Therapeutic vapor ablation

Abstract

Medical devices, systems, and methods for therapeutic vapor ablation treatment of airway-related diseases are disclosed. An exemplary ablation catheter includes an elongate catheter shaft having a proximal end region and a distal end region and including a lumen extending between the proximal end region and the distal end region; an expandable basket positioned adjacent a distal end region of the elongate catheter shaft and in fluid communication with the lumen, the expandable basket configured to move between an unexpanded configuration and an expanded configuration; and a nozzle positioned in a longitudinal direction along the expandable basket and configured to eject vapor to ablate tissue proximate thereto.

Description

Technical Field

[0001] This disclosure relates to medical systems, medical devices, and methods for performing therapeutic steam ablation using the medical systems and devices. More specifically, this disclosure relates to medical systems, devices, and methods related to therapeutic steam ablation treatment for airway-related diseases. Background Technology

[0002] A wide variety of medical devices have been developed for medical use. Some of these devices include guidewires, catheters, etc. These devices are manufactured using any of a variety of different manufacturing methods and can be used according to any of these methods. Each of the known medical devices and methods has certain advantages and disadvantages. There is a ongoing need to provide alternative medical devices and alternative methods for manufacturing and using these devices. Summary of the Invention

[0003] This disclosure provides designs, materials, manufacturing methods, and alternatives for use in medical devices.

[0004] The first example is an ablation catheter for vapor ablation of tissue, comprising: an elongated catheter shaft having a proximal end region and a distal end region and including a lumen extending between the proximal end region and the distal end region; an expandable basket positioned adjacent to the distal end region of the elongated catheter shaft and in fluid communication with the lumen, the expandable basket being configured to move between an unexpanded configuration and an expanded configuration; and a nozzle positioned longitudinally along the expandable basket and configured to eject vapor to ablate the tissue in its vicinity.

[0005] As an alternative to or supplement to any of the examples in this article, in another example, the expandable basket is configured to maintain a threshold distance between the tissue and the nozzle when the expandable basket is in an expanded configuration.

[0006] As an alternative to or supplement to any of the examples in this article, in another example, the threshold distance is in the range of about 0.5 mm to about 1.5 mm.

[0007] As an alternative to or supplement to any of the examples in this article, in another example, the expandable basket includes multiple legs, and nozzles are arranged along the multiple legs.

[0008] As an alternative to or supplement to any example in this article, in another example, the proximal end of each of the plurality of legs is coupled to the distal end region of the elongated conduit shaft, and the distal end of each leg is coupled to the distal cap.

[0009] As an alternative to or supplement to any of the examples in this article, in another example, each leg is an arched leg.

[0010] As an alternative to or supplement to any of the examples in this article, in another example, each leg is a generally convex leg.

[0011] As an alternative to or supplement to any of the examples in this article, in another example, the expandable basket includes multiple struts, and nozzles are arranged along the multiple struts.

[0012] As an alternative to or supplement to any example in this article, in another example, the proximal end of each strut is coupled to the distal end region of the elongated conduit shaft, and the distal end of each strut is coupled to the distal cap.

[0013] As an alternative or supplement to any example herein, in another example, each strut includes a first inclined section, a second inclined section, and a linear central section connecting the distal end of the first inclined section to the proximal end of the second inclined section; and a nozzle is located at least on the first and second inclined sections.

[0014] As an alternative to or supplement to any of the examples in this article, in another example, at least some of the nozzles are located on the inner surface of the expandable basket.

[0015] As an alternative to or supplement to any of the examples in this article, in another example, each nozzle is located on the inner surface of the expandable basket.

[0016] As an alternative to or supplement to any of the examples in this article, in another example, at least some of the nozzles are located on the outer surface of the expandable basket.

[0017] As an alternative to or supplement to any of the examples in this article, in another example, each nozzle is located on the outer surface of the expandable basket.

[0018] As an alternative to or supplement to any of the examples in this article, in another example, each nozzle is positioned along a portion of the expandable basket that does not contact the tissue when the expandable basket is in an expanded configuration.

[0019] Another example is an ablation catheter comprising: an elongated catheter shaft having a proximal end region and a distal end region and including a lumen extending between the proximal end region and the distal end region; an expandable basket positioned adjacent to the distal end region of the elongated catheter shaft and in fluid communication with the lumen, the expandable basket being configured to move between an unexpanded configuration and an expanded configuration; and a nozzle positioned longitudinally along the expandable basket and configured to eject vapor to ablate tissue in its vicinity, wherein the expandable basket is configured to maintain a threshold distance between the tissue and the nozzle when the expandable basket is in an expanded configuration.

[0020] As an alternative to or supplement to any example in this article, in another example, the outer surface of the expandable basket is free of ablation electrodes.

[0021] Another example is a system for tissue vapor ablation, comprising: a console configured to generate water vapor; and an ablation catheter coupled to the console, the ablation catheter comprising: an elongated catheter shaft having a proximal end region, a distal end region including a distal end, and a lumen extending between the proximal end region and the distal end region; an expandable basket positioned adjacent to the distal end region of the elongated catheter shaft and in fluid communication with the lumen, the expandable basket being configured to move between an unexpanded configuration and an expanded configuration; and a nozzle in fluid communication with the lumen and extending through the outer surface of an expandable balloon, wherein the nozzle is configured to eject water vapor to ablate tissue in a target region near the nozzle, wherein the expandable basket is configured to maintain a threshold distance between the tissue in the target region and the nozzle when the expandable basket is in an expanded configuration.

[0022] As an alternative to or supplement to any example herein, in another example, the expandable basket includes a plurality of legs configured to move between an unexpanded configuration and an expanded configuration, and each of the plurality of legs includes a central portion without a nozzle.

[0023] As an alternative to or supplement to any example in this article, in another example, the lumen includes a steam lumen, and the nozzle is in fluid communication with the steam lumen.

[0024] The above overview of some embodiments is not intended to describe every disclosed embodiment or implementation of the invention. The accompanying drawings and the following detailed description illustrate these embodiments in more specific terms. Attached Figure Description

[0025] The above overview of some embodiments is not intended to describe every disclosed embodiment or implementation of the invention. The accompanying drawings and the following detailed description illustrate these embodiments in more specific terms.

[0026] This disclosure will be more fully understood in light of the following detailed description taken in conjunction with the accompanying drawings, in which:

[0027] Figures 1A-1H A schematic diagram of an example system for performing steam ablation therapy within a body pathway is shown;

[0028] Figure 2A-2B A schematic diagram of an example ablation catheter placed within a body pathway is shown;

[0029] Figures 3A-3B A schematic representation of a side view of an ablation catheter is shown, which includes an exemplary expandable device configured to perform steam ablation therapy within a body pathway;

[0030] Figure 3C-3D A schematic diagram of a partial cross-section of an example steam ablation catheter is shown;

[0031] Figures 4A-4D A schematic representation of a side view of a steam ablation catheter is shown, which includes an expandable device configured to perform steam ablation therapy within a body pathway;

[0032] Figure 5 A schematic representation of a side view of an ablation catheter is shown, which includes an expandable device configured to perform steam ablation therapy within a body pathway;

[0033] Figure 6 A cross-sectional view of an example ablation catheter including a heating enhancement layer is shown; and

[0034] Figure 7 An example flowchart of a method for performing steam ablation therapy within a body pathway is shown.

[0035] While this disclosure is adaptable to various modifications and alternatives, its details have been illustrated by way of example in the accompanying drawings and will be described in detail. However, it should be understood that it is not intended to limit the invention to the specific embodiments described. Rather, the invention encompasses all modifications, equivalents, and alternatives falling within the spirit and scope of this disclosure. Detailed Implementation

[0036] The terms defined below shall apply unless otherwise specified in the claims or elsewhere in this specification.

[0037] Whether explicitly stated or not, this document assumes that all numerical values ​​are modified by the term "about". The term "about" generally refers to a range of numbers that a person skilled in the art would consider equivalent to the value stated (e.g., having the same function or result). For example, "about" may refer to a value within a percentage range (e.g., 10%, 5%, etc.). In many cases, the term "about" may include numbers rounded to the nearest significant figure.

[0038] The numerical range represented by the endpoints includes all numbers within that range (for example, 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

[0039] As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural indicators unless expressly stated otherwise. As used in this specification and the appended claims, the term “or” is generally used to mean “and / or” unless expressly stated otherwise.

[0040] It should be noted that references to "embodiments," "some embodiments," "other embodiments," etc., in the specification indicate that the described embodiments may include one or more specific features, structures, and / or characteristics. However, such descriptions do not necessarily imply that all embodiments include the specific features, structures, and / or characteristics. Furthermore, when a specific feature, structure, and / or characteristic is described in connection with an embodiment, it should be understood that, unless explicitly stated to the contrary, these features, structures, and / or characteristics may also be used in conjunction with other embodiments, whether explicitly described or not.

[0041] As used herein, “proximal” refers to the direction or position closest to the user (medical professional, clinician, technician, operator, or physician, etc.; these terms are used interchangeably herein without limitation and include automated control systems or other systems), such as when using the device (e.g., introducing the device into a patient, or during implantation, positioning, or delivery), and / or furthest from the delivery device, while “distal” refers to the direction or position furthest from the user, such as when using the device (e.g., introducing the device into a patient, or during implantation, positioning, or delivery), and / or closest to the delivery device. “Longitudinal” refers to extending along the longer or larger dimension of the element. “Longitudinal axis” extends along the longitudinal extent of the element, although it is not necessarily straight and does not necessarily maintain a fixed configuration if the element flexes or bends, and “axial” generally refers to along the longitudinal axis. However, it should be understood that axial or longitudinal movement of the aforementioned system or its elements is not strictly limited to axial and / or longitudinal movement along the longitudinal axis or central axis of the element. "Center" means at least approximately bisecting the center point and / or approximately equidistant from the periphery or boundary. For an opening, "central axis" means a line at least approximately bisecting the center point of the opening, which extends longitudinally along the length of the opening when the opening includes, for example, a tubular element, channel, cavity, or hole. As used herein, "cavity," "channel," or "passage" is not limited to a circular cross-section. As used herein, the "free end" or "farthest end" of an element is the terminating end beyond which the element does not extend. It should be understood that, unless otherwise stated, terms such as at one end, on one end, adjacent to one end, or along one end are used interchangeably herein and are not for limitation, but are intended to indicate general relative spatial relationships rather than precisely limited locations. Finally, reference to "at" a location or place means included and / or approximately in the vicinity of such a location or place (e.g., along, adjacent, near, etc.). As understood herein, correspondences are intended to convey relationships between parts, components, elements, etc., which are configured to interact with each other or have another anticipated relationship.

[0042] The following detailed description should be read with reference to the accompanying drawings, in which similar elements in different drawings are numbered the same. The drawings (not necessarily to scale) depict illustrative embodiments and are not intended to limit the scope of the invention.

[0043] This invention relates to medical systems, devices, and methods for treating obstructive and / or inflammatory lung diseases, and more specifically, to minimally invasive medical systems, devices, and methods for vapor ablation of the inner walls of the airways to limit airway constriction and obstruction.

[0044] Chronic obstructive pulmonary disease (COPD) and asthma are inflammatory diseases of the lungs that affect many people. Each disease is characterized by airflow limitation, which interferes with normal breathing. While COPD encompasses several conditions, including chronic bronchitis and emphysema, it is typically characterized by airflow obstruction. People with airflow obstruction may experience a variety of symptoms, including smooth muscle contractions, a chronic cough with excessive sputum production, and widespread thickening of the airway walls, all of which contribute to obstruction of normal breathing. Furthermore, because COVID-19 affects the respiratory system, COPD-related lung damage and functional loss may be exacerbated when patients are infected with COVID-19.

[0045] Various methods of treating COPD and asthma include pharmacological and interventional therapies. For example, inhaled bronchodilators (short-acting or long-acting) can be administered (e.g., daily) to relax and temporarily open the airways. However, side effects of these medications include nausea and vomiting, diarrhea, palpitations, rapid heartbeat, irregular heartbeat, headache, and sleep problems (insomnia), all of which are undesirable.

[0046] Interventional treatments, including various surgical and thermal ablation-based interventions, have been described as therapies for treating diseased airways. For example, endobronchial valves (EBSs) can be surgically implanted (e.g., permanently) to treat diseased airways. However, this approach is invasive, among other issues, and can be prone to surgical complications during or after the procedure.

[0047] Furthermore, some prior methods employed electrode-based radiofrequency (RF) ablation techniques, which deliver RF energy via electrodes to the airway walls to thermally ablate diseased tissue (e.g., reduce excess smooth muscle in the airway). These methods may non-selectively ablate individual layers of the airway walls, often undesirably ablating non-target tissue beyond the epithelium. Damage to tissues outside the epithelial treatment target can trigger an inflammatory cascade, leading to inflammation, which may result in worsening and remodeling. Consequently, the airway lumen may further narrow. Additionally, these methods may position the electrodes in direct contact with the tissue and, at least therefore, may tend to overheat the tissue and / or surrounding tissues; may be expensive; and / or may have a large profile (e.g., may be unsuitable for reaching smaller vascular systems, such as those further within the lungs).

[0048] Therefore, systems, devices, and methods for treating obstructive pulmonary disease and inflammatory diseases still need to overcome the aforementioned challenges. The systems, devices, and methods described in this article can employ bronchoscopic thermal vapor ablation (BTVA). BTVA is an endoscopic lung volume reduction (ELVR) treatment that helps reduce overinflation and improve respiratory mechanics in patients with severe emphysema. An inflammatory response is induced by steam ablation of the target segment (e.g., steam causes heat to be applied directly and uniformly to the wall tissue of the target area), resulting in a reduction in tissue and volume in most diseased emphysematous segments. As a result of BTVA, adjacent, healthier lung segments may function better (e.g., manifested as a reduction in lung overinflation), making breathing easier for the patient. Therefore, BTVA can improve symptoms and lung function, thereby improving the patient's quality of life. Furthermore, compared to other methods employing large-volume ablation electrodes (e.g., RF electrodes), the systems and methods described in this article are capable of treating smaller vascular systems (e.g., grade 3–5 bronchi).

[0049] Several systems, devices, and methods have been disclosed in the context of treating bronchial hyperresponsiveness (BHR) or chronic obstructive pulmonary disease (COPD) using steam ablation devices. However, the systems, devices, and methods of other embodiments can be used for other applications, such as renal nerve ablation. The expandable device described herein can be delivered via a bronchoscope or catheter and can be inserted into the bronchus in a slender configuration through the working channel of the bronchoscope or the lumen of the catheter.

[0050] Figure 1AA system 10 for performing steam ablation therapy (e.g., BTVA) within a body pathway is shown. The system 10 includes a console 40 and an ablation catheter 200 coupled to the console 40. The ablation catheter 200 may be a steam ablation catheter configured to eject steam (e.g., heated water vapor) from a nozzle included in the steam ablation catheter 200, as described in detail herein.

[0051] The ablation catheter 200 has a catheter shaft 205 that can remain outside the patient's body and a distal end region 216 suitable for insertion into the patient's body. Although not shown, the proximal end region of the catheter shaft 205 may include a hub attached thereto for connecting other diagnostic and / or therapeutic devices.

[0052] The catheter shaft 205 may have an elongated configuration with a circular cross-section or other suitable cross-section. Similarly, as described herein, the expandable device 230 may have a substantially circular cross-section or other suitable cross-section. Other suitable cross-sectional configurations are also contemplated, such as, but not limited to, rectangular, elliptical, irregular shapes, or other similar configurations. Furthermore, the catheter shaft 205 (and the expandable device 230) may be adapted for use via the trachea (e.g., as... Figure 2A-2B The trachea 102 shown is received in the desired body lumen, such as the bronchus (e.g., as shown in the image). Figure 2A-2B The cross-sectional configuration of the bronchus 104 shown. It should be noted that the dimensions of the duct shaft 205 can be controlled to guide it through any desired body lumen, such as through a bronchiole.

[0053] It is conceivable that the stiffness of the catheter shaft 205 can be varied to form an ablation catheter 200 for various vessel diameters. For this purpose, the material used to manufacture the catheter shaft 205 can include any suitable biocompatible material, such as, but not limited to, polymers, metals, and alloys, used in combination or alone. The material employed can have sufficient stiffness for various lumen diameters and sufficient flexibility to maneuver skillfully through tortuous and / or narrow lumens, thereby avoiding any undesirable tissue damage.

[0054] The catheter shaft 205 may further include one or more lumens (not shown) extending therethrough. For example, the catheter shaft 205 may include a guidewire lumen and / or one or more auxiliary lumens. The lumens may be configured in any suitable manner, such as those commonly used in medical devices. For example, the guidewire lumen may extend the entire length of the catheter shaft 205, as in an on-wire catheter, or it may extend only along the distal portion of the catheter shaft 205, as in a single operator exchange (SOE) catheter. These examples are not limiting but rather examples of possible configurations.

[0055] Although Figure 1AWhile not explicitly shown, the ablation catheter 200 may further include a temperature sensor / wire, an injection lumen, a radiopaque marker band, a fixed guidewire tip, a guidewire lumen, an external sheath, and / or other components to facilitate the use and advancement of the ablation catheter 200 within the patient's body.

[0056] Although the catheters described in this article (such as ablation catheter 200) can be used for both mapping and ablation functions, catheters that are particularly suitable for mapping may also be considered.

[0057] like Figure 1A As shown, the ablation catheter 200 may include an expandable device 230. As described herein, the expandable device 230 may be a compliant, non-compliant, or semi-compliant expandable balloon, expandable basket, or expandable stent-like structure. The expandable device 230 typically has a first low-profile unexpanded delivery configuration (e.g., an uninflated configuration) and a second expanded radially dilating configuration (e.g., an inflated configuration), in which a portion of the expandable device 230 contacts the wall of the blood vessel in which the ablation catheter 200 is deployed.

[0058] In some cases, a separate expandable device 230 may be provided along the ablation conduit 200. Using a separate expandable device 230 can facilitate various aspects of this text, such as precise delivery of steam to the target area while mitigating the emission of steam (e.g., water vapor) outside the target area. However, in some embodiments, a greater number of expandable devices may be employed.

[0059] It is also conceivable that, although not explicitly shown, the ablation catheter 200 may include other structures such as a deflectable tip, an anchoring protrusion, a handle, one or more sealing balloons located proximally and / or distally relative to the expandable device 230, and / or a coiling structure or other anchoring structures, such as those that can be used to bring the expandable device 230 into contact with and / or very close to the desired treatment area. In some embodiments, the system herein may include at least one thermistor (e.g., a thermistor assembly, thermistor array, etc.) electrically coupled to a console 40 (e.g., a control unit). Such a thermistor may be electrically configured to have temperature sensing capabilities. For example, the system may include a thermistor located in the console 40, in a handle (e.g., handle 220) positioned along the ablation catheter 200, and / or in the ablation catheter 200, among other possibilities.

[0060] The console 40 may include various components, including an energy generator (e.g., a steam generator, etc.) for delivering energy (e.g., steam energy) to the ablation catheter 200. That is, the console 40 may be fluidly connected (e.g., in fluid communication) to the ablation catheter 200. Furthermore, the console may be communicatively connected to the ablation catheter 200. Further details of the console 40 and the ablation catheter 200 are described herein.

[0061] In some embodiments, the ablation catheter described herein (e.g., ablation catheter 200) may be without an ablation electrode (e.g., an RF electrode). In some other methods, the ablation electrode is disposed on the outer surface of the medical device (e.g., on the outer surface of an expandable balloon and / or expandable basket) and configured to perform tissue ablation via the electrode. Employing a vapor ablation catheter without an ablation electrode (e.g., without an ablation electrode) can mitigate problems typically associated with electrode-based ablation methods (e.g., electrical short circuits and / or accidental tissue damage) and / or can produce ablation catheters with a relatively small cross-section, at least in the first (unexpanded configuration) (e.g., compared to electrode-based ablation catheters).

[0062] Figure 1B A schematic diagram of a system 20 for performing steam ablation therapy within a body pathway is shown. Figure 1B As shown, the control console 40 may include a reservoir 50, a pump 52, and heating elements that function as a first heating element 54 and a second heating element 56. However, other configurations of the control console 40 are also possible. For example, the control console 40 may include an autoclave as described herein.

[0063] Storage 50 can be a storage container configured to store liquids, such as liquid water, liquid deionized water, liquid distilled water, and other types of liquids. For example, storage 50 can be a water tank or other container configured to store liquid deionized water.

[0064] Pump 52 may be a pump configured to pump liquid stored in reservoir 50 to heating elements (such as first heating element 54 and second heating element 56). Pump 52 may control the flow rate of liquid supplied to the heating elements and / or the flow rate of water vapor supplied to ablation conduit 202. For example, water vapor generated from console 40 will enter the lumen of ablation conduit 202 (e.g., as shown in the image). Figure 3CThe steam is supplied to the ablation conduit 202 via the distal end of the ablation conduit 202 and / or via a nozzle (e.g., via a nozzle in the expandable device and / or in the ablation conduit 202) at the distal end region of the ablation conduit 202. In some embodiments, all steam supplied to the ablation conduit 202 is released via a nozzle in the expandable device. However, in some cases, a portion of the steam supplied to the ablation conduit 202 may be released via a nozzle in the expandable device, and the remainder of the steam may be released via the distal end of the ablation conduit 202, as described herein.

[0065] Heating elements 54 and 56 can be configured to heat the liquid via conduction, convection, and / or radiation. The first heating element 54 and the second heating element 56 can be resistance heating elements and / or tubular heating elements, as well as other types of heating elements. The first heating element 54 and the second heating element 56 can be positioned along the flow path between the pump 52 and the ablation conduit 202. The first heating element 54 and the second heating element 56 can be arranged in parallel or in series along the flow path between the pump 52 and the ablation conduit 202. For example, the first heating element 54 and the second heating element 56 can be arranged in series, such as... Figure 1B As shown. Arranging the first heating element 54 and the second heating element 56 in series can facilitate various aspects of this document, such as providing superheated steam (e.g., superheated water steam) to the ablation conduit 200. Although in Figure 1B The diagram shows two heating elements, but system 20 may include fewer or additional heating elements. Furthermore, although in Figure 1B The system is shown to include heating elements only in console 40, but in some cases, additional or alternative heating elements may be included in other places in system 20, such as along the length of the ablation catheter (e.g., along the catheter axis and / or in the handle of the ablation catheter).

[0066] The ablation catheter 202 may include a handle, such as Figure 1B The handle 220 is shown. Handle 220 may include circuitry and / or be otherwise configured to allow a physician to move the ablation catheter 202 within the patient's body, alter the configuration of the expandable device (to inflate or deflate the expandable balloon), and / or allow the physician to control the rate at which steam is supplied to the distal end region of the ablation catheter 202. For example, handle 220 may include one or more controllers (e.g., control knobs) configured to change the flow rate of water vapor delivered from console 40 via the steam lumen in the ablation catheter 202 to the distal end region of the ablation catheter 202 (e.g., to a nozzle in the expandable balloon).

[0067] As described in detail herein, the expandable device 230 may include a plurality of nozzles configured to eject steam. The expandable device 230 and the nozzles may be located in the distal end region of the ablation catheter 202. For example, the expandable device 230 may be an expandable balloon or expandable basket located in the distal end region 216 of the ablation catheter 202, which, as described in detail herein, is configured to eject steam to ablate tissue near the nozzles.

[0068] Although Figure 1A The presence of the expandable device 230 is shown, but an ablation catheter without the expandable device may be used (e.g., without the expandable device located in the distal end region of the ablation catheter). For example, as per [reference to...] Figure 1C and Figure 1D As described in detail, in the absence of an expandable device, the ablation catheter may include a nozzle located at the distal end region (e.g., along the outer surface of the ablation catheter and / or at the distal end of the ablation catheter). Using an ablation catheter without an expandable device can further reduce the profile of the ablation catheter and thereby facilitate various aspects of this document, such as allowing vapor to be ejected into the target area located in a relatively small blood vessel.

[0069] like Figure 1B As shown, Figure 1A The expandable device 230 can be embodied as an expandable balloon 231. The expandable balloon 231 may include a plurality of nozzles 232 configured to eject steam (represented as element 209). The expandable balloon 231 may be located in the distal end region 216 of the ablation catheter 202. Positioning the expandable device 231 and thus the nozzles 232 in the distal end region 216 facilitates aspects of this document, such as allowing steam to be ejected to a target area located in a relatively small blood vessel. For example, as described herein, in some embodiments, the expandable device 230 may be located at the distal end 210 of the ablation catheter.

[0070] In some embodiments, the ablation catheter, such as ablation catheter 202, may include a nozzle or opening 208 located at its distal end 210. The nozzle or opening 208 may be in fluid communication with a steam lumen in the ablation catheter. In this case, the nozzle, such as nozzle 232, and the nozzle or opening 208 may each be in fluid communication with a common (separate) lumen in the ablation catheter, which is configured to supply steam to the nozzle and the nozzle or opening 208. For example, water vapor may be supplied to the nozzle 232 via the steam lumen in the ablation catheter 202, and the remainder of the water vapor may continue to travel distally via the steam lumen until it is ejected by the nozzle or opening 208.

[0071] Figure 1CA schematic diagram of a system 22 for performing steam ablation therapy within a body pathway is shown. System 22 is similar to system 20, except that the ablation catheter 202 and the expandable balloon 231 are replaced by an ablation catheter 203 including a nozzle 232. Furthermore, unlike the ablation catheter 202, the ablation catheter 203 does not include a nozzle or opening located at its distal end 210. Thus, steam is delivered via a lumen in the ablation catheter 203 (e.g., Figure 1C (Not shown in the image) All the steam 209 supplied to the nozzle 232 can be ejected by the nozzle 232.

[0072] Figure 1D A schematic diagram of a system 24 for performing steam ablation therapy within a body pathway is shown. System 24 is identical to system 22, except that system 24 includes a nozzle or opening 208 located at the distal end 210 of the ablation catheter 204, instead of a nozzle 232. Thus, as described herein, the entire amount of steam 209 supplied to the nozzle or opening 208 via the steam lumen in the ablation catheter 204 can be ejected from the nozzle or opening 208.

[0073] Figure 1E A schematic diagram of a system 25 for performing steam ablation therapy within a body pathway is shown. System 25 is identical to system 22, except that system 25 includes a retractable motor actuator 83 configured to automatically retract the catheter shaft 205 of the ablation catheter. For example, the retractable motor actuator 83 may be a variable-speed motor configured to retract the elongated catheter at a given retraction rate and / or a predetermined retraction rate, the given retraction rate being determined, for example, by a user via input provided to a handle.

[0074] In some embodiments, the retraction of the elongated ablation catheter by the retractable motor driver 83 can occur at a predetermined retraction rate. For example, the distal end region 216 of the elongated catheter shaft 205 can be retracted into the blood vessel at a predetermined retraction rate while steam is ejected from a nozzle 232 located in the distal end region 216, thereby treating a larger area within the blood vessel more uniformly compared to a fixed position where the elongated catheter is deployed within the blood vessel.

[0075] The predetermined retraction rate can be fixed (e.g., constant) or variable. It can be determined based on vessel diameter (e.g., inner diameter), such as bronchial diameter, steam flow rate, steam temperature, disease severity, or the desired depth of heat penetration from steam 209 into the tissue, or any combination thereof. For example, as the elongated catheter retracts, the retraction rate can decrease gradually or incrementally. That is, as the distal end region of the catheter retracts, the vessels adjacent to the distal end region may become larger (e.g., with a gradually increasing inner diameter). Thus, a gradual or incremental decrease in the retraction rate can ensure a uniform effect on the tissue along the vessel (e.g., tissue further away from nozzle 232 is exposed to steam for a longer duration to ensure uniform treatment of the tissue along the retraction path).

[0076] Automatic retraction can occur in response to input to handle 220. For example, a physician can provide input to initiate and / or terminate the automatic retraction of the slender catheter. In some cases, automatic retraction of the slender catheter (e.g., longitudinally) can be combined with rotation of the slender catheter about its longitudinal axis. Combining automatic rotation about the longitudinal axis of the slender catheter (e.g., at a fixed or variable angular velocity) with automatic retraction of the slender catheter can facilitate aspects of this paper, such as promoting uniform application of steam along the length and circumference of the vessel.

[0077] Figure 1F A schematic diagram of a system 29 for performing steam ablation therapy within a body pathway is shown. System 29 is identical to system 22, except that system 29 includes a coil 88 extending from the distal end 210 of the ablation catheter 207. The coil 88 can be used to bring the nozzle 232 within a threshold distance of the desired treatment area. For example, the diameter of the coil 88 can be larger than the diameter of the elongated catheter shaft 205 of the ablation catheter 203 and thereby contact the vessel wall to anchor the nozzle 232 of the ablation catheter 203 at a threshold distance from the tissue in the vessel wall.

[0078] In some embodiments, the nozzle 232 may be micromachined into a tube or otherwise disposed within an ablation catheter, such as the elongated catheter shaft 205 of the ablation catheter 203. For example, the nozzle 232 may be micromachined into a substantially circular or elliptical opening extending longitudinally and / or circumferentially around the elongated catheter shaft 205, such as... Figure 1F As shown.

[0079] However, in some cases, the nozzle 232 may be an elongated slit extending substantially circumferentially around a portion of the conduit axis 205. For example, the nozzle may be formed by a series of elongated slits 237 positioned longitudinally along the elongated conduit axis 205 and extending substantially circumferentially around the elongated conduit axis, such as... Figure 1GAs shown. The use of a series of elongated slits 237 allows for the application of steam 209 through the elongated slits 237, and also provides greater flexibility for the catheter shaft 205, thereby facilitating the insertion of the ablation catheter.

[0080] In some embodiments, the outer surface of the ablation catheter may have a hydrophilic and / or friction-reducing coating. For example, a hydrophilic and / or friction-reducing coating on the outer surface of the distal end region of the elongated shaft can facilitate insertion and advancement of the distal end region into the patient. The use of a hydrophilic and / or friction-reducing coating can minimize discomfort and / or otherwise improve patient outcomes. These specialized sheaths offer numerous advantages over conventional sheaths, including improved patient comfort, reduced risk of infection, and faster recovery time.

[0081] The ablation catheter described in this article may include: Figures 1A-1H The lumen extending between the proximal end region 214 and the distal end region 216 of the ablation catheter (in Figures 1A-1H (Not shown in the document). As described herein, the lumen may include at least one steam lumen. The steam lumen may be in fluid communication with the console 40 and nozzles (e.g., nozzles in the distal end region and / or distal end of the ablation catheter and / or nozzles in the expandable device). In any case, the nozzle may be configured to receive and eject steam (e.g., superheated steam) via the steam lumen, for example, to perform BTVA. Furthermore, in embodiments having an expandable balloon 231, the lumen may include an expansion lumen fluidly coupled to the expandable balloon 231, as described herein.

[0082] Although Figure 1A-1G The presence of various components (e.g., heating elements 54, 56) in console 40 is shown, but some or all of the components in console 40 can be replaced by an autoclave. For example, Figure 1H A system 30 for performing steam ablation therapy within a body pathway is shown. Figure 1H System 30 and Figure 1B The system is the same as system 20, except that the reservoir 50, pump 52, and heating elements (e.g., first heating element 54 and second heating element 56) are replaced by an autoclave 60. Autoclave 60 refers to a device configured to supply heated steam to an ablation conduit, such as ablation conduit 202. Autoclave 60 may include a reservoir (not shown) configured to store a liquid (e.g., deionized water) and may include heating elements (not shown) configured to heat the liquid to form heated steam.

[0083] Figure 2A An exemplary ablation catheter (shown as) arranged along a body lumen is schematically illustrated. Figure 1BThe ablation catheter 202 includes an expandable balloon 231 with a nozzle (not shown). Similarly, Figure 2B An exemplary ablation catheter (shown as) arranged along a body lumen is schematically illustrated. Figure 4A The ablation catheter 202 includes an expandable basket 241 with a nozzle (not shown).

[0084] In these examples, the ablation catheter 202 extends through the trachea 102 and into the bronchus 104. For example... Figure 2A-2B As shown, compared to other methods, such as those using large-volume ablation electrodes (e.g., RF electrodes), the system and method of this paper can treat smaller vascular systems (e.g., 3rd-5th grade bronchi). The ablation catheter 202 can be used to identify target nerves along the bronchus 104 for treatment, for example, BHR disease, thereby reducing the probability of acute exacerbations of COPD (AECOPD). Although the ablation catheter 202 can be used to treat muscles and / or nerves along the patient's bronchus 104, it should be noted that the ablation catheter 202 can be used to identify and treat muscles and / or nerves along other body lumens, including those along the airways, blood vessels, etc. Furthermore, the ablation catheter 202 can be used to treat muscles and / or nerves located in other body areas such as the kidneys, heart, bladder, etc. As described above, ablation can be performed using BTVA, an endoscopic lung volume reduction (ELVR) treatment that helps reduce overinflation and improve respiratory mechanics in patients with various conditions, such as severe emphysema, thereby making breathing easier.

[0085] Figures 3A-3B A schematic side view of an ablation catheter 202 is shown, which includes an expandable device configured to perform ablation therapy within a body pathway. Figures 3A-3B As shown, the expandable device can be embodied as an expandable balloon 231. The expandable balloon 231 can be coupled to a corresponding position on the outer surface of the catheter shaft 205 and can be configured to expand radially (e.g., relative to the outer surface of the catheter shaft 205) to the expansion configuration, thereby bringing a portion of the expandable balloon 231 into contact with tissue in a target region of the blood vessel.

[0086] In other words, the expandable device described herein (e.g., expandable balloon and expandable basket) can be configured to switch between a first (unexpanded) configuration and a second (expanded) configuration. In the first configuration, the expandable device can remain in a straight configuration (e.g., having anchoring protrusions, legs, and / or struts arranged substantially parallel to the length of the conduit axis). Conversely, in the second configuration, the expandable device can switch to an expanded configuration (e.g., such that the anchoring protrusions, legs, and / or struts extend radially outward, for example, a configuration presenting an arcuate shape, such as an arcuate leg).

[0087] Typically, in the delivery state, for example when an ablation catheter, such as ablation catheter 202, penetrates the patient's body, especially body lumens, such as the trachea 102 (e.g. Figure 2A-2B When (as shown), the expandable device of this invention remains in the first extended configuration. Upon reaching the target position (e.g., as shown) Figures 2A-2B Within the patient's bronchus 104 (as shown), a physician can expand an expandable device (e.g., an expandable balloon 231). For example, the physician can inflate the expandable balloon 231 with fluid delivered via the expansion lumen and / or manipulate a proximal region of the ablation catheter to switch the expandable basket, as described herein, from a first (unexpanded) configuration to a second (expanded) configuration. In the second configuration, as detailed herein, the anchoring protrusions and / or legs can be adjusted and arranged such that one or more nozzles are positioned at a threshold distance away from but not in contact with the airway wall of the bronchus. In this case, treatment can be delivered to the target area to treat one or more symptoms in a COPD patient. For example, Figures 3A-3B The expandable balloon shown is illustrated in a second (expandable) configuration.

[0088] The expandable balloon 231 can be positioned on the elongated shaft, such as the distal end region of the elongated catheter shaft 205. In some cases, the expandable balloon 231 can be located at the distal end 210 of the elongated catheter shaft 205. For example, as... Figures 3A-3B As shown, the distal end of the expandable balloon 231 can be located at the distal end 210 of the elongated catheter shaft 205.

[0089] In some embodiments, the distal end of the expandable device (e.g., expandable balloon 231) and / or the distal end of the ablation catheter (e.g., distal tip 210 of the ablation catheter) may be blunt (e.g., generally rounded) and / or flexible. The blunt and / or flexible distal ends of the expandable device (e.g., expandable balloon and / or expandable basket) and / or the distal ends of the ablation catheter can facilitate aspects of this document, thereby promoting easier navigation of the ablation catheter and / or reducing any unintended damage to tissue compared to other methods employing sharp and / or rigid catheter tips.

[0090] The expandable device may include multiple nozzles disposed on the outer surface of the expandable device. For example, as described herein, the multiple nozzles may be arranged on the legs of the expandable basket or on the outer surface of the expandable balloon. For example, as... Figures 3A-3B As shown, multiple nozzles 232 and multiple anchoring protrusions 236 may be arranged around the outer surface 270 of the expandable balloon 231.

[0091] In some cases, the total amount of the anchoring protrusions 236 may be less than or equal to the total amount of the nozzles 232. For example, the total amount of the anchoring protrusions 236 may be less than the total amount of the nozzles 232, such as... Figure 3A As shown. However, in some cases, the total amount of the anchoring protrusions 236 can be equal to the total amount of the nozzles 232, such as... Figure 3B As shown. In some embodiments, the ratio of the total amount of nozzles 232 to the total amount of anchoring protrusions can be in the range of 20:1, 10:1, 6:1, 3:1, 2:1 or 1:1, and other possibilities.

[0092] The anchoring protrusions 236 and nozzles 232 can be located at corresponding (different) positions on the outer surface 270 of the expandable device (e.g., the expandable balloon 231). Each nozzle of the nozzles 232 can be located at its own distinct position. The anchoring protrusions 236 and nozzles 232 can be longitudinally positioned along the outer surface 270 of the expandable balloon 231 and / or circumferentially positioned around the outer surface. For example, the anchoring protrusions 236 and nozzles 232 can be longitudinally positioned along the outer surface 270 of the expandable balloon 231 and circumferentially positioned around the outer surface in a patterned array at different corresponding positions, such as... Figures 3A-3B As shown.

[0093] The anchoring protrusion 236 can be connected to the expansion lumen in the elongated catheter shaft 205 of the ablation catheter (e.g., as shown in the image). Figure 3C (The expansion lumen 311 is shown). In this case, the expansion of the outer surface 270 of the expandable balloon 231, or the expansion of the outer surface 270 and the expansion of the anchoring protrusion 236 itself (which is disposed on the outer surface 270), can cause the anchoring protrusion 236 to expand radially (e.g., relative to the outer surface of the elongated catheter shaft 205 and / or relative to the outer surface 270 of the expandable balloon 231). For example, causing the anchoring protrusion to expand radially relative to the outer surface 270 of the expandable balloon 231 (e.g., in addition to the radial expansion of the outer surface 270 of the expandable balloon 231 itself) can facilitate aspects such as facilitating the anchoring of the expandable balloon 231 at the target region in the blood vessel, maintaining the nozzle 232 at a threshold distance from the tissue in the target region, and / or facilitating the navigation of the ablation catheter (e.g., when the anchoring protrusion and the expandable balloon are in an unexpanded configuration).

[0094] In some cases, each anchoring protrusion 236 may be the same size and / or shape. For example, as Figure 3A , Figure 3B and Figure 3DAs shown, each anchoring protrusion 236 can be an elongated protrusion of the same size and shape (e.g., each protrusion has a tapered distal end and a proximal end). Using anchoring protrusions of the same size and shape can facilitate aspects of this document, such as facilitating anchoring of the expandable balloon 231 at the target location, facilitating uniform blood flow through the gap 296 between adjacent anchoring protrusions 236, and / or maintaining a threshold distance between the nozzle 232 and tissue in the target region. However, in some cases, the anchoring protrusions 236 can be of different sizes and / or shapes.

[0095] In some cases, the anchoring protrusions 236 may include a patterned array of anchoring protrusions positioned longitudinally and circumferentially around the outer surface 270 of the expandable balloon 231. That is, a plurality of anchoring protrusions 236 may extend longitudinally along the outer surface 270 of the expandable balloon 231, and a plurality of anchoring protrusions may extend circumferentially around the outer surface of the expandable balloon 231. For example, the anchoring protrusions 236 may be circumferentially positioned around the outer surface 270 of the expandable balloon 231 in a uniform pattern (e.g., with substantially equal distances between equivalent positions on adjacent anchoring protrusions 236), such as... Figures 3A-3B As shown. Positioning the anchoring protrusions 236 circumferentially around the outer surface 270 of the expandable balloon 231 in a uniform pattern array can facilitate aspects of this invention, such as facilitating anchoring of the expandable balloon 231 at the target location, facilitating uniform blood flow through the gaps 296 between adjacent anchoring protrusions, and / or maintaining a threshold distance between the nozzle 232 and tissue in the target region. However, in some cases, the anchoring protrusions 236 may be positioned non-uniformly around the outer surface 270 of the expandable balloon.

[0096] In some embodiments, the anchoring protrusions 236 may be constructed in substantially the same direction. For example, each anchoring protrusion 236 may be constructed in a first direction, such as... Figure 3A As shown, or it can be constructed in the second direction, such as Figure 3B As shown. For example, as Figure 3A As shown, each anchoring protrusion 236 can be constructed in a first direction substantially perpendicular to the longitudinal axis of the inflatable balloon 231. However, in some cases, such as Figure 3B As shown, each anchoring protrusion can be constructed in a second direction that extends substantially along the longitudinal axis of the expandable balloon 231.

[0097] like Figures 3A-3BAs shown, nozzle 232 can be located on the outer surface 270 of the expandable balloon 231 near the anchoring protrusion 236. As used herein, placing nozzle 232 near the anchoring protrusion 236 means that nozzle 232 is adjacent to the anchoring protrusion 236 but not in contact with it. For example, nozzle 232 can be positioned near at least one anchoring protrusion 236, such as... Figures 3A-3B As shown. Positioning the nozzle 232 adjacent to the anchoring protrusion 236 can facilitate some aspects of this paper, such as facilitating the ejection of steam through the nozzle 232 to ablate nearby tissue. That is, when the expandable balloon 231 is in a second (expanded) configuration, the anchoring protrusion 236 can anchor the expandable balloon 231 within a blood vessel in the patient's body.

[0098] However, unlike other methods, such as ejecting steam from a nozzle that directly contacts the inner wall 280 of a blood vessel, this method ensures that a threshold distance between the nozzle 232 and the inner wall 280 is maintained. For example, a threshold distance 290 can be maintained between the nozzle 232 on the outer surface 270 of the expandable device of, for example, an expandable balloon 231, and the inner wall 280 in the target region (e.g., the bronchus 104). Figure 3D As shown in the figure, this diagram illustrates a cross-section of the expandable balloon 231 (in... Figure 3A (Taken at section line 252 in the diagram). For example, when the expandable balloon 231 is in the expansion configuration, the expandable balloon 231 can be configured to maintain a threshold distance 290 between the tissue of the inner wall 280 and the nozzle (e.g., from the radially distal end of the nozzle 232), as... Figure 3C As shown. For example, nozzle 232 can be in a first position, in which nozzle 232 extends a first distance 292 from outer surface 270, and anchoring protrusion 236 can be in a second position, in which anchoring protrusion 236 extends a second distance 294 from outer surface 270, wherein the second distance 294 is greater than the first distance 292, as shown. Figure 3C As shown.

[0099] Maintaining the threshold distance 290 when the expandable balloon 231 is in the second (expanded) configuration can facilitate aspects of this paper, such as facilitating the precise application of steam to the inner wall 280 via the nozzle 232, and also preventing the unintentional application of steam to the tissue surrounding the target area.

[0100] In some embodiments, the threshold distance 290 may range from approximately 0.5 mm to approximately 1.5 mm. This includes all individual values ​​and sub-ranges from approximately 0.5 mm to approximately 1.5 mm. For example, the threshold distance may be approximately 0.5 mm, approximately 0.6 mm, approximately 0.7 mm, approximately 0.8 mm, approximately 0.9 mm, approximately 1.0 mm, approximately 1.1 mm, approximately 1.2 mm, approximately 1.3 mm, approximately 1.4 mm, or approximately 1.5 mm. In some embodiments, a distance of at least approximately 0.1 mm, at least approximately 0.2 mm, at least approximately 0.3 mm, at least approximately 0.4 mm, or at least approximately 0.5 mm may be maintained between the nozzle and the tissue (e.g., between the tissue on the inner wall of the blood vessel and the location on the nozzle closest to the (radial) tissue).

[0101] Unlike sealed balloons, the expandable devices of this invention (e.g., expandable balloons and / or expandable baskets) can be configured in some embodiments to allow blood flow through the expandable device when it is in a second (expanded) configuration. For example, anchoring protrusions 236 may contact tissue near the outer surface of the expandable balloon 231 and may allow blood to flow longitudinally through gaps 296 between adjacent anchoring protrusions 236. Allowing blood flow when the expandable device is in a second (expanded) configuration can improve patient experience and / or reduce complications compared to other methods of isolating intravascular regions using sealed balloons (e.g., compared to surgical procedures using sealed balloons).

[0102] As described above, nozzle 232 can be in fluid communication with the steam cavity. Figure 3C A cross-section of a portion of the ablation catheter (vapor ablation catheter) is shown. Figure 3A A schematic diagram (taken at section line 248). As described above, the elongated conduit shaft 205 may include a lumen 310 extending between a proximal end region and a distal end region of the elongated conduit shaft 205. In some embodiments, the lumen 310 may include a steam lumen 307 and an expansion lumen 311, such as... Figure 3C As shown. Figure 3C As shown, the steam cavity 307 and the expansion cavity 311 can be separate and independent respective cavities. The steam cavity 307 can be configured to allow steam (denoted as 309) to flow from a control console (e.g., as shown in the diagram). Figure 1AThe outlet of the console 40 shown is supplied to a nozzle (e.g., nozzle 232) in an expandable device within the ablation catheter. For example, steam can be supplied to nozzle 232 via a steam lumen 307, which ejects steam to ablate tissue adjacent to the nozzle. An expansion lumen 311 can be configured to allow fluid (denoted as 313) to be supplied from the console outlet to the anchoring protrusion 236. Fluid 313 can be a gas (e.g., compressed air) or a liquid (e.g., liquid water at room temperature or ambient temperature) having sufficient volume and / or pressure to cause expansion of the expandable balloon 231 and / or to cause expansion of the anchoring protrusion 236, as described herein.

[0103] like Figure 3D As shown, the nozzle 232 and the anchoring protrusion 236 can each be uniformly spaced around the circumference of the outer surface 270 of the expandable balloon 231. This uniform spacing of the nozzle 232 and the anchoring protrusion 236 around the circumference of the outer surface 270 facilitates various aspects of this invention, such as facilitating the anchoring of the expandable balloon 231 to the target region within the blood vessel, maintaining a threshold distance between the nozzle 232 and the tissue in the target region, and / or promoting uniform and effective vapor ablation of the tissue in the target region.

[0104] like Figures 3A-3B As shown, the expandable device 230 can be embodied as an expandable balloon 231. However, in some cases, the expandable device 230 can be embodied as a different structure, such as an expandable basket.

[0105] Figure 4A A schematic representation of a side view of an ablation catheter 272 is shown, which includes an expandable device configured to perform steam ablation therapy within a body channel. Figure 4A As shown, the expandable device can be represented as an expandable basket 241 coupled to the catheter shaft 205. Similar to the expandable balloon 231, the expandable basket 241 can also be configured to switch between first and second configurations, wherein the expandable basket 241 can remain straight in the first configuration and can switch to an expanded state in the second configuration. In some embodiments, the ablation catheter 272 may include a manipulating member or filament (not shown) that can be manipulated to change the expandable basket 241 from a first configuration (e.g., a generally straight configuration) to a second (expanded) configuration including a curved portion. For example, the manipulating member or filament can be configured to apply a longitudinal force to the distal cap 211, thereby causing the distal cap to translate longitudinally closer to the catheter shaft 205. Movement of the distal cap 211 can further cause the legs 226 to deflect axially outward, thereby forming a curved portion that can contact tissue at the target region.

[0106] The expandable basket 241 may include a plurality of legs 226 extending longitudinally along the expandable basket 241. Each leg 226 may be an arcuate leg with an arcuate configuration, such that the proximal end of each leg 226 can be coupled to a confluence 219 in the distal end region 216 of the ablation catheter 202, while the distal end of the leg 226 can be coupled to a distal cap 211. For example, the arcuate leg may be a fundamentally convex leg having a generally convex shape (e.g., a retainable convex arc) relative to the longitudinal axis of the expandable basket 241, such as... Figure 4A As shown. The outrigger 226 can be connected to the guide shaft 205 and the distal cap 211 using mechanisms such as adhesive bonding, brazing, soldering, thermal bonding, or mechanical adhesion. Although in Figure 4A The figure shows the distal end of a leg having a distal cap 211 connected to the ablation catheter 272, but in some cases, both the proximal and distal ends of the leg 226 can be connected to two different parts of the catheter shaft 205 (instead of connecting the distal end of the leg 226 to the distal cap 211).

[0107] One or more outriggers 226 may include one or more nozzles 232. Figure 4A In the illustrated embodiment, each leg 226 has four nozzles 232, which may be evenly arranged along the length of each leg 226. However, it should be noted that the leg 226 may include any number of nozzles 232 positioned evenly or non-evenly along the length of each leg 226.

[0108] In some embodiments, each nozzle 232 may be configured in an outward direction to direct steam outward (away) from each leg 226, such as Figure 4A As shown. Orienting at least some nozzles outward can facilitate aspects of this paper, such as minimizing the distance between the steam discharged from nozzle 232 and tissue at the target area (e.g., tissue at a threshold distance from nozzle 232).

[0109] However, in some embodiments, at least some of the nozzles 232 may be configured in an inward direction to guide steam inward (towards at least one adjacent leg). For example, each nozzle 232 may be oriented inward, such as... Figure 4B The ablation catheter 274 is shown in the diagram. Orienting at least some of the nozzles inward can facilitate aspects of this paper, such as ensuring a threshold distance is maintained between nozzle 232 and tissue adjacent to the nozzles.

[0110] In some embodiments, the central or most central nozzle may be configured inwards, while other more distal or more proximal nozzles may be configured outwards, such as... Figure 4CAs shown. Therefore, the outrigger 226 can secure the expandable basket 241 in place against the blood vessel wall (e.g., in direct contact with tissue) at the target location, and steam can be ejected via each nozzle 232, at least due to the inward-facing configuration of the central or most central nozzle, each nozzle is located at a threshold distance from the tissue (e.g., the tissue in contact with the outrigger 226) at the target area.

[0111] Similarly, in some embodiments, the central portion 234 of the outrigger 226 may be nozzle-free. For example, as Figure 4C As shown, the central portion 234 (e.g., the radialmost region of the leg 226 when the expandable basket 241 is in the second configuration) may be nozzle-free. In this way, the central portion 234 of the leg portion 226 can be configured to contact tissue at the target region, and the nozzles 232 disposed adjacent to the central portion 234 (e.g., proximal or distal from the central portion 234) can each maintain a threshold distance from the tissue at the target region.

[0112] In some embodiments, each outrigger 226 may include a nozzle 232, such as Figures 4A-4C As shown. However, in some embodiments, a portion (but not all) of the outrigger 226 may include the nozzle 232. For example, a first subset 226 of the outrigger 226 may include the nozzle 232, while a second subset 229 of the outrigger may not include the nozzle, as shown. Figure 4D As shown. For example, as Figure 4D As shown, the legs can alternate between having nozzles and not having nozzles, such that (circumferentially around the longitudinal axis of the ablation catheter 278) every other leg includes a nozzle 232. In this case, the leg 226 without a nozzle can be configured to extend a first (larger) distance from the longitudinal axis of the ablation catheter 202, thereby allowing direct contact with tissue in the target area, while the leg with nozzle 232 can be configured to extend a second (smaller) distance from the longitudinal axis of the ablation catheter 202, thereby allowing the nozzle 232 to maintain a threshold distance from the tissue in the target area.

[0113] Although Figures 4A-4D An ablation catheter including a basket with a curved central portion is shown, but in some embodiments, the basket may include different configurations. For example, an expandable basket may include a strut with a linear central portion, such as... Figure 5 As shown.

[0114] Figure 5An exemplary ablation catheter 560 is shown, having a catheter shaft 205 with an expandable basket 555 formed by a plurality of struts 561. The catheter shaft 205 may include a plurality of longitudinal struts 561 extending distally therefrom. One or more struts 561 may have at least one nozzle 232 disposed thereon. Any number of struts, legs, balloons, baskets, and / or nozzles may be applied to the expandable device herein. As described herein, the nozzle 232 may extend inward (e.g., configured in an inward direction) or outward (e.g., configured in an outward direction) from the strut 561 and may be coupled to a vapor lumen (not shown) in the catheter shaft 205.

[0115] In some embodiments, each strut 561 may include a first inclined segment 582, a second inclined segment 584, and a linear central segment 580 connecting the distal end of the first inclined segment 582 to the proximal end of the second inclined segment 584, such as Figure 5 As shown. That is, the first inclined segment 582 can be the closest element of the strut, the second inclined segment 584 can be the furthest segment of the strut, and the linear center segment 580 can be located between the first inclined segment 582 and the second inclined segment 584. When the expandable basket is in an expanded configuration, the inclined segments 582, 584 can extend relative to the longitudinal axis of the expandable basket 555 at a non-zero angle (e.g., in the range from about 1 degree to about 60 degrees), as shown. Figure 5 As shown. Figure 5 As shown, the linear central segment 580 can extend substantially coaxially or substantially parallel to the longitudinal axis of the expandable basket 555.

[0116] In such embodiments, the linear center segment 580 may include one or more nozzles (e.g., one or more inwardly configured nozzles). However, in some embodiments, the linear center segment 580 may be nozzle-less (e.g., without any nozzles), such as... Figure 5 As shown. In some embodiments, the linear center segment 580 of the strut 561 may be nozzle-free (e.g., without nozzles), and one or both of the inclined segments 582, 584 may include nozzles. In some embodiments, nozzles 232 are located at least on the first inclined segment and the second inclined segment. For example, each of the first inclined segment 582 and the second inclined segment 584 of the strut 561 may include a plurality of nozzles 232 thereon, and the linear center segment 580 may be nozzle-free, such as... Figure 5As shown. That is, the first inclined section 582 and the second inclined section 584 of the strut 561 may include a plurality of nozzles 232 thereon, which are configured in an outward direction (e.g., configured to eject steam in a direction away from the longitudinal axis of the expandable basket 555), and the linear center section 580 may be nozzle-free, as... Figure 5 As shown.

[0117] However, in some embodiments, one or more inclined segments 582, 584 and / or linear center segment 580 may include nozzles configured in an inward direction (e.g., configured to eject steam in a direction toward the longitudinal axis of the expandable basket 555). For example, in some embodiments, inclined segments 582, 584 may include nozzles configured in an outward direction, and linear center segment 580 may include nozzles configured in an inward direction. However, in some embodiments, each of inclined segments 582, 584 and linear center segment 580 may include nozzles configured in an inward direction (e.g., only nozzles configured in an inward direction).

[0118] Employing an expandable basket with the configuration described herein ensures that each nozzle can maintain a threshold distance from the tissue at the target region when the expandable basket 555 is in its expanded configuration. That is, nozzle 232 can be located on the inner and / or outer surfaces of the legs and / or struts of the expandable basket herein. For example, in some embodiments, the expandable baskets herein (e.g., expandable baskets 241 and / or 555) can include at least some nozzles located on the inner surface of the expandable basket. As used herein, the inner surface of a leg or strut refers to the portion of the leg or strut closest to the longitudinal axis of the expandable basket. That is, the inner surface of the leg or strut can be oriented toward the longitudinal axis of the expandable basket. For example, in some embodiments, each nozzle in the expandable basket herein can be located on the inner surface of the legs or struts of the expandable basket. For example, a nozzle can be located on the inner surface of a leg or strut and configured to eject vapor in a direction substantially toward the longitudinal axis of the expandable basket. However, in some embodiments, one or more nozzles can be located on the outer surface of the expandable basket herein. As used herein, the outer surface of a leg or strut refers to the portion of the leg or strut that is least close to (or relatively close to) the longitudinal axis of the expandable basket. That is, the outer surface of the leg or strut may be oriented away from the longitudinal axis of the expandable basket. For example, in some embodiments, each nozzle in the expandable basket herein may be located on the outer surface of the leg or strut of the expandable basket. For example, a nozzle may be located on the outer surface of the leg or strut and configured to eject steam in a direction substantially away from the longitudinal axis of the expandable basket.

[0119] Similar to the expandable basket 241 with legs described herein, an expandable basket 555 with strut 561 can also be configured to switch between first and second configurations, wherein the expandable basket 555 can remain straight in the first configuration and can switch to an expanded state in the second configuration. In some embodiments, the ablation catheter 560 may include a manipulating member or filament (not shown) that can be manipulated to change the expandable basket 555 from a first configuration (e.g., a generally straight configuration) to a second (expanded) configuration, the second (expanded) configuration including a strut (e.g., extending axially from the expandable basket 555) in the expanded configuration. For example, the manipulating member or filament may be configured to apply a longitudinal force on the distal cap 511, thereby causing the distal cap 511 to translate longitudinally closer to the catheter axis 205. The movement of the distal cap 511 can then cause the strut 561 to deflect axially outward, thereby forming a strut with a linear central segment 580 that can contact tissue at the target region. For example, the linear central segment 580 can contact the tissue at the target region, and the inclined segments, such as the first inclined segment 582 and the second inclined segment 584, can be spaced apart from the tissue. Therefore, when the expandable basket 555 is in its expanded configuration, the expandable basket 555 can be configured to maintain a threshold distance between the tissue and the nozzle. Although Figure 5 The nozzle 232 in a specific position is shown, but other nozzle configurations, such as those described above, are also possible. Figures 4A-4D The expandable baskets described in section 421 are also possible.

[0120] Figure 6 An exemplary cross-sectional view of a portion of an ablation catheter 200, including a heating enhancement layer 670, is shown. The heating enhancement layer 670 is positioned along the catheter axis of the ablation catheter 200 (e.g., as shown in the diagram). Figure 1A , Figures 4A-4D and / or Figure 5 The presence of at least a portion or all of the illustrated conduit shaft 205 may facilitate aspects of this document. For example, the heat-enhancing layer 670 may be heated to temperatures above ambient temperature and / or above normal body temperature. For example, among other possibilities, the heat-enhancing layer may be heated to temperatures greater than about 36.5 degrees Celsius or greater than about 37.5 degrees Celsius.

[0121] like Figure 6 As shown, the heat enhancement layer 670 can be disposed between the inner layer 668 and the outer layer 676. For example, the heat enhancement layer 670 can be disposed around the entire circumference of the inner layer 668, such as... Figure 6 As shown. The inner layer 668 can define a lumen (e.g., see reference). Figure 3C The cavity 310 is described. The inner layer 668 can be formed of a thermally conductive material, such as various polymers and / or metals. The outer layer 676 can be disposed around the entire circumference of the heat-enhancing layer 670, such as... Figure 6 As shown. The outer layer 676 may be formed of an insulating material configured to retain or reflect heat from the heating enhancement layer 670 within the conduit shaft.

[0122] The heating reinforcement layer 670 may be formed of a hybrid braided structure comprising at least two different materials. For example, a first material 672 may form a portion of the heating reinforcement layer 670, and a second material 674 may form the remainder of the heating reinforcement layer 670. In some embodiments, the first material 672 may be configured to be heated, while the second material 674 may be configured to provide structural integrity and / or flexibility to the ablation catheter. For example, the heating reinforcement layer 670 may be a carbon fiber-based heating reinforcement layer, wherein the first material 672, the second material 674, or both the first material 672 and the second material 674 are carbon fibers. Using carbon fibers in one or both of the first material 672 and the second material 674 can facilitate aspects described herein, such as facilitating the heating of vapors within the lumen of the ablation catheter 200 and maintaining a relatively small diameter of the ablation catheter 200, and can also facilitate the structural integrity and / or maneuverability of the ablation catheter 200. For example, in some embodiments, the first material 672 may be formed of carbon fiber (e.g., formed of carbon fiber only), and the second material 674 may be formed of a metal such as stainless steel, a polymer (e.g., a doped polymer), and / or another material. The first material 672 and the second material 674 may be present in a 1:1 ratio as well as other possible ratios.

[0123] In some embodiments, the methods described herein may include applying heat to steam in the lumen (e.g., steam lumen) of the ablation conduit 200 via a heat-reinforcing layer 670 (e.g., a carbon fiber-based heat-reinforcing layer). Similarly, these methods can reduce heat loss from the steam during its longitudinal transport along the ablation conduit (e.g., the length of the ablation conduit may be in the range of 1.5 m to 2.5 m, thus facilitating heat dissipation from the steam). For example, the first material 672 may be formed of carbon fiber, which may be inductively heated (or otherwise heated) at its proximal end, and heat may be transferred longitudinally along the longitudinal axis of the ablation conduit 200 and at least radially from the first material 672 to the steam in the steam lumen along the longitudinal axis of the ablation conduit 200.

[0124] Figure 7 An example flowchart of a method 770 for therapeutic steam ablation of tissue is shown. Method 770 employs the steam ablation catheter described herein.

[0125] In 772, method 770 includes providing a vapor ablation catheter. In some embodiments, method 770 includes providing a vapor ablation catheter configured to eject steam via a nozzle and configured to maintain a threshold distance between the nozzle and tissue in a target region, as described herein. For example, a vapor ablation catheter including an expandable device may be provided. In some embodiments, the expandable device may be an expandable balloon or an expandable basket. The expandable device may be positioned adjacent to a distal end region of an elongated catheter shaft and have a nozzle thereon. In some embodiments, the expandable device is an expandable balloon coupled to a distal end region of an elongated catheter shaft, wherein the expandable balloon includes an anchoring protrusion, as described herein. However, in some embodiments, the expandable device is an expandable basket coupled to a distal end region of an elongated catheter shaft and includes legs and / or struts thereon having nozzles, as described herein.

[0126] In 774, method 770 may include advancing a vapor ablation catheter through a body lumen to a location adjacent to a target region. In some embodiments, advancing the vapor ablation catheter through a body lumen includes advancing the vapor ablation catheter at least through a bronchus. For example, the distal end region of the ablation catheter may be advanced through the trachea to a location within the left bronchus. As described above, the vapor ablation catheter may be advanced in a first (undilated) configuration (e.g., from a location outside the patient to a target region inside the body).

[0127] In 776, the method may include expanding the expandable device. For example, after advancing the expandable device to a target area, the expandable device may be changed from a first (unexpanded) configuration to a second (expanded) configuration. For example, an operator may actuate a vapor ablation catheter to expand a balloon or basket, thereby anchoring the balloon or basket at the target area and maintaining a threshold distance between the nozzle and the tissue in the target area. In some embodiments, this includes moving the expandable basket relative to the catheter axis to radially expand at least one of the expandable legs and / or struts. Alternatively, this may include expanding the expandable balloon (e.g., until a portion of the anchoring mechanism contacts the tissue in the target area) by introducing fluid and / or increasing the fluid pressure via the expansion lumen, as described herein. Other mechanisms for expanding and / or anchoring the expandable device are possible.

[0128] In 778, method 770 may include applying steam to tissue in a target area. For example, when the expandable device is in a second configuration, at least one nozzle may be used to stimulate the target area by spraying heated water vapor for a therapeutic duration. In some embodiments, as described herein, applying steam may manifest as applying heated water vapor heated to a temperature above normal body temperature (e.g., 36.5 to 37.5 degrees Celsius). In some embodiments, method 770 includes retracting the steam ablation catheter while applying steam. In some embodiments, method 770 includes automatically retracting the steam ablation catheter at a predetermined retraction rate while applying steam, as described herein. In some embodiments, as described herein, the predetermined retraction rate is based on vessel diameter, steam flow rate, steam temperature, or any combination thereof. In some embodiments, as described herein, the predetermined retraction rate decreases as the elongated catheter is retracted. After steam discharge, the operator may actuate the catheter to retract the expandable device (e.g., change the expandable basket from the second configuration to the first configuration) and then remove the ablation catheter (e.g., the distal end region of the ablation catheter) from the patient.

[0129] Although the above embodiments have been described in conjunction with methods and appendages for ablating nerves located within a patient's bronchi, those skilled in the art will understand that the principles described herein can be applied to any method and / or device considered advantageous for modulating nerves. Conversely, construction details, including manufacturing techniques and materials, are entirely within the understanding of those skilled in the art and are not elaborated herein. These, and other modifications and variations, are entirely within the scope of this disclosure and can be conceived and implemented by those skilled in the art.

[0130] Materials that can be used in the various medical devices and / or components disclosed herein may include metals, metal alloys, polymers (some examples of which are disclosed below), metal-polymer composites, ceramics, combinations thereof, etc., or other suitable materials. Some examples of suitable polymers may include polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), and polyoxymethylene (POM, e.g., available from DuPont). Polyether block esters, polyurethanes (e.g., polyurethane 85A), polypropylene (PP), polyvinyl chloride (PVC), and polyether esters (e.g., available from DSM Engineering Plastics). ), ether or ester copolymers (e.g., butene / poly(alkylene ether) phthalates and / or other polyester elastomers, such as those available from DuPont). ), polyamide (e.g., available from Bayer) Or it may be available from Elf Atochem ), elastic polyamide, block polyamide / ether, polyether block amide (PEBA, for example, can be used in Acquired under a trademark), ethylene vinyl acetate copolymer (EVA), silicone, polyethylene (PE), Marlex high-density polyethylene, Marlex low-density polyethylene, linear low-density polyethylene (e.g., Polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polypropylene terephthalate, polyethylene naphthalate (PEN), polyetheretherketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene ether (PPO), poly(p-phenylene terephthalamide) (e.g., Polysulfone, nylon, nylon-12 (e.g., available from EMS American Grilon) Perfluoropropyl vinyl ether (PFA), ethylene vinyl alcohol, polyolefins, polystyrene, epoxy resins, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (e.g., SIBS and / or SIBS 50A), polycarbonate, ionomers, biocompatible polymers, other suitable materials, or mixtures, combinations, copolymers, polymer / metal composites thereof. In some embodiments, the sheath may be blended with a liquid crystal polymer (LCP). For example, the blend may contain up to about 6 percent LCP.

[0131] Some examples of applicable metals and metal alloys include stainless steels such as 304V, 304L, and 316LV stainless steels; low-carbon steels; nickel-titanium alloys such as linearly elastic and / or hyperelastic nickel-titanium alloys; and other nickel alloys such as nickel-chromium-molybdenum alloys (e.g., UNS: N06625, for example...). 625, UNS: N06022, for example UNS: N10276, for example other Alloys, etc.), nickel-copper alloys (e.g., UNS: N04400, for example). 400, 400, 400, etc.), nickel-cobalt-chromium-molybdenum alloy (e.g., UNS: R30035, for example). (etc.), nickel-molybdenum alloys (e.g., UNS: N10665, for example) alloy Other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, other nickel-tungsten or tungsten alloys, etc.; cobalt-chromium alloys, cobalt-chromium-molybdenum alloys (e.g., UNS: R30003, for example...). (etc.); platinum-rich stainless steel, titanium, combinations thereof, or any other suitable material.

[0132] In some embodiments, the linear elastic and / or non-hyperelastic nickel-titanium alloy may be in the range of about 50 wt% to about 60 wt% nickel, with the remainder being substantially titanium. In some embodiments, the nickel content in the composition ranges from about 54 wt% to about 57 wt%. An example of a suitable nickel-titanium alloy is the FHP-NT alloy, which is available from Furukawa Techno Material Co., Kanagawa, Japan. Examples of nickel-titanium alloys are disclosed in U.S. Patent Nos. 5,238,004 and 6,508,803, which are incorporated herein by reference. Other suitable materials may include ULTANIUM. TM (Available from Neo-Metrics) and GUM METAL TM (Available from Toyota). In some other embodiments, the desired properties can be achieved using a superelastic alloy (e.g., superelastic nitinol).

[0133] In at least some embodiments, the devices disclosed herein may be partially or entirely doped with, made of, or otherwise comprised of a radiopaque material. A radiopaque material is understood to be a material capable of producing a relatively bright image on a fluorescent examination screen or other imaging technique during medical procedures. This relatively bright image helps the user determine the location of the device within the patient's body. Some examples of radiopaque materials may include, but are not limited to, gold, platinum, palladium, tantalum, tungsten alloys, polymeric materials loaded with radiopaque fillers, etc. Additionally, other radiopaque marking strips and / or coils may be incorporated into the designs disclosed herein to achieve the same results.

[0134] In some embodiments, a degree of magnetic resonance imaging (MRI) compatibility is endowed to the devices disclosed herein. For example, the devices and / or components thereof disclosed herein may be made of materials that substantially do not distort images or produce significant artifacts (i.e., gaps in the image). For example, certain ferromagnetic materials may be unsuitable because they can produce artifacts in MRI images. The devices or portions thereof disclosed herein may also be made of materials that an MRI machine can image. Some materials exhibiting these properties include, for example, tungsten, cobalt-chromium-molybdenum alloys (e.g., UNS: R30003, etc.). (etc.), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035, for example) (etc.), nickel-titanium, etc., and others.

[0135] Other embodiments of this disclosure will be apparent to those skilled in the art from the description and practice of the embodiments disclosed herein. This specification and examples are intended to be illustrative only and deviations in form and detail may be made without departing from the scope and spirit of this disclosure as defined by the appended claims.

Claims

1. An ablation catheter for tissue vapor ablation, the ablation catheter comprising: A slender catheter shaft having a proximal end region and a distal end region, and including a lumen extending between the proximal end region and the distal end region; An expandable basket, positioned adjacent to the distal end region of an elongated conduit axis and in fluid communication with the lumen, is configured to move between an unexpanded configuration and an expanded configuration; and The nozzle is positioned longitudinally along the expandable basket and configured to eject steam to ablate the tissue in its vicinity.

2. The ablation catheter according to claim 1, wherein, The expandable basket is configured to maintain a threshold distance between the tissue and the nozzle when the expandable basket is in an expanded configuration.

3. The ablation catheter according to any one of claims 1-2, wherein, The threshold distance is in the range of approximately 0.5 mm to approximately 1.5 mm.

4. The ablation catheter according to any one of claims 1-3, wherein, The expandable basket includes a plurality of legs, wherein the nozzle is disposed along the plurality of legs.

5. The ablation catheter according to claim 4, wherein, The proximal end of each of the plurality of legs is connected to the distal end region of the elongated conduit shaft, and the distal end of each leg is connected to the distal cap.

6. The ablation catheter according to claim 4, wherein, Each support leg is an arched support leg.

7. The ablation catheter according to claim 4, wherein, Each leg is roughly convex in shape.

8. The ablation catheter according to any one of claims 1-7, wherein, The expandable basket includes a plurality of support rods, wherein the nozzle is disposed along the plurality of support rods.

9. The ablation catheter according to claim 8, wherein, The proximal end of each strut is connected to the distal end region of the elongated conduit shaft, and the distal end of each strut is connected to the distal cap.

10. The ablation catheter according to claim 8, wherein: Each strut includes a first inclined section, a second inclined section, and a linear central portion connecting the distal end of the first inclined section to the proximal end of the second inclined section; and The nozzle is located at least on the first inclined section and the second inclined section.

11. The ablation catheter according to any one of claims 1-10, wherein, At least some of the nozzles are located on the inner surface of the expandable basket.

12. The ablation catheter according to any one of claims 1-11, wherein, Each nozzle is located on the inner surface of the expandable basket.

13. The ablation catheter according to any one of claims 1-12, wherein, At least some of the nozzles are located on the outer surface of the expandable basket.

14. The ablation catheter according to any one of claims 1-13, wherein, Each nozzle is located on the outer surface of the expandable basket.

15. The ablation catheter according to claim 14, wherein, Each nozzle is positioned along a portion of the expandable basket that does not contact the tissue when the expandable basket is in an expanded configuration.

16. An ablation catheter for tissue vapor ablation, the ablation catheter comprising: A slender catheter shaft having a proximal end region and a distal end region, and including a lumen extending between the proximal end region and the distal end region; An expandable basket, positioned adjacent to the distal end region of an elongated conduit axis and in fluid communication with the lumen, is configured to move between an unexpanded configuration and an expanded configuration; and The nozzle is positioned longitudinally along the expandable basket and configured to eject steam to ablate the tissue in its vicinity.

17. The ablation catheter according to claim 16, wherein, The expandable basket is configured to maintain a threshold distance between the tissue and the nozzle when the expandable basket is in an expanded configuration.

18. The ablation catheter according to claim 17, wherein, The threshold distance is in the range of approximately 0.5 mm to approximately 1.5 mm.

19. The ablation catheter according to claim 16, wherein, The expandable basket includes a plurality of legs, wherein the nozzle is disposed along the plurality of legs.

20. The ablation catheter according to claim 19, wherein, The proximal end of each of the plurality of legs is connected to the distal end region of the elongated conduit shaft, and the distal end of each leg is connected to the distal cap.

21. The ablation catheter according to claim 19, wherein, Each support leg is an arched support leg.

22. The ablation catheter according to claim 16, wherein, Each leg is roughly convex in shape.

23. The ablation catheter according to claim 16, wherein, The expandable basket includes a plurality of struts, wherein the nozzle is disposed along the plurality of struts.

24. The ablation catheter according to claim 23, wherein, The proximal end of each strut is connected to the distal end region of the elongated conduit shaft, and the distal end of each strut is connected to the distal cap.

25. The ablation catheter according to claim 23, wherein: Each strut includes a first inclined section, a second inclined section, and a linear central portion connecting the distal end of the first inclined section to the proximal end of the second inclined section; and The nozzle is located at least on the first inclined section and the second inclined section.

26. The ablation catheter according to claim 16, wherein, At least some of the nozzles are located on the inner surface of the expandable basket.

27. The ablation catheter according to claim 16, wherein, Each nozzle is located on the inner surface of the expandable basket.

28. The ablation catheter according to claim 16, wherein, At least some of the nozzles are located on the outer surface of the expandable basket.

29. The ablation catheter according to claim 16, wherein, Each nozzle is located on the outer surface of the expandable basket.

30. The ablation catheter according to claim 29, wherein, Each nozzle is positioned along a portion of the expandable basket that does not contact the tissue when the expandable basket is in an expanded configuration.

31. An ablation catheter, the ablation catheter comprising: A slender catheter shaft having a proximal end region and a distal end region, and including a lumen extending between the proximal end region and the distal end region; An expandable basket, positioned adjacent to the distal end region of an elongated conduit axis and in fluid communication with the lumen, is configured to move between an unexpanded configuration and an expanded configuration; and A nozzle, which is positioned longitudinally along an expandable basket and configured to eject steam to ablate nearby tissue, wherein the expandable basket is configured to maintain a threshold distance between the tissue and the nozzle when the expandable basket is in an expanded configuration.

32. The ablation catheter according to claim 31, wherein, The outer surface of the expandable basket has no ablation electrode.

33. A system for vapor ablation of tissues, the system comprising: The console is configured to generate water vapor; and The ablation catheter connected to the control console includes: A slender catheter shaft having a proximal end region, including a distal end region, and a lumen extending between the proximal end region and the distal end region; An expandable basket, positioned adjacent to the distal end region of an elongated conduit axis and in fluid communication with the lumen, is configured to move between an unexpanded configuration and an expanded configuration; and A nozzle, which is in fluid communication with the lumen and extends through the outer surface of the expandable balloon, wherein the nozzle is configured to eject water vapor to ablate tissue in a target region near the nozzle, wherein the expandable basket is configured to maintain a threshold distance between the tissue in the target region and the nozzle when the expandable basket is in an expanded configuration.

34. The system according to claim 33, wherein, The expandable basket includes a plurality of legs configured to move between an unexpanded configuration and an expanded configuration, and each of the plurality of legs includes a central portion without a nozzle.

35. The system according to claim 33, wherein, The cavity includes a steam cavity, and the nozzle is in fluid communication with the steam cavity.

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