US20220096153A1 - Catheter apparatuses for modulation of nerves in communication with the pulmonary system and associated systems and methods - Google Patents

Abstract

Devices, systems, and methods for the selective positioning of an intravascular neuromodulation device are disclosed herein. Such systems can include, for example, an elongated shaft and a therapeutic assembly carried by a distal portion of the elongated shaft. The therapeutic assembly is configured for delivery within a blood vessel. The therapeutic assembly can include a pre-formed shape and can be transformable between a substantially straight delivery configuration; and a treatment configuration having the pre-formed helical shape to position the therapeutic assembly in stable contact with a wall of the body vessel. The therapeutic assembly can also include a mechanical decoupler operably connected to the therapeutic assembly that is configured to absorb at least a portion of a force exerted on the therapeutic assembly by the shaft so that the therapeutic assembly maintains a generally stationary position relative to the target site.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
• This application claims the benefit of U.S. Provisional Application No. 62/080,189, filed Nov. 14, 2014, U.S. Provisional Application No. 62/080,248, filed Nov. 14, 2014, and U.S. Provisional Application No. 62/082,638, filed Nov. 21, 2014, all of which are incorporated herein by reference in their entireties. Further, components and features of embodiments disclosed in the applications incorporated by reference may be combined with various components and features disclosed and claimed in the present application.
TECHNICAL FIELD
• The present technology relates generally to modulation of nerves that communicate with the pulmonary system (e.g., pulmonary neuromodulation or “PN”) and associated systems and methods. In particular, several embodiments are directed to radio frequency (“RF”) ablation catheter apparatuses for intravascular modulation of nerves that communicate with the pulmonary system and associated systems and methods.
BACKGROUND
• Pulmonary hypertension is an increase in blood pressure in the pulmonary vasculature. When portions of the pulmonary vasculature are narrowed, blocked, or destroyed, it becomes harder for blood to flow through the lungs. As a result, pressure within the lungs increases and makes it hard for the heart to push blood through the pulmonary arteries and into the lungs, thereby causing the pressure in the arteries to rise. Also, because the heart is working harder than normal, the right ventricle becomes strained and weak, which can lead to heart failure. While there are pharmacologic strategies to treat pulmonary hypertension, there is no curative therapy other than lung transplantation. Thus, there is a strong public-health need for alternative treatment strategies.
BRIEF DESCRIPTION OF THE DRAWINGS
• Many aspects of the present technology can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale. Instead, emphasis is placed on illustrating clearly the principles of the present technology.
• FIG. 1 is a partially-schematic view of a neuromodulation system configured in accordance with an embodiment of the present technology.
• FIG. 2A is an enlarged side view illustrating a therapeutic assembly of the catheter ofFIG. 1 in a low-profile configuration configured in accordance with an embodiment of the present technology.
• FIG. 2B is a further enlarged cut-away view of a portion of the therapeutic assembly ofFIG. 2A configured in accordance with an embodiment of the present technology.
• FIG. 2C is a cross-sectional end view taken alongline2C-2C inFIG. 2A.
• FIG. 3A is an illustrative cross-sectional anatomical front view showing the advancement of the catheter shown inFIG. 1 along an intravascular path in accordance with an embodiment of the present technology.
• FIG. 3B is a side view of the therapeutic assembly shown inFIG. 2A within the main pulmonary artery in a low-profile configuration configured in accordance with an embodiment of the present technology.
• FIG. 3C is a side view of the therapeutic assembly shown inFIG. 2A within the main pulmonary artery in a deployed configuration configured in accordance with an embodiment of the present technology.
• FIG. 3D is a side view of the therapeutic assembly shown inFIG. 2A within the left pulmonary artery in a deployed configuration configured in accordance with an embodiment of the present technology.
• FIG. 3E is a side view of the therapeutic assembly shown inFIG. 2A within the right pulmonary artery in a deployed configuration configured in accordance with an embodiment of the present technology.
• FIG. 4 is an illustrative cross-sectional anatomical front view showing the advancement of the catheter shown inFIG. 1 along another intravascular path in accordance with an embodiment of the present technology.
• FIG. 5 is a side view of a therapeutic assembly having a single wire electrode configured in accordance with an embodiment of the present technology.
• FIGS. 6A-6B are schematic representations illustrating rotational directions of the therapeutic assembly as noted by opposite arrow directions.
• FIG. 7 is a schematic side view of a catheter having an inner sheath configured in accordance with an embodiment of the present technology.
• FIGS. 8A-8B are side views of a catheter having an inner sheath positioned within the left pulmonary artery configured in accordance with an embodiment of the present technology.
• FIG. 9 is a side view of a therapeutic assembly in a deployed configuration having an anchoring device positioned within the left pulmonary artery configured in accordance with an embodiment of the present technology.
• FIG. 10 is a side view of a therapeutic assembly in a deployed configuration having an anchoring device positioned within the left pulmonary artery configured in accordance with an embodiment of the present technology.
• FIG. 11 is a side view of a therapeutic assembly having an anchoring device (shown in cross-section) within the right pulmonary artery in a deployed configuration configured in accordance with an embodiment of the present technology.
• FIG. 12 is a side view of a therapeutic assembly having an anchoring device within the right pulmonary artery in a deployed configuration configured in accordance with an embodiment of the present technology.
• FIG. 13 is a side view of a therapeutic assembly having an extendable shaft within the left pulmonary artery in a deployed configuration configured in accordance with an embodiment of the present technology.
• FIG. 14 is a side view of a therapeutic assembly mechanically isolated from the shaft within the right pulmonary artery in a deployed configuration configured in accordance with an embodiment of the present technology.
• FIG. 15 is a side view of therapeutic assemblies in a deployed configuration configured in accordance with an embodiment of the present technology.
• FIG. 16 is a side view of a therapeutic assembly having an inflection section in a deployed configuration configured in accordance with an embodiment of the present technology.
• FIG. 17A is a side view of a catheter in a low-profile state configured in accordance with an embodiment of the present technology. A few exemplary deployed states are shown in phantom lines for purposes of illustration.
• FIG. 17B is an enlarged side view of a portion of the distal portion of the catheter ofFIG. 17A in a low-profile state configured in accordance with an embodiment of the present technology.
• FIG. 17C is a cross-sectional end view of the shaft shown inFIG. 17B taken along theline17C-17C.
• FIG. 18A is a perspective view of a distal portion of a catheter in a low-profile state configured in accordance with an embodiment of the present technology.
• FIG. 18B is an isolated, enlarged view of the treatment member ofFIG. 18A configured in accordance with an embodiment of the present technology.
• FIG. 18C is a side view of the distal portion of the catheter shown inFIG. 18A in a low-profile state configured in accordance with an embodiment of the present technology.
• FIG. 18D is a side view of the distal portion of the catheter shown inFIG. 18A in a deployed state configured in accordance with an embodiment of the present technology.
• FIG. 19 is a schematic representation of a magnetically-deformable catheter system configured in accordance with an embodiment of the present technology.
• FIG. 20 is a cross-sectional end view of a non-occlusive catheter system shown deployed in a vessel and configured in accordance with an embodiment of the present technology.
• FIG. 21 is a cross-sectional end view of a non-occlusive catheter system shown deployed in a vessel and configured in accordance with another embodiment of the present technology.
• FIG. 22A is an enlarged isometric view of a therapeutic assembly configured in accordance with an embodiment of the present technology.
• FIG. 22B is an enlarged partially schematic view of a distal portion of a treatment device within a blood vessel in accordance with an embodiment of the present technology.
• FIG. 23A is an enlarged isometric view of an electrode assembly configured in accordance with another embodiment of the present technology.
• FIG. 23B is an enlarged partially schematic view of a distal portion of a treatment device within a blood vessel in accordance with another embodiment of the present technology.
• FIG. 23C is an enlarged partially schematic view of a distal portion of a treatment device within a blood vessel in accordance with yet another embodiment of the present technology.
• FIG. 24 is an enlarged partially schematic side view of a distal portion of a treatment device within a blood vessel in accordance with a further embodiment of the present technology.
• FIG. 25 is an enlarged side view of a distal portion of a treatment device within a blood vessel in accordance with yet another embodiment of the present technology.
• FIG. 26 is an enlarged side view of a distal portion of a treatment device within a blood vessel in accordance with a further embodiment of the present technology.
• FIG. 27 is an enlarged side view of a distal portion of a treatment device within a blood vessel in accordance with an additional embodiment of the present technology.
• FIG. 28 is a block diagram illustrating a method of endovascularly monitoring nerve activity in accordance with an embodiment of the present technology.
• FIG. 29 is a block diagram illustrating a method of endovascularly monitoring nerve activity in accordance with another embodiment of the present technology.
DETAILED DESCRIPTION
• The present technology is directed to neuromodulation devices and associated systems and methods. Some embodiments of the present technology, for example, are directed to catheters and associated systems and methods for pulmonary neuromodulation (“PN”). Specific details of several embodiments of the technology are described below with reference toFIGS. 1-29. PN is the partial or complete incapacitation or otherwise effective disruption of nerves that communicate with the pulmonary system. For example, PN may inhibit, reduce, and/or block neural communication along neural fibers (i.e., efferent and/or afferent nerve fibers) innervating the pulmonary vessels. Such incapacitation can be long-term (e.g., permanent or for periods of months, years, or decades) or short-term (e.g., for periods of minutes, hours, days, or weeks). PN is expected to efficaciously treat pulmonary hypertension. Subjects with pulmonary hypertension generally have high blood pressure in the lung vasculature that may lead to heart failure and they may, for example, experience symptoms such as dyspnea (shortness of breath), syncope, fatigue, chest pain and/or edema, and/or other symptoms as well. PN using methods and/or devices described herein may provide a therapeutically beneficial reduction in one or more of these symptoms. Additionally, PN using the methods and/or devices of the present technology may modulate the release of circulating mediators of the nervous system (e.g., the sympathetic nervous system) and/or neuroendocrine system, thereby providing systemic modulation of such mediators and/or modulating the function of specific body organs other than the lungs. For example, the lungs produce significant quantities of catecholamines that affect heart rate, blood pressure, blood glucose levels, etc., and PN using the methods and/or devices of the present technology may increase or decrease the amount of catecholamines released from the lungs.
• The catheters, systems and methods of the present technology may effect PN in and/or near one or more pulmonary vessels. As used herein, “pulmonary vessel(s)” include any blood vessel that is adjacent to and/or provides intravascular access proximate to neural pathways that communicate with the pulmonary system. For example, pulmonary vessels can include pulmonary veins and pulmonary arteries, such as the main pulmonary artery (“MPA”), the bifurcated portion of the pulmonary artery, the right pulmonary artery (“RPA”), the left pulmonary artery (“LPA”), segmental pulmonary arteries, and sub-segmental pulmonary arteries. Other non-limiting examples of pulmonary vessels include the right ventricular outflow tract, pulmonary arterioles, and/or any branch and/or extension of any of the pulmonary vessels described above. In some embodiments, the catheters, systems and methods of the present technology may effect PN in and/or near one or more pulmonary arteries (pulmonary arterial neuromodulation or “PAN”). For example, the present technology may effect neuromodulation at a distal portion of the MPA and/or in one or more branches (e.g., distal branches) of the MPA. In certain embodiments, the present technology may effect neuromodulation at or near the pulmonary valve (e.g., to affect nerves above and/or below the pulmonary valve).
• As used herein, the terms “distal” and “proximal” define a position or direction with respect to the treating clinician or clinician's control device (e.g., a handle assembly). “Distal” or “distally” are a position distant from or in a direction away from the clinician or the clinician's control device. “Proximal” and “proximally” are a position near or in a direction toward the clinician or clinician's control device.
• It is typically advantageous to at least generally maintain the position of a neuromodulation unit relative to the surrounding anatomy during a neuromodulation treatment. For example, it can be advantageous to at least generally maintain stable contact between a therapeutic element of a neuromodulation unit and an inner wall of a body lumen (e.g., a blood vessel, a duct, an airway, or another naturally occurring lumen within the human body) during a neuromodulation treatment. In an alternative embodiment, it may be advantageous to maintain the position of the therapeutic element at the center of the vessel lumen or in some cases, offset from the center of the vessel lumen by a particular distance. This can enhance control and/or monitoring of the treatment, reduce trauma to the body lumen, and/or have other advantages. In some cases, at least generally maintaining the position of a neuromodulation unit relative to the target anatomy during a neuromodulation treatment can be challenging. For example, certain organs and/or body tissues may move in response to respiration, cardiac contraction and relaxation, peristaltic movement within blood vessels, and patient movement. Such movement of organs and other tissues in a patient's body can cause movement of a catheter shaft within a vessel or other disadvantageous relative movement between a neuromodulation unit connected to the shaft and the anatomy at a target site. Moreover, it may be challenging to maintain a device at the target site. For example, a pulmonary artery may generally be tapered, which can make it difficult to securely deploy certain device configurations in that location.
• Another difficulty may exist with respect to initial positioning of a neuromodulation unit. When a neuromodulation unit is initially positioned at a treatment location within a pulmonary vessel or other body lumen (e.g., a renal vessel), the position of the neuromodulation unit may be suboptimal. For example, a catheter and/or a sheath carrying the catheter may be insufficiently flexible to match the curvature of anatomy near the treatment location (e.g., the curvature of a pulmonary artery between the MPA and the RPA and/or LPA). This may cause the catheter and/or the sheath to enter the body lumen out of alignment with a longitudinal dimension or other feature of the body lumen. When a neuromodulation unit of a misaligned catheter is initially moved into an expanded form, the neuromodulation unit may also be misaligned with the body lumen. When a neuromodulation unit is misaligned, one or more therapeutic elements of the neuromodulation unit may be out of contact or in poor contact with an inner wall of a body lumen, thereby resulting in suboptimal (or no) energy delivery to a target site. Even when the neuromodulation unit is sufficiently well aligned for treatment to begin, misalignment and migration may occur later and disturb the wall contact, potentially requiring the treatment to be aborted. Correcting misalignment of a neuromodulation unit can be challenging when the neuromodulation unit remains directly attached to an associated shaft trapped at a sharp turn.
I. Selected Embodiments of Catheter Apparatuses
• FIG. 1 is partially-schematic diagram illustrating a pulmonary neuromodulation system100 (“system100”) configured in accordance with an embodiment of the present technology. Thesystem100 includes anintravascular catheter110 operably coupled to an energy source orenergy generator132 via a connector130 (e.g., a cable). Thecatheter110 can include anelongated shaft116 having aproximal portion114 and adistal portion118. Thecatheter110 also includes ahandle assembly112 at theproximal portion114. Thecatheter110 can further include atherapeutic assembly104 carried by or affixed to thedistal portion118 of theelongated shaft116, and thetherapeutic assembly104 can have one or moreenergy delivery elements106 configured to modulate nerves at or near the treatment location. Theelongated shaft116 can be configured to intravascularly locate thetherapeutic assembly104 at a treatment location within a pulmonary artery, renal artery, or other blood vessel, or in a non-vascular delivery, such as through the esophagus, a bronchus, or another naturally occurring body lumen of a human patient (for example, via a natural orifice transluminal endoscopic surgery (NOTES) procedure). In certain embodiments, an extracorporeal approach may be employed, such as by using extracorporeal ultrasound.
• Theenergy generator132 can be configured to generate a selected form and/or magnitude of energy for delivery to the treatment site via theenergy delivery elements106 of thetherapeutic assembly104. For example, theenergy generator132 can include an energy source (not shown) configured to generate RF energy (e.g., monopolar and/or bipolar, pulsed and/or non-pulsed, intravascular or extravascular, etc.), microwave energy, optical energy, ultrasound energy (e.g., intravascularly delivered ultrasound, extracorporeal ultrasound, high-intensity focused ultrasound (HIFU), etc.), direct heat energy, radiation (e.g., infrared, visible, gamma, etc.), or another suitable type of energy. For embodiments having multiple independentenergy delivery elements106, energy can be delivered to all or a portion of theenergy delivery elements106 simultaneously or at different times. Different firing sequences may be used, as appropriate. As an example, a single energy delivery element may be selected at a time, or a combination of certain energy delivery elements or all of the energy delivery elements may be selected at a time. Energy delivery elements may be fired sequentially or simultaneously and/or may be fired according to a particular algorithm and/or operator input. In some embodiments, thetherapeutic assembly104 and/orenergy delivery elements106 can be configured for use with a source of cryotherapeutic energy, and/or for use with a source of one or more chemicals, such as drugs or other agents (e.g., to provide the cryotherapeutic energy and/or chemical(s) to a target site for PN). It is believed that cryotherapeutic energy, for example, may be especially effective for PN, where air within the lungs may function as an insulator. Cryotherapeutic energy may provide a relatively deep and/or uniform freezing of tissue.
• In some embodiments, instead of or in addition to theenergy delivery elements106, thetherapeutic assembly104 can include one or more substance delivery features (e.g., ports) to produce chemically based neuromodulation by delivering one or more chemicals (e.g., guanethidine, one or more alcohols (e.g., ethanol), phenol, a neurotoxin (e.g., vincristine)), and/or other suitable agents selected to alter, damage, or disrupt nerves. Additionally, in some embodiments the substance delivery features can be configured to deliver one or more pain management agents (e.g., an anesthetic agent) to the treatment site and/or one or more substances that enhance or otherwise control energy delivered by one or moreenergy delivery element106 and/or effect nerve sensitivity or activation. For example, in some embodiments thetherapeutic assembly104 can include one or more puncture or piercing elements such as needles (not shown) having one or more inlet ports. The puncture or piercing elements can be configured, when deployed, to extend from thetherapeutic assembly104 into the vessel wall at the treatment site to deliver one or more chemicals. In some embodiments, one or more puncture or piercing elements may be deployed and/or positioned using x-ray fluoroscopy. In certain embodiments, thetherapeutic assembly104 can include at least one expandable element (not shown), such as a balloon, a basket, or a wire cage, that is configured to carry one or more chemicals and release the chemical(s) once the expandable element is expanded and in apposition with the vessel wall. For example, in some embodiments a radially exterior surface of the expandable element can be coated with selected chemical(s). In yet other embodiments, the expandable element can be configured to release the chemical(s) from an interior portion of the expandable element when submitted to a predetermined force threshold (e.g., radial forces exerted by the vessel walls).
• Furthermore, theenergy generator132 can be configured to control, monitor, supply, or otherwise support operation of thecatheter110. For example, a control mechanism, such asfoot pedal144, may be connected (e.g., pneumatically connected or electrically connected) to theenergy generator132 to allow an operator to initiate, terminate and/or adjust various operational characteristics of the energy generator, such as power delivery. In some embodiments, theenergy generator132 may be configured to provide delivery of a monopolar electric field via the energy delivery element(s)106. In such embodiments, one or more neutral ordispersive electrode142 may be electrically connected to theenergy generator132 and selectively positioned at a location within the patient's body (e.g., at, near, or within the esophagus, a bronchus, etc.) and/or attached to the exterior of the patient (not shown). Thedispersive electrode142 can be positioned to direct the applied electric field in a particular direction and/or towards or away from a particular anatomical location. Also, it can be advantageous to position the dispersive electrode such that it does not interfere with the line of sight of the imaging device.
• In some embodiments, thesystem100 includes a remote control device (not shown) that can be configured to be sterilized to facilitate its use within a sterile field. The remote control device can be configured to control operation of thetherapeutic assembly104, theenergy generator132, and/or other suitable components of thesystem100. For example, the remote control device can be configured to allow for selective activation of thetherapeutic assembly104. In other embodiments, the remote control device may be omitted and its functionality may be incorporated into thehandle112 orenergy generator132.
• As shown inFIG. 1, theenergy generator132 can further include an indicator ordisplay screen136. Theenergy generator132 can include other indicators, including one or more LEDs, a device configured to produce an audible indication, and/or other suitable communicative devices. In the embodiment shown inFIG. 1, thedisplay136 includes a user interface configured to receive information or instructions from a user and/or provide feedback to the user. For example, theenergy generator132 can be configured to provide feedback to an operator before, during, and/or after a treatment procedure via thedisplay136. The feedback can be based on output from one or more sensors (not shown) associated with thetherapeutic assembly104 such as temperature sensor(s), impedance sensor(s), current sensor(s), voltage sensor(s), flow sensor(s), chemical sensor(s), ultrasound sensor(s), optical sensor(s), pressure sensor(s) and/or other sensing or monitoring devices. In some embodiments, the sensors can be used to monitor or detect the presence or location of target neural structures and/or assess the extent or efficacy of the treatment, as discussed in greater detail below with reference toFIGS. 22-29.
• Thesystem100 can further include acontroller146 having, for example, memory (not shown) and processing circuitry (not shown). The memory and storage devices are computer-readable storage media that may be encoded with non-transitory, computer-executable instructions such as diagnostic algorithm(s)133, control algorithm(s)140, and/or evaluation/feedback algorithm(s)138. Thecontrol algorithms140 can be executed on a processor (not shown) of thesystem100 to control energy delivery to theenergy delivery elements106. In some embodiments, selection of one or more parameters of anautomated control algorithm140 for a particular patient may be guided bydiagnostic algorithms133 that measure and evaluate one or more operating parameters prior to energy delivery. Thediagnostic algorithms133 provide patient-specific feedback to the clinician prior to activating theenergy delivery elements106 which can be used to select anappropriate control algorithm140 and/or modify thecontrol algorithm140 to increase the likelihood of efficacious neuromodulation.
• Although in the embodiment shown inFIG. 1 thecontroller146 is incorporated into theenergy generator132, in other embodiments thecontroller146 may be a separate component distinct from theenergy generator132. For example, additionally or alternatively, thecontroller146 can be a personal computer(s), server computer(s), handheld or laptop device(s), multiprocessor system(s), microprocessor-based system(s), programmable consumer electronic(s), digital camera(s), network PC(s), minicomputer(s), mainframe computer(s), and/or any suitable computing environment.
• In some embodiments, theenergy source132 may include apump150 or other suitable pressure source (e.g., a syringe) operably coupled to an irrigation port (not shown) at thedistal portion118 of thecatheter110. In other embodiments, thepump150 can be a standalone device separate from theenergy source132. Positive pressure generated by thepump150 can be used, for example, to push a protective agent (e.g., saline) through the irrigation port to the treatment site. In yet other embodiments, thecatheter110 can include an adapter (not shown) (e.g., a luer lock) configured to be operably coupled to a syringe (not shown) and the syringe can be used to apply pressure to theshaft116. In a particular embodiment, thepump150 or other suitable pressure source can be configured to push one or more of the aforementioned deliverable agents through the irrigation port to the treatment site (e.g., chemically-based neuromodulation agents, pain management agents, energy-enhancement/control agents, agents that affect nerve sensitivity or activation, etc.).
• FIG. 2A is a side view of thetherapeutic assembly104 in a low-profile or delivery state in accordance with an embodiment of the present technology. Aproximal region208 of thetherapeutic assembly104 can be carried by or affixed to thedistal portion118 of theelongated shaft116. For example, all or a portion (e.g., a proximal portion) of thetherapeutic assembly104 can be an integral extension of theshaft116. Adistal region206 of thetherapeutic assembly104 may terminate distally with, for example, an atraumatic, flexiblecurved tip214 having anopening212 at its distal end. In some embodiments, thedistal region206 of thetherapeutic assembly104 may also be configured to engage another element of thesystem100 orcatheter110.
• FIG. 2B is an enlarged view of a portion of thetherapeutic assembly104 ofFIG. 2A, andFIG. 2C is a cross-sectional end view taken alongline2C-2C inFIG. 2A. Referring toFIGS. 2A-2C together, thetherapeutic assembly104 can include the one or moreenergy delivery elements106 carried by a helical/spiral-shapedsupport structure210. The helical/spiral support structure210 can have one or more turns (e.g., two turns, etc.). Theenergy delivery elements106 can be RF electrodes, ultrasound transducers, cryotherapeutic cooling assemblies, direct heat elements or other therapeutic delivery elements. Theenergy delivery elements106, for example, can be separate band electrodes axially spaced apart along the support structure210 (e.g., adhesively bonded, welded (e.g., laser bonded) or bonded by mechanical interference to thesupport structure210 at different positions along the length of the support structure210). In other embodiments, thetherapeutic assembly104 may have a singleenergy delivery element106 at or near thedistal portion118 of theshaft116.
• In embodiments including where thesupport structure210 includes more than oneenergy delivery element106, thesupport structure210 can include, for example, between 1 and 12 energy delivery elements (e.g., 1 energy delivery element, 4 energy delivery elements, 10 energy delivery elements, 12 energy delivery elements, etc.). In particular embodiments, thetherapeutic assembly104 can include an even number ofenergy delivery elements106. In some embodiments, theenergy delivery elements106 can be spaced apart along thesupport structure210 every 1 mm to 50 mm, such as every 2 mm to every 15 mm (e.g., every 10 mm, etc.). In the deployed configuration, thesupport structure210 and/ortherapeutic assembly104 can have an outer diameter between about 12 mm and about 20 mm (e.g., between about 15 mm and about 18 mm). Additionally, thesupport structure210 andenergy delivery elements106 can be configured for delivery within a guide catheter between 5 Fr and 9 Fr. In other examples, other suitable guide catheters may be used, and outer dimensions and/or arrangements of thecatheter110 can vary accordingly.
• In some embodiments, theenergy delivery elements106 are formed from a metal, such as gold, platinum, alloys of platinum and iridium or other suitable electrically conductive materials. The number, arrangement, shape (e.g., spiral and/or coil electrodes) and/or composition of theenergy delivery elements106 may vary. Each of the individualenergy delivery elements106 can be electrically connected to theenergy generator132 by a conductor or bifilar wire300 (FIG. 2C) extending through a lumen302 (FIG. 2C) of theshaft116 and/orsupport structure210. For example, the individualenergy delivery elements106 may be welded or otherwise electrically coupled to correspondingenergy supply wires300, and thewires300 can extend through theelongated shaft116 for the entire length of theshaft116 such that proximal ends of thewires300 are coupled to thehandle112 and/or to theenergy generator132.
• In a particular embodiment, thecatheter110 can include an electrical element211 (FIG. 2A) positioned along theshaft116 between theenergy delivery elements106 and the proximal portion of theshaft116. Theelectrical element211 can be electrically coupled to theenergy delivery elements106 via their respectivebifilar wires300. Thecatheter110 can include an additional bifilar wire (not shown) that electrically couples theelectrical element211 and theenergy generator132. The additional bifilar wire, for example, can extend proximally from theelectrical element211 through theshaft116 such that the proximal end of the wire is coupled to thehandle112 and/or to thegenerator132. In some embodiments, theelectrical element211 can include an analog-to-digital converter configured to receive an analog signal from theenergy generator132 and transmit a digital signal to theenergy delivery elements106. Use of an analog-to-digital converter can be advantageous because, unlike analog signals, digital signals are not susceptible to interference. In these and other embodiments, theelectrical element211 can include a multiplexer configured to independently transmit signals to and/or from one or more of the energy delivery elements. As discussed below with respect to sensing neural activity at the target nerves, neural activity from the target nerves sensed by thecatheter110—for example, by contacts (e.g., the energy delivery elements) at the distal portion of theshaft116—can be digitized and similarly processed by the multiplexer and transmitted optionally through theshaft116. Including a multiplexer in thecatheter110 may, in some embodiments, allow for sensing of clean signals from nerves. Neural signals may be generated using stimulation or may, in some cases, not be generated using stimulation. Devices described herein (e.g., devices including hard-wired catheter electrodes and/or a multiplexer) may be used to sense with or without stimulating.
• As shown in the enlarged cut-away view ofFIG. 2B, thesupport structure210 can be a tube (e.g., a flexible tube) and thetherapeutic assembly104 can include apre-shaped control member220 positioned within the tube. Upon deployment, thecontrol member220 can form at least a portion of thetherapeutic assembly104 into a deployed state (FIG. 3C-3E). For example, thecontrol member220 can have a pre-set configuration that gives at least a portion of the therapeutic assembly104 a helical/spiral configuration in the deployed state (FIG. 3C-3E). In some embodiments, thecontrol member220 includes a tubular structure comprising a Nitinol multifilar stranded wire with alumen222 therethrough and sold under the trademark HELICAL HOLLOW STRAND™ (HHS), and commercially available from Fort Wayne Metals of Fort Wayne, Ind. Thelumen222 can define a passageway for receiving a guide wire (not shown) that extends proximally from the opening212 (FIG. 2A) at thetip214 of thetherapeutic assembly104. In other embodiments, thecontrol member220 may be composed of different materials and/or have a different configuration. For example, thecontrol member220 may be formed from nickel-titanium (Nitinol), shape memory polymers, electro-active polymers or other suitable shape memory materials that are pre-formed or pre-shaped into the desired deployed state. Alternatively, thecontrol member220 may be formed from multiple materials such as a composite of one or more polymers and metals.
• As shown inFIG. 2C, thesupport structure210 can be configured to fit tightly against thecontrol member220 and/orwires300 to reduce space between an inner portion of thesupport structure210 and the components positioned therein. For example, thecontrol member220 and the inner wall of thesupport structure210 can be in intimate contact such that there is little or no space between thecontrol member220 and thesupport structure210. Such an arrangement can help to reduce or prevent the formation of wrinkles in thetherapeutic assembly104 during deployment. Thesupport structure210 may be composed of one or more polymer materials such as polyamide, polyimide, polyether block amide copolymer sold under the trademark PEBAX®, polyethylene terephthalate (PET), polypropylene, aliphatic, polycarbonate-based thermoplastic polyurethane sold under the trademark CARBOTHANE®, ELASTHANE™ TPU, a polyether ether ketone (PEEK) polymer, or another suitable material that provides sufficient flexibility to thesupport structure210.
• In some embodiments, when thetherapeutic assembly104 and/orsupport structure210 is in deployed configuration, thetherapeutic assembly104 and/orsupport structure210 preferably define a minimum width of greater than or equal to approximately 0.040 inches. Additionally, thesupport structure210 andenergy delivery elements106 are configured for delivery within a guide catheter no smaller than a 5 French guide catheter. In other examples, other suitable guide catheters may be used, and outer dimensions and/or arrangements of thecatheter110 can vary accordingly.
• Referring toFIG. 2A, thecurved tip214 can be configured to provide an exit (e.g., via the opening212) for a guide wire that directs the guide wire away from a wall of a vessel or lumen at or near a treatment location. As a result, thecurved tip214 can facilitate alignment of thetherapeutic assembly104 in the vessel or lumen as it expands from the delivery state shown inFIG. 2A. Furthermore, thecurved tip214 can reduce the risk of injuring a wall of the vessel or lumen when a distal end of a guide wire is advanced from theopening212. The curvature of thetip214 can be varied depending upon the particular sizing/configuration of thetherapeutic assembly104 and/or anatomy at a treatment location. In some embodiments, thetip214 may also comprise a radiopaque marker and/or one or more sensors (not shown) positioned anywhere along the length of thetip214. For example, in some embodiments, thetip214 can include one or more layers of material (e.g., the same or different materials) and the radiopaque marker can be sandwiched between two or more layers. Alternatively, the radiopaque marker can be soldered, glued, laminated, or mechanically locked to the exterior surface of thetip214. In other embodiments, theentire tip214 or a portion of thetip214 can be made of or include a radiopaque material and/or thetip214 can be coated with a radiopaque material. Thetip214 can be affixed to the distal end of thesupport structure210 via adhesive, crimping, over-molding, or other suitable techniques.
• The flexiblecurved tip214 can be made from a polymer material (e.g., polyether block amide copolymer sold under the trademark PEBAX™), a thermoplastic polyether urethane material (e.g., sold under the trademarks ELASTHANE™ or PELLETHANE®), or other suitable materials having the desired properties, including a selected durometer. As noted above, thetip214 is configured to provide an opening for the guide wire, and it is desirable that the tip itself maintain a desired shape/configuration during operation. Accordingly, in some embodiments, one or more additional materials may be added to the tip material to help improve tip shape retention. In one particular embodiment, for example, about 5 to 30 weight percent of siloxane can be blended with the tip material (e.g., the thermoplastic polyether urethane material), and electron beam or gamma irradiation may be used to induce cross-linking of the materials. In other embodiments, thetip214 may be formed from different material(s) and/or have a different arrangement. For example, in some embodiments thetip214 may be straight.
• In some embodiments, thedistal portion118 of the catheter can include one or more irrigation ports (not shown) configured to emit one or more protective agents (e.g., saline) before, during, and/or after energy delivery to cool the energy delivery elements and surrounding tissue. The irrigation port(s) may be located anywhere along thesupport structure210 and/ordistal portion118 of theshaft116. The irrigation port(s) can be in fluid connection with one or more corresponding irrigation lumens that extends proximally along theshaft116 from the irrigation port to thehandle112 and/orenergy generator132. In some embodiments, the catheter can include multiple irrigation ports, all in fluid communication with a corresponding irrigation lumen. In particular embodiments, an irrigation lumen can be coupled to a pump150 (seeFIG. 1) or syringe (not shown) to facilitate conveyance of the protective agent along the irrigation lumen and irrigation of protective agent through the irrigation port(s).
II. Selected Delivery Embodiments
• Referring toFIG. 3A, intravascular delivery of thetherapeutic assembly104 can include percutaneously inserting aguide wire115 within the vasculature at an access site (e.g., femoral (FIG. 3A), brachial, radial, axillary, jugular (seeFIG. 4) or subclavian arteries or veins) and progressing the guidewire to the MPA. The lumen222 (FIG. 2C) of theshaft116 and/ortherapeutic assembly104 can be configured to receive aguide wire115 in an over-the-wire or rapid exchange configuration. As shown inFIG. 3B, theshaft116 and the therapeutic assembly104 (in the delivery state) can then be advanced along theguide wire115 until at least a portion of thetherapeutic assembly104 reaches the treatment location. As illustrated inFIGS. 3A and 4, a section of theproximal portion114 of theshaft116 can be extracorporeally positioned and manipulated by the operator (e.g., via theactuator128 shown inFIG. 1) to advance theshaft116 through the intravascular path and remotely manipulate thedistal portion118 of theshaft116.
• Image guidance, e.g., computed tomography (CT), fluoroscopy, intravascular ultrasound (IVUS), optical coherence tomography (OCT), intracardiac echocardiography (ICE), or another suitable guidance modality, or combinations thereof, may be used to aid the clinician's positioning and manipulation of thetherapeutic assembly104. For example, a fluoroscopy system (e.g., including a flat-panel detector, x-ray, or c-arm) can be rotated to accurately visualize and identify the treatment site. In other embodiments, the treatment site can be located using IVUS, OCT, and/or other suitable image mapping modalities that can correlate the treatment site with an identifiable anatomical structure (e.g., a spinal feature) and/or a radiopaque ruler (e.g., positioned under or on the patient) before delivering thecatheter110. Further, in some embodiments, image guidance components (e.g., IVUS, OCT) may be integrated with thecatheter110 and/or run in parallel with thecatheter110 to provide image guidance during positioning of thetherapeutic assembly104. For example, such image guidance components can be coupled to a distal portion of thecatheter110 to provide three-dimensional images of the vasculature proximate the site to facilitate positioning or deploying thetherapeutic assembly104 within the pulmonary blood vessel.
• Once thetherapeutic assembly104 is positioned at a treatment location within a pulmonary artery, theguide wire115 can be at least partially removed (e.g., withdrawn) from or introduced (e.g., inserted) into thetherapeutic assembly104 to transform or otherwise move thetherapeutic assembly104 to a deployed configuration.FIG. 3C is a side view of thetherapeutic assembly104 shown inFIG. 2A within the main pulmonary artery in a deployed configuration,FIG. 3D is a side view of thetherapeutic assembly104 within the left pulmonary artery, andFIG. 3E is a side view of thetherapeutic assembly104 within the right pulmonary artery in accordance with an embodiment of the present technology. As shown inFIGS. 3C-3E, in the deployed state, at least a portion of thetherapeutic assembly104 can be configured to contact an inner wall of a pulmonary artery and to cause a fully-circumferential lesion without the need for repositioning. For example, thetherapeutic assembly104 can be configured to form a continuous or discontinuous lesion that is fully-circumferential within a single plane perpendicular to the longitudinal axis of the vessel (see, for example,FIG. 23A). In other embodiments, thetherapeutic assembly104 can be configured to form a continuous or discontinuous lesion that wraps around the circumference of the vessel (one or more times) along a particular length of the vessel (e.g., generally non-circumferential at longitudinal segments of the treatment location). In several of such embodiments, the lesion can have a helical/spiral configuration. This can facilitate precise and efficient treatment with a low possibility of vessel stenosis. In other embodiments, thetherapeutic assembly104 can be configured to form a partially-circumferential lesion or a fully-circumferential lesion at a single longitudinal segment of the treatment location. In some embodiments, thetherapeutic assembly104 can be configured to cause therapeutically-effective neuromodulation (e.g., using ultrasound energy) without contacting a vessel wall.
• As shown inFIGS. 3C-3E, in the deployed state, thetherapeutic assembly104 defines a substantially helical/spiral structure in contact with the pulmonary artery wall along a helical/spiral path. One advantage of this arrangement is that pressure from the helical/spiral structure can be applied to a large range of radial directions without applying pressure to a circumference of the pulmonary vessel. Thus, the spiral/helically-shapedtherapeutic assembly104 is expected to provide stable contact between theenergy delivery elements106 and the pulmonary vessel wall when the wall moves in any direction. Furthermore, pressure applied to the pulmonary vessel wall along a helical/spiral path is less likely to stretch or distend a circumference of a vessel that could thereby cause injury to the vessel tissue. Still another feature of the expanded helical/spiral structure is that it may contact the pulmonary vessel wall in a large range of radial directions and maintain a sufficiently open lumen in the pulmonary vessel allowing blood to flow through the helix/spiral during therapy. In other embodiments, thetherapeutic assembly104 can define a circular structure (see, for example,FIG. 23A) in contact with the pulmonary artery wall along a circular or fully-circumferential path.
• In some procedures it may be necessary to adjust the positioning of thetherapeutic assembly104 one or more times. For example, thetherapeutic assembly104 can be used to modulate nerves proximate the wall of the main pulmonary artery, the left pulmonary artery, and/or the right pulmonary artery and/or any branch or extension, and/or other pulmonary vessels or sites proximate to neural pathways in communication with the pulmonary system. Additionally, in some embodiments thetherapeutic assembly104 may be repositioned within the same pulmonary vessel or at the same site multiple times within the same procedure. After repositioning, the clinician may then re-activate thetherapeutic assembly104 to modulate the nerves.
• Often times it may be advantageous to modulate nerves and/or electrical signals at two or more locations within the body. As an example, one device may be used to modulate renal nerves, while another device is used to modulate electrical signals in the heart. As another example, pulmonary neuromodulation may be effected in one location in the body, while modulation of electrical signals may be effected in the heart (e.g., simultaneously or sequentially). In some embodiments, modulation may result in denervation of one or more of the treated locations. In certain embodiments, cardiac tissue (e.g., the right atrium of the heart) of a patient may be ablated to modulate electrical signals within the heart (e.g., preventing abnormal electrical signals from occurring), and one or more renal arteries of the patient may also be ablated to modulate nerves proximate the renal artery or renal arteries (e.g., nerves extending along the outside of the renal artery or renal arteries). The modulation of nerves and/or electrical signals may result in a reduction in clinical symptoms of pulmonary hypertension. Two or more different locations in the body may be modulated in the same procedure (at the same time or at different times) and/or in different procedures (e.g., one taking place immediately after the other has been completed, or days, weeks or months after the other has been completed). Additionally, different types of denervation may be employed in one patient.
• In some methods, mechanical devices may be used, such as a device (e.g., an implant) that modulates blood flow, creates an anastomosis, and/or affects baroreceptors. Such devices may be used alone (e.g., multiple of the same type of device in different locations), in combination with each other, and/or in combination with devices that modulate nerves and/or electrical signals.
• Although the embodiments shown inFIGS. 3C-3E show a deployedtherapeutic assembly104 in a spiral/helically-shaped configuration, in other embodiments, thetherapeutic assembly104 and/or other portions of thetherapeutic assembly104 can have other suitable shapes, sizes, and/or configurations (e.g., bent, deflected, zig-zag, Malecot, etc.). Other suitable devices and technologies are described in, for example, U.S. patent application Ser. No. 12/910,631, filed Oct. 22, 2010; U.S. patent application Ser. No. 13/279,205, filed Oct. 21, 2011; U.S. patent application Ser. No. 13/279,330, filed Oct. 23, 2011; U.S. patent application Ser. No. 13/281,360, filed Oct. 25, 2011; U.S. patent application Ser. No. 13/281,361, filed Oct. 25, 2011; PCT Application No. PCT/US11/57754, filed Oct. 25, 2011; U.S. Provisional Patent Application No. 61/646,218, filed May 5, 2012; U.S. patent application Ser. No. 13/793,647, filed Mar. 11, 2013; U.S. Provisional Patent Application No. 61/961,874, filed Oct. 24, 2013; and U.S. patent application Ser. No. 13/670,452, filed Nov. 6, 2012. All of the foregoing applications are incorporated herein by reference in their entireties. Non-limiting examples of devices and systems include the Symplicity Flex™, the Symplicity Spyral™ multielectrode RF ablation catheter, and the Arctic Front Advance™ cardiac cryoablation system.
• FIG. 5 shows another embodiment of atherapeutic assembly404 comprising a support structure410 defined by a single wire electrode406. For example, the support structure410 can be a unipolar single metal wire (e.g., Nitinol) that is pre-formed into a helical/spiral shape. The single wire electrode406 can have a continuous electrically conductive surface along all or a significant part of its length such that it forms a continuous helical lesion around a complete or nearly complete turn of the spiral/helix. In some embodiments, the wire electrode406 can have a diameter of between about 0.002 inches and about 0.010 inches (e.g., about 0.008 inches). In other embodiments, thetherapeutic assembly404 can include a “ground” electrode that is electrically insulated from the spiral at a more proximal portion of the spiral/helix (e.g., a bipolar configuration). The spiral/helix can have a constant diameter, or in other embodiments the spiral/helix can have a varying diameter. For example, spiral/helix can have a diameter that tapers in a distal direction or a proximal direction. In other embodiments, the single wire electrode has discrete dielectric coating segments that are spaced apart from each other to define discrete energy delivery elements between the dielectric coating segments. The single wire electrode can be made from a shape memory metal or other suitable material. Additionally, the control algorithm140 (FIG. 1) can be adjusted to account for the increased surface area contact of the single wire electrode406 such that sufficient ablation depths can be achieved without charring or overheating the inner wall of the vessel.
• In some embodiments, the single wire electrode406 can be delivered with the guide catheter (not shown) or an additional sheath (not shown) for precise positioning and deployment. The guide catheter (not shown) can be advanced and/or manipulated until positioned at a desired location proximate the treatment site. Thetherapeutic assembly404 can then be inserted through the guide catheter. In some embodiments, thetherapeutic assembly404 expands into a helical/spiral shape immediately once exiting a distal end of the guide catheter. In other embodiments, the single wire electrode406 can be tubular and transforms into a helical/spiral shape when a guide wire (placed therethrough) is removed in a proximal direction. In yet other embodiments, thetherapeutic assembly404 expands into a circular shape immediately once exiting a distal end of the guide catheter.
A. Rotation Devices and Methods
• As shown inFIGS. 6A and 6B, thetherapeutic assembly104 can be configured to rotate about a longitudinal axis A when advanced distally from theshaft116 or retracted proximally from theshaft116. For example, when thetherapeutic assembly104 is advanced distally, the spiral/helical structure can be rotated in a first direction, as shown by arrows D1 inFIG. 6A). Likewise, when thetherapeutic assembly104 is retracted proximally, the spiral/helical structure can rotate in a second direction, as shown by arrows D2 inFIG. 6B. Such a rotational feature can be particularly advantageous in the pulmonary vessels, since, at least at the MPA and proximal portions of the LPA and RPA, the pulmonary vessels have relatively large diameters that can require a large number of lesions to provide fully-circumferential coverage and/or effective treatment. To compensate for this, effective treatment in the pulmonary vessels can often times require multiple rotations of thetherapeutic assembly104 to reposition thetherapeutic assembly104 and achieve such a fully-circumferential lesion. Additionally, rotation of thetherapeutic assembly104 can aid in maneuvering thetherapeutic assembly104 through a turn in a vessel, such as when accessing a branch or segment of a larger vessel (e.g., accessing the LPA and RPA from the MPA).
• FIG. 7 is a side view of another embodiment of a catheter configured in accordance with the present technology. The catheter can include atherapeutic assembly604 generally similar to the previously described therapeutic assembly104 (referenced herein with respect toFIGS. 1-4). As shown inFIG. 7, the catheter includes aninner sheath617 slidably positioned within aguide catheter616 between theguide catheter616 and thetherapeutic assembly604. In certain vessels, contact forces between thetherapeutic assembly604 and the vessel wall can make it difficult to rotate thetherapeutic assembly604 distally and/or proximally. Likewise, a catheter and/or a sheath carrying the catheter may be insufficiently flexible to match the curvature of anatomy near the treatment location, such as the curvature of a pulmonary artery between the MPA and the RPA and/or LPA. This may cause the catheter and/or the sheath to enter the body lumen out of alignment with a longitudinal axis of the body lumen. Because of theinner sheath617 of the present technology, theguide catheter616 and theinner sheath617 can rotate along a central axis independently of one another. Moreover, theinner sheath617 can be sufficiently flexible to de-couple at least the therapeutic assembly604 (positioned within a relatively stable pulmonary vessel) from the catheter (e.g., the guide catheter616) positioned within or nearer to the contracting and expanding heart. This feature can be advantageous because, for example, when at least a portion of the catheter and/or shaft is positioned within the heart, theguide catheter616 often time translates the pumping movement of the heart to thetherapeutic assembly604. In addition, theinner sheath617 can also selectively position thetherapeutic assembly604 relative to the vessel wall. For example, in some embodiments it may be advantageous to position thetherapeutic assembly604 at a central location within the vessel lumen before, during, or after energy delivery.
• FIGS. 8A and 8B show examples of various deployment configurations of the catheter with theinner sheath617. As shown inFIG. 8A, theshaft616 can be advanced along the MPA just proximal to the ostium of the LPA (or RPA (not shown)). The inner sheath617 (containing the therapeutic assembly604) can then be advanced past the distal end of theshaft616 and into the LPA for deployment of thetherapeutic assembly604. As shown inFIG. 8B, in some embodiments theshaft616 can be advanced just distal of the pulmonary valve. Theinner sheath617 can then be advanced past the distal end of theshaft616, past the bifurcation, and into the LPA for deployment of thetherapeutic assembly604.
B. Anchoring Devices and Methods
• The PN systems and/or therapeutic assemblies discloses herein can include one or more anchoring devices for stabilizing the distal portion and/or therapeutic assembly relative to the vessel wall and/or selectively positioning the distal portion and/or therapeutic assembly relative to the vessel wall (e.g., at a central location within the vessel lumen, selectively offset from the center of the vessel lumen).
• FIG. 9, for example, is a side view of another embodiment of a catheter shown in the deployed configuration within the LPA in accordance with the present technology. The catheter can be generally similar to the previously describedcatheters110 or (referenced herein with respect toFIGS. 1-7A). However, as shown inFIG. 9, the catheter includes fixation members801 (shown schematically for illustrative purposes only) along at least a portion of itsshaft816 and/orinner sheath817. Thefixation members801 can be configured to contact the inner wall of the pulmonary vessel and stabilize thedistal portion818 and/ortherapeutic assembly804 with respect to the pulmonary vessel. Such stabilization can be advantageous because the pulmonary vessels constantly move as a result of the surrounding anatomy, particularly the contraction and relaxation of the heart, and also the respiratory cycle. As previously discussed, the most common intravascular approach to the pulmonary vessel involves the positioning of at least a portion of the catheter and/or shaft within the heart. As a result, the shaft translates the pumping movement of the heart to thetherapeutic assembly804. Thefixation members801 can stabilize at least thetherapeutic assembly804 within the pulmonary vessel so that movement of the catheter (e.g., the shaft816) will not affect the alignment and/or contact of thetherapeutic assembly804 and the vessel wall. In some embodiments, thefixation members801 can be atraumatic or non-tissue penetrating, and in other embodiments thefixation members801 can be tissue-penetrating (e.g., embedded in the tissue by radial force). Thefixation members801 can have any size or configuration suitable to stabilize thetherapeutic assembly804 relative to the vessel.
• FIG. 10 is a side view of another embodiment of a catheter shown in the deployed configuration within the LPA in accordance with the present technology. The catheter can include an expandableinner sheath901 that, when in the deployed configuration, expands to an outer radius generally equal to or greater than the inner radius of the vessel at the target location (e.g., a pulmonary vessel). As such, at least adistal end903 of thesheath901 can expand to engage the vessel wall thereby exerting a radially outward force against the vessel wall and stabilizing thesheath901. In some embodiments, thesheath901 can comprise an expandable stent-like structure which is collapsed in a delivery state within the elongated shaft916 and expanded to a deployed state when advanced beyond a distal end915 of the elongated shaft916. Once deployed, thesheath901 helps to mechanically isolate thetherapeutic assembly904 from the shaft916. Thesheath901 can have a generally tapered shape such that thedistal end903 of thesheath901 has a greater diameter than a proximal end (not shown). In some embodiments, at least a portion of thesheath901 can include one or more fixation members configured to engage the vessel wall.
• FIG. 11 is a side view of another embodiment of a catheter shown in the deployed configuration within the RPA in accordance with the present technology. The catheter can include aguide sheath1006 and a circumferentially grooved or threadedelongated member1010 slideably positioned therethrough. As shown inFIG. 11, theelongated member1010 can be mated with ananchor1002. Once deployed, theanchor1002 can be fixed or secured to the vessel wall by frictional force and/or fixation members (not shown) (seeFIG. 9 and accompanying description). In operation, insertion of the catheter1017 from its proximal end (not shown) causes thetherapeutic assembly1004 to rotate in a distal direction while theanchor1002 remains relatively generally stationary. In some embodiments (not shown), theanchor1002 can be fixed to theguide sheath1006.
• FIG. 12 is a side view of another embodiment of a catheter shown in the deployed configuration within the RPA in accordance with the present technology. The catheter can include anexpandable anchor1101 configured to expand against at least a portion of the vessel wall and secure the therapeutic assembly1104 relative to the local anatomy. For example, as shown inFIG. 12, once advanced distally past thecatheter shaft1106, theexpandable anchor1101 can expand and exert an outward force against the vessel wall. In particular embodiments, theanchor1101 can engage and/or exert a contact force in one or more branches of the pulmonary artery simultaneously. For example, as shown in the illustrated embodiment, theanchor1101 can span the bifurcation of the MPA into the LPA and/or RPA. Additionally, theanchor1101 can have a tapered shape in the proximal and/or distal directions, and in other embodiments, theanchor1101 can have a relatively uniform cross-sectional area along its length. In yet other embodiments, theanchor1101 can have a main body and one or more branches (not shown) configured to be positioned within at least a portion of the MPA and the LPA or RPA, respectively. In some embodiments, theexpandable anchor1101 can be a stent, balloon, self-expanding basket or other suitable expandable or shape-changing structures or devices.
C. Tension-Relieving Devices and Methods
• FIG. 13 is a side view of another embodiment of the catheter having a collapsibleinner shaft1201 configured in accordance with an embodiment of the present technology. At least a proximal portion of the therapeutic assembly1204 can be carried by theinner shaft1201. As shown inFIG. 13, theinner shaft1201 can have a “telescoping” design that allows theinner shaft1201 to extend and retract freely such that proximal and distal movement of theshaft1216 caused by the cardiac cycle, respiration, etc. will not pull or push thetherapeutic assembly104 out of position. Instead such motion is absorbed by the collapsible/extendable design of theinner shaft1201. In some embodiments, the catheter can include a locking and/or activation mechanism (not shown) so that the timing and/or extent of the extension/retraction of theinner shaft1201 can be controlled by the clinician. In further embodiments, the inner shaft can be corrugated along at least a portion of length to allow extension and retraction. Likewise, in a particular embodiment, theinner shaft1201 can be a braided structure having a plurality of sections with alternating flexibility (e.g., by altering wire diameter, wire count, etc.) As a result, the sectionedinner shaft1201 would allow for compression and extension with motion, thus mechanically isolating (at least in part) the therapeutic assembly1204 from the shaft1206.
• FIG. 14 is a side view of another embodiment of the catheter having atherapeutic assembly1304 mechanically isolated from theshaft1316 by an isolatingelement1315. The isolatingelement1315 can include afirst portion1303 operably connected to thetherapeutic assembly1304, asecond portion1305 operably connected to theshaft1316, and aconnector1301 therebetween. Theconnector1301 can have enough slack such that the position of thetherapeutic assembly1304 with respect to the vessel in which it is expanded is generally unaffected by movement of theshaft1316. As discussed above, often times during cardiac contraction and relaxation the movement of theshaft1316 is strong enough to pull or push thetherapeutic assembly1304 along the pulmonary vessel. For example, when the heart contracts, theshaft1316 can be pulled distally by the contracting heart muscles, thereby pulling thetherapeutic assembly1304 distally (and likely out of position). The isolatingelement1315 of the present technology mechanically isolates thetherapeutic assembly1304 from thecatheter shaft1316, allowing the shaft to move while thetherapeutic assembly1304 remains relatively stationary. In some embodiments, the catheter can include a locking and/oractivation mechanism1307 operably connected to the isolatingmember1315 so that the timing of the release of thetherapeutic assembly1304 from theshaft1316 can be controlled by the clinician. Additional devices and deployment methods for mechanical isolation of the therapeutic assembly from the shaft and/or catheter can be found in U.S. patent application Ser. No. 13/836,309, filed Mar. 15, 2013, titled “CATHETERS HAVING TETHERED NEUROMODULATION UNITS AND ASSOCIATED DEVICES, SYSTEMS, AND METHODS,” which is incorporated herein by reference in its entirety.
• In some embodiments, the therapeutic assembly and/or support structure can be modified to relieve tension between therapeutic assembly and the shaft. For example, as shown inFIG. 14, the support structure1410 can include anextended segment1401 at a proximal section of the helical/spiral portion1403 of the support structure1410 and/ortherapeutic assembly1404. Such an extension can provide more slack and greater flexibility at the proximal section of the helical/spiral portion 1403. Additionally, one or more turns (labeled (1), (2), (3) and (4) inFIG. 14) can be added to the support structure1410 to increase flexibility and/or the lengthening potential of thetherapeutic assembly1404. In a particular embodiment shown inFIG. 16, aninflection section1501 can be included along the generally straight portion of thesupport structure1510. Similar to the features described above with reference toFIG. 15, theinflection section1501 can provide the added slack to absorb the disruptive motion of theshaft1516.
D. Additional Embodiments
• FIG. 17A is a side view of a catheter apparatus1700 (“catheter1700”) configured in accordance with an embodiment of the present technology. Thecatheter1700 can include aproximal portion1702, adistal portion1704, ahandle assembly1706 at theproximal portion1702, and anelongated shaft1710 extending distally from thehandle assembly1706. Thedistal portion1704 of theelongated shaft1710 can include anactuatable portion1716 and one or more energy delivery elements1712 (e.g., electrodes). For example, as shown inFIG. 17A, thecatheter1700 can include a singleenergy delivery element1712 positioned at a distal-most portion of theshaft1710. In other embodiments, thecatheter1700 can include more than oneenergy delivery element1712 and/or one or moreenergy delivery elements1712 can be positioned at any location along the length of theshaft1710.
• Thehandle assembly1706 can include acontrol1708 that is electrically coupled to theactuatable portion1716 at thedistal portion1704 of theshaft1710. For example, thecatheter1700 can include one or more wires (not shown inFIG. 17A) extending distally from thehandle assembly1706 through or along the shaft to theactuatable portion1716. As indicated by arrow A, movement of theactuatable portion1716 by thecontrol1708 can deflect, flex and/or bend thedistal portion1704 of theshaft1710 to space theenergy delivery element1712 apart from a longitudinal axis L of theshaft1710. Such movement by theactuatable portion1716 can be used, for example, to place theenergy delivery element1712 in apposition with a vessel wall at a treatment site, as explained in greater detail below.
• FIG. 17B is an enlarged side view of a portion of thedistal portion1716, andFIG. 17C is a cross-sectional end view of theshaft1710 taken alongline17C-17C inFIG. 17B. Referring toFIGS. 17A-17C together, theactuatable portion1716 can include fourdeflectable members1714a-d (referred to collectively as deflectable members1714) spaced apart about the circumference of theshaft1710. In the embodiment shown inFIGS. 17A-17C, the deflectable members1714 are evenly spaced apart about the circumference of theshaft1710 such that each deflectable member1714a-dcorresponds to a distinct quadrant of theshaft1710. In other embodiments, theactuatable portion1716 can include more or less than four deflectable members1714 (e.g., one deflectable member, two deflectable members, six deflectable members, etc.) and/or the deflectable members1714 can have any spacing about theshaft1710. Each of the deflectable members1714a-dcan include a wire1718a-d, respectively, running therethrough (referred to collectively as wires1718). Each wire1718a-dcan extend proximally from a proximal portion of one of the corresponding deflectable members1714a-dalong theshaft1710 to thehandle1706. The wires1718 can be electrically isolated from one another in the shaft1710 (e.g., via separate lumens (not shown), embedding the wires in a polymer, etc.). As such, each of the deflectable members1714a-dcan be independently electrically controlled from thehandle assembly1706.
• In operation, upon positioning thedistal portion1704 of theshaft1710 at a treatment site adjacent a vessel wall (not shown), one or more of the deflectable members1714 can be actuated to bend thedistal portion1704 in a desired direction. For example, selection ofdeflectable member1714a(e.g., via the control) sends a current distally along thewire1718ato thedeflectable member1714a,thereby causing thedeflectable member1714ato bend outwardly (see arrow B_a) and away from the longitudinal axis of theshaft1710. The second-fourthdeflectable members1714b-dcan be actuated in a similar fashion. The ability of the present technology to independently manipulate the distal portion of the shaft (relative to the rest of the shaft) can be advantageous, especially in a pulmonary setting, to compensate for the pulsatile, dynamic flow conditions present with vessels in close proximity to the heart. Moreover, such independent control can be advantageous to finely tune the deformation of the distal portion to position or navigate tortuous vasculature at and near the pulmonary system.
• In some embodiments, the deflectable members1714a-dcan individually comprise a bimetallic strip including a first material having a first coefficient of thermal expansion (CTE) positioned adjacent a second material having a second coefficient of thermal expansion (CTE) that is different than the first CTE. The individual wires1718a-dcan be positioned between the corresponding first and second materials, and the first and second materials can be coupled to one another along their lengths. As the current flows through the wire1718, the first and second materials begin to heat. Because the first and second materials have different CTE's, the lengths of the first and second materials will expand at different rates. As a result, the deflectable member will bend in the direction of the material with the lower CTE. In some embodiments, the first and second materials can comprise platinum (linear CTE of about 9 (10⁻⁶K⁻¹)), aluminum (CTE of about 22.2 (10⁻⁶K⁻¹)), silver (linear CTE of about 429 (10⁻⁶K⁻¹)), and steel (linear CTE of about 13 (10⁻⁶K⁻¹)).
• Additionally, the deflectable members1714a-dcan individually comprise a piezoelectric material (e.g., an electrical-mechanical polymer) positioned on or adjacent a substrate material. The piezoelectric material and the substrate material can be coupled to one another along their lengths such that, when current is applied to the deflectable member (e.g., via the wire1718), the piezoelectric material elongates while the substrate does not, thereby bending the deflectable member.
• In some embodiments, thecatheter1700 can include a plurality of actuatable portions spaced apart along the length of theshaft1710. When actuated, the plurality of actuatable portions can bend theshaft1710 at multiple locations and/or in different directions. In such embodiments, the number, size, shape and/or spacing of the deflectable members can be the same or different amongst the actuatable portions.
• FIG. 18A is a perspective view of a portion of acatheter1800 in a low-profile state configured in accordance with another embodiment of the present technology. As shown inFIG. 18A, thecatheter1800 can include ashaft1810 having a proximal portion (not shown) and a distal portion configured to be intravascularly positioned at a treatment site. The distal portion can include a recessedportion1816 and an atraumaticdistal end region1812. The recessedportion1816 can house adeformable member1802. An isolated, enlarged view of thedeformable member1802 is shown inFIG. 18B. Referring toFIGS. 18A and 18B together, thedeformable member1802 can comprise a firstconductive member1806 positioned on a secondconductive member1808. The first andsecond members1806,1808 can individually comprise a metal. In some embodiments, thefirst member1806 can be a first material having a first CTE and thesecond member1808 can be a second material having a second CTE different than the first CTE. Awire1814 extending from a proximal portion of the catheter1800 (not shown) can be coupled to the first and secondconductive members1806,1808. For example, thewire1814 can be positioned between the first andsecond members1806,1808. The first andsecond members1806,1808 can be coupled to one another along their lengths. In some embodiments, the first and second members can individually comprise platinum (linear CTE of about 9 (10⁻⁶K⁻¹)), aluminum (CTE of about 22.2 (10⁻⁶K⁻¹)), silver (linear CTE of about 429 (10⁻⁶K⁻¹)), and steel (linear CTE of about 13 (10⁻⁶K⁻¹)).
• Referring still toFIGS. 18A-18B, the first and secondconductive members1806,1808 can be coated or otherwise surrounded by an insulative material. The firstconductive member1806 can include twoenergy delivery elements1804 comprising an exposed portion of the first conductive member1806 (e.g., an opening in the insulative material). In other embodiments, thedeformable member1804 can include more or less than two energy delivery elements (e.g., one energy delivery element, three energy delivery elements, etc.).
• FIG. 18C is a side view of the distal portion of thecatheter1800 in a low-profile state, andFIG. 18D is a side view of the distal portion of thecatheter1800 in a deployed state. The sidewalls of the recessedportion1816 are shown in phantom lines for ease of illustration. Referring toFIGS. 18A-18D together, as the current flows through thewire1814, the first and secondconductive members1806,1808 begin to heat. Because the first and secondconductive members1806,1808 have different CTE's, the lengths of the first and secondconductive members1806,1808 will expand at different rates. As a result, thedeformable member1802 will bend in the direction of the material with the lower CTE, thereby extending away from the longitudinal axis of theshaft1810 and into apposition with the vessel wall at the treatment site.
• FIG. 19 is a schematic representation of a magnetically-deformable catheter system1900 configured in accordance with an embodiment of the present technology. As shown inFIG. 19, thecatheter system1900 can include a magnetic field generator1902 (e.g., a magnetic resonance imaging (MRI) system, etc.) configured to be positioned external to the patient P and acatheter1904. Thecatheter1904 can include anelongated shaft1910 and amagnetically actuatable portion1906 coupled to a distal portion of theelongated shaft1910. When themagnetic field generator1902 is activated, the magnetic field deforms themagnetically actuatable portion1906 of the shaft1910 (not shown) to achieve a desiredshaft1910 configuration.
• Thecatheter1904 ofFIG. 19 can have only a singleenergy delivery element1908 or, in other embodiments thecatheter1900 can include more than oneenergy delivery element1908 positioned along theshaft1910. Additionally, thecatheter1900 can include more than onemagnetically actuatable portion1906 positioned along theshaft1910.
• When modulating the nerves from within a pulmonary vessel, it is desirable to avoid total occlusion of the vessel since 100% of the body's blood flows through portions of the pulmonary vasculature (e.g., the MPA). Several embodiments of the catheters, catheter systems, and methods of the present technology provide non-occlusive means for effectively modulating the nerves communicating with the pulmonary system. In other embodiments, the catheters, catheter systems, and methods of the present technology can provide occlusive means for effectively modulating nerves communicating with the pulmonary system.
• FIGS. 20-21 are cross-sectional views of two additional embodiments of such non-occlusive catheters.FIG. 20 shows anon-occlusive catheter2000 in a deployed state positioned in a vessel V and configured in accordance with an embodiment of the present technology. As shown inFIG. 20, thecatheter2000 can include anultrasound transducer2002, a first expandable member2004 (e.g., a balloon, a wire cage, etc.) positioned around theultrasound transducer2002, and a second expandable member2006 (e.g., a balloon, a wire cage, etc.) positioned adjacent the firstexpandable member2004. When deployed, the first and secondexpandable members2004,2006 together position theultrasound transducer2002 near the vessel wall V at a desired distance to achieve effective neuromodulation. As shown inFIG. 20, the diameters of the first and secondexpandable members2004,2006 can be selected such that sufficient space S remains adjacent thecatheter2000 within the vessel V, thereby allowing blood flow during treatment.
• FIG. 21 is a cross-sectional end view of anothernon-occlusive catheter2100 in a deployed state positioned in a vessel V and configured in accordance with an embodiment of the present technology. As shown inFIG. 21, thecatheter2100 can include anultrasound transducer2102 positioned within a donut-shaped expandable member2104 (e.g., a balloon, a wire cage, etc.). During treatment, blood can flow through the opening in theexpandable member2104. It will be appreciated that the expandable members of the present technology can have any suitable size, shape, and configuration. For example, in some embodiments, the expandable members can have a helical/spiral shape in a deployed state.
E. Nerve Monitoring Devices and Methods
• Any of the pulmonary neuromodulation systems and/or therapeutic assemblies described herein can be configured to stimulate nerves proximate the treatment site and/or record the resultant nerve activity. For example, several embodiments of the pulmonary neuromodulation systems and/or therapeutic assemblies described herein can include a nerve monitoring assembly.FIG. 22A, for example, is an enlarged isometric view of one embodiment of a nerve monitoring assembly2300 (also referred to herein as “monitoring assembly2300”) configured in accordance with the present technology. Themonitoring assembly2300 is configured to provide stimulation to neural fibers and/or record activity of nerves in communication with the pulmonary system. As shown inFIG. 22A, themonitoring assembly2300 can include a first loop electrode orconductor2302aand a second loop electrode orconductor2302b(referred to collectively as loop electrodes2302) electrically isolated from thefirst loop electrode2302aand positioned at adistal portion2312 of anelongated catheter shaft2306. In the illustrated embodiment, the two loop electrodes2302 form a generally circular shape. However, the term “loop electrode” as used herein should be construed broadly to include electrodes2302 having other shapes configured to contact at least a portion of the interior wall of a vessel. In various embodiments, thefirst loop electrode2302acan be an anode, the other loop electrode2302 can be a cathode, and aninsulated portion2304 can electrically isolate the anode and cathode loop electrodes2302 from one another and space the loop electrodes2302 laterally apart from one another. For example, the distal end of thefirst loop electrode2302aand the proximal end of thesecond loop electrode2302bcan terminate at or within a portion of the insulatingportion2304, and the insulatingportion2304 can space apart the loop electrodes2302. In various embodiments, the separation between the loop electrodes2302 (e.g., provided by the insulating portion2304) can be selected to enhance the signal to noise ratio for recording nerve activity (e.g., delta fibers and/or C-fibers). For example, the first andsecond loop electrodes2302aand2302bcan be spaced about 5 mm apart from one another for recording action potentials from delta fibers, and may be positioned further apart from one another for recording C-fibers.
• When the first andsecond loop electrodes2302aand2302bare configured as an anode and a cathode, themonitoring assembly2300 can deliver bipolar stimulation to nerves proximate a target site in a vessel (e.g., nerves that communicate with the pulmonary system) or provide bipolar recording of nerve activity proximate the target site. For example, a nerve monitoring device configured in accordance with one embodiment of the present technology can include two electrode assemblies2300: a first electrode assembly configured to stimulate nerves and a second electrode assembly spaced apart from the first electrode assembly along the vasculature and configured to measure the action potential of the nerves resulting from the stimuli of the first electrode assembly. Action potential is the electrical activity developed in a nerve cell during activity (e.g., induced by a stimulus from the first electrode assembly).
• The loop electrodes2302 can have an outer diameter at least equal to an inner diameter of a target vessel and, in some cases, larger (e.g., 1.5 times larger) than the inner diameter of the target vessel.
• Each loop electrode2302 can be made from a separate shape memory wire that defines the electrode2302. The shape memory wire allows the loop electrodes2302 to be positioned in a low profile, delivery state during intravascular delivery to the target vessel and open transverse to the longitudinal axis of the target vessel to an expanded or deployed state (shown inFIG. 22A). For example, the loop electrodes2302 can be made from nitinol wires that can self-expand to a predefined shape upon delivery at the target vessel. In various embodiments, the shape memory material can be coated (e.g., sputter coated) with gold, platinum, platinum iridium, and/or other suitable materials. The coating can be selected to substantially optimize the impedance of theassembly2300 and/or enhance the signal-to-noise ratio recorded by theelectrode assembly2300. In other embodiments, the loop electrodes2302 can be made from other suitable materials (e.g., platinum, gold, platinum iridium, stainless steel, aluminum, etc.). The wire thickness of each loop electrode2302 can be sized such that the loop electrode2302 is stable enough to maintain its shape during nerve monitoring, yet flexible enough to allow for intravascular delivery in a low profile arrangement to a peripheral vessel (e.g., a pulmonary blood vessel).
• Each loop electrode2302 of themonitoring assembly2300 can have an exposed abluminal surface2308 (e.g., an outer surface proximate the vessel wall during nerve monitoring) to deliver and/or receive electrical signals to neural fibers proximate to a target vessel and an insulated adluminal or luminal surface2310 (e.g., an inner surface facing away from the vessel wall and toward the lumen formed by the target vessel) to reduce the likelihood that blood flowing through the target vessel will short circuit the loop electrodes2302. Theluminal surface2310 may be insulated using a coating with a high dielectric constant, strong adhesive properties to prevent it from rubbing off during delivery, biocompatible properties suitable for intravascular use, and/or other suitable characteristics.
• As mentioned previously, the total exposedabluminal surface2308 of themonitoring assembly2300 can be selected to enhance the signal-to-noise ratio of theassembly2300.
• Themonitoring assembly2300 can be delivered intravascularly to a treatment site before and/or after neuromodulation. Thedistal portion2312 of theshaft2306 can be made from various flexible polymeric materials, such as a polyethylene block amide copolymer (e.g., PEBAX®, available from Arkema of France), high-density polyethylene (HDPE), nylon, polyimide, and/or other suitable materials, to facilitate navigation through tortuous vasculature. Thedistal portion2312 can also include braid reinforcement comprised of polymeric materials to improve column strength, torque, and reduce kinking. A proximal portion (not shown) of theshaft2306 can be more stiff than thedistal portion2312, and can therefore transmit force to track theshaft2306 through the vasculature to the target site (e.g., proximate a pulmonary blood vessel). Theproximal portion2313 can be made from PEBAX®, HDPE, low-density polyethylene (LDPE), nylon, polyimide, nylon, nitinol, a stainless steel hypotube, and/or other suitable materials. In various embodiments, the distal end portion of theassembly2300 can include an atraumatic tip when themonitoring assembly2300 is in the delivery state to reduce trauma to vessel walls as themonitoring assembly2300 advances through the vasculature and deploys at the target site. This atraumatic tip material can be made from various soft materials, such as PEBAX®, LDPE, other polymers, and/or other suitable materials. The distal tip can also include a radiopaque tip marker (electrically isolated from the loop electrodes2302) to provide visualization of the distal tip under fluoroscopy.
• Signal wires2311 (referred to individually as afirst signal wire2311aand asecond signal wire2311b;shown in broken lines) can be operatively coupled to themonitoring assembly2300 to drive nerve stimulation, record nerve activity, and/or otherwise provide a signal to the loop electrodes2302. The signal wires2311, for example, can be welded, soldered, crimped, and/or otherwise connected to theshaft2306. A distal portion of thefirst signal wire2311acan be operably coupled to thefirst loop electrode2302a,and a distal portion of thesecond signal wire2311bcan be operably coupled to thesecond loop electrode2302b.The signal wires2311 can extend through theshaft2306 to a proximal end of the shaft where the signal wires2311 can be operatively connected to a signal processing console (e.g., theenergy generator132 ofFIG. 1) suitable for nerve stimulation. In various embodiments, for example, one ormore electrode assemblies2300 can be operatively coupled to a NIM-Response Nerve Integrity Monitor (“NIM”) made available by Medtronic Xomed of Jacksonville, Fla., which provides intraoperative nerve monitoring capabilities using visual and/or audible indications of nerve activity. Additionally, in those embodiments where the catheter and/or treatment device includes an electrical element211 (FIG. 2A), the signal wires2311 can extend from themonitoring assembly2300 to theelectrical element211. In such embodiments, the catheter can include an additional set of wires (not shown) that extends between (and electrically couples) theelectrical element211 and theenergy generator132.
• FIG. 22B is an enlarged partially schematic side view of adistal portion2350 positioned in a blood vessel A (e.g., a pulmonary blood vessel) and configured in accordance with an embodiment of the present technology. Thedistal portion2350 can include a therapeutic assembly2320 (shown schematically) and anerve monitoring assembly2330. Thetherapeutic assembly2320 can include features generally similar to the features of the therapeutic assemblies described above with reference toFIGS. 1-21. Thenerve monitoring assembly2330 can be generally similar to thenerve monitoring assembly2300 ofFIG. 22A. In the illustrated embodiment, thetherapeutic assembly2320 is operatively coupled to and positioned between two electrode assemblies (identified individually as afirst electrode assembly2300aand asecond electrode assembly2300b) which together define thenerve monitoring assembly2330. In other embodiments, thetherapeutic assembly2320 and thenerve monitoring assembly2330 may be stand-alone devices that can be delivered independently to a target site (e.g., within the pulmonary artery). For example, in some embodiments thesecond electrode assembly2300b, thetherapeutic assembly2320 and thefirst electrode assembly2300aare coupled to separate catheter shafts and delivered sequentially to the target site to provide a configuration similar to that shown inFIG. 22B. In still other embodiments, the first andsecond electrode assemblies2300aand2300bcan be integrally coupled to one another and delivered to the target site before and/or after neuromodulation.
• Thenerve monitoring assembly2330 can be configured to stimulate nerves in communication with the pulmonary system proximally with thefirst electrode assembly2300aand record nerve activity distally with thesecond electrode assembly2300b.Thesecond electrode assembly2300bcan be positioned distal to thefirst electrode assembly2300a.In further embodiments, thesecond electrode assembly2300bcan be configured to provide stimulation and thefirst electrode assembly2300acan be configured to record the resultant nerve activity.
• The first andsecond electrode assemblies2300aand2300bcan be spaced far enough apart from one another such that the signal artifact associated with the bipolar stimulation from thefirst electrode assembly2300a,which is less than that which would be produced by monopolar stimulation, does not substantially engulf or otherwise interfere with the signal being recorded at thesecond electrode assembly2300b.The magnitude of the signal artifact at thesecond electrode assembly2300bdepends at least in part on the conduction velocity of the nerve fibers and the spacing between the stimulus and recording electrodes. C-fibers and delta-fibers, such as those found in nerves, have relatively low conduction velocities (e.g., no more than 2 m/s for C-fibers and about 3-13 m/s for delta fibers). As such, when thesecond electrode assembly2300bis configured to record activity of nerves in communication with the pulmonary system, thesecond electrode assembly2300bcan be positioned laterally apart from thefirst electrode assembly2300aalong the axis of the pulmonary vessel A to reduce the signal artifact recorded by thesecond electrode assembly2300b.In further embodiments, at least one of theelectrode assemblies2300 can be positioned outside the pulmonary blood vessel A. For example, in some embodiments thesecond electrode assembly2300bcan be positioned in the pulmonary blood vessel A to record nerve activity, and thefirst electrode assembly2300acan be positioned elsewhere within the vasculature that can deliver a stimulus to nerves in communication with the pulmonary system. In still other embodiments, thefirst electrode assembly2300acan be configured to stimulate nerves from a location outside the human body (e.g., at the brain stem), and thesecond electrode assembly2300bcan be configured to record the resultant nerve activity at a site within or proximate to the pulmonary blood vessel A. In additional embodiments, theelectrode assemblies2300 can be configured to be placed at other suitable locations for stimulating and recording nerve activity.
• In various embodiments, thefirst electrode assembly2300acan be configured to provide biphasic and bipolar stimulation. Thesecond loop electrode2302b₁(i.e., the electrode closest to the recording/second electrode assembly2302b) can be a cathode and thefirst loop electrode2302a₁an anode. Thesecond electrode assembly2300bcan be configured to provide bipolar recording of nerve activity resulting from the stimulation induced by thefirst electrode assembly2300a.As such, thefirst loop electrode2302a₂can be one of an anode or a cathode, and thesecond loop electrode2302b₂can be the other of the anode or the cathode. Thesecond electrode assembly2300bcan pick up the relatively small action potentials associated with activity of nerves in communication with the pulmonary system, and can be sensitive to relatively small signals to differentiate nerve stimulation from noise. In order to pick up the small action potentials and differentiate the nerve activity from noise (e.g., from the signal artifact, action potentials of proximate muscle fibers, etc.), thesecond electrode assembly2300bcan be configured to record a plurality of samples that can be averaged (e.g., using an NIM or other suitable console). In one embodiment, for example, thesecond electrode assembly2300bcan average 160 samples within 12 seconds to identify the nerve activity. In other embodiments, more or less samples can be averaged to identify the nerve activity.
• As shown inFIG. 22B, the first andsecond electrode assemblies2300aand2300band thetherapeutic assembly2320 can be attached to thedistal portion2312 of thesame shaft2306 such that thenerve monitoring assembly2330 and thetherapeutic assembly2320 can be delivered as a unit to the target site. In one embodiment, for example, thetherapeutic assembly2320 includes a neuromodulation loop electrode that is connected between the first andsecond electrode assemblies2300aand2300b.The first andsecond electrode assemblies2300aand2300bcan be stiffer than the neuromodulation loop electrode such that theelectrode assemblies2300a-bstay substantially planar in the vessel A and provide adequate contact with the arterial walls to stimulate the nerves and record the resultant nerve activity. The neuromodulation loop electrode may be more flexible, allowing it to be pulled into a helix or corkscrew configuration during deployment at the target site while the first andsecond electrode assemblies2300aand2300bstay anchored against the vessel A due to self-expansion. In other embodiments, eachelectrode assembly2300a-band/or thetherapeutic assembly2320 can be attached to separate shafts and delivered independently to the target site.
• In various embodiments, the nerve monitoring assembly2330 (in conjunction with or independent of the therapeutic assembly2320) can be delivered intravascularly to the pulmonary artery A or other peripheral vessel via a delivery sheath (not shown). The delivery sheath can extend along the length of theshaft2306, and can be made from PEBAX®, nylon, HDPE, LDPE, polyimide, and/or other suitable materials for navigating the vasculature. The delivery sheath can cover theelectrode assemblies2300a-bsuch that they are positioned in a low profile, delivery state suitable for navigation through the vasculature. At the pulmonary vessel A, the delivery sheath can be moved relative to theelectrode assemblies2300a-b(e.g., the sheath can be retracted or theelectrode assemblies2300a-bcan be advanced) to expose theelectrode assemblies2300a-bfrom thesheath2300. This allows theelectrode assemblies2300a-bto deploy (e.g., self-expand) into an expanded state where theabluminal surfaces2308 of the loop electrodes2302 contact the vessel wall. In other embodiments, the delivery sheath is not integrated with thenerve monitoring assembly2330, and is advanced over a guide wire to the treatment site via a guide catheter. In this embodiment, the delivery sheath can be made from a soft, flexible material that allows it to navigate tortuous vessels. Once the delivery sheath is at the target site in the pulmonary vessel A, theelectrode assemblies2300a-bcan be positioned in a proximal opening of the delivery sheath and advanced distally to the treatment site where they can be deployed to the expanded state by moving the delivery sheath and theelectrode assemblies2300a-brelative to one another.
• As shown inFIG. 22B, in the expanded state, the loop electrodes2302 of the first andsecond electrode assemblies2300aand2300bare sized to press against or otherwise contact the interior wall of the pulmonary vessel A. Thenerve monitoring assembly2330 can first monitor nerve activity in real time before neuromodulation by delivering an electrical current proximal to a treatment site via thefirst electrode assembly2300aand recording the resultant nerve activity at thesecond electrode assembly2300b.The first andsecond loop electrodes2302a₁and2302b₁of thefirst electrode assembly2300acan be operably coupled to first andsecond signal wires2311a₁and2311b₁, respectively, to provide bipolar stimulation, and the first andsecond loop electrodes2302a₂and2302b₂of thesecond electrode assembly2300bcan be operably coupled to twoseparate signal wires2311a₂and2311b₂, respectively, to provide bipolar recording, or vice versa. Since theabluminal surface2308 of the loop electrodes2302 are fully exposed, thefirst electrode assembly2300acan deliver stimulation to nerves positioned around the full circumference of the pulmonary vessel A. The exposedabluminal surface2308 also allows thesecond electrode assembly2300bto capture nerve activity regardless of nerve orientation around the circumference of the vessel A. The insulatedluminal surface2310 of the loop electrodes2302 insulates theelectrode assemblies2300 from blood flowing through the pulmonary vessel A to avoid a short circuit between the electrode loops2302. The recording can be visualized using a console (e.g., an NIM) coupled to the proximal portion (not shown) of theshaft2306.
• Thetherapeutic assembly2320 can then apply an energy field to the target site to cause electrically-induced and/or thermally-induced partial or full denervation of the nerves in communication with the pulmonary system (e.g., using electrodes or cryotherapeutic devices). Thenerve monitoring assembly2330 can again stimulate and record the nerve activity to determine whether sufficient neuromodulation occurred. If thenerve monitoring assembly2330 indicates the presence of a higher level of nerve activity than desired, thetherapeutic assembly2320 can again apply the energy field to effectuate neuromodulation. This process of supplying a current, recording the resultant nerve activity, and applying neuromodulation to the treatment site can be repeated until the desired nerve lesion is achieved. In some embodiments, such as when thetherapeutic assembly2320 uses cryotherapeutic cooling, thenerve monitoring assembly2330 can also record nerve activity during denervation. Once nerve monitoring at the treatment site is complete, the delivery sheath can again be advanced over theelectrode assemblies2300a-band/or theelectrode assemblies2300a-bcan be retracted into the delivery sheath, thereby moving theelectrode assemblies2300a-bback into the delivery state for removal from the patient.
• In further embodiments, thenerve monitoring assembly2330 can be operatively coupled to thetherapeutic assembly2320 such that nerve monitoring and neuromodulation can run automatically as part of a preset program. In other embodiments, thenerve monitoring assembly2330 is not positioned around thetherapeutic assembly2320, but instead delivered to the treatment site separately before and/or after neuromodulation by thetherapeutic assembly2320.
• In various embodiments, the first andsecond electrode assemblies2300aand2300bcan be delivered after neuromodulation to confirm the desired neuromodulation has occurred. For example, the twoelectrode assemblies2300a-bcan be delivered proximate the treatment site as separate components or as an integrated unit to a vessel (e.g., the pulmonary vessel) during the neuromodulation procedure a short time after neuromodulation occurs (e.g., 5 minutes after neuromodulation). In other embodiments, theelectrode assemblies2300a-bcan be used to monitor nerve activity during a separate procedure following the neuromodulation procedure (e.g., 1, 2 or 3 days after the neuromodulation procedure).
• FIG. 23A is an enlarged isometric view of anelectrode assembly2400 configured in accordance with another embodiment of the present technology. Theelectrode assembly2400 can include features generally similar to theassembly2300 described above with reference toFIGS. 22A and 22B. For example, theelectrode assembly2400 includes a loop2402 (e.g., a nitinol wire) at adistal portion2412 of anelongated shaft2406 that is configured to provide bipolar, biphasic nerve stimulation and/or record the resultant nerve activity. However, theelectrode assembly2400 shown inFIG. 23A includes a plurality of electrodes2414 (identified individually as first throughsixth electrodes2414a-f, respectively) positioned around the circumference of theloop2402 spaced apart and electrically insulated from one another by insulatingsections2416. Theelectrodes2414 can be made from stainless steel, gold, platinum, platinum iridium, aluminum, nitinol, and/or other suitable materials, and theinsulation sections2416 can be made from a suitable dielectric material (e.g., a high-k dielectric with strong adhesive properties). Theelectrodes2414 can be substantially coplanar with an outer surface of the insulatingsections2416 and/or theshaft2406, or may project beyond the insulatingsections2416 by a distance. In various embodiments, for example, theelectrodes2414 can extend a radial distance from the adjacent insulatingportions2416 and include a smoothed edge (e.g., a beveled edge) to reduce denuding of the adjacent arterial wall. The coplanar or projectingelectrodes2414 can facilitate contact with the arterial wall to enhance stimulation and/or recording. In other embodiments, one or more of theelectrodes2414 may be recessed from the insulating portions416.
• In the illustrated embodiment, themulti-electrode loop2402 includes sixelectrodes2414a-f, which may be suitable for loops having outer diameters of approximately 8 mm. In other embodiments, however, theloop2402 can include more or less electrodes2414 (e.g., four to eight electrodes2414) depending at least in part on the outer diameter of theloop2402. Each of theelectrodes2414 can be designated as a cathode, anode, or inactive by a nerve monitoring console (e.g., an NIM and/or other suitable console) operably coupled to themulti-electrode loop2402 via signal wires extending through theshaft2406. For example, theelectrodes2414 can alternate as anodes and cathodes around the circumference of the loop2402 (e.g., the first, third andfifth electrodes2414a,2414cand2414ecan be anodes and the second, fourth andsixth electrodes2414b,2414dand2414fcan be cathodes) such that thesingle loop2402 can provide bipolar stimulation or recording. Similar to the loop electrodes2302 described above, aluminal surface2410 of themulti-electrode loop2402 can also be insulated to inhibit short circuits across the electrodes2414 (e.g., via blood or other conductive pathways), while anabluminal surface2408 can remain exposed to allow theelectrodes2414 to contact a vessel wall (e.g., the pulmonary blood vessel).
• In various embodiments, theelectrode assembly2400 can include twoloops2402 spaced laterally apart from one another (e.g., similar to the dualloop electrode assembly2300 shown inFIG. 22A). This arrangement allows all theelectrodes2414 on onemulti-electrode loop2402 to be configured as anodes, while all theelectrodes2414 on the othermulti-electrode loop2402 can be configured as cathodes. Much like the loop electrodes2302 shown inFIG. 22A, the double multi-electrode loop configuration can increase the surface area with which theelectrode assembly2400 can stimulate and/or capture nerve activity, and can therefore enhance nerve monitoring.
• FIG. 23B is an enlarged partially schematic side view of a distal portion of atreatment device2450B within a blood vessel A (e.g., a pulmonary vessel) configured in accordance with another embodiment of the present technology. Thetreatment device2450B includes features generally similar to the features of thetreatment device2350 described above with reference toFIG. 22B. For example, thetreatment device2450B includes atherapeutic assembly2420 positioned between and optionally operably coupled to afirst electrode assembly2400aand asecond electrode assembly2400b.Thefirst electrode assembly2400aincludes two multi-electrode loops2402 (identified individually as a firstmulti-electrode loop2402aand a secondmulti-electrode loop2402b). In various embodiments, all theelectrodes2414 of the firstmulti-electrode loop2402acan be anodes, and all theelectrodes2414 of the secondmulti-electrode loop2402bcan be cathodes such that thefirst electrode assembly2400acan provide bipolar nerve stimulation. In the embodiment illustrated inFIG. 23B, thesecond electrode assembly2400bincludes onemulti-electrode loop2402 having both anodes and cathodes spaced around the circumference to provide bipolar recording of nerve activity. In other embodiments, thesecond electrode assembly2400bcan include twomulti-electrode loops2402 and designate one as a cathode and the other as an anode. In further embodiments, thefirst electrode assembly2400aand/or thesecond electrode assembly2400bcan include two bare loop electrodes2302 as shown inFIG. 22B. In still further embodiments, theelectrode assemblies2400 can be configured to provide monopolar nerve stimulation or recording.
• FIG. 23C is an enlarged partially schematic side view of a distal portion of atreatment device2450C within a blood vessel A (e.g., a pulmonary blood vessel) in accordance with yet another embodiment of the present technology. Thetreatment device2450C includes features generally similar to the features of thetreatment device2450B described above with reference toFIG. 22B. For example, thetreatment device2450C includes thetherapeutic assembly2420 positioned between thefirst electrode assembly2400aand thesecond electrode assembly2400b. In the embodiment illustrated inFIG. 23C, however, thefirst electrode assembly2400aincludes only onemulti-electrode loop2402 such that theloop2402 includes both anodes and cathodes to provide the desired bipolar stimulation.
• FIG. 24 is an enlarged partially schematic side view of a distal portion of atreatment device2550 within a blood vessel A (e.g., a pulmonary blood vessel) in accordance with a further embodiment of the present technology. Thetreatment device2550 includes features generally similar to the features of the treatment devices described above with reference toFIGS. 22B, 23B and 23C. Thetreatment device2550, for example, includes a therapeutic assembly2520 (shown schematically) and anerve monitoring assembly2530 at adistal portion2512 of ashaft2506. Thetherapeutic assembly2520 is positioned between afirst electrode assembly2500athat provides bipolar nerve stimulation and asecond electrode2500bthat provides bipolar recording of nerve activity (collectively referred to as electrode assemblies2500). In the illustrated embodiment, each electrode assembly2500 includes a balloon2532 (identified individually as afirst balloon2532aand a second balloon2532b) having one or more conductive portions2534 (identified individually as a firstconductive portion2534aand a secondconductive portion2534b) that serve as electrodes. The conductive portions2534 can be made from a conductive ink that is sufficiently flexible to allow the balloons2532 to fold into a guide catheter (not shown) during delivery and removal of thetreatment device2550. In other embodiments, the conductive portions2534 can be made from other suitable materials that attach to the balloons2532, such as platinum iridium wires.
• In the embodiment illustrated inFIG. 24, each balloon2532 includes two spaced apart conductive portions2534 around at least a portion of the circumference of the balloon2532 such that the conductive portions2534 can contact the inner wall of the blood vessel A when the balloons2532 are inflated (e.g., as shown inFIG. 24). The balloons2532 can be inflated by flowing gas (e.g., air) or liquid (e.g., saline solution) into the balloons2532 through one or more openings2537 (referred to individually as afirst opening2537aand asecond opening2537b) in atube2535 that is coupled to a fluid source (not shown) at a proximal end portion and extends through the balloons2532 at a distal end portion. Similar to the multi-loop electrode assemblies described above, the two conductive portions2534 of each balloon2532 can be designated as an anode and as a cathode to provide bipolar nerve stimulation and recording. In other embodiments, at least one of the electrode assemblies2500 can include a dual balloon, and each balloon can include one conductive portion2534 such that thenerve monitoring assembly2530 includes three or four balloons.
• In various embodiments, thetherapeutic assembly2520 can be omitted. As such, the electrode assemblies2500 can be intravascularly delivered to the treatment site (e.g., at the pulmonary vessel) to record nerve activity before neuromodulation. The electrode assemblies2500 can then be removed from the target site to allow thetherapeutic assembly2520 to be delivered. After neuromodulation, the electrode assemblies2500 can be delivered back to the target site to record the nerve activity. If a sufficient nerve lesion has not been formed, thetherapeutic assembly2520 can again be delivered to the treatment site to deliver an energy field to ablate or otherwise modulate the nerves. Thetherapeutic assembly2520 can then be removed from the treatment site to allow the electrode assemblies2500 to be delivered and monitor the resultant nerve activity. This process can be repeated until a sufficient nerve lesion is formed at the target site.
• FIG. 25 is an enlarged side view of a distal portion of atreatment device2650 within a blood vessel A (e.g., a pulmonary blood vessel) in accordance with yet another embodiment of the present technology. Thetreatment device2650 includes a number of features generally similar to the features of the treatment devices described above with reference toFIGS. 22B, 23B, 23C and 24. For example, thetreatment device2650 includes an array of electrodes (identified individually as afirst electrode array2600aand asecond electrode array2600b,and referred to collectively as electrode arrays2600) proximal and distal to a neuromodulation area2643 (shown in broken lines). In the embodiment illustrated inFIG. 25, thetreatment device2650 has a double balloon configuration in which a first inflatable body orouter balloon2640 is disposed over a second inflatable body orinner balloon2642. Theinner balloon2642 can be configured to deliver therapeutic neuromodulation to nerves proximate a treatment site (e.g., a pulmonary blood vessel). For example, theinner balloon2642 can define an expansion chamber in which a cryogenic agent (e.g., nitrous oxide (N₂O)) can expand to provide therapeutically-effective cooling to tissue adjacent to the inflated inner balloon2642 (e.g., in the neuromodulation area2643). In other embodiments, theinner balloon2642 can be configured to provide therapeutic neuromodulation using other suitable means known in the art such as ultrasound (e.g., HIFU). In further embodiments, theinner balloon2642 may be omitted, and energy deliver elements (e.g., electrodes) can be disposed on an outer surface of theouter balloon2640 to deliver RF ablation energy and/or other forms of energy for neuromodulation.
• As shown inFIG. 25, a proximal end portion of theouter balloon2640 can be coupled to adistal portion2612 of anouter shaft2606 and a proximal end portion of theinner balloon2642 can be coupled to aninner shaft2644 that extends through theouter shaft2606. In the illustrated embodiment, theinner shaft2644 extends through the outer andinner balloons2640 and2642 such that the distal end portions of the outer andinner balloons2640 and2642 can connect thereto, and therefore theinner shaft2644 can provide longitudinal support along theballoons2640 and2642. In other embodiments, theinner shaft2644 can extend partially into theballoons2640 and2642 or terminate proximate to the distal end of theouter shaft2606. The outer andinner shafts2606 and2644 can define or include supply lumens fluidly coupled at proximal end portions to one or more fluid sources and fluidly coupled at distal end portions to the outer andinner balloons2640 and2642. For example, theinner shaft2644 can include one ormore openings2646 through which fluids (e.g., refrigerants or other cryogenic agents) can be delivered to the inner balloon2642 (e.g., as indicated by the arrows) to inflate or expand theinner balloon2642. Fluids (e.g., saline or air) can be delivered to theouter balloon2640 through a space oropening2646 between the outer andinner shafts2606 and2644 (e.g., as indicated by the arrows) and/or by a supply lumen spaced therebetween to inflate or expand theouter balloon2640.
• Theinner balloon2642 can have smaller dimensions than theouter balloon2640 such that theouter balloon2640 expands into full circumferential contact with the vessel wall along a length of the vessel and theinner balloon2642 expands to press against or otherwise contact a segment of the inner wall of theouter balloon2640. In the embodiment illustrated inFIG. 25, for example, the outer andinner balloons2640 and2642 contact each other at an interface extending around a full circumference of theinner balloon2642 spaced laterally inward of the electrode arrays2600. The portion of theouter balloon2640 in contact with the inflatedinner balloon2642 can deliver therapeutically-effective neuromodulation (e.g., via cryotherapeutic cooling) to nerves proximate the adjacent vessel wall. Accordingly, the double balloon arrangement shown inFIG. 25 can deliver fully-circumferential neuromodulation. Non-targeted tissue proximal and distal to the contacting balloon walls is shielded or protected from neuromodulation by an inflation medium (e.g., saline solution, air, etc.) within theouter balloon2640, which may effectively act as insulation.
• The outer andinner balloons2640 and2642 can be made from various compliant, non-compliant, and semi-compliant balloons materials. The outer balloon640, for example, can be made from a compliant balloon material (e.g., polyurethane or silicone) such that when theouter balloon2640 is inflated, it can press against the inner wall of a vessel to provide stable contact therebetween. Theinner balloon2642 can be made from semi-compliant and or non-compliant materials (e.g., formed from polyether block amide, nylon, etc.) to define a smaller expanded size. In other embodiments, the outer andinner balloons2640 and2642 can be made from other suitable balloon materials.
• As shown inFIG. 25, thefirst electrode array2600aand thesecond electrode array2600bmay be located at the outer wall of theouter balloon2640 and positioned proximal and distal to the neuromodulation area2643 (i.e., the region of theouter balloon2640 that contacts the inflated inner balloon2642). Each electrode array2600 can include a firstconductive portion2634aand a secondconductive portion2634b(referred to collectively as conductive portions2634) that extend around the circumference of theouter balloon2640 to define first and second electrode loops. In other embodiments, one or both of the electrode arrays2600 can include a single conductive portion or strip extending around the circumference of theouter balloon2640. The conductive portions2634 can be made from a conductive ink printed on the outer wall of theouter balloon2640 and/or other conductive materials that can attach to theouter balloon2640. In operation, thefirst electrode array2600acan stimulate nerves proximal to theneuromodulation area2643 and thesecond electrode array2600bcan sense the resultant stimulation, or vice versa. The first and second conductive portions2634 of each electrode array2600 can be configured to provide bipolar or monopolar stimulation and/or recording depending upon which mode provides the highest signal response. For example, thefirst electrode array2600acan include one electrode (e.g., one conductive strip2634) for monopolar stimulation and thesecond electrode array2600bcan include two electrodes (e.g., two conductive strips2634) for bipolar recording. In other embodiments, however, the electrode arrays2600 may have other arrangements and/or include different features.
• Thetreatment device2650 can provide nerve stimulation and recording before, during, and/or after neuromodulation. For example, the electrode assemblies2600 can stimulate nerves and record the resultant nerve activity before neuromodulation to provide a set point against which subsequent nerve monitoring can be compared. This information can also be used to determine the level of power or current that must be delivered to ablate the nerves since each patient typically has different base line levels nerve activity. Therefore, the electrode arrays2600 can also provide diagnostic nerve monitoring. During the neuromodulation procedure, the electrode arrays2600 can monitor the reduction of nerve signal strength to confirm the effectiveness of the neuromodulation. For example, the electrode assemblies2600 can continually monitor nerve activity during neuromodulation by interleaving stimulation pulses and recording periods. In other embodiments, nerve monitoring periods can be spaced between neuromodulation periods to determine whether the nerves have been sufficiently modulated or if subsequent neuromodulation cycles are necessary to provide the desired modulation.
• FIG. 26 is an enlarged side view of a distal portion of atreatment device2750 within a blood vessel A (e.g., a pulmonary blood vessel) in accordance with a further embodiment of the present technology. Thetreatment device2750 includes a number of features generally similar to the features of thetreatment device2650 described above with reference toFIG. 25. For example, thetreatment device2750 includes anouter balloon2740 in fluid communication with a first supply lumen via anopening2746 at adistal portion2712 of anouter shaft2706, and aninner balloon2742 in fluid communication with a second supply lumen via anopening2746 of an inner shaft2744. Theouter balloon2740 can be inflated with a non-therapeutically effective fluid (e.g., air) to press against and maintain contact with the inner vessel wall. Theinner balloon2742 can be inflated with a cryogenic agent (e.g., a refrigerant) and/or other fluid to contact a portion of theouter balloon2740 and provide neuromodulation (e.g., via cryotherapeutic cooling or ultrasound) about the full circumference of an adjacent vessel wall (e.g., within a neuromodulation region2743).
• Thetreatment device2750 also includes first andsecond electrode arrays2700aand2700b(referred to collectively as electrode arrays2700) proximal and distal to the portion at which theinner balloon2742 contacts theouter balloon2740. Rather than continuous conductive strips around the circumference of theouter balloon2740, however, the electrode arrays2700 illustrated inFIG. 26 include a plurality ofpoint electrodes2748 on or in an outer wall of theouter balloon2740. Thepoint electrodes2748, for example, can be made from conductive ink printed on theouter balloon2740, conductive pads adhered to theouter balloon2740, and/or other suitable conductive features. Theindividual point electrodes2748 can be oriented about the circumference of theouter balloon2740 in various different patterns and provide monopolar and/or bipolar nerve stimulation and recording before, during and/or after neuromodulation.
• FIG. 27 is an enlarged side view of a distal portion of atreatment device2850 within a blood vessel A (e.g., a pulmonary blood vessel) in accordance with an additional embodiment of the present technology. Thetreatment device2850 includes several features generally similar to the features of thetreatment device2650 described above with reference toFIG. 25. For example, thetreatment device2850 includes first andsecond electrode arrays2800aand2800b(referred to collectively as electrode arrays2800) on anouter balloon2840 and positioned proximal and distal to aneuromodulation region2843 provided by aninner balloon2842. In the embodiment illustrated inFIG. 27, theinner balloon2842 has a smaller outer diameter in an inflated state than that of theouter balloon2840 and is attached to an interior surface of theouter balloon2840 using an adhesive, a heat-bond and/or other types of balloon connection. Theouter balloon2840 can be fluidly coupled to a supply lumen defined by ashaft2844 that delivers an insulative medium (e.g., a heated liquid, heated gas, ambient air, etc.) to theouter balloon2840 viaopenings2846, and theinner balloon2842 can be fluidly coupled to a separate supply lumen (not shown) that delivers an inflation fluid (e.g., a cryogenic agent) to theinner balloon2842.
• In use, theouter balloon2840 expands into full circumferential contact with the vessel wall to provide tissue apposition for signal transfer to and from the vessel wall via the electrode arrays2800. Theinner balloon2842 is essentially radially pulled toward only the portion of the vessel wall adjacent to where theinner balloon2842 is attached to theouter balloon2840. When a cryogenic agent and/or other therapeutic medium is introduced into theinner balloon2842, non-targeted tissue that is not adjacent to theinner balloon2842 is shielded or protected from ablation by the inflation medium located within theouter balloon2840. The targeted tissue adjacent to theinner balloon2842 is ablated, resulting in a partial circumferential neuromodulation. Theinner balloon2842 can be shaped or otherwise configured to provide a non-continuous, helical, and/or other type of ablation pattern.
• FIG. 28 is a block diagram illustrating amethod2900A of endovascularly monitoring nerve activity in accordance with an embodiment of the present technology. Themethod2900A can include deploying a nerve monitoring assembly and a therapeutic assembly in a vessel (e.g., a pulmonary blood vessel; block2902). The nerve monitoring assembly can include a plurality of multi-electrode rings (e.g., similar to themulti-electrode loops2402 described above with reference toFIGS. 23A-23C) connected to a distal portion of a catheter shaft. The multi-electrode rings can be made of nitinol or other shape memory materials such that they can be deployed by simply moving the catheter shaft and a sheath covering the multi-electrode rings relative to one another (e.g., pulling the sheath proximally, pushing the catheter shaft distally, etc.). Each multi-electrode ring can include a plurality of electrodes spaced around the circumference of the ring and communicatively coupled to signal wires extending through the catheter shaft. The signal wires can extend outside the body where they are operably coupled to a signal generator and/or receiver (e.g., an NIM) to generate stimuli and record the resultant action potential of the proximate neural fibers.
• When the therapeutic assembly is deployed, at least one and often two or more multi-electrode rings (“distal rings”) or another distal electrode assembly can be positioned distal to the therapeutic assembly and at least one multi-electrode ring (“proximal ring”) or other proximal electrode assembly can be positioned proximal to the therapeutic assembly. In other embodiments, the nerve monitoring assembly can include one, two, or more multi-electrode rings on either side of the therapeutic assembly. In further embodiments, other types of electrode arrays can be positioned proximal and distal to the therapeutic assembly. The therapeutic assembly, such as a single- or multi-electrode device or a cryoballoon, can be integrated with the same catheter shaft as the multi-electrode rings and positioned between the proximal and distal rings. In other embodiments, the therapeutic assembly can be attached to a separate catheter shaft and deployed between proximal and distal multi-electrode rings.
• Themethod2900A can further include delivering a plurality of short, high current stimulus pulses through the electrodes on one or both of the multi-electrode rings positioned distal to the therapeutic assembly (block2904), and analyzing an electrogram of at least one of the electrodes on the proximal ring resulting from the stimulus pulse (block2906). For example, a signal generator can pass a current having a magnitude of about 10-60 mA (e.g., 20 mA, 50 mA, etc.) for a pulse length of about 25-1,500 μs (e.g., 100-400 μs, 1 ms, etc.) between the electrodes of the distal rings in the deliveringprocess2904. The signal generator can also control the frequency of the signal such that the signal has a frequency of about 10-50 Hz (e.g., 20 Hz). After a predetermined time interval, a separate electrogram can be recorded through at least one electrode on the proximal ring. For example, a separate electrogram can be recorded through each of the electrodes of the proximal electrode ring. The length of the time interval between stimulation and recording depends on the separation of the distal and proximal rings along the length of the vessel such that the proximal ring picks up the signal resulting from the induced stimulus. For example, the time interval can be about 10-50 ms for rings spaced 10-50 mm apart. In an alternative embodiment, the delivering process (block2904) of themethod2900A can include delivering the short, high current stimulus pulses through at least one of the proximal electrode rings (e.g., proximal electrode assembly), and the analyzing process (block2906) of themethod2900A can include analyzing an electrogram of at least one of the electrodes of the distal electrode rings (e.g., distal electrode assembly).
• Themethod2900A can further include providing therapeutically-effective neuromodulation energy (e.g., cryogenic cooling, RF energy, ultrasound energy, etc.) to a target site using the therapeutic assembly (block2908). After providing the therapeutically-effective neuromodulation energy (block2908), themethod2900A includes determining whether the neuromodulation therapeutically treated or otherwise sufficiently modulated nerves or other neural structures proximate the treatment site (block2910). For example, the process of determining whether the neuromodulation therapeutically treated the nerves can include determining whether nerves were sufficiently denervated or otherwise disrupted to reduce, suppress, inhibit, block or otherwise affect the afferent and/or efferent pulmonary signals.
• FIG. 29 is a block diagram illustrating amethod2900B of endovascularly monitoring nerve activity in accordance with an embodiment of the present technology. Themethod2900B can include deploying a nerve monitoring assembly and a therapeutic assembly in a vessel (block2902) and delivering short, high current signal pulses through an electrode assembly (block2904) as described above with respect to themethod2900A inFIG. 28. In this embodiment, the analyzing process (block2906 ofFIG. 28) can optionally include recording the electrograms for each electrode on the proximal electrode ring or other proximal electrode assembly (block2906-1) and signal averaging a plurality of the recorded electrode signals (e.g., 10-100 recorded electrode signals) resulting from a corresponding plurality of stimulus pulses to enhance the recorded signal (block2906-2).
• Themethod2900B can optionally include identifying the nerve location proximate one or more of the electrode rings. For example, one or more of the recorded electrode signals may include a deflection or other change in the recorded current indicating an action potential caused by the stimulus (e.g., identified via signal averaging) indicating the transmission of an electrical impulse from the stimulus pulse via adjacent nerves. Electrode signals that include changes in current intensity correspond with the electrodes on the proximal ring positioned proximate to nerves. The higher the deflection or change in current intensity, the closer the electrode is to the nerves. This information can be used to identify electrodes on the proximal ring close to the nerves for effective nerve stimulation or recording (block2907-1). Optionally, the method2900 can include stimulating nerves via the proximal ring and recording electrograms of the individual electrodes at one of the distal rings to determine the location of nerves proximate the distal rings (block2907-2).
• Themethod2900B can also include providing therapeutically-effective neuromodulation energy (e.g., cryogenic cooling, RF energy, ultrasound energy, etc.) to a target site using the therapeutic assembly (block2908). In this embodiment, the process of determining whether the neuromodulation treated the nerves proximate the target site (block2910 inFIG. 28) can include repeating the nerve stimulation (block2904) and analyzing processes (block2906) discussed above to assess whether the neuromodulation caused any changes in the nerve activity (block2910-1). For example, short, high current stimulus pulses can be transmitted via the proximal or distal rings and the resultant nerve activity can be recorded by the opposing ring(s). Themethod2900B can then determine whether the nerves have been adequately modulated (block2912). For example, if the current density or other parameter observed in the recording electrodes proximate the nerve locations is below a threshold value, then the neuromodulation step may have effectively modulated or stopped conduction of the adjacent nerves and the neuromodulation process can be complete. On the other hand, if nerve activity is detected above a threshold value, the process of neuromodulating (block2908) and monitoring the resultant nerve activity (block2910-1) can be repeated until the nerves have been effectively modulated.
• In various embodiments, themethods2900A and2900B can also include repeating the nerve monitoring and neuromodulation steps in the opposite direction to confirm that the nerves have been adequately modulated. Themethods2900A and2900B can also optionally be repeated after a time period (e.g., 5-30 minutes, 2 hours, 1 day, etc.) to confirm that the nerves were adequately ablated (e.g., rather than merely stunned) and have not resumed conduction.
• In other embodiments, themethods2900A and2900B can be performed using other nerve monitoring assemblies or electrode arrays described above with reference toFIGS. 22A-29 and/or other suitable electrode arrangements. For example, the therapeutic assembly can include multiple point electrodes spaced around the circumference of a balloon as described above with respect toFIG. 27. In other embodiments, continuous wire loop electrodes and/or conductive strips on balloons can be used to identify nerve location and monitor nerve activity.
III. Examples
• 1. A catheter apparatus, comprising:
• • an elongated shaft having a proximal portion and a distal portion, wherein the distal portion of the shaft is configured for intravascular delivery to a body vessel of a human patient;
  • an energy delivery element positioned along the distal portion of the shaft; and
  • a plurality of deflectable members spaced apart about a circumference of the distal portion of the shaft, wherein each of the deflectable members is configured to transform from a low-profile state to a deployed state, thereby bending the distal portion and placing the energy delivery element in apposition with a wall of the body vessel.
• 2. The catheter apparatus of example 1 wherein the distal portion of the elongated shaft is sized and configured for intravascular delivery into the pulmonary artery.
• 3. The catheter apparatus of example 1 or example 2 wherein the each of the deflectable members comprises a bimetallic strip including a first material having a first coefficient of thermal expansion (CTE) positioned adjacent a second material having a second CTE that is different than the first CTE.
• 4. The catheter apparatus of any of examples 1-3 wherein each of the deflectable members comprises a bimetallic strip including a piezoelectric material and a substrate material coupled to one another along their lengths, wherein the piezoelectric material has a first CTE and the substrate material has a second CTE that is different than the first CTE.
• 5. The catheter apparatus of any of examples 1-4 wherein the therapeutic assembly comprises four deflectable members, wherein each of the deflectable members corresponds to a distinct quadrant of the shaft.
• 6. The catheter apparatus of any of examples 1-5 wherein the deflectable members extend along a length of the shaft and have a proximal terminus within the distal portion of the elongated shaft.
• 7. The catheter apparatus of any of examples 1-6 wherein the deflectable members have a length less than a length of the elongated shaft and a proximal terminus spaced distally apart from a proximal portion of the shaft.
• 8. The catheter apparatus of any of examples 1-7 wherein the deflectable members have distal terminus spaced proximally of the energy delivery device and a proximal terminus within the distal portion of the elongated shaft.
• 9. The catheter apparatus of any of examples 1-8 wherein the energy delivery element is a single energy delivery element positioned at a distal terminus of the shaft.
• 10. The catheter apparatus of any of examples 1 and 3-10 wherein the distal portion of the elongated shaft is sized and configured for intravascular delivery into the renal artery.
• 11. The catheter apparatus of any of examples 1-10, further comprising a handle at the proximal portion of the shaft, the handle including an actuator that is electrically coupled to each of the deflectable members, and wherein the deflectable members are independently transformable between their respective low-profile states and deployed states by activating the actuator.
• 12. The catheter apparatus of any of examples 1-11 wherein the energy delivery element is spaced apart from the deflectable members along the shaft.
• 13. The catheter apparatus of any of examples 1-11 wherein the energy delivery element is positioned on one or more of the deflectable members.
• 14. The catheter apparatus of any of examples 1-13 wherein the energy delivery element is a first energy delivery element, and wherein the catheter apparatus further comprises a second delivery element.
• 15. A catheter apparatus, comprising:
• • an elongated shaft having a proximal portion and a distal portion, wherein the distal portion of the shaft is configured for intravascular delivery to a body vessel of a human patient;
  • a deflectable member at the distal portion of the shaft and electrically coupled to the proximal portion, wherein the deflectable member comprises a bimetallic strip including a first material having a first CTE positioned adjacent a second material having a second CTE that is different than the first CTE; and
  • an energy delivery element on the deflectable member,
  • wherein heating the deflectable member deforms the deflectable member, thereby placing the energy delivery element in apposition with a wall of the body vessel.
• 16. The catheter apparatus of example 15 wherein the energy delivery element is a first energy delivery element, and wherein the catheter apparatus further comprises a second delivery element on the deflectable member.
• 17. The catheter apparatus of example 15 or example 16 wherein the energy delivery element is in direct contact with the deflectable member.
• 18. The catheter apparatus of any of examples 15-17 wherein the deflectable element is a first deflectable element, and wherein the catheter apparatus further comprises a second deflectable element.
• 19. A method, comprising:
• • intravascularly positioning a therapeutic assembly at a treatment site within a blood vessel, wherein the therapeutic assembly includes a deflectable member and an energy delivery element;
  • heating the deflectable member to position the energy delivery element in apposition with the blood vessel wall; and
  • ablating nerves proximate the treatment site via the energy delivery element.
• 20. The method of example 19 wherein intravascularly positioning the therapeutic assembly includes intravascularly positioning the therapeutic assembly within a pulmonary blood vessel.
• 21. The method of example 19 wherein intravascularly positioning the therapeutic assembly includes intravascularly positioning the therapeutic assembly within a renal blood vessel.
• 22. A treatment device, comprising:
• • a shaft including a proximal portion and a distal portion, wherein the shaft is configured to intravascularly locate the distal portion at a treatment site within a pulmonary blood vessel of a human patient;
  • a balloon at the distal portion of the shaft;
  • a lumen extending distally from a proximal portion of the shaft to an output port at the distal portion, wherein the output port is positioned along a portion of the shaft within the balloon, and wherein the output port is configured to deliver a cooling agent to an interior portion of the balloon;
  • a first electrode positioned on the outer surface of the balloon and extending about at least a portion of the circumference of the balloon;
  • a second electrode positioned on the outer surface of the balloon and extending about at least a portion of the circumference of the balloon, wherein the first electrode is spaced apart from and out of contact with the second electrode along the balloon;
  • wherein the first and second electrodes are configured to—
    • deliver therapeutic neuromodulation to nerves in communication with the pulmonary system proximate the treatment site, and
    • stimulate nerves and/or record nerve activity at the treatment site.
• 23. The treatment device of example 22 wherein the first electrode is configured to stimulate nerves proximate the treatment site and the second electrode is configured to record nerve activity at the treatment site during and/or after the therapeutic neuromodulation.
• 24. The treatment device of example 22 or example 23, further comprising an insulated portion between the first electrode and the second electrode on the outer surface of the balloon.
• 25. The treatment device of any of examples 22-24 wherein:
• • the first electrode is configured to deliver energy sufficient to modulate the nerves in communication with the pulmonary system; and
  • the second electrode is configured for bipolar recording of the nerve activity before, during, and/or after energy application.
• 26. The treatment device of any of examples 22-25 wherein the lumen is a first lumen, and wherein the shaft further includes a second lumen extending distally to an inlet port positioned along a portion of the shaft within the balloon.
• 27. The treatment device of any of examples 22-26 wherein at least one of the first and second electrodes includes a multi-electrode loop having at least two electrodes spaced circumferentially about the loop.
• 28. The treatment device of any of examples 22-27 wherein at least one of the first electrode and the second electrode is configured to deliver radio frequency (RF) energy sufficient to ablate nerves in communication with the pulmonary system proximate the treatment site.
• 29. The treatment device of any of examples 22-28 wherein the balloon is transformable between a delivery state and a deployed state and wherein, in the deployed state, the balloon is sized and shaped to occlude the pulmonary blood vessel.
• 30. The treatment device of any of examples 22-29 wherein the balloon is transformable between a delivery state and a deployed state and wherein, in the deployed state, the balloon is sized and shaped to place the first electrode and second electrode in apposition with an inner wall of the pulmonary blood vessel.
• 31. A method, comprising:
• • intravascularly deploying a treatment device in a pulmonary blood vessel of a human patient at a treatment site, wherein the treatment device includes an elongated shaft, and first and second electrodes;
  • ablating target nerves in communication with the pulmonary system via radio frequency (RF) energy delivered from the first electrode and/or the second electrode;
  • before ablation, stimulating the nerves in communication with the pulmonary system near the treatment site and recording the resulting nerve activity; and
  • after ablation, stimulating the nerves and recording the resulting nerve activity.
• 32. The method of example 31, further comprising confirming the effectiveness of the ablation on the nerves based on the post-ablation recording.
• 33. The method of example 31 or example 32 wherein stimulating the nerves in communication with the pulmonary system before and/or after ablation is performed by the first electrode and recording nerve activity before and/or after ablation is performed with the second electrode.
• 34. The method of any of examples 31-33 wherein:
• • stimulating the nerves in communication with the pulmonary system before and after ablation comprises providing bipolar stimulation to the nerves; and
  • recording nerve activity before and after ablation comprises providing bipolar recording of the nerve activity with the second electrode, wherein the second electrode is distal to the first electrode.
• 35. The method of any of examples 31-34 wherein:
• • stimulating the nerves in communication with the pulmonary system before and/or after ablation comprises delivering a plurality of stimulus pulses with the first electrode; and
  • recording nerve activity before and after ablation is performed by the second electrode, wherein recording comprises recording an electrogram of the second electrode and that corresponds to the nerve activity resulting from the corresponding stimulus pulses.
• 36. The method of any of examples 31-35 wherein deploying the treatment device includes deploying the first electrode proximal to the second electrode, wherein the first and second electrodes each comprise a loop electrode.
• 37. The method of any of examples 31-36 wherein deploying the treatment device in the pulmonary blood vessel comprises deploying the first electrode proximal to the second electrode.
• 38. The method of any of examples 31-37 wherein the treatment device further includes a balloon at a distal portion of the shaft and the first and second electrodes are positioned on an outer surface of the balloon, and wherein deploying the treatment device in the pulmonary blood vessel comprises inflating the balloon within a pulmonary artery, wherein the inflated balloon contacts an inner wall of the pulmonary artery.
• 39. The method of any of examples 31-38 wherein the treatment device further includes a balloon at a distal portion of the shaft and the first and second electrodes are positioned on an outer surface of the balloon, and wherein deploying the treatment device in the pulmonary blood vessel comprises inflating the balloon within a pulmonary artery, wherein the inflated balloon, the first electrode, and the second electrode contact an inner wall of the pulmonary artery.
• 40. The method of any of examples 31-39 wherein:
• • stimulating nerves after ablation and recording the resulting nerve activity is performed after delivering a first cycle of ablation to nerves in communication with the pulmonary system; and
  • the method further comprises delivering a second cycle of ablation to nerves in communication with the pulmonary system with the first and/or second electrodes when the recorded post-ablation nerve activity from the first cycle is above a predetermined threshold.
• 41. The method of any of examples 31-40 wherein recording nerve activity before and after ablation comprises providing bipolar recording of the nerve activity with the second electrode, wherein the second electrode is distal to the first electrode.
• 42. The method of any of examples 31-40 wherein recording nerve activity before and after ablation is performed by the second electrode, wherein recording comprises recording an electrogram of the second electrode and that corresponds to the nerve activity resulting from the corresponding stimulus pulses.
• 43. The method of any of examples 31-42 further comprising delivering a second cycle of ablation to nerves in communication with the pulmonary system with the first and/or second electrodes when the recorded post-ablation nerve activity from the first cycle is above a predetermined threshold.
• 44. A method, comprising:
• • intravascularly deploying a treatment device in a pulmonary blood vessel of a human patient at a treatment site, wherein the treatment device includes an elongated shaft and first and second electrodes at a distal portion of the shaft;
  • monitoring neural activity associated with target nerves in communication with the pulmonary system near the treatment site;
  • ablating the target nerves via radio frequency (RF) energy delivered from the first electrode and/or the second electrode; and
  • determining a location of the target nerves in communication with the pulmonary system before ablating the target nerves and/or an extent of ablation of the target nerves after ablation based on information obtained in the monitoring step.
• 45. The method of example 44 wherein monitoring neural activity associated with the target nerves in communication with the pulmonary system comprises inducing neural activity associated with the target nerves and recording the neural activity at the target nerves.
• 46. The method of example 44 wherein inducing the neural activity comprises stimulating the target nerves in communication with the pulmonary system.
• 47. A method, comprising:
• • intravascularly deploying a treatment device in a pulmonary blood vessel of a human patient at a treatment site;
  • ablating nerves in communication with the pulmonary system via the treatment device; and
  • recording activity of the nerves in communication with the pulmonary system.
• 48. The method of example 47 wherein the treatment device comprises an elongated shaft and first and second electrodes at a distal portion of the shaft.
• 49. The method of example 48 wherein ablating nerves in communication with the pulmonary system via the treatment device comprises delivering radio frequency (RF) energy from the first electrode and/or the second electrode to tissue of the pulmonary blood vessel.
• 50. The method of example 48 wherein ablating nerves in communication with the pulmonary system via the treatment device comprises delivering one or more chemicals to tissue of the pulmonary blood vessel.
• 51. The method of example 50 wherein ablating nerves in communication with the pulmonary system via the treatment device comprises delivering ethanol to tissue of the pulmonary blood vessel.
• 52. The method of example 48 wherein the treatment device further comprises a balloon at a distal portion of the shaft and the first and second electrodes are located on an outer surface of the balloon.
• 53. The method of example 48 wherein the treatment device further comprises a distal helical portion including the first and second electrodes.
• 54. The method of any one of examples 47-53 wherein recording activity of the nerves in communication with the pulmonary system comprises recording the activity after ablation of the nerves to confirm the effectiveness of the ablation.
• 55. The method of any one of examples 47-54, further comprising stimulating the nerves in communication with the pulmonary system before and/or after ablation is performed.
• 56. The method of example 47 wherein:
• • the treatment device comprises a first electrode and a second electrode;
  • the method further comprises stimulating the nerves in communication with the pulmonary system before and/or after ablation by providing bipolar stimulation to the nerves; and
  • recording nerve activity comprises providing bipolar recording of the nerve activity with the second electrode, wherein the second electrode is distal to the first electrode.
• 57. The method of example 47 wherein:
• • the treatment device comprises a first electrode and a second electrode;
  • the method further comprises stimulating the nerves in communication with the pulmonary system before and/or after ablation by delivering a plurality of stimulus pulses with the first electrode; and
  • recording nerve activity is performed by the second electrode, wherein recording comprises recording an electrogram of the second electrode and that corresponds to the nerve activity resulting from the corresponding stimulus pulses.
• 58. The method of example 47 wherein the treatment device comprises a first electrode and a second electrode.
• 59. The method of example 58, further comprising stimulating the nerves in communication with the pulmonary system with the first electrode before and/or after ablation is performed and recording nerve activity with the second electrode before and/or after ablation is performed.
• 60. The method of example 58 wherein deploying the treatment device includes deploying the first electrode proximal to the second electrode, wherein the first and second electrodes each comprise a loop electrode.
• 61. The method of example 58 wherein deploying the treatment device in the pulmonary blood vessel comprises deploying the first electrode proximal to the second electrode.
• 62. The method of example 47 wherein the treatment device comprises a balloon and wherein deploying the treatment device in the pulmonary blood vessel comprises inflating the balloon within a pulmonary artery, wherein the inflated balloon contacts an inner wall of the pulmonary artery.
• 63. The method of example 47 wherein the treatment device comprises a balloon and wherein deploying the treatment device in the pulmonary blood vessel comprises inflating the balloon within a pulmonary artery, wherein the inflated balloon, the first electrode, and the second electrode contact an inner wall of the pulmonary artery.
• 64. The method of example 55 wherein:
• • stimulating the nerves and recording the resulting nerve activity is performed after delivering a first cycle of ablation to nerves in communication with the pulmonary system; and
  • the method further comprises delivering a second cycle of ablation to nerves in communication with the pulmonary system when the recorded post-ablation nerve activity from the first cycle is above a predetermined threshold.
• 65. The method of example 47 wherein the pulmonary blood vessel comprises a pulmonary artery.
IV. Conclusion
• Although many of the embodiments are described below with respect to systems, devices, and methods for PN, the technology is applicable to other applications such as modulation of other nerves that communicate with the renal system, modulation of peripheral nerves, and/or treatments other than neuromodulation. Any appropriate site within the body may be modulated or otherwise treated including, for example, the pulmonary inflow tract, pulmonary veins, pulmonary arteries, the carotid artery, renal arteries and branches thereof. In some embodiments, cardiac tissue (e.g., the left and/or right atrium of the heart) may be modulated (e.g., to modulate electrical signals). Moreover, as further described herein, while the technology may be used in helical or spiral neuromodulation devices, it may also be used in non-helical or non-spiral neuromodulation devices as appropriate. Furthermore, other embodiments in addition to those described herein are within the scope of the technology. For example, in some embodiments the therapeutic assembly can include an expandable basket structure having one or more energy delivery elements positioned on the arms of the basket. Additionally, several other embodiments of the technology can have different configurations, components, or procedures than those described herein. A person of ordinary skill in the art, therefore, will accordingly understand that the technology can have other embodiments with additional elements, or the technology can have other embodiments without several of the features shown and described above with reference toFIGS. 1-29.
• Although many embodiments of the present technology are described for use in an intravascular approach, it is also possible to use the technology in a non-vascular approach, such as a cutaneous and/or transcutaneous approach to the nerves that innervate the pulmonary system. For example, the vagal and phrenic nerves may lie outside the lungs (e.g., in the neck region and/or in the inlet to the thoracic cavity) at various locations that may render them amenable to access via cutaneous puncture or to transcutaneous denervation. As such, devices and/or methods described herein may be used to effect modulation of vagal and/or phrenic nerves from within a carotid vein and/or a jugular vein. Neuromodulation at one or both of those locations may be effective (e.g., may provide a therapeutically beneficial effect with respect to treating pulmonary hypertension).
• The above detailed descriptions of embodiments of the technology are not intended to be exhaustive or to limit the technology to the precise form disclosed above. Although specific embodiments of, and examples for, the technology are described above for illustrative purposes, various equivalent modifications are possible within the scope of the technology, as those skilled in the relevant art will recognize. For example, while steps are presented in a given order, alternative embodiments may perform steps in a different order. The various embodiments described herein may also be combined to provide further embodiments.
• From the foregoing, it will be appreciated that specific embodiments of the technology have been described herein for purposes of illustration, but well-known structures and functions have not been shown or described in detail to avoid unnecessarily obscuring the description of the embodiments of the technology. Where the context permits, singular or plural terms may also include the plural or singular term, respectively.
• Moreover, unless the word “or” is expressly limited to mean only a single item exclusive from the other items in reference to a list of two or more items, then the use of “or” in such a list is to be interpreted as including (a) any single item in the list, (b) all of the items in the list, or (c) any combination of the items in the list. Additionally, the term “comprising” is used throughout to mean including at least the recited feature(s) such that any greater number of the same feature and/or additional types of other features are not precluded. It will also be appreciated that specific embodiments have been described herein for purposes of illustration, but that various modifications may be made without deviating from the technology. Further, while advantages associated with certain embodiments of the technology have been described in the context of those embodiments, other embodiments may also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages to fall within the scope of the technology. Accordingly, the disclosure and associated technology can encompass other embodiments not expressly shown or described herein.

Claims (21)

1-40. (canceled)

41: A non-occlusive catheter comprising:

an elongated shaft comprising a proximal portion and a distal portion; and

a therapeutic assembly carried by the distal portion, the therapeutic assembly comprising:

a therapeutic element carried by the distal portion; and

at least one expandable balloon attached to the distal portion, wherein, when in a deployed state, the at least one expandable balloon is configured to position the therapeutic element at a desired distance relative to a vessel wall and allow blood flow past the at least one expandable balloon.

42: The non-occlusive catheter ofclaim 41, wherein the at least one expandable balloon comprises a first balloon and a second balloon radially adjacent to the first balloon.

43: The non-occlusive catheter ofclaim 42, wherein the therapeutic element is within the first balloon.

44: The non-occlusive catheter ofclaim 41, wherein the at least one expandable balloon comprises a donut-shaped expandable balloon, which, in the deployed state, defines a longitudinally extending opening through which blood can flow.

45: The non-occlusive catheter ofclaim 44, wherein the longitudinally extending opening radially centrally located.

46: The non-occlusive catheter ofclaim 44, wherein the therapeutic element is within the donut-shaped expandable balloon.

47: The non-occlusive catheter ofclaim 41, wherein the therapeutic element comprises an energy delivery element.

48: The non-occlusive catheter ofclaim 47, wherein the energy delivery element comprises at least one of a radiofrequency electrode, a microwave transducer, an optical transducer, an ultrasound transducer, heating element, or a cryotherapeutic element.

49: The non-occlusive catheter ofclaim 48, wherein the therapeutic element comprises a substance delivery feature configured to deliver a neuromodulation chemical.

50: The non-occlusive catheter ofclaim 49, wherein the neuromodulation chemical comprises guanethidine, an alcohol, a phenol, a neurotoxin or an anesthetic agent.

51: The non-occlusive catheter ofclaim 41, wherein the distal portion and the therapeutic assembly are configured to be positioned in a pulmonary vessel.

52: A method comprising:

delivering a therapeutic assembly carried by a distal portion of an elongated shaft of a non-occlusive catheter within a blood vessel;

expanding at least one expandable balloon attached to the distal portion to a deployed state, wherein, when in the deployed state, the at least one expandable balloon is configured to position a therapeutic element of the therapeutic assembly at a desired distance relative to a vessel wall and allow blood flow past the at least one expandable balloon; and

delivering therapy to at least one nerve adjacent the blood vessel using the therapeutic element.

53: The method ofclaim 52, wherein the at least one expandable balloon comprises a first balloon and a second balloon radially adjacent to the first balloon, and wherein expanding at least one expandable balloon comprises expanding the first balloon and the second balloon.

54: The method ofclaim 53, wherein the therapeutic element is within the first balloon.

55: The method ofclaim 52, wherein the at least one expandable balloon comprises a donut-shaped expandable balloon, and wherein expanding at least one expandable balloon comprises expanding the donut-shaped expandable balloon to contact the vessel wall and define a longitudinally extending opening through which blood can flow.

56: The method ofclaim 55, wherein the longitudinally extending opening radially centrally located.

57: The method ofclaim 55, wherein the therapeutic element is within the donut-shaped expandable balloon.

58: The method ofclaim 52, wherein the therapeutic element comprises an energy delivery element, and wherein delivering therapy to the at least one nerve adjacent the blood vessel comprises delivery energy to the at least one nerve adjacent the blood vessel.

59: The method ofclaim 58, wherein the energy delivery element comprises at least one of a radiofrequency electrode, a microwave transducer, an optical transducer, an ultrasound transducer, heating element, or a cryotherapeutic element.

60: The method ofclaim 59, wherein the therapeutic element comprises a substance delivery feature configured to deliver a neuromodulation chemical, and wherein delivering therapy to at least one nerve adjacent the blood vessel comprises delivering the neuromodulation chemical to the at least one nerve adjacent the blood vessel.

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