Catheter for transvenous nerve ablation

Abstract

This document relates to a catheter system that delivers electrical stimulation to targeted neural tissue proximate the spinal column of a patient. The catheter system can include an inner shaft comprising an inner shaft electrode attached to a distal end of the inner shaft and an outer sheath comprising an outer sheath electrode attached to a distal end of the outer sheath, the outer sheath defining a lumen sized to receive the inner shaft. The inner shaft is movable within the lumen relative to the outer sheath to position the inner shaft electrode and the outer sheath electrode for delivering the electrical stimulation to the targeted neural tissue.

Description

Attorney Docket No.: 07039-2336WO1 / 2023-446CATHETER FOR TRANSVENOUS NERVE ABLATION

[0001] This application claims the benefit of priority to U.S. Application No. 63 / 685,909, filed on August 22, 2024, the contents of which are hereby incorporated by reference.TECHNICAL FIELD

[0002] This document relates to devices and methods for using a catheter to ablate pain generating and autonomic nerves. For example, this document relates to a catheter that includes one or more electrodes disposed therein.BACKGROUND

[0003] A transvascular catheter can be used to deliver electrical stimulation to a targeted site within a patient. For example, transvascular catheters can perform ablation procedures. Some procedures involve advancing a catheter to the targeted treatment site through the cardiovascular system (e.g., through an artery or vein) so that the catheter can deliver the electrical stimulation. These procedures can include ablation procedures, or other kinds of procedures involving a catheter delivering electrical stimulation.

[0004] The basivertebral nerve is a branch of the sinuvertebral nerve that enters the vertebral body through the posterior cortex via the nutrient foramen and courses centrally within the vertebral body, innervating the vertebral endplates. The basivertebral nerve can play an important role in transmitting nociceptive signals associated with vertebrogenic low back pain, particularly when endplate changes (such as Modic changes) occur. Ablation of the basivertebral nerve, such as through radiofrequency or other energy-based techniques, can be beneficial in reducing chronic low back pain by interrupting these pain pathways at their source.

[0005] The sinuvertebral nerve is a branch of the dorsal root ganglia that innervates the intervertebral disc. The sinuvertebral nerve can play an important role in transmitting nociceptive signals associated with discogenic low back pain. Ablation of the sinuvertebral nerve, such as through radiofrequency or other energy-based techniques, can be beneficial in reducing chronic low back pain by interrupting these pain pathways at their source.

[0006] The sphenopalatine ganglion, trigeminal ganglion and sympathetic ganglia have multiple branches which innervate the meninges of the brain. These nerves play an important role in transmitting nociceptive signals associated with headache. Ablation of these nerves, such as through radiofrequency or other energy -based techniques, can beAttorney Docket No.: 07039-2336WO1 / 2023-446 beneficial in reducing chronic low back pain by interrupting these pain pathways at their source.SUMMARY

[0007] This document describes devices and methods for using a catheter system to ablate pain generating and autonomic nerves within the craniofacial and spinal vascular axis. For example, this document relates to a catheter that includes one or more electrodes disposed therein. In one example, the catheter system can include an inner shaft and an outer sheath, the inner shaft movable relative to the outer sheath. The inner shaft can include an inner shaft electrode attached to a distal end of the inner shaft and the outer sheath can include an outer sheath electrode attached to a distal end of the outer sheath. By adjusting the inner shaft relative to the outer sheath, a clinician can adjust a position of the inner shaft electrode relative to the outer sheath electrode to position these electrodes for delivery of electrical stimulation (e g., ablation). Examples of nerves that the catheter system can ablate include the basivertebral nerve, the trigeminal nerve, the occipital nerve, the supraorbital nerve, and nerves and ganglia affecting the autonomic nervous system.

[0008] The inner shaft electrode and the outer sheath electrode can define a bipolar electrode system in some embodiments. Each of the inner shaft electrode and the outer sheath electrode can be connected to a conductor that is also attached to an electrical stimulation generator. In some cases, the conductor attached to the outer sheath electrode can wrap around the outer surface of the outer sheath so that the catheter can withstand bending that occurs as the catheter system navigates through the vasculature of the patient. The spiral pattern can prevent kinks and make it easier to track the catheter system as it advances towards the targeted treatment site.

[0009] In one aspect, a catheter system delivers electrical stimulation to targeted neural tissue proximate the spinal column of a patient. The catheter system can include an inner shaft comprising an inner shaft electrode attached to a distal end of the inner shaft and an outer sheath comprising an outer sheath electrode attached to a distal end of the outer sheath, the outer sheath defining a lumen sized to receive the inner shaft. The inner shaft is movable within the lumen relative to the outer sheath to position the inner shaft electrode and the outer sheath electrode for delivering the electrical stimulation to the targeted neural tissue.Attorney Docket No.: 07039-2336WO1 / 2023-446

[0010] In one aspect, a medical device system includes one or more electrodes; and a catheter including an outer wall. The one or more electrodes are disposed within the outer wall of the catheter. The outer wall defines one or more openings such that the one or more electrodes can deliver electrical stimulation to a patient via the one or more openings.

[0011] In another aspect, a medical device system includes a sheath defining a lumen, one or more electrodes, and a catheter including an outer wall. The catheter is slidably disposed within the lumen, the one or more electrodes being disposed within the outer wall of the catheter. The outer wall defines one or more openings such that the one or more electrodes can deliver electrical stimulation to a patient via the one or more openings.

[0012] Particular embodiments of the subject matter described in this document can be implemented to realize one or more of the following advantages. For example, The catheter system can be sized to adjust the distance between the inner shaft electrode and the outer sheath electrode by moving the inner shaft relative to the outer sheath. This allows the clinician to navigate the inner shaft relative and the outer sheath to a targeted treatment site simultaneously and adjust the position of the inner shaft electrode and the outer sheath electrode once at the targeted treatment site. The clinician can confirm that the electrodes are sufficiently placed under visualization and deliver electrical stimulation when the electrodes are sufficiently placed.

[0013] In some cases, the catheter can include very narrow openings, or “etchings’' that expose electrodes disposed within the outer wall to the patient’s tissue. Since ablation can involve inducing necrosis or apoptosis to destroy certain targeted tissue cells, it is important in ablation procedures for electrical stimulation to destroy only tissue that is targeted and to refrain from inducing necrosis in tissue neighboring the targeted tissue. By including narrow openings to expose the electrodes within the outer wall, the catheter can deliver stimulation in a targeted location without delivering stimulation to tissue that is not targeted. Furthermore, the narrow openings limit the amount of stimulation that is delivered to the targeted tissue, which prevents the stimulation from inducing necrosis in tissue beyond the targeted area.

[0014] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Although methods and materials similar or equivalent to those described herein can be used to practice the invention, suitable methods and materials are described herein. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, theAttorney Docket No.: 07039-2336WO1 / 2023-446 present specification, including definitions, will control. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.

[0015] The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description herein. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.BRIEF DESCRIPTION OF THE DRAWINGS

[0016] FIGS. 1 A- IE illustrate a first catheter system including an inner shaft and an outer sheath.

[0017] FIGS. 1 A-1B illustrate a second example of a catheter system including a catheter with a spiral-shaped opening and a sheath.

[0018] FIG. 2 is a third example of a catheter system including a catheter with two spiralshaped openings and a sheath.

[0019] FIG. 3 is a fourth example of a catheter system including two pairings of a catheter and a sheath, each catheter having a spiral-shaped opening.

[0020] FIG. 4 is a fifth example of a catheter system including a catheter with slit openings and a sheath.

[0021] FIG. 5 is a sixth example of a catheter system including a balloon catheter for infusing saline in an occluded vein.

[0022] FIG. 6 is a conceptual diagram illustrating a first view of a catheter system at a targeted treatment site.

[0023] FIG. 7 is a conceptual diagram illustrating a second view of a catheter system at a targeted treatment site.

[0024] FIG. 8 is a flow diagram illustrating an example technique for navigating a catheter system to targeted neural tissue.DETAILED DESCRIPTION

[0025] This document describes devices and methods for using a catheter to ablate the pain generating and autonomic nerves within the craniofacial and spinal vascular axis. According to one embodiment, this document relates to a catheter that includes an inner shaft and an outer sheath that can move relative to each other to place electrodes for delivering electrical stimulation. According to another embodiment, this document relates to a catheter that includes one or more electrodes disposed therein, the catheter including etchings that allow the electrodes to deliver stimulation to the patient. The systems andAttorney Docket No.: 07039-2336WO1 / 2023-446 techniques described herein include example catheter systems for delivering electrical stimulation to targeted area in a patient without the stimulation affecting tissue outside of the targeted area. The catheter, in some examples, can be used to perform ablation and / or pulsed field ablation or electroporation (PFE).

[0026] Ablation can be a beneficial treatment for several patient conditions, such as in the context of chronic pain conditions. In some cases, ablation works by using radiofrequency (RF) signals to emit heat in a way that disrupts the function of nerves responsible for transmitting pain signals to the brain. In other cases, electroporation using alternating electrical signals can be use to disrupt nerve function. This disruption can prevent nerves from effectively communicating pain, thereby reducing the sensation of pain and improving the patient’s quality of life.

[0027] In some embodiments, ablation can offer a targeted, minimally invasive, and effective solution for managing chronic pain when ablation is delivered by a transvascular catheter configured to target a very specific area of tissue for stimulation. For example, a medical device system including a catheter can deliver electrical stimulation to induce ablation in a way that specifically targets nerves that transmit pain signals, effectively reducing or eliminating pain in the treated area. Nerves that can be targeted for ablation include the basivertebral nerve, the trigeminal nerve, the occipital nerve, the supraorbital nerve, and nerves and ganglia affecting the autonomic nervous system It is important that the catheter limit stimulation to the targeted nerves and tissue so that ablation is not induced in tissue that does not relate to the chronic pain condition of the patient. This is because ablation often involves necrosis (death) of tissue cells and inducing necrosis in tissue areas not intended for treatment can have a negative effect.

[0028] The amount of stimulation delivered to a targeted tissue area and a direction of the stimulation delivery can have an effect on whether stimulation is confined to the targeted area or whether the stimulation is spread beyond the targeted tissue area and / or affects an area that is not intended for treatment. For example, if stimulation is too high, is delivered for too long, or is delivered to an area that is too large, this can lead to tissue being ablated beyond the targeted tissue area. It can be beneficial for a catheter to have properties that allow a clinician to control where stimulation is delivered and to control an amount of stimulation that is delivered.

[0029] A catheter advanced through the vascular system (e.g., through the lumbar vein, azygous vein or vertebral vein) can provide basivertebral nerve and sinuvertebral nerve ablation in a way that treats chronic low back pain associated with the basivertebral nerve.Attorney Docket No.: 07039-2336WO1 / 2023-446A clinician can advance the catheter through the venous system to access the basivertebral nerve within the vertebral body in a way that is less invasive as compared with other techniques. Basivertebral nerve ablation is a procedure for treating chronic low back pain, particularly for patients whose pain originates from vertebral endplates. Other applications include ablation headache pain generating nerves including the sphenopalatine ganglion (i.e. via the sphenopalatine vein or artery), occipital nerve (i.e. via the occipital nerve or artery); as well as the ablation of autonomic nerves and ganglia (i.e. sympathetic ganglia along the neuraxis via spinal veins). These can be performed both trans-arterially via external carotid artery branches or transvenously.

[0030] As described above, the catheter is not limited to delivering ablation to the basivertebral nerve. The catheter can be advanced through the vascular system to a targeted treatment site at the basivertebral nerve or another nerve such as the trigeminal nerve, sphenopalatine ganglia the occipital nerve, or the supraorbital nerve. Using the patient’s venous system to advance an ablation catheter to a targeted treatment site of a patient can be beneficial for several reasons. For example, advancing a catheter through the vascular system can be minimally invasive or less invasive as compared with other catheter delivery methods, because a small incision to reach a vein or artery allows the catheter to advance through that vein or artery without a need for larger cuts or incisions.

[0031] During a procedure to provide nerve ablation using a transvascular catheter, a clinician can advance the catheter to the targeted treatment side under direct visualization from one or more imaging systems. For example, fluoroscopy and / or computed tomography (CT) can be used to provide visualization so that the clinician can see the position of the catheter relative to the targeted treatment site even when the catheter is inserted within the patient’s body. When the catheter is proximate the targeted treatment site, the clinician can control the catheter to deliver electrical stimulation therapy according to one or more therapy programs. This electrical stimulation therapy can include RF ablation, PFE, or other kinds of electrical stimulation therapy.

[0032] For example, to deliver a catheter to a targeted treatment site within a patient, a clinician can make one or more incisions to access a vein or artery (e.g.. the lumbar vein, the azygous vein, the vertebral vein, the jugular vein, the femoral artery, the sphenopalatine vein, the sphenopalatine artery, the middle meningeal artery the occipital nerve, the occipital artery) of the patient. In some embodiments, the clinician can insert a guidewire into the vein or artery of the patient via an access needle and advance the guidewire through the vascular system of the patient. The clinician can advance theAttorney Docket No.: 07039-2336WO1 / 2023-446 guidewire to the targeted treatment site. The clinician can advance the catheter to the targeted treatment site over the guidewire such that the guidewire helps the catheter to navigate the vascular system to reach the targeted treatment site. A guidewire is not necessary to advance the catheter to the targeted treatment site. In some embodiments, the catheter can advance to a targeted treatment site without advancing over a guidewire. For example, the clinician can advance the catheter through the incision without first inserting a guidewire.

[0033] The clinician can, in some examples, control the catheter as the catheter advances to the targeted treatment site. For example, the catheter system may have one or more controls that allow- the clinician to bend the catheter or otherwise move the catheter. These can allow the clinician to cause the catheter to round comers and navigate bends in the patient’s vasculature. As described above, the catheter and / or a guidewire is visible to the clinician under direct visualization from one or more imaging systems. This allows the clinician to determine whether the catheter and / or the guidewire has reached the targeted treatment site. The direct visualization also can allow the clinician to perform one or more actions to guide the catheter and / or the guidewire. In some cases, fiducial markers are located on the catheter and / or the guidewire that are visible in the imaging from the direct visualization.

[0034] When the ablation catheter has reached the targeted treatment site, the clinician can control the catheter to deliver ablation energy to the targeted treatment site. The clinician can withdraw the catheter from the vasculature of the patient along the path through which the catheter advanced.

[0035] Referring now' to FIGS. 1A-1B, a catheter system 10 can include an inner shaft and an outer sheath 14. In some examples, the inner shaft 12 extends between a proximal end and a distal end. The outer sheath 14 defines a lumen that can receive the inner shaft 12. The inner shaft 12 is configured to move w ithin the lumen defined by outer sheath 14 distally and / or proximally. For example, a clinician can move the inner shaft 12 relative to the outer sheath 14 distally so that a distal end of inner shaft 12 moves distally away from a distal end of outer sheath 14. In some cases, a clinician can move the inner shaft 12 relative to the outer sheath 14 proximally so that a distal end of the inner shaft 12 moves proximally tow ards the distal end of the outer sheath 14.

[0036] The inner shaft 12 can extend distally beyond a distal opening of the lumen defined by outer sheath 14 in some cases and extend proximally beyond a proximal opening of the lumen defined by outer sheath 14. Thus, the inner shaft 12 can be longerAttorney Docket No.: 07039-2336WO1 / 2023-446 than the lumen defined by outer sheath 14 through which the inner shaft 12 is sized to move. As depicted in FIG. 1 A, a proximal portion of the inner shaft 12 can include a connector 20 and a proximal end 21. In some cases, a clinician can grip the connector 20 and / or the proximal end 21 to move the inner shaft 12 relative to the outer sheath 14. For example, the clinician can grip the connector 20 and / or the proximal end 21 with one hand and grip the outer sheath 14 with another hand and move the inner shaft 12 relative to the outer sheath 14 proximally and / or distally.

[0037] The outer sheath 14 can be attached to a connector 16, which is attached to a shaft 18. In some examples, the connector 16 can include a single distal opening and two proximal openings. The outer sheath 14 can extend distally out of the single distal opening, the inner shaft 12 can extend into one of the proximal openings into a lumen defined by the outer sheath 14 while a portion of the inner shaft 12 remains outside of the lumen, and the shaft 18 can extend proximally out of the second proximal opening. In some cases, the connector 16 can define a “Y"’ shape such that the shaft 18 extends at an angle relative to the inner shaft 12 at the connector 16.

[0038] In some examples, a diameter of the outer sheath 14 can be within a range from 2 French (Fr) to 5 Fr (e.g., 4 Fr). In some examples, an inner diameter of the outer sheath 14 (e.g., a diameter of the lumen defined by the outer sheath 14) can be within a range from 0.014 inches (in) to 0.027 in. Because the inner shaft 12 is sized to fit within the lumen defined by outer sheath 14, an outer diameter of the inner shaft 12 can be within a range from 0.014 inches (in) to 0.027 in. In some embodiments, a length of outer sheath 14 can be within a range from 90 centimeters (cm) 135 cm. In some embodiments, a length of inner shaft 12 can be within a range from 90 cm to 135 cm. Dimensions of the outer sheath 14 and the inner shaft 12 can be set so that catheter system 10 can navigate through the vasculature of the patient to reach a targeted treatment site proximate targeted neural tissue such as the basivertebral nerve and / or the sinuvertebral nerve.

[0039] To move the inner shaft 12 relative to the outer sheath 14 distally, the connector 20 and / or the proximal end 21 can move distally which causes part of the inner shaft 12 to enter an opening of the lumen defined by outer sheath 14 at a proximal end and causes part of the inner shaft 12 to exit a distal opening of the outer sheath 14. Thus, the portion of the inner shaft 12 beyond the distal opening increases in length and the part of the inner shaft 12 proximal of the proximal opening decreases in length. To move the inner shaft 12 relative to the outer sheath 14 proximally, the connector 20 and / or the proximal end 21 can move proximally which causes part of the inner shaft 12 to exit an opening of the lumenAttorney Docket No.: 07039-2336WO1 / 2023-446 defined by outer sheath 14 at a proximal end and causes part of the inner shaft 12 to withdraw into the distal opening of the outer sheath 14. Thus, the portion of the inner shaft 12 beyond the distal opening decreases in length and the part of the inner shaft 12 proximal of the proximal opening increases in length.

[0040] In some embodiments, the inner shaft 12 comprises an inner shaft electrode 22 and a distal tip 24. The inner shaft electrode 22 can be attached to a distal end of the inner shaft 12 such that the inner shaft electrode 22 moves proximally and distally relative to the distal end of the outer sheath 14. The inner shaft electrode 22, in some examples, can extend around the inner shaft 12 such that the inner shaft electrode 22 occupies a maximum diameter of the inner shaft 12. The inner shaft electrode 22 can occupy a distal portion of the inner shaft 12 between the distal tip 24 located at a distal end of inner shaft electrode 22 and a proximal end of inner shaft electrode 22.

[0041] The inner shaft electrode 22 can include a cylinder shape in some embodiments. Using a cylinder-shaped inner shaft electrode 22 at the end of inner shaft 12 can result in beneficial tissue stimulation because the cylinder geometry can provide a focused yet evenly distributed current density over a defined surface area, reducing the risk of tissue damage from high current concentrations that occur with sharp or point electrodes. The cylindrical shape of inner shaft electrode 22 can ensure more consistent contact with the target tissue, even if there is slight variation in positioning, which improves reliability and reproducibility of stimulation. The alignment of inner shaft electrode 22 with the inner shaft 12 can allow' for precise placement and directional control, making it easier to reach specific tissue regions while minimizing unintended stimulation of surrounding areas. This combination of safety, control, and effectiveness makes cylindrical electrodes such as inner shaft electrode 22 well-suited for both research and clinical applications in neural and muscular stimulation.

[0042] The inner shaft electrode 22 can be connected to a conductor that runs along the inner shaft 12 in some cases. For example, the conductor connected to inner shaft electrode 22 can be sized to fit within an interior of the inner shaft 12 such that the conductor is not exposed on an outer surface of the inner shaft 12. This can allow the inner shaft 12 to slide relative to the outer sheath 14 such that the conductor does not interfere with the movement of inner shaft 12 relative to outer sheath 14. As depicted in FIGs. 1 A-1B, a diameter of the lumen defined by the outer sheath 14 can be greater than or equal to a diameter of the inner shaft 12 such that the inner shaft 12 is sized to fit within the lumen of the outer sheath 14. In some embodiments, a diameter of inner shaft electrode 22 can beAttorney Docket No.: 07039-2336WO1 / 2023-446 greater than a diameter of the inner shaft 12 such that the inner shaft electrode 22 cannot advance proximally into the lumen of the outer sheath 14, but this is not required. In some embodiments, the inner shaft electrode 22 is sized to fit within the lumen of the outer sheath 14.

[0043] The distal tip 24 of the inner shaft 12 can, in some embodiments, include a rounded tip. A rounded distal tip 24 on the inner shaft 12 can be beneficial because it minimizes trauma and irritation to blood vessels or other tissues during insertion and navigation, reducing the risk of perforation, abrasion, or unintended injury. The smooth, curved surface of distal tip 24 can help the inner shaft 12 glide more easily through anatomical pathways, improving patient comfort and lowering the likelihood of complications compared to sharp or irregular tips. Additionally, a rounded design of inner shaft 12 can enhance steerability and control for the clinician, while also reducing the chances of the inner shaft 12 snagging on vessel walls, valves, or other delicate structures. This can make rounded distal tip 24 safer and more effective for a wide range of diagnostic and therapeutic catheterization procedures.

[0044] In some examples, the outer sheath 14 can include an outer sheath electrode 26 located at a distal end of the outer sheath 14. In some cases, the outer sheath electrode 26 can be disposed around an outer surface of the outer sheath 14. In some cases, the outer sheath electrode 26 can be formed as part of an outer surface of the outer sheath 14. The outer sheath electrode 26 can have a cylindrical shape, in some examples. As depicted in FIGS. 1 A-l B, the outer sheath electrode 26 can be connected to a conductor 28 that extends along the outer sheath 14. The outer sheath electrode 26, in some embodiments, can be displaced from a distal tip of the outer sheath 14 rather than being located directly at the distal tip of the outer sheath 14. In some embodiments, outer sheath electrode 26 can be located directly at the distal tip of the outer sheath 14.

[0045] In some cases, inner shaft electrode 22 and outer sheath electrode 26 define a bipolar electrode system where one of the inner shaft electrode 22 and outer sheath electrode 26 represents an anode and the other of the inner shaft electrode 22 and outer sheath electrode 26 represents a cathode. In some cases, an anode-cathode bipolar electrode system includes two closely spaced conductive surfaces — one serving as the anode (positive) and the other as the cathode (negative) — that work together to deliver or record electrical signals within a localized region of tissue. Unlike monopolar configurations, where current flows between a single electrode and a distant reference, the bipolar design confines current flow primarily to the area between the two poles, whichAttorney Docket No.: 07039-2336WO1 / 2023-446 enhances spatial specificity and reduces stimulation or recording of unintended surrounding tissue. This arrangement provides more precise targeting, improved signal-to- noise ratio in recordings, and better control over stimulation intensity and spread, making bipolar electrodes especially valuable in applications such as neuromodulation, electrophysiological mapping, and therapeutic stimulation.

[0046] The conductor 28, in some examples, can extend around an outer surface of the outer sheath 14 in a spiral pattern. For example, the conductor 28 can extend along the outer sheath 14 from the outer sheath electrode 26 to a pulse generator connected to an end of the conductor 28. The spiral pattern of the conductor 28 can provide several advantages. For example, the spiral pattern of the conductor 28 can improve an ability to track the outer sheath 14, because the spiral pattern of the conductor 28 can be recognizable in direct visualization. The spiral pattern of conductor 28 can also prevent kinking of the conductor 28 by maintaining tension on the conductor 28 even in situations where the conductor 28 bends to navigate spaces within the anatomy of the patient.

[0047] By adjusting a position of the inner shaft 12 relative to the outer sheath 14, it can be possible to adjust a position of the inner shaft electrode 22 relative to the outer sheath electrode 26. For example, by moving the inner shaft 12 distally relative to outer sheath 14, this moves inner shaft electrode 22 distally away from outer sheath electrode 26, thus increasing a distance between inner shaft electrode 22 and outer sheath electrode 26. Alternatively, withdrawing the inner shaft 12 proximally into outer sheath 14 moves inner shaft electrode 22 proximally toward outer sheath electrode 26, thus decreasing a distance between inner shaft electrode 22 and outer sheath electrode 26.

[0048] It can be beneficial for a clinician to adjust the distance between inner shaft electrode 22 and outer sheath electrode 26 to deliver stimulation to a targeted tissue area within the patient. For example, some targeted tissue areas are larger and benefit from a greater distance between inner shaft electrode 22 and outer sheath electrode 26 (e.g., electrons passing betw een inner shaft electrode 22 and outer sheath electrode 26 stimulate a larger area when the distance is greater), and some targeted tissue areas are smaller and benefit from a smaller distance between inner shaft electrode 22 and outer sheath electrode 26 (e.g., electrons passing between inner shaft electrode 22 and outer sheath electrode 26 stimulate a smaller area when the distance is smaller).

[0049] In use, in some implementations, a clinician can advance the inner shaft 12 and the outer sheath 14 simultaneously to a targeted tissue area of the patient. In some cases, the distal end of inner shaft 12 and the distal end of outer sheath 14 are closely aligned as theAttorney Docket No.: 07039-2336WO1 / 2023-446 inner shaft 12 and the outer sheath 14 simultaneously to a targeted tissue area. For example, the inner shaft electrode 22 can be just outside of the distal opening of the lumen defined by the outer sheath 14, just inside of the distal opening of the lumen, or therebetween. When the inner shaft 12 and the outer sheath 14 reach the targeted tissue location, the clinician can position the inner shaft electrode 22 and the outer sheath electrode 26 to deliver electrical stimulation to the targeted tissue area of the patient. This positioning can involve adjusting the distance between the inner shaft electrode 22 and the outer sheath electrode 26 so that the electrical stimulation is delivered to the targeted tissue area.

[0050] For example, when the inner shaft electrode 22 and the outer sheath electrode 26 can be placed to generate an electromagnetic field that stimulates the targeted tissue area. The location of inner shaft electrode 22 and outer sheath electrode 26 can be determined using imaging so that the clinician can place these electrodes to sufficiently provide electrical stimulation to the targeted tissue. When the clinician is satisfied that the inner shaft electrode 22 and outer sheath electrode 26 are properly placed, the clinician can cause an electrical stimulator to deliver the electrical stimulation via inner shaft electrode 22 and outer sheath electrode 26 and conductors connected thereto. For example, the electrical stimulator can cause one of the inner shaft electrode 22 and the outer sheath electrode 26 to emit electricity, while the other one of inner shaft electrode 22 and outer sheath electrode 26 serves as a return path for the emitted electricity.

[0051] Referring now to FIGS. 1 A-l C, the connector 1 can receive the inner shaft 12 via a first proximal opening 32 and receive the shaft 18 via a second proximal opening 33. A connector 20 and a proximal end 21 can be attached to a proximal end of the inner shaft 12. A clinician can grip the connector 20 and / or the proximal end 21 to advance the inner shaft 12 into the first proximal opening 32 or withdraw the inner shaft 12 from the first proximal opening 32. In some cases, this causes the inner shaft electrode 22 to move relative to the outer sheath electrode 26, adjusting the distance between the inner shaft electrode 22 and the outer sheath electrode 26. As depicted in FIG. 1C, the conductor 28 that is connected to the outer sheath electrode 26 can be wrapped around an outer surface of the outer sheath 14 in a spiral pattern. In some cases, at the connector 1 , the conductor 28 can be located within an outer housing and extend along an inner lumen of the shaft 18. The conductor 28 can be connected to an electrical stimulation generator in some cases which can deliver electrical stimulation to the outer sheath electrode 26 via conductor 28 and / or receive electrical stimulation from the outer sheath electrode 26 via conductor 28.Attorney Docket No.: 07039-2336WO1 / 2023-446In some cases, the conductor connected to inner shaft electrode 22 can extend within the inner shaft 12 to a proximal end 21. The conductor connected to inner shaft electrode 22 can be attached to an electrical stimulation generator such that the electrical stimulation generator can deliver electrical stimulation to inner shaft electrode 22 and / or receive electrical stimulation from inner shaft electrode 22.

[0052] Referring now to FIGS. 1D-1E, the connector 16 can serve as an interface between the outer sheath 14, the shaft 18, the inner shaft 12. and the conductor 28 disposed around the outer sheath 14. For example, the conductor 28 can be wrapped in a spiral pattern around the outer sheath 14 on the portion of the outer sheath 14 that extends distally from the distal opening of connector 16. The conductor 28 can extend through an inner portion of the connector 16 along an arm of the connector 16 to which the shaft 18 is connected. The conductor 28 can extend through an inner portion of the shaft 18 to reach a plug 42. A proximal portion of the shaft 18 includes the plug 42 and a handle 44. In some examples, the connector 16 can also include another leg through which the inner shaft 12 can be inserted via the first proximal opening 32. In some examples, the inner shaft 12 can be inserted into the first proximal opening 32. through the connector 16, and into the lumen defined by the outer sheath 14. Through the other leg of the connector 16, the conductor 28 can extend to reach the outer surface of the outer sheath 14, where the conductor 28 wraps around the outer surface of the outer sheath 14. In some cases, the plug 42 can connect to a signal generator which can supply energy to the outer sheath electrode 26 via the conductor 28 and / or receive energy from the outer sheath electrode 26 via the conductor 28.

[0053] The inner shaft 12 can include a plug 52 and a handle 54. The inner shaft 12 can include the inner shaft electrode 22 and the distal tip attached to a distal end of the inner shaft 12. As depicted in FIG. IE, an inner shaft conductor 56 can extend through an inner portion of the inner shaft 12 to connect to the inner shaft electrode 22. The inner shaft conductor 56 can extend through the inner portion of the inner shaft 12, through the connector 20, and to the plug 52. The plug 52 can connect to an electrical stimulation generator which can generate stimulation for delivery via inner shaft electrode 22 via the inner shaft conductor 56 and / or receive signals from the inner shaft electrode 22 via the inner shaft conductor 56.

[0054] Referring now to FIG. 2A, catheter 110 can include one or more electrodes for delivering electrical stimulation to a patient. Catheter 110 can extend from a proximal end to a distal end. In some examples, catheter 110 is sized to be advanced through theAttorney Docket No.: 07039-2336WO1 / 2023-446 vascular system of a patient so that catheter 110 can be located at a targeted treatment site proximate to one or more veins or arteries of the patient. For example, catheter 110 can be advanced through the lumbar vein into the epidural space proximate the basivertebral nerve. The catheter 110 can be used to deliver electrical stimulation to the basivertebral nerve in order to treat chronic pain relating to the basivertebral nerve. This could also be applied to other pain generating or autonomic nerves in the craniofacial and spinal vascular axis.

[0055] Catheter 110 can include one or more electrodes for delivering the electrical stimulation to the patient. In some examples, the one or more electrodes of catheter 110 can include electrical conductors that extend within an outer wall of catheter 110. The outer wall of catheter 110 may, in some examples, include a material that defines an outer surface of the catheter 110, the one or more electrodes extending within this material that defines the outer wall. In some embodiments, the one or more electrodes form a portion of the outer wall of the catheter 110, the outer wall also including non-electrode portions so that the outer surface of catheter 110 includes both electrode portions and non-electrode portions.

[0056] In some embodiments, the outer wall of catheter 110 includes a non-conductive material and the electrode 112 of catheter 110 includes a conductive material. The conductive material of the electrode 112 may, in some cases, be disposed within the non- conductive material of the outer wall so that the non-conductive material of the outer wall is between the one or more electrodes and the tissue of the patient. The outer wall of catheter 110 can include one or more openings such that electrical stimulation can flow from the electrode 112 through the outer wall to reach the tissue of the patient.

[0057] Electrode 112, in some embodiments, includes a conductor that extends from a power source (e.g., a pulse generator) through a center of catheter 110. Electrode 112 can extend through proximal portion 114 of catheter 110 and distal portion 116 of catheter 110. The conductor of electrode 112 can be made of a conductive material such as copper, silver, nickel, or another metal or metal alloy. Since electrode 112 extends through catheter 110. a cross-section of catheter 110 along at each location along catheter 110 may include an outer wall area representing the outer wall of the catheter 110 and a conductor area within the outer wall area.

[0058] In some examples, electrode 112 extends along at least a portion of catheter 110 that includes an opening in the outer wall of catheter 110 to expose electrode 112. In some embodiments, the outer wall of catheter 110 on the proximal portion 1 14 of the catheterAttorney Docket No.: 07039-2336WO1 / 2023-446110 can be solid without any openings and the outer wall of catheter 110 on the distal portion 116 of catheter 110 can include the one or more openings that expose electrode 112 to tissue of the patient. The non-conductive material of the outer wall can limit an amount of electrical stimulation that reaches the tissue of the patient by preventing electrical stimulation from flowing to areas that are “covered” by the outer wall. In other words, electrical stimulation can be limited to flowing in areas where there is an opening in the outer wall that allows electrical stimulation to flow from the electrode 112 disposed within the outer wall and past the non-conductive material to the tissue of the patient.

[0059] Electrode 112, in some examples, extends from a proximal end to a distal end of catheter 110. In some examples, electrode 112 represents a conductor that extends through a center of an outer wall of the catheter 110 through both a proximal portion 114 of the catheter 110 and a distal portion 116 of the catheter 110. In some examples, electrode 112 extends for a length that is longer than a greatest width of the electrode 112. An opening can extend from a proximal end 113 to a distal end 115 along the distal portion 116 of the catheter 110. Electrode 112 can extend within the outer wall of catheter 110 along both of the proximal portion 114 and the distal portion 116, with electrode 1 12 being covered completely by the non-conductive material of the outer wall in the proximal portion 1 14 and the electrode 112 being exposed in in the distal portion 116.

[0060] In some embodiments, catheter 110 includes a single electrode 112 disposed within the outer wall of catheter 110. The techniques of this disclosure are not limited to examples where the catheter 1 10 includes one electrode. Some catheters 10 can include more than one electrode disposed within the outer wall. As described in further detail below, when catheter 110 includes a single cathode, electrical stimulation may return via an anode located separately from catheter 110.

[0061] catheter 110 may, in some embodiments, include a spiral-shaped opening in the non-conductive material of the outer wall of catheter 110 along distal portion 116. The spiral-shaped opening can expose the electrode 112 extending through the catheter 110. In some examples, a greatest width of the opening is substantially narrower than a length of opening along the distal portion 116 of catheter 110. For example, a greatest width of the opening can be within a range from 0.01 millimeters (mm) to 1mm. The width of the opening can, in some examples, can be substantially narrow such that the opening is not visible to the human eye except upon close inspection. When the opening is very' narrow, the opening occupies small percentage of the surface area of the distal portion 116 ofAttorney Docket No.: 07039-2336WO1 / 2023-446 catheter 110. In some examples, the percentage of the surface area of distal portion 116 corresponding to the opening is within a range from 0.05% to 2%.

[0062] The narrow width of the opening is beneficial for several reasons. For example, catheter 110 can deliver stimulation to a targeted tissue site along an entire length of the distal portion 116 of catheter 110 that is exposed, while the narrow' width limits the amount of stimulation delivered at any given point along catheter 110. The narrow width prevents the stimulation from targeting an area that is too large to prevent tissue outside of the target area from being ablated.

[0063] In some embodiments, electrode 112 may extend in a spiral-shaped pattern around a circumference of catheter 110 and about a longitudinal axis of catheter 110 in a spiralshaped pattern that follows the spiral-shaped opening in the wall of the catheter 110. That is, the spiral-shaped opening in the outer wall of the catheter 110 can expose the spiralshaped electrode 112.

[0064] catheter 110 is not limited to examples in which electrode 112 extends to a distal end of catheter 110. In some examples, an electrode 112 opening can extend along a portion of a catheter that extends from a first location to a second location proximal to the distal end of the catheter. In any case, the spiral shape of catheter 110 can further limit the amount of stimulation applied to the targeted area because only portions of the electrode 112 adjacent to the targeted tissue deliver stimulation to the tissue while portions of the electrode 112 covered by the outer wall of catheter 110 do not deliver stimulation to the tissue.

[0065] The opening can be cut into the surface of catheter 110 using a cutting tool designed to make narrow openings. For example, a laser can be used to cut the opening into the non-conducting material of the outer wall of catheter 110 so that the conductor material of the electrode 112 is exposed through the laser-cut opening. Since the opening is narrow, this limits an amount of electrical stimulation that is able to pass through the opening in the outer w all to the tissue of the patient. Since an amplitude of RF ablation pulses can be very high, it is beneficial for the opening to be narrow so that the stimulation effect is limited in a w ay that prevents tissue outside of the targeted area from being ablated.

[0066] Referring now to FIG. 2B, one way that the system of catheter 110 can limit stimulation exposure is through the use of sheath 120. For example, sheath 120 can define a lumen 122 that extends from a proximal end to a distal end 121 of the sheath. Catheter 110 can be slidably disposed within the lumen 122 such that catheter 110 can moveAttorney Docket No.: 07039-2336WO1 / 2023-446 relative to sheath 120 along a longitudinal axis of sheath 120. In some examples, some or all of the distal portion 116 of catheter 110 can extend beyond a distal end 121 of the sheath 120. As seen in FIG. 2, a portion 118 of the catheter 130 extends beyond distal end 121 of sheath 120. A clinician can control sheath 120 and catheter 110 to set the amount of catheter 110 that extends beyond the distal end 121 of sheath 120.

[0067] In some embodiments, it is possible to regulate the amount of stimulation delivered to targeted tissue by regulating an extent to which catheter 110 extends out beyond the distal end 121 of sheath 120. For example, since electrode 112 extends along the distal portion 116 of catheter 110, a greater amount of distal portion 116 that extends beyond distal end 121 of sheath 120 corresponds to a greater amount of electrode 112 that is not covered by the sheath 120. As seen in FIG. 2B, for example, at least some of electrode 112 is covered by sheath 120 and at least some of electrode 112 extends beyond distal end 121 of sheath 120.

[0068] Sheath 120 can be made of a non-conductive material so that electrical stimulation cannot travel from the electrode of catheter 110 to tissue of the patient. This means that the parts of catheter 1 10’s distal portion 116 that are within sheath 120 do not deliver electrical stimulation to the patient event though these parts include electrode 112. Catheter 110 delivers electrical stimulation to the patient via parts of electrode 112 that extend beyond the distal end of sheath 120. A greater amount of catheter 110 extends out of the sheath 120 corresponds to a greater amount of electrical stimulation delivered to the patient and a smaller amount of catheter 110 that extends out of the sheath 120 corresponds to a smaller amount of electrical stimulation delivered to the patient.

[0069] Thus, a clinician can control an amount of electrical stimulation delivered to the patient by controlling an extent to which electrode 112 is outside of the sheath 120. For example, the clinician can cause catheter 110 to slide outwards relative to sheath 120 to increase the amount of catheter 110 outside of sheath 120 or retract catheter 110 within sheath 120 to decrease the amount of catheter 110 inside of sheath 120. During a procedure to deliver electrical stimulation using catheter 110, catheter 110 and sheath 120 can be under direct visualization by one or more imaging systems so that the clinician can see an amount of catheter 110 that is exposed outside of the sheath 120, allowing the clinician to control the catheter 110 accordingly.

[0070] Sheath 120, in some examples, can include one or more electrodes located on a surface of sheath 120. For example, in cases where catheter 110 includes a single electrode (e.g., a cathode) disposed within the outer wall, sheath 120 can include a single electrodeAttorney Docket No.: 07039-2336WO1 / 2023-446(e.g., an anode) located on a distal end 121 of the sheath 120. In this example, catheter 110 can deliver electrical stimulation to the patient’s tissue via the portion of the electrode 112 that is exposed outside of sheath 120, and this electrical stimulation can return via the anode 124 located on the sheath 120. When anode 124 is located at the distal end 121 of the sheath, stimulation can be contained to an area proximate to the portion of catheter 110 that extends beyond the distal end 121 of sheath 120.

[0071] The system including sheath 120 and catheter 110 is not limited to examples where a return anode is located on sheath 120. In some examples, a return electrode can be placed on a skin of the patient or in another location. In any case, stimulation can be controlled based on an amount of catheter 110 that is exposed and outside of sheath 120, with a greater amount of exposure corresponding to a greater amount of stimulation and a smaller amount of exposure corresponding to a smaller amount of stimulation.

[0072] In some embodiments, sheath 120 and catheter 110 can advance together to the targeted treatment site through the vasculature of the patient while the catheter 110 is fully retracted within the lumen 122 of sheath 120. When the sheath 120 and catheter 110 reach the targeted treatment site, catheter 110 can slide within lumen 122 to move distally relative to sheath 120 so that a portion of catheter 110 is exposed. Catheter 110 can deliver electrical stimulation to a patient via a portion of electrode 112 that is beyond the distal end of sheath 120. This electrical stimulation can return via anode 124 or another anode in another location (e.g.. a skin electrode).

[0073] Referring now to FIG. 2C, a medical device system can include a catheter 130 that includes two or more electrodes disposed within an outer wall. In some examples, catheter 130 can extend from a proximal end to a distal end. Catheter 130 can include a first electrode 132 that is exposed by a first opening in the outer wall and a second electrode 134 that is exposed by a second opening in the outer wall. In some examples, the first electrode 132 is a cathode and the second electrode 134 is an anode. The electrodes 132, 134 can, in some embodiments, extend through a body of catheter 130 on an inside of the outer wall of catheter 130. The catheter 130 can be cut. or "‘etched’’ in a way that exposes the electrodes passing through the center of the catheter 130. These cuts allow electrical energy to cross from the electrodes 132, 134 to the patient’s tissue via the outer wall of the catheter 130.

[0074] The outer wall of catheter 130 includes a non-conductive, insulating material. This non-conductive material significantly or completely attenuates electrical signals such that electrical stimulation from one or both of electrodes 132, 134 cannot cross the outer wallAttomey Docket No.: 07039-2336WO1 / 2023-446 of catheter 130. Electrical stimulation corresponding to electrodes 132, 134 can pass through the openings in the outer wall in areas where the openings expose electrodes 132. 134 to tissue surrounding the catheter 130. In some examples, the first opening in the outer wall of catheter 130 and the second opening in the outer wall of catheter 130 extend along a length of a distal catheter portion 136 of the catheter 130. This distal catheter portion 136 represents a portion of catheter 130 that includes openings or etchings that expose electrodes 132, 134 located within the outer wall of catheter 130.

[0075] In some embodiments, first electrode 132 comprises a first conductor disposed within the outer wall and the second electrode 134 comprises a second conductor disposed within the outer wall. The first conductor of first electrode 132 can extend along an inside of the outer wall of catheter 130 adjacent the first opening in the outer wall and the second conductor of second electrode 134 can extend along an inside of the outer wall of catheter 130 adjacent the second opening in the outer wall. This allows electrical energy corresponding to the first electrode 132 to travel through the first opening and electrical energy corresponding to the second electrode 134 to travel through the second opening.

[0076] As described above, the first opening that exposes first electrode 132 and the second electrode that exposes the second electrode 134 can both extend along the distal catheter portion 136 of the catheter 130. This means that the first opening and the second opening both expose portions of the first electrode 132 and the second electrode 134 along the same portion of the catheter 130. It can be beneficial for a cathode and an anode of an ablation catheter to be located near each other so that electrical signals do not travel a long distance from the cathode to the anode.

[0077] A first conductor of the first electrode 132 and a second conductor of the second electrode 134 may each independently conduct electricity so that electrical signals can travel along the first conductor independent of the second conductor and electrical signals can travel along the second conductor independent of the first conductor. This means that the catheter 130 can deliver electrical stimulation via the first conductor representing a cathode and the electrical stimulation can return through the second conductor representing an anode.

[0078] First electrode 132 and second electrode 134 may, in some embodiments, each include a spiral-shaped conductor within catheter 130 in the distal catheter portion 136. In areas of catheter 130 proximal to the distal catheter portion 136, first electrode 132 and second electrode 134 can be straight, spiraled, or take another shape. In the distal catheter portion 136, each of the first electrode 132 and the second electrode 134 can be spiral -Attorney Docket No.: 07039-2336WO1 / 2023-446 shaped. Each of the first electrode 132 and the second electrode 134 can extend along a corresponding spiral-shaped opening in the outer wall of the catheter 130. That is. first electrode 132 can follow a first opening in a first spiral along distal catheter portion 136 and second electrode 134 can follow a second opening in a second spiral along distal catheter portion 136.

[0079] In some examples, the greatest width of the first opening corresponding to first electrode 132 is substantially narrower than a length of first opening along the distal portion of catheter 130 and a greatest width of the second opening corresponding to second electrode 134 is substantially narrower than a length of second opening along the distal portion of catheter 130. A greatest width of each of the first opening and the second opening can be within a range from 0.01 millimeters (mm) to 1mm. The width of each of the first opening and the second opening can, in some examples, can be substantially narrow such that the first opening and the second opening are not visible to the human eye except upon close inspection. When the first opening and the second opening are both very narrow, the first opening and the second opening may occupy small percentage of the surface area of the distal portion of catheter 130. In some examples, the percentage of the surface area of the distal portion corresponding to the first opening and the second opening is within a range from 0.1% to 4%.

[0080] Each of the first opening corresponding to first electrode 132 and the second opening corresponding to second electrode 134, in some embodiments, can be spiralshaped. This means that the first opening extends around a circumference of the catheter 130 along the distal portion of catheter 130 and the second opening likewise extends around a circumference of the catheter 130 along the distal portion of catheter 130. In some cases, the first opening and the second opening can extend in the same direction around the circumference of catheter 130 moving distally (e.g., both clockwise moving distally or both counterclockwise moving distally. The first opening and the second opening can be separate openings that do not intersect with each other such that electrical signals can independently pass through one of the first opening and the second opening without concurrently passing through the other of the first opening and the second opening.

[0081] The first opening and the second opening can be cut into the surface of catheter 130 using a cutting tool designed to make narrow openings. For example, a laser can cut the first opening and the second opening into the non-conductive material of the outer wall of catheter 130 so that the first electrode 132 and the second electrode 134 are exposedAttorney Docket No.: 07039-2336WO1 / 2023-446 through the laser-cut openings. Since the first opening and the second opening represent narrow, spiral-shaped etchings, this limits an amount of electrical stimulation that can cross the outer wall of catheter 130 to the tissue of the patient. Since an amplitude of RF ablation pulses can be very high, it is beneficial for the first opening and the second opening to be narrow so that the stimulation effect is limited in a way that prevents tissue outside of a targeted area from being ablated.

[0082] In some examples, catheter 130 can be slidably received within a lumen 142 of sheath 140. Sheath 140 can extend from a proximal end to a distal end 141. Catheter 130 can move within lumen 142 relative to sheath 140 such that catheter 130 can extend out of the lumen 142 and retract within the lumen 142. The clinician can control an amount of electrical stimulation that a patient receives based on an amount of catheter 130 that is exposed outside of sheath 140. A greater amount of catheter 130 that is exposed outside of sheath 140 corresponds to a greater amount of stimulation that is delivered to the patient and a smaller amount of catheter 130 that is exposed outside of sheath 140 corresponds to a smaller amount of stimulation that is delivered to the patient.

[0083] In some examples, it is beneficial for catheter 130 to include two electrodes (e.g.. an anode and a cathode) that extend along the distal portion of catheter 130. This is because when catheter delivers electrical stimulation using a catheter via a first opening, this electrical stimulation can return via the anode through a second opening at a position that is close to the first opening. This allows catheter 130 to stimulate a targeted area without the stimulation reaching tissue outside of the targeted area.

[0084] In some embodiments, sheath 140 and catheter 130 can advance together to the targeted treatment site through the vasculature of the patient while the catheter 130 is fully retracted within the lumen 142 of sheath 140. When the sheath 140 and catheter 130 reach the targeted treatment site, catheter 130 can slide within lumen 142 to move distally relative to sheath 140 so that a portion of catheter 130 is exposed. Catheter 130 can deliver electrical stimulation to a patient via a portion of the first opening that is beyond the distal end 141 of sheath 140. This electrical stimulation can return via the second opening.

[0085] In some examples, catheter 130 can include a bendable distal tip. First electrode 132 and second electrode 134 can extend along a distal portion of catheter 130 to a location just proximal to the bendable distal tip. In some examples, the bendable distal tip may be bendable responsive to user input during a procedure to maneuver catheter 130 to the targeted treatment site. In some examples, the bendable distal tip can be bent to a select formation prior to the catheter being inserted into the patient.Attorney Docket No.: 07039-2336WO1 / 2023-446

[0086] Referring now to FIG. 3, a medical device system can include two catheter systems. As seen in FIG. 3, the medical device system can include a first catheter system 152 and a second catheter system 154. In some examples, each of the two catheter systems can be an example of the catheter system illustrated in FIG. 1 including catheter 1 10 and sheath 120. That is, each of first catheter system 152 and second catheter system 154 can include one electrode disposed within the catheter. The catheter of each of the first catheter system 152 and the second catheter system 154 can define a spiral-shaped opening on a distal portion of the outer wall that exposes the electrode within the outer wall.

[0087] In some embodiments, both of the first catheter system 152 and the second catheter system 154 can be advanced to a targeted treatment site 156. In some examples, each of the first catheter system 152 and the second catheter system 154 can be advanced through the patient’s vasculature to the targeted treatment site 156 (e.g., each through a separate artery or vein), but this is not required. In some examples, one or both of the first catheter system 152 and the second catheter system 154 can be advanced to the targeted treatment site not within a vein or artery’.

[0088] The first catheter system 152 may. in some examples, include a first electrode and the second catheter system 154 may, in some examples, include a second electrode. The first electrode can be disposed within an outer wall of the catheter of the first catheter system 152 and the second electrode can be disposed within an outer wall of the catheter of the second catheter system 154. In some cases, the first catheter system 152 can deliver electrical stimulation to the targeted treatment site 156 via the opening in the distal end of the catheter of the first catheter system 152 and this electrical stimulation can travel through the targeted treatment site to return via the second electrode of the second catheter system 154.

[0089] Each of the first catheter system 152 and the second catheter system 154 can include a catheter with a non-conductive outer w all and a conductive electrode within the outer wall. The non-conductive outer walls can each include an opening that extends around the catheter in a spiral-shaped pattern. Electrical signals can travel through these spiral-shaped openings to reach the electrodes within the respective outer walls. In some cases, it is beneficial for each of the catheters to define a narrow and spiral-shaped opening so that electrical stimulation is limited to a target area and does not spread to tissue outside of the target area.

[0090] Furthermore, each of the first catheter system 152 and second catheter system 154 can include a sheath that defines a lumen. A clinician can control a position of a catheterAttorney Docket No.: 07039-2336WO1 / 2023-446 within the lumen of the sheath for each of the first catheter system 152 and second catheter system 154. This means that the clinician can control an amount of each of the first electrode and the second electrode that is outside of its respective sheath. This in turn controls the amount of electrical stimulation that reaches the targeted treatment site 156.

[0091] Referring now to FIG. 4, a catheter system can include a catheter 170 including an outer wall with slit openings that expose an electrode. As seen in FIG. 4, catheter 170 includes slit openings 172A-172J (collectively, “slit openings 172”). In some examples, each of slit openings 172 is separate from other slit openings so that the slit openings are not connected to each other. Slit openings 172 can be spaced along a distal portion of catheter 170 such that approximately the same distance separates each pair of consecutive slit openings. For example, a first distance separates slit openings 172A and 172B, a second distance equal to the first distance separates slit openings 172B and 172C, and so on.

[0092] As with other catheter system designs described herein, catheter 170 can slidably move within a lumen 82 of sheath 180. A portion of catheter 170 can extend out of the lumen 82 such that slit openings 172 are exposed and sheath 180 does not cover the slit openings 172. The number of slits that are exposed outside of sheath 180 is controllable by a clinician who can retract or extend catheter 170 relative to sheath 180. For example, a clinician could retract catheter 170 within sheath 180 such that slit openings 172A and 172B are covered by sheath 180 while slit openings 172C-172J remain uncovered by sheath 180.

[0093] An amount of stimulation that a patient receives can depend on a number of slits that are exposed outside of sheath 180, with a greater number of exposed slits corresponding to more stimulation and a smaller number of exposed slits corresponding to less stimulation. In some examples, the slit openings 172 are marked with fiducial markers such that slit openings 172 are visible under direct visualization. This allows a clinician to see exactly how many slits are exposed even when the catheter is inserted within the vasculature of the patient. If necessary, the clinician can adjust the number of exposed slits by extending or retracting the catheter 170.

[0094] Catheter 170 includes an exposed tip 173. In some examples, exposed tip 173 includes a bare conductor that is not covered by any portion of the outer wall 71 of the catheter 170. In some cases, it is beneficial for exposed tip 173 to be completely uncovered for cases in which catheter 170 barely extends out of sheath 180 and is almost completely retracted within sheath 180. In these cases, the surface area of the electrode that is exposedAttorney Docket No.: 07039-2336WO1 / 2023-446 is already small, and laser-etched openings are not necessarily helpful to limit stimulation. It is not necessary for catheter 170 to include an exposed tip 173. In some examples, catheter 170 is completely covered with a non-conductive material except for areas corresponding to slit openings 172.

[0095] Referring now to FIG. 5, in some cases, a catheter system can include a balloon catheter 190. This balloon catheter can include a first balloon 192and a second balloon 194. The first balloon 192can be located on a first side of targeted treatment site 188 and the second balloon 194 can be on a second side of targeted treatment site 188. The first balloon 192and the second balloon 194 can be inflated to secure catheter 190 at the targeted treatment site. The catheter 190 can infuse saline into a space between the first balloon 192and the second balloon 194. In some examples, catheter 190 can be advanced to the targeted treatment site and the first balloon 192and the second balloon 194 can be inflated to secure the catheter 190 at the targeted treatment site 188.

[0096] In some embodiments, the saline infused into the space between the first balloon 192 and the second balloon 194 can act as a virtual cathode that disperses electrical energy from the catheter 190. For example, the targeted treatment site 188 can include one or more branched vessels that are too small for catheter 190 to maneuver within. The infused saline can help to propagate electrical energy' through the network of smaller vessels to reach nerves proximate to the smaller vessels.

[0097] Referring now to FIGS. 2A-5, any of the example catheters described herein may be connected to a pulse generator configured to generate electrical stimulation for delivery to the patient via the catheter. For example, the pulse generator can be electrically connected to a conductor corresponding to each electrode. The pulse generator can generate electrical stimulation for performing one or more medical procedures such as RF ablation, PFE, or other kinds of electrical stimulation. The pulse generator may be configured to generate one or more pulses according to one or more pulse patterns. A clinician can control the electrical stimulation generated by the pulse generator byproviding user inputs to controls.

[0098] While this specification contains many specific implementation details, these should not be construed as limitations on the scope of any invention or of what may be claimed, but rather as descriptions of features that may be specific to particular embodiments of particular inventions. Certain features that are described in this specification in the context of separate embodiments can also be implemented in combination in a single embodiment. Conversely, various features that are described in theAttorney Docket No.: 07039-2336WO1 / 2023-446 context of a single embodiment can also be implemented in multiple embodiments separately or in any suitable sub combination. Moreover, although features may be described herein as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination may be directed to a sub combination or variation of a sub combination.

[0099] Referring now to FIG. 6. an implementation of the catheter system involves advancing a catheter system 10 including an inner shaft 12 and an outer sheath 14 to a targeted treatment site. As depicted in FIG. 6, the catheter system 10 can include the catheter system 10 from FIGs. 1A-1E, but this is not required. The catheter system 10 can, in some examples, include one or more catheters from FIGs. 2A-4. As depicted in FIG. 6. one or more blood vessels can be in proximity to vertebra of one or more patients. In some examples, an ascending lumbar vein 202, a foraminal vein 204, and an epidural vein 206 can run in proximity to one or more vertebral bodies, including vertebral body 208 and vertebral body 210.

[0100] In some embodiments, the segmental venous system refers to paired veins that accompany each segmental (or segmentally arranged) artery along the vertebral column, draining blood from the vertebrae, paraspinal muscles, and surrounding tissues. In the lumbar region, each lumbar segmental vein can originate from venous plexuses around the vertebral body and neural foramen (e.g., including the basivertebral and intervertebral veins), then course laterally with the corresponding lumbar artery toward the posterior abdominal wall. These lumbar segmental veins empty into the lumbar veins, which are larger longitudinal trunks that run along the posterior abdominal wall and connect medially with the internal vertebral venous plexus (e.g., via the intervertebral veins) and laterally with the ascending lumbar veins and ultimately the inferior vena cava. This arrangement can form an extensive valveless venous network that provides bidirectional flow between the spine and systemic circulation, facilitating both normal drainage and potential spread of pathology.

[0101] In use, in some implementations, catheter system 10 can be introduced into the lumbar vein. The catheter system 10 can first be advanced under imaging guidance (e.g., fluoroscopic guidance) through the segmental venous system. In some cases, lumbar veins can run transversely across the posterior abdominal wall, draining into ascending lumbar veins (including ascending lumbar vein 202) and then communicate with the inferior vena cava or azygos system. In some cases, catheter system 10 can be navigated proximallyAttorney Docket No.: 07039-2336WO1 / 2023-446 within the ascending lumbar vein 202 until it approaches the vertebral body region, where small tributaries branch medially toward the intervertebral foramina. These tributaries include the foraminal veins (e.g., foraminal vein 204), which provide a venous connection between the extravertebral lumbar veins and the internal vertebral venous plexus within the spinal canal. In the example depicted in FIG. 6, the catheter system 10 can be advanced up the ascending lumbar vein 202 to reach a junction with the foraminal vein 204. At this junction, the catheter system 10 can be deflected to enter the foraminal vein 204.

[0102] Once the catheter system 10 is guided into the foraminal vein 204, the catheter system 10 can follow the foraminal vein 204 medially and posteriorly through the intervertebral foramen. Here, the foraminal vein 204 can course alongside the segmental artery and nerve root, entering the anterior epidural venous plexus that lies adjacent to the posterior surface of the vertebral body 208. At this location, the foraminal vein 204 serves as a critical vascular conduit linking the systemic lumbar venous system to the Batson’s plexus, a valveless internal vertebral venous network. This can allow catheter-based interventions or contrast injections to reach the venous pathways surrounding the vertebral body and spinal meninges.

[0103] As depicted in FIG. 6, catheter system 10 includes an outer sheath 14 and an inner shaft 12. The inner shaft 12 can move relative to the outer sheath 14 (and within the foraminal vein 204) in order to adjust a distance between the inner shaft electrode 22 and the outer sheath electrode 26. Adjusting the distance between the inner shaft electrode 22 and the outer sheath electrode 26 in this way can allow a clinician to tailor electrical stimulation therapy to the needs of a patient. For example, it can be beneficial for the catheter system 10 to stimulate one or more nerves proximate the vertebral body 208 and / or the vertebral body 209 (e.g., the basivertebral nerve and / or the sinuvertebral nerve). To sufficiently stimulate these nerves, the clinician can adjust the distance between the inner shaft electrode 22 and the outer sheath electrode 26 by moving the inner shaft 12 relative to the outer sheath 14 under imaging, and cause the catheter system 10 to deliver electrical stimulation when the inner shaft electrode 22 and the outer sheath electrode 26 are properly spaced.

[0104] Referring now to FIG. 7, the catheter system 10 can be navigated through the patient’s venous system to the anterior epidural space 211 proximate the vertebral body 208. In some examples, In the anterior epidural space 211, the catheter system 10 can deliver electrical stimulation to the sinuvertebral nerve 212 and / or the basivertebral nerve 214. In some cases, the anterior epidural space 211 represents the portion of the spinalAttorney Docket No.: 07039-2336WO1 / 2023-446 epidural space located between a posterior surface of the vertebral body 208 an interavertebral disc 215, and the dura mater surrounding the spinal cord. In some cases, the anterior epidural space 21 1 can be narrow and occupied by the anterior internal vertebral venous plexus, loose connective tissue, and the nerves such as the sinuvertebral nerve 212. The anterior epidural space 211 can form an anatomical corridor for venous drainage and neural innervation of the vertebral bodies and discs.

[0105] The sinuvertebral nerve 212 can arise from the spinal nerve just distal to the dorsal root ganglion, re-enter the vertebral canal through the intervertebral foramen, and course medially within the anterior epidural space 211 along the posterior longitudinal ligament. From this position, branches of the sinuvertebral nerve 212 can penetrate the posterolateral surface of the vertebral body 208 through small nutrient canals accompanying basivertebral veins. Once inside the vertebral body 208, these branches of the sinuvertebral nerve 212 represent a basivertebral nerve 214. This basivertebral nerve 214 travels within the bony trabeculae and distributes to the vertebral marrow and endplates. Continuity can allow nociceptive and autonomic fibers from the sinuvertebral nerve 212 to innervate the vertebral body 208 itself, providing a sensory supply linked to vertebrogenic pain.

[0106] In use, in some implementations, the catheter system 10 can deliver electrical stimulation to the basivertebral nerve 214. In some cases, a clinician can navigate the catheter system 10 to a location proximate the basivertebral nerve 214 so that the inner shaft electrode 22 and the outer sheath electrode 26 are on opposite sides of the basivertebral nerve 214 within the anterior epidural space 21 1 . As depicted in FIG. 7, the outer sheath electrode 26 can be located on a first side of the basivertebral nerve 214 and the inner shaft electrode 22 can be located on a second side of the basivertebral nerve 214. As described herein, a clinician can advance the inner shaft 12 and the outer sheath 14 to a targeted tissue location proximate the basivertebral nerve 214. At this location, the clinician can adjust a position of the inner shaft electrode 22 relative the outer sheath electrode 26 by moving the inner shaft 12 relative to the outer sheath 14 until the outer sheath electrode 26 and the inner shaft electrode 22 are sufficiently placed on either side of the basivertebral nerve 214. When the outer sheath electrode 26 and the inner shaft electrode 22 are positioned adequately, the clinician can cause the catheter system 10 to deliver electrical stimulation to the basivertebral nerve 214.

[0107] Positioning the outer sheath electrode 26 and the inner shaft electrode 22 can, in some examples, involve moving the inner shaft 12 relative to the outer sheath 14 while the outer sheath 14 remains stationary, moving the outer sheath 14 relative to the inner shaftAttorney Docket No.: 07039-2336WO1 / 2023-44612 while the inner shaft 12 remains stationary', moving the inner shaft 12 and the outer sheath 14 simultaneously, or any combination thereof. As described above, positioning the outer sheath electrode 26 and the inner shaft electrode 22 can be done under imaging so that the clinician can confirm adequate placement of outer sheath electrode 26 and the inner shaft electrode 22 before delivering stimulation. The inner shaft electrode 22 and the outer sheath electrode 26 can represent a bipolar electrode system where the outer sheath electrode 26 serves as one of a cathode / anode pair and the inner shaft electrode 22 can serve as the other of the cathode / anode pair.

[0108] Because the inner shaft electrode 22 and the outer sheath electrode 26 can serve as a bipolar electrode pair, the inner shaft electrode 22 and the outer sheath electrode 26 can generate an electromagnetic field that stimulates the basivertebral nerve 214 when the inner shaft electrode 22 and the outer sheath electrode 26 are placed on either side of the basivertebral nerve 214. In the bipolar electrode system, electrons can flow from an anode and return via the anode. The inner shaft electrode 22 and the outer sheath electrode 26 can occupy a first configuration where the inner shaft electrode 22 represents a cathode and the outer sheath electrode 26 represents an anode or a second configuration where the inner shaft electrode 22 represents an anode and the outer sheath electrode 26 represents a cathode.

[0109] FIG. 8 is a flow diagram illustrating an example technique for navigating a catheter system to targeted neural tissue. For example, an inner shaft and an outer sheath of the catheter system can be advanced through vasculature of a patient simultaneously to reach targeted neural tissue (302). In this navigation, the inner shaft and the outer sheath can advance through the left ascending lumbar vein to reach the foraminal vein, where the inner shaft and outer sheath bend to enter the foraminal vein (304). The inner shaft and the outer sheath can further advance to the targeted neural tissue through the foraminal vein. The clinician can adjust the inner shaft and the outer sheath to position an inner shaft electrode and outer sheath electrode for delivering stimulation. The clinician can cause the catheter system to deliver electrical stimulation (306) when the electrodes are positioned.

[0110] Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order show n or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Moreover, the separation of various system modules and components in the embodiments described herein should not be understood as requiringAttorney Docket No.: 07039-2336WO1 / 2023-446 such separation in all embodiments, and it should be understood that the described program components and systems can generally be integrated together in a single product or packaged into multiple products.[OHl] Particular embodiments of the subject matter have been described. Other embodiments are within the scope of the following claims. For example, the actions recited in the claims can be performed in a different order and still achieve desirable results. As one example, the processes depicted in the accompanying figures do not necessarily require the particular order shown, or sequential order, to achieve desirable results. In certain implementations, multitasking and parallel processing may be advantageous.

Claims

Attorney Docket No.: 07039-2336WO1 / 2023-446CLAIMSWhat is claimed is:

1. A catheter system for delivering electrical stimulation to targeted neural tissue proximate a spinal column of a patient, the catheter system comprising: an inner shaft comprising an inner shaft electrode attached to a distal end of the inner shaft; and an outer sheath comprising an outer sheath electrode attached to a distal end of the outer sheath, the outer sheath defining a lumen sized to receive the inner shaft, wherein the inner shaft is movable within the lumen relative to the outer sheath to position the inner shaft electrode and the outer sheath electrode for delivering the electrical stimulation to the targeted neural tissue.

2. The catheter system of claim 1, wherein the outer sheath electrode is attached to an outer sheath conductor that extends along an outer surface of the outer sheath electrode in a spiral pattern, wherein the outer sheath conductor is attached to an electrical stimulation generator.

3. The catheter system of claim 2, wherein the inner shaft electrode is attached to an inner shaft conductor that extends along an interior space of the inner shaft, wherein the outer sheath conductor is attached to the electrical stimulation generator.

4. The catheter system of claim 3, further comprising the electrical stimulation generator, wherein the electrical stimulation generator is configured to: cause the inner shaft electrode and the outer sheath electrode to deliver the electrical stimulation to the targeted neural tissue, the inner shaft electrode and the outer sheath electrode representing a bipolar electrode system comprising a cathode and an anode.

5. The catheter system of claim 4, wherein the inner shaft electrode comprises an anode and the outer sheath electrode comprises a cathode.Attorney Docket No.: 07039-2336WO1 / 2023-4466. The catheter system of claim 4, wherein the inner shaft electrode comprises a cathode and the outer sheath electrode comprises an anode.

7. The catheter system of claim 3, further comprising: a Y-shaped connector having a distal opening, a first proximal opening, and a second proximal opening, wherein a proximal end of the outer sheath is connected to the distal opening of the Y-shaped connector. wherein the inner shaft is sized to fit within the first proximal opening of the Y- shaped connector, extend through the lumen defined by the outer sheath and beyond a distal opening of the outer sheath so that the inner shaft electrode extends distally from the distal opening of the outer sheath; and a shaft connected to the second proximal opening, wherein the outer sheath conductor extends through the shaft to the outer sheath and extends along the outer surface of the outer sheath in the spiral pattern.

8. The catheter system of claim 1. wherein the inner shaft and the outer sheath are sized to advance through vasculature of the patient simultaneously to the targeted neural tissue, wherein the inner shaft is slidable within the lumen defined by the outer sheath to advance distally from a distal opening of the outer sheath, increasing a distance between the inner shaft electrode and the outer sheath electrode, and wherein the inner shaft is slidable within the lumen defined by the outer sheath to withdraw proximally into a distal opening of the outer sheath, decreasing a distance between the inner shaft electrode and the outer sheath electrode.

9. The catheter system of claim 8, wherein to advance through the vasculature of the patient, the inner shaft and the outer sheath: advance through an advanced lumbar vein of the patient to reach a junction between the advanced lumbar vein and a foraminal vein; bend to navigate into the foraminal vein from the advanced lumbar vein to further advance toward the targeted neural tissue, wherein a spiral pattern of an outer sheath conductor causes the outer sheath conductor to remain attached to the outer surface of the outer sheath at the bend.Attorney Docket No.: 07039-2336WO1 / 2023-44610. The catheter system of claim 1, wherein the targeted neural tissue comprises a basivertebral nerve.

11. A medical device system comprising: one or more electrodes; and a catheter including an outer wall, wherein the one or more electrodes are disposed within the outer wall of the catheter, wherein the outer wall defines one or more openings such that the one or more electrodes can deliver electrical stimulation to a patient via the one or more openings.

12. The medical device system of claim 11, further comprising a sheath defining a lumen, wherein the catheter is slidably disposed within the lumen of the sheath.

13. The medical device system of claim 12, wherein the catheter and the sheath are configured to advance to a targeted tissues site of the patient, wherein the catheter is configured to slidably move within the lumen relative to the sheath so that a distal portion of the catheter extends beyond a distal end of the sheath, and wherein the one or more electrodes are configured to deliver the electrical stimulation to the patient via a portion of the one or more openings located on the distal portion of the catheter that extends beyond the distal end of the sheath.

14. The medical device system of claim 11, wherein each opening of the one or more openings extends along the outer wall from a proximal end to a distal end, wherein a first opening of the one or more openings corresponds to a catheter of the one or more electrodes, and wherein a second opening of the one or more openings corresponds to an anode of the one or more electrodes.

15. The medical device system of claim 14, wherein the first opening extends along the outer wall in a first spiral-shaped pattern, and wherein the second opening extends along the outer wall in a second spiral-shaped pattern.Attorney Docket No.: 07039-2336WO1 / 2023-44616. The medical device system of claim 11, wherein the one or more openings include a plurality of slits, wherein each slit of the plurality of slits is substantially perpendicular to a longitudinal axis of the catheter.

17. The medical device system of claim 16, wherein the plurality of slits correspond to a catheter of the one or more electrodes, and wherein the one or more electrodes are configured to deliver the electrical stimulation to the patient via the catheter so that the electrical stimulation returns via an anode of the one or more electrodes.

18. A medical device system comprising: a sheath defining a lumen; one or more electrodes; and a catheter including an outer wall, wherein the catheter is slidably disposed within the lumen, wherein the one or more electrodes are disposed within the outer wall of the catheter, and wherein the outer wall defines one or more openings such that the one or more electrodes can deliver electrical stimulation to a patient via the one or more openings.

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