contemplated by the present disclosure. For example, the elongate structure may be a catheter or a guide configured to deliver electroporation energy to electroporate tissue that can cause sensation during pacing. Additionally, although the electroporation device is described herein primarily as being located outside the body of patient 13, IMD 12 may additionally or alternatively include a signal generator configured to provide electrical pulses to perform an electroporation protocol in accordance with the techniques of the present disclosure.

[0041] Figure 2is a conceptual diagram of the lead 14. As Figure 2 shown, the distal portion 20 may define a wavy configuration 32 distal to a substantially linear portion 30 (“linear portion 30”). Specifically, the distal portion 20 may define a wavy pattern (such as a zigzag, a meander, a sine curve, a serpentine, or other pattern) as it extends towards the distal end of the distal portion 20. The wavy configuration 32 may be substantially disposed in a plane defined by a longitudinal axis (“x”) and a transverse axis (“y”). In some examples, the lead body 16 may not have a linear portion 30 as it extends distally, but may begin the wavy configuration 32 immediately after bending.

[0042] The wavy configuration 32 may include a plurality of peaks along the length of the distal portion 20, such as peaks 34A to 34C (collectively referred to as “peaks 34”). The wavy configuration 32 may include any number of peaks 34. For example, the number of peaks 34 may be less than or more than three, depending on the frequency of the wavy configuration 32. The wavy configuration 32 may define a peak-to-peak amplitude or distance “d” (as Figure 2 shown), which may vary or be constant along the length of the wavy configuration 32. As Figure 2 shown, the wavy configuration 32 may define a substantially sine curve configuration with a constant peak-to-peak distance “d” of approximately 2.0 centimeters to 5.0 centimeters (cm). The wavy configuration 32 may also define a peak-to-peak width “w” (as Figure 2 shown), which may also vary or be constant along the length of the wavy configuration 32. In other cases, the wavy configuration 32 may define other shapes and / or patterns, such as an S-shape, a wavy shape, etc.

[0043] The distal portion 20 may include defibrillation electrodes, such as defibrillation electrodes 36A to 36B (collectively referred to as “defibrillation electrodes 36”). The defibrillation electrodes may be Figure 1An example of the electrode 22 as shown. The defibrillation electrode 36 may be configured to deliver cardioversion / defibrillation shocks. The defibrillation electrode 36 may include a plurality of segments or sections spaced apart from each other along the length of the distal portion 20, such as sections 38A to 38B (collectively referred to as "section 38"). The section 38 may be disposed around or within the distal portion 20 of the lead body 16, or alternatively, may be embedded within the wall of the lead body 16. In one configuration, the section 38 may be a coil electrode formed of a conductor. The conductor may be formed of one or more conductive polymers, ceramics, metal-polymer composites, semiconductors, metals, or metal alloys, including but not limited to one or a combination of the following: platinum, tantalum, titanium, niobium, zirconium, ruthenium, indium, gold, palladium, iron, zinc, silver, nickel, aluminum, molybdenum, stainless steel, MP35N, carbon, copper, polyaniline, polypyrrole, and other polymers. In another configuration, each of the sections 38 may be a flat strip electrode, paddle electrode, woven or knitted electrode, mesh electrode, directional electrode, patch electrode, or another type of electrode configured to deliver cardioversion / defibrillation shocks to a patient's heart.

[0044] The section 38 may be electrically connected to one or more conductors, which may be disposed within the body wall of the lead body 16, or alternatively, may be disposed within one or more insulating lumens (not shown) defined by the lead body 16. In an exemplary configuration, each of the sections 38 is connected to a common conductor such that a voltage may be applied simultaneously to all of the sections 38 to deliver a defibrillation shock to the patient's heart. In other configurations, the section 38 may be attached to individual conductors such that each of the sections 38 may have a voltage applied independently of the other sections 38. For example, the IMD 12 or the lead 14 may include one or more switches or other mechanisms to electrically connect the sections 38 together to act as a common polarity electrode such that, in addition to being able to apply voltage independently, a voltage may also be applied simultaneously to all of the sections 38.

[0045] The distal portion 20 may define one or more gaps 40 between adjacent sections 38. The gaps 40 may define any length. In the case where there are more than two sections 38, each of the gaps 40 may define the same or substantially the same length as the other gaps 40, or may define a length different from the other gaps 40 in the distal portion 20. One or more electrodes are disposed within the respective gaps 40. For example, electrodes 25A to 25B (collectively referred to as "electrode 25") may be disposed within the respective gaps 40. Additionally or alternatively, the electrode 25 may be disposed along the distal portion 20 of the lead body 16 (e.g., adjacent to section 38A and / or distal to section 38B). The electrode 25 may be Figure 1 an example of the electrode 22 as shown.

[0046] The electrode 25 and / or the defibrillation electrode 36 (e.g., via the segment 38) may be configured to deliver electroporation energy in accordance with the techniques of the present disclosure.

[0047] Figure 3 FIG. is a conceptual diagram of a portion of the lead 14 carrying the shield 42 in accordance with the techniques of the present disclosure. In some examples, the distal portion 20 of the lead 16 may include one or more shields 42. The shield 42 may be configured to impede the delivery of electrotherapy by an electric field. For example, the shield 42 may be positioned relative to the electrode 22 (e.g., the electrode 25, the defibrillation electrode 36, etc.). For example, the shield 42 may cover or otherwise be disposed over a portion of the outer surface of the electrode 22. The shield 42 may not cover the entire outer surface of the electrode 22. The pulsed electrical energy delivered by the lead 14 via the electrode 22 may result in an electric field adjacent to the electrode 22 that “diffuses” from the electrode 22. The shield 42 may impede the electric field in the direction from the electrode 22 toward the shield 42 and allow diffusion in the direction away from the shield 42 from the electrode 22. In this way, the shield 42 may be configured to direct the electrode 22.

[0048] The shield 42 may be positioned between the electrode 22 and the heart 6 such that the shield 42 impedes the delivery of electroporation energy from the electrode 22 toward the heart 6. Thus, the shield 42 may reduce the likelihood that the electric field from the electrode 22 will electroporate cardiac tissue by redirecting the electric field from the heart 6 toward extracardiac tissues such as bone tissue and intercostal nerves. Thus, in an example where the electrode 22 is a circumferential electrode or an annular electrode, the shield 42 may be used to prevent unintended electroporation of the heart 6 during an electroporation procedure in accordance with the techniques of the present disclosure.

[0049] As Figure 3 shown, the shield 42 may extend laterally away from the electrode 22 (e.g., in a substantially planar manner) such that the shield 42 is larger in size in one plane than the electrode 22 in that plane. In this way, the shield 42 may further (or more effectively) limit the direction of diffusion of the electric field generated by a pacing pulse (e.g., pulsed electrical energy) from the electrode 22, e.g., the radial angle. The plane in which the shield 42 extends laterally from the electrode 22 may be the same plane in which the peak 34 of the wavy configuration extends, or a substantially parallel plane. In some examples (such as Figure 3 the example shown), the shield 42 extends symmetrically from the electrode 22, e.g., symmetric about the longitudinal axis and / or the transverse axis of the electrode 22 such that the electrode 22 is substantially centered within the outer contour of the shield 42 in the plane.

[0050] The shield 42 can be electrically insulating. In some examples, the shield 42 can comprise a polymer, such as polyurethane. In some examples, the shield 42 can be configured to fold or wrap around the electrode 22 for delivery via the lumen of an implantation tool and to elastically unfold or open to a relaxed state when released from the lumen, e.g., such as Figure 3 the state shown in. In some examples, the shield 42 includes an elastic or superelastic polymer or metal structure, such as a nitinol structure, to facilitate deployment of the shield 42, support articulation of the shield 42, and / or support the shield 42 in a deployed, relaxed configuration. The deployed and / or articulated configuration can be substantially planar, as Figure 3 shown in, or can be non-planar. For example, portions of the shield 42 that are laterally spaced farther from the electrode 22 can be positioned more posteriorly compared to portions closer to the electrode 22, e.g., in the shape of a cup or bowl.

[0051] Such support structures can be partially or fully embedded within the primary material of the shield 42 or attached to one or more outer surfaces of the shield 42. In some examples, the support structures are circumferentially positioned around the perimeter of the shield 42, e.g., laterally spaced from the shield 42 by a maximum distance. However, other support structure positions are possible. For example, one or more support structures can extend radially or laterally from the electrode 22.

[0052] After electroporation according to the techniques of the present disclosure, the shield 42 can be repositioned on the lead 14 and / or reconfigured to allow stimulation energy to reach the heart unimpeded by the shield 42. For example, the lead 14 can be withdrawn from the patient's body and the shield 42 can be repositioned on the lead 14 such that when the electrode 22 is navigated to the implantation site and oriented relative to the heart 19, the electrode 22 is disposed between the shield 42 and the heart 19. In some examples, the shield 42 can be removed or placed in a closed configuration (e.g., folded, wrapped, etc.). In some examples, instead of repositioning the shield 42, the lead 14 can be reoriented relative to the heart 19, e.g., rotated about its longitudinal axis.

[0053] Figures 4A to 4B is a conceptual diagram of a lead 14 carrying a balloon 26. The lead 14 can include a balloon 26 located at the distal portion 20. The balloon 26 can be attached to the distal portion 20. As Figure 4A shown in, an inflation lumen 44 can extend into the balloon 26 such that the balloon 26 and the inflation lumen 44 are in fluid communication.

[0054] In some examples, the lead body 16 may be positioned within a guide. In some examples, the guide is a delivery catheter. The guide may include an inner wall defining a guide lumen and further include a guide opening leading to the guide lumen. The lead 14 may be configured to translate through the guide lumen and through the guide opening when the balloon 26 is in a deflated configuration.

[0055] In any case, the balloon 26 may be inflated en route to position the distal portion 20 near the target site within the patient 13. Figure 4A Illustrated is a balloon 26 in a deflated configuration and defining a maximum initial size D1 (e.g., inner diameter). The lead 14 may define the maximum initial size D1, e.g., to permit the lead body 16 to translate through the guide lumen and the guide opening.

[0056] Figure 4B Illustrated is the lead 14 with the balloon 26 in an inflated configuration. The balloon 26 may define an internal volume 46 that is configured to receive an inflation medium (e.g., air, saline, or another inflation medium) to cause the balloon 26 to transition from Figure 4A the deflated configuration to Figure 4B the inflated configuration depicted therein. In some examples, the internal volume 46 may be at least partially defined by an inner surface 46 of the balloon 26 and an outer surface 50 of the distal portion 20. The lead body 16 may define an inflation lumen 44 that is configured to supply the inflation medium to the internal volume 46. For example, the inflation lumen 44 may extend into the internal volume 46 such that the balloon 26 and the internal volume 46 are in fluid communication.

[0057] In the inflated configuration, the balloon 26 may define a maximum inflated size D2 (e.g., inner diameter). The maximum inflated size D2 of the inflated configuration is greater than the maximum initial size D1 of the deflated configuration. When in the inflated configuration, the balloon 26 may decrease the distance between the electrode 22 and the thoracic wall 15 and increase the distance between the electrode 22 and the heart 19. Thus, when in the inflated configuration, the balloon 26 may position the electrode 22 toward the thoracic wall 15 and away from the heart 19, thereby advantageously reducing the likelihood of inadvertently electroporating the heart 19 when electroporating tissue that can cause an undesired sensation according to the techniques of the present disclosure. In some examples, the balloon 26 may be longitudinally coextensive with the electrode 22 and also act as a shield when in the inflated configuration.

[0058] It should be understood that any of the examples described herein may be combined without limitation and such examples are contemplated by the present disclosure. For example, the lead 14 may carry both the balloon 26 and the shield 42 to prevent or reduce electrical stimulation of non-intended tissue (e.g., IRE).

[0059] Figure 5FIG. 0 is a conceptual diagram of a system 10 that also includes a introducer 52. The introducer 52 may define a lumen 54 sized to permit insertion of a lead 14 into the introducer 52. The introducer 52 may be configured to facilitate navigation of the lead 14 from an entry point on a patient 13 to an implantation site within the patient 13. Additionally, the introducer 52 may be configured to facilitate delivery of electroporation energy to electroporate tissue adjacent to the thorax 15 and in front of the heart 19. In some examples, the introducer may support or otherwise include (e.g., carry) one or more introducer electrodes 56 configured to deliver electroporation energy to electroporate tissue adjacent to the thorax 15 and in front of the heart 19. The introducer electrodes 56 may be configured to be oriented toward the posterior sternal surface. In some examples, the introducer electrodes 56 may be electrically connected to a signal generator, and the introducer electrodes 56 may deliver electroporation energy to the target tissue. In other examples, electrodes 22 (e.g., electrodes on the lead 14) may be electrically connected via a conductor to one or more of the introducer electrodes 56, the conductor being configured to conduct electroporation energy from the electrodes 22 to the introducer electrodes 56.

[0060] In some examples, the introducer 52 may define at least one slot 58 that exposes the electrodes 22 when the electrodes 22 are adjacent to the implantation site and oriented relative to the heart 19. Additionally or alternatively, the introducer 52 may define a porous structure that facilitates delivery of electroporation energy from the electrodes 22.

[0061] In some examples, the introducer 52 may be coupled at a proximal end to an electroporation device and configured to deliver electroporation energy received by the introducer 52 from the electroporation device. In addition to or instead of the lead 14, the introducer 52 may be configured to deliver electroporation energy. It should be understood that the introducer 52 is one example of an elongate structure in accordance with the techniques of the present disclosure, and the present disclosure contemplates other tools configured to facilitate advancement of a lead or catheter toward a target site and deliver electroporation energy.

[0062] Figure 6 FIG. 10 is a conceptual diagram of a system 10 that also includes an external electrode 60. The external electrode 60 may be worn by the patient 13, such as attached to the patient. The system 10 may perform IRE on tissue that can cause an unwanted sensation using the electrodes 22 of the lead 14 and the external electrode 60 in accordance with the techniques of the present disclosure. In some examples, the external electrode 60 may be a removable pad or patch configured to be placed on the patient's body. The external electrode 60 may be placed and replaced to electroporate various target tissues (e.g., various sites adjacent to the sternum 11) for ablation.

[0063] It should be understood that any of the examples described herein can be combined without limitation and these examples are contemplated by the present disclosure. For example, system 10 may include an external electrode 60, a balloon 26, and a shield 42 to perform IRE in accordance with the techniques of the present disclosure while preventing or reducing electrical stimulation of unintended tissue.

[0064] Figure 7 is a block diagram illustrating an example configuration of an electroporation device 35 configured to configure electroporation energy according to the techniques of the present disclosure. As Figure 7 shown, the electroporation device 35 includes a processing circuit 62, a signal generator 64, and a memory 68. The electroporation device 35 may be electrically connected to the electrode 22 via a lead 14. For example, the proximal portion 18 of the lead body 16 may be electrically connected to the electroporation device 35. In some examples, the memory 68 includes computer-readable instructions that, when executed by the processing circuit 62, cause the electroporation device 35 and the processing circuit 62 to perform the various functions attributed herein to the electroporation device 35 and the processing circuit 62. The memory 68 may include any volatile, non-volatile, magnetic, optical, or dielectric medium, such as random access memory (RAM), read-only memory (ROM), non-volatile RAM (NVRAM), electrically erasable programmable ROM (EEPROM), flash memory, or any other digital medium.

[0065] The processing circuit 62 may include fixed-function circuitry and / or programmable processing circuitry. The processing circuit 62 may include any one or more of the following: a microprocessor, a controller, a digital signal processor (DSP), an application specific integrated (ASIC) circuit, a field programmable gate array (FPGA), or equivalent discrete or analog logic circuitry. In some examples, the processing circuit 62 may include multiple components (such as any combination of one or more microprocessors, one or more controllers, one or more DSPs, one or more ASICs, or one or more FPGAs) and other discrete or integrated logic circuitry. The functions attributed herein to the processing circuit 62 may be embodied as software, firmware, hardware, or any combination thereof.

[0066] The signal generator 64 may be selectively coupled to the electrode 22. The signal generator 64 may be configured to provide electrical pulses to the electrode 22 to perform an electroporation protocol. For example, the signal generator 64 may be configured and programmed to deliver pulsed high-voltage electric fields suitable for achieving a desired pulsed high-voltage ablation via IRE and / or pulsed RF ablation. In some examples, the signal generator 64 may be coupled to the external electrode 60 (e.g., in addition to the lead 14).

[0067] Generally, IRE can be an acute procedure, meaning it may only need to be performed once to achieve the advantages disclosed herein. IRE can be performed at any time (e.g., perioperatively, postoperatively, etc.). However, IRE is mainly described herein as being performed perioperatively.

[0068] The signal generator 64 can provide electrical pulses to perform an electroporation procedure on extracardiac tissue within the cardiothoracic space or other tissue within the body (such as renal tissue or airway tissue). "Electroporation" utilizes high-amplitude pulses to effect a physiological modification (i.e., permeabilization) of the cells to which the energy is applied. Such pulses can preferably be transient (e.g., nanosecond, microsecond, or millisecond pulse widths) to allow the application of high voltage, high current (e.g., 20 amperes or more), without a long-duration current flow that causes significant tissue heating. In particular, the pulse energy induces the formation of microscopic pores or openings in the cell membrane.

[0069] The signal generator 64 can be configured and programmed to deliver a pulsed high-voltage electric field suitable for achieving a desired pulsed high-voltage ablation (or pulsed-field ablation). As a reference point, the pulsed, high-voltage non-radiofrequency ablation effects of the present disclosure can be distinguished from DC current ablation and heat-induced ablation associated with conventional RF techniques. For example, the train of pulses delivered by the signal generator 64 can be delivered at a frequency less than 3 kHz and, in an exemplary configuration, at a frequency of 1 kHz (which is a lower frequency than radiofrequency processing). The pulsed-field energy according to the present disclosure can be sufficient to induce cell death to prevent a sensory response to cardiac pacing or other electrical stimulation as described herein.

[0070] In some examples, the electrodes 22 can deliver therapeutic biphasic pulses having a pre-programmed pattern and duty cycle. For example, each pulse cycle can include an applied voltage amplitude A, a pulse width B (in microseconds (μs)), an interphase delay C (in μs), an interpulse delay D (in μs), and a pulse cycle length E. In an exemplary configuration, the pulse width B can be from 1 μs to 15 μs, the interphase delay C can be from 0 μs to 4 μs, the interpulse delay D can be from 5 μs to 30,000 μs, the pulse train can include from 20 to 1000 pulses, and the applied voltage can be from about 300 V to 4000 V. In some examples, the pulse width can be set to 5 μs, the interphase delay can be 5 μs, the interpulse delay can be 800 μs, and the pulse train can include 80 pulses with an applied voltage of 700 V. When delivered from a bipolar electrode array, such a pulse train can create lesions in the tissue in a depth range of approximately 2 mm to 3 mm. An increased voltage can correspondingly increase the lesion depth. In another example, four pulse trains can be delivered at each target tissue site.

[0071] An energy pulse field can be delivered in a bipolar manner, as single-phase or biphasic pulses. In the context of tissue ablation, applying biphasic electrical pulses can produce unexpected beneficial results. For biphasic electroporation pulses, the direction of the pulses completing one cycle alternates within a few microseconds. Thus, the cells to which the biphasic electrical pulses are applied can experience an alternation of the electric field bias. Changing the direction of the bias reduces prolonged post-ablation depolarization and / or ion charging. Thus, prolonged muscle excitation can be reduced. Additionally, biphasic electrical pulses can overcome the high impedance characteristics of adipocytes, which are typically problematic in ablation procedures.

[0072] In some examples, the pulse width B can be 5 μs or less, at least partially based on an evaluation of the bubble output at high voltages and / or evidence of thermal effects on the tissue surface. Regarding the presence of bubbles, a pulse width greater than 15 μs is more likely to produce a significant bubble volume, and a pulse width of 20 μs or longer may produce thermal effects on the tissue surface. No loss of efficacy was observed when the pulse width was varied from 100 μs to 5 μs. Additionally, pulses having a pulse width as brief as 5 μs can reduce non-incidental tissue stimulation.

[0073] The applied voltage amplitude between about 200 V and about 300 V can be a threshold amplitude at which irreversible damage is caused to cells in direct contact with electrode 22. Generally, if the E-field distribution is oriented such that the highest field strength is applied along (or parallel to) the long axis of the targeted cells, an irreversible electroporation effect can be obtained. However, if multiple field vectors are applied to the targeted cells, a maximum irreversible electroporation effect can be achieved because different cells can respond differently to specific E-field orientations. The polarities of adjacent electrodes 22 can be alternated to achieve the widest possible variation in field directions. If more than one vector is used, a greater percentage of cells can be affected and more thorough damage can be produced. Although not shown, additional distal portion 20 configurations can be used to generate multiple E-field vectors. As a non-limiting example, the distal portion 20 can include a mesh-covered balloon, a balloon with embedded surface electrodes, or a spline basket with multiple electrodes. Additionally or alternatively, additional electrodes can be added to an existing device to deliver some of the pulses in the pulse train to add new field directions.

[0074] Figure 8is a flowchart of an example technique for using system 10 in accordance with the techniques of the present disclosure. Lead 14 may be inserted into the body of patient 13 (800). Lead 14 may be navigated to an implantation site within patient 13 (e.g., a location adjacent to heart 19) such that electrode 22 is adjacent to the implantation site. When adjacent to the implantation site, electrode 22 may be oriented relative to heart 19 of patient 13. For example, in an example where electrode 22 is a segmented electrode (e.g., a directional electrode), electrode 22 may be oriented toward the posterior sternal surface such that the electric field generated by electrode 22 is simultaneously directed toward the target tissue for ablation and away from heart 19.

[0075] Lead 14 may deliver electroporation energy to irreversibly electroporate tissue (802) that can cause an undesired sensation. For example, lead 14 may be electrically connected to an electroporation device 35. Electroporation device 35 may include a signal generator 64 that provides electrical pulses to electrode 22 to perform an electroporation protocol. For example, signal generator 64 may deliver pulsed high voltage electric fields suitable for achieving desired pulsed high voltage ablation via IRE and / or pulsed RF ablation.

[0076] The pulsed field energy in accordance with the present disclosure may be sufficient to induce cell death to disrupt the ability of the thus ablated tissue to propagate or conduct electrical signals associated with sensation. In this manner, electrode 22 may be configured to deliver electroporation energy to tissue that can cause sensation during pacing to thereby irreversibly electroporate the tissue. The target tissue may include tissue adjacent to chest wall 15 of patient 13 and in front of heart 19, such as intercostal nerves, transected chest muscle tissue, and the like.

[0077] In response to completion of the IRE, lead 14 may be electrically disconnected from electroporation device 35 and electrically connected to IMD 12.

[0078] Figure 9 is a flowchart of an example technique for using system 10 in accordance with the techniques of the present disclosure. Lead 14 may be inserted into the body of patient 13 and navigated to the implantation site (900). When adjacent to the implantation site, electrode 22 may be oriented relative to heart 19 of patient 13. Balloon 26 may be inflated (902). When in the inflated configuration, balloon 26 may reduce the distance between electrode 22 and chest wall 15 and increase the distance between electrode 22 and heart 19. Thus, when in the inflated configuration, balloon 26 may position electrode 22 toward chest wall 15 and away from heart 19, thereby advantageously reducing the likelihood of inadvertently electroporating heart 19. Then, lead 14 may deliver electroporation energy to electroporate tissue (904) that can cause an undesired sensation.

[0079] Figure 10is a flow chart of an example technique for using system 10 in accordance with the techniques of the present disclosure. The shield 42 may be positioned on the lead 14 such that when the electrode 22 is navigated to the implantation site and oriented relative to the heart 19, the shield 42 is disposed between the electrode 22 and the heart 19 (1000). The lead 14 may be inserted into the body of the patient 13 and navigated to the implantation site (1002). When adjacent the implantation site, the electrode 22 may be oriented relative to the heart 19 of the patient 13. The lead 14 may deliver electroporation energy to electroporate tissue that can cause an undesired sensation (1004). The lead 14 may be withdrawn from the body of the patient (1006). The shield 42 may be repositioned on the lead 14 such that when the electrode 22 is navigated to the implantation site and oriented relative to the heart 19, the electrode 22 is disposed between the shield 42 and the heart 19 (1008). Then the IMD 12 may be implanted with the lead 14 secured to the implantation site (1010).

[0080] Figure 11 is a flow chart of an example technique for using system 10 in accordance with the techniques of the present disclosure. The introducer 52 may be inserted into the body of the patient (1100). The lead 14 may be inserted into the body of the patient 13 via the introducer 52 and navigated to the implantation site (1102). When adjacent the implantation site, the electrode 22 may be oriented relative to the heart 19 of the patient 13. The electrode 22 of the lead 14 may deliver electroporation energy to electroporate tissue that can cause an undesired sensation (1104). In some examples, the introducer 52 may facilitate delivery of electroporation energy to electroporate tissue adjacent the thorax 15 and in front of the heart 19. For example, the introducer 52 may deliver electroporation energy via the introducer electrode 56 to electroporate tissue adjacent the thorax 15 and in front of the heart 19. The introducer electrode 56 may be oriented toward the posterior sternal surface. In some examples, the introducer electrode 56 may be electrically connected to a signal generator and the introducer electrode 56 may deliver electroporation energy to the target tissue. In other examples, the electrode 22 may be electrically connected via a conductor to one or more of the introducer electrodes 56 that conduct electroporation energy from the electrode 22 to the introducer electrode 56.

[0081] In some examples, the introducer 52 may define at least one slot 58 that exposes the electrode 22 when the electrode 22 is adjacent the implantation site and oriented relative to the heart 19. Additionally or alternatively, the introducer 52 may define a porous structure that facilitates delivery of electroporation energy from the electrode 22.

[0082] Figure 12is a flowchart of an example technique for using system 10 in accordance with the techniques of the present disclosure. Lead 14 may be inserted into the body of patient 13 (1200). Lead 14 may be navigated to an implantation site within patient 13's body (e.g., a location adjacent to heart 19) such that electrode 22 is adjacent to the implantation site. When adjacent to the implantation site, electrode 22 may be oriented relative to patient 13's heart 19. For example, in an example where electrode 22 is a segmented electrode (e.g., a directional electrode), electrode 22 may be oriented toward the posterior sternal surface such that the electric field generated by electrode 22 is simultaneously directed toward the target tissue for ablation and away from heart 19.

[0083] Lead 14 may deliver electroporation energy to reversibly electroporate tissue that can cause an undesired sensation (1202). Electrode 22 may be configured to deliver electroporation energy to tissue that can cause a sensation during pacing, thereby reversibly electroporating the tissue. The target tissue may include tissue adjacent to patient 13's chest wall 15 and in front of heart 19, such as intercostal nerves, transected chest muscle tissue, etc. The clinician may confirm that the desired effect (e.g., no stimulation) has been temporarily achieved due to the electroporation of the target tissue. In response to confirmation of the target tissue, lead 14 may deliver IRE or a therapeutic agent to cause cell death in the reversibly electroporated cells. In some examples, the therapeutic agent may be preferentially placed on lead 14 to target the side of lead 14 closer to patient 13's chest wall 15. Additionally or alternatively, local or systemic injection of the therapeutic agent may cause cell death after the reversibly electroporating energy, thereby allowing the same ablation effect.

[0084] The following examples illustrate the techniques described herein.

[0085] Example 1: A medical system comprising a medical device, the medical device comprising: an elongate structure configured to be navigated from an access point of a patient to an implantation site within the patient's body; and at least one electrode carried on a distal portion of the elongate structure, wherein the at least one electrode is configured to be oriented relative to the patient's heart when adjacent to the implantation site, and wherein the at least one electrode is configured to deliver electroporation energy to electroporate tissue adjacent to the patient's chest wall and in front of the heart.

[0086] Example 2: The medical system according to Example 1, wherein the at least one electrode comprises one or more segmented electrodes configured to be oriented toward the posterior sternal surface.

[0087] Example 3: The medical system according to Example 1 or 2, the medical system further comprising a balloon configured to position the at least one electrode toward the chest wall and away from the heart when in an inflated configuration.

[0088] Example 4: The medical system according to any one of Examples 1 to 3, further comprising a shield configured to impede delivery of electroporation energy from the at least one electrode towards the heart.

[0089] Example 5: The medical system according to any one of Examples 1 to 4, wherein the tissue comprises at least one of muscle tissue or nerve tissue.

[0090] Example 6: The medical system according to any one of Examples 1 to 5, wherein the elongate structure is a catheter, a introducer, or an implantable medical lead.

[0091] Example 7: The medical system according to any one of Examples 1 to 6, wherein the at least one electrode is configured to deliver electroporation energy to effect irreversible electroporation or reversible electroporation of the tissue.

[0092] Example 8: The medical system according to any one of Examples 1 to 7, wherein the elongate structure is further configured to deliver a therapeutic agent to the tissue, wherein the therapeutic agent comprises at least one of an anti-inflammatory agent, an analgesic, a neurotoxin, or an antimicrobial agent.

[0093] Example 9: The medical system according to Example 8, wherein the therapeutic agent comprises bleomycin.

[0094] Example 10: The medical system according to Example 8 or 9, wherein the therapeutic agent is preferably placed on the elongate structure to target a side of the elongate structure closer to the patient's chest wall.

[0095] Example 11: The medical system according to any one of Examples 1 to 10, further comprising an introducer defining a lumen, wherein the elongate structure is configured to navigate from the access point to the implantation site within the patient using the introducer, wherein the size of the lumen is sized to permit insertion of the implantable medical lead into the introducer.

[0096] Example 12: The medical system according to Example 11, wherein the at least one electrode carried on the distal portion of the implantable medical lead comprises at least one lead electrode, and wherein the introducer comprises at least one introducer electrode configured to deliver electroporation energy to effect electroporation of tissue adjacent the chest wall and in front of the heart.

[0097] Example 13: The medical system according to Example 12, wherein the introducer further comprises a conductor configured to conduct the electroporation energy from the at least one lead electrode to the at least one introducer electrode.

[0098] Example 14: The medical system according to any one of Examples 11 to 13, wherein the introducer defines at least one slot that exposes at least one electrode of the implantable medical lead when the at least one electrode is adjacent to the implantation site and oriented relative to the patient's heart.

[0099] Example 15: The medical system according to any one of Examples 11 to 14, wherein the introducer defines a porous structure that facilitates delivery of electroporation energy from the at least one electrode.

[0100] Example 16: The medical system according to any one of Examples 1 to 15, the medical system further comprising configuring the electroporation energy to electroporate the tissue; and delivering the electroporation energy to the at least one electrode of the medical device.

[0101] Example 17: A medical device, the medical device comprising: an elongate structure configured to navigate from an access point of a patient to an implantation site within the patient; and at least one electrode carried on a distal portion of the elongate structure, wherein the at least one electrode is configured to be oriented relative to the patient's heart when adjacent to the implantation site, and wherein the at least one electrode is configured to deliver electroporation energy to irreversibly electroporate tissue adjacent to the patient's chest wall and in front of the heart.

[0102] Example 18: The medical device according to Example 17, wherein the at least one electrode comprises one or more segmented electrodes configured to be oriented toward the posterior sternal surface.

[0103] Example 19: The medical device according to Example 17 or 18, the medical device further comprising a balloon configured to position the at least one electrode toward the chest wall and away from the heart when in an inflated configuration.

[0104] Example 20: The medical device according to any one of Examples 17 to 19, the medical device further comprising a shield configured to impede delivery of electroporation energy from the at least one electrode toward the heart.

[0105] Example 21: The medical device according to any one of Examples 17 to 20, wherein the tissue comprises at least one of muscle tissue or nerve tissue.

[0106] Example 22: The medical device according to any one of Examples 17 to 21, wherein the elongate structure is a catheter, an introducer, or an implantable medical lead.

[0107] Example 23: A method that includes: delivering electroporation energy through at least one electrode carried on a distal portion of an elongate structure that is navigated from an access point of a patient to an implantation site within the patient's body to effect irreversible electroporation of tissue adjacent to the patient's chest wall and in front of the heart, wherein the at least one electrode is oriented relative to the patient's heart.

[0108] Example 24: The method according to Example 23, further comprising: inflating a balloon to position the at least one electrode toward the chest wall and away from the heart.

[0109] Example 25: The method according to Example 23 or 24, further comprising: positioning a shield relative to the at least one electrode such that the shield is disposed between the at least one electrode and the heart when the at least one electrode delivers electroporation energy.

[0110] Example 26: The method according to any one of Examples 23 to 25, further comprising: inserting a introducer into the access point of the patient, wherein navigating the elongate structure from the access point to the implantation site includes: inserting the elongate structure into the introducer.

[0111] Example 27: The method according to any one of Examples 23 to 26, wherein the introducer includes at least one introducer electrode configured to deliver electroporation energy to effect irreversible electroporation of the tissue adjacent to the chest wall and in front of the heart.

[0112] Example 28: A medical system that includes: a medical device including an elongate structure configured to be navigated from an access point of a patient to an implantation site within the patient's body; and at least one electrode carried on a distal portion of the elongate structure, wherein the at least one electrode is configured to be oriented relative to the patient's heart when adjacent to the implantation site and wherein the at least one electrode is configured to deliver electroporation energy to effect irreversible electroporation of tissue adjacent to the patient's chest wall and in front of the heart; and an electroporation device configured to: condition the electroporation energy to effect irreversible electroporation of the tissue; and deliver the electroporation energy to the at least one electrode of the medical device.

[0113] Example 29: The medical system according to Example 28, wherein the at least one electrode includes one or more segmented electrodes configured to be oriented toward a posterior sternal surface.

[0114] Example 30: The medical system according to Example 28 or 29, further comprising a balloon configured to position the at least one electrode towards the thoracic cavity and away from the heart when in an inflated configuration.

[0115] Example 31: The medical system according to any one of Examples 28 to 30, further comprising a shield configured to impede the delivery of electroporation energy from the at least one electrode towards the heart.

[0116] Example 32: The medical system according to any one of Examples 28 to 31, wherein the tissue comprises at least one of muscle tissue or nerve tissue.

[0117] Example 33: The medical system according to any one of Examples 28 to 32, wherein the elongate structure is a catheter, a introducer, or an implantable medical lead.

[0118] Example 34: The medical system according to any one of Examples 28 to 33, further comprising an external electrode configured to be placed adjacent to the patient's sternum, wherein the at least one electrode comprises one or more circumferential electrodes.

[0119] Various aspects of the disclosure have been described. These aspects and other aspects are within the scope of the following claims.

Claims

1. A medical system, the medical system comprising: a medical device, the medical device comprising: an elongate structure configured to navigate from an access point of a patient to an implantation site within the patient's body; and at least one electrode carried on a distal portion of the elongate structure, wherein the at least one electrode is configured to be oriented relative to the patient's heart when adjacent the implantation site, and wherein the at least one electrode is configured to deliver electroporation energy to electroporate tissue adjacent the patient's chest wall and in front of the heart.

2. The medical system according to claim 1, wherein the at least one electrode comprises one or more segmented electrodes configured to be oriented toward the posterior sternal surface.

3. The medical system according to claim 1 or 2, the medical system further comprising a balloon configured to position the at least one electrode toward the chest wall and away from the heart when in an inflated configuration.

4. The medical system according to any one of claims 1 to 3, the medical system further comprising a shield configured to impede delivery of electroporation energy from the at least one electrode toward the heart.

5. The medical system according to any one of claims 1 to 4, wherein the tissue comprises at least one of muscle tissue or nerve tissue.

6. The medical system according to any one of claims 1 to 5, wherein the elongate structure is a catheter, a guide, or an implantable medical lead.

7. The medical system according to any one of claims 1 to 6, wherein the at least one electrode is configured to deliver electroporation energy to irreversibly electroporate the tissue or reversibly electroporate the tissue.

8. The medical system according to any one of claims 1 to 7, wherein the elongate structure is further configured to deliver a therapeutic agent to the tissue, wherein the therapeutic agent comprises at least one of an anti-inflammatory agent, an analgesic, a neurotoxin, or an antimicrobial agent.

9. The medical system according to claim 8, wherein the therapeutic agent comprises bleomycin.

10. The medical system according to claim 8 or 9, wherein the therapeutic agent is preferably placed on the elongate structure to target a side of the elongate structure closer to the patient's chest wall.

11. The medical system according to any one of claims 1 to 10, the medical system further comprising a guide defining a lumen, wherein the elongate structure is configured to navigate from the access point to the implantation site within the patient's body using the guide, and wherein the lumen is sized to allow insertion of the implantable medical lead into the guide.

12. The medical system according to claim 11, wherein the at least one electrode carried on the distal portion of the implantable medical lead comprises at least one lead electrode, and wherein the guide comprises at least one guide electrode configured to deliver electroporation energy to electroporate the tissue adjacent the chest wall and in front of the heart.

13. The medical system according to claim 12, wherein the introducer further comprises a conductor configured to conduct the electroporation energy from the at least one lead electrode to the at least one introducer electrode.

14. The medical system according to any one of claims 11 to 13, wherein the introducer defines at least one slot that exposes the at least one electrode of the implantable medical lead when the at least one electrode is adjacent to the implantation site and oriented relative to the patient's heart.

15. The medical system according to any one of claims 11 to 14, wherein the introducer defines a porous structure that facilitates delivery of the electroporation energy from the at least one electrode.

16. The medical system according to any one of claims 1 to 15, the medical system further comprising an electroporation device configured to: configure the electroporation energy to electroporate the tissue; and deliver the electroporation energy to the at least one electrode of the medical device.

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