Device and method for esophageal protection

Abstract

A heat transfer device for circulating a heat transfer medium therethrough and methods for protecting the esophagus or other area of the body while an ablation or heat generating procedure is performed nearby. The device generally includes an elongate outer shaft, an elongate inner shaft positioned within the outer inflow shaft. A distal tip portion includes a fluid opening such that the outer shaft is in fluid communication with the inner shaft. An insulating member, such as a sleeve, is positioned along a portion of an inner surface of the outer shaft, thereby defining an insulating portion and an active heat transfer portion of the delivery device. The outer shaft may further include a radiopaque or other imaging material so that the device is detectable using imaging modalities. A cooling fluid is circulated through the device during the ablation procedure to protect esophagus from injury.

Description

[0001] UTILITY PATENT APPLICATION

[0002] DEVICE AND METHOD FOR ESOPHAGEAL PROTECTION

[0003] RELATED APPLICATIONS

[0004] The present disclosure claims the benefit and priority to U.S. Provisional Application No. 63 / 594,685, filed October 31, 2023, the entire disclosure of which is incorporated herein by reference.

[0005] TECHNICAL FIELD

[0006] The present disclosure is directed to esophageal protection. More specifically, the present disclosure is directed to devices and methods for targeted or localized esophageal cooling using a circulating fluid.

[0007] BACKGROUND

[0008] Pulmonary diseases are some of the most common medical conditions, affecting millions of people in the United States alone. Pulmonary diseases result from problems in the respiratory tract that interfere with proper respiration. Many of these diseases require medical attention or intervention to restore proper lung function and improve a patient's overall quality of life. Some of the more common pulmonary diseases include asthma and chronic obstructive pulmonary disease (COPD). Symptoms of pulmonary diseases like asthma and COPD vary but often include a persistent cough, shortness of breath, wheezing, chest tightness, and breathlessness. Generally, these symptoms are exacerbated when performing somewhat strenuous activities, such as running, jogging, brisk walking, etc. However, these symptoms may be noticed when performing non- strenuous activities if the disease is allowed to progress unchecked. Over time, especially if medical attention is not sought, a person's daily activities will be significantly impaired, thus reducing their overall quality of life.

[0009] A variety of treatments are available for pulmonary diseases includes reducing exposure to harmful agents, administering medications (e.g., bronchodilators, steroids, phosphodiesterase inhibitors, theophylline, antibiotics, etc.), administering lung therapy (e.g., oxygen therapy, pulmonary rehabilitation), and surgical intervention, such as bronchial thermoplasty. While these treatments are sometimes effective, typically the treatments are not without their drawbacks. For example, pharmacological treatment requires patient compliance, can cause undesirable or even harmful side effects, and may not always treat the underlying cause of the disease. Similarly, surgical intervention can result in the destruction of smooth muscle tone and nerve function, such that the patient is unable to respond favorably to inhaled irritants, systemic hormones, and both local and central nervous system input.

[0010] A relatively new and promising treatment for pulmonary diseases is targeted lung denervation (TLD). This method utilizes ablation, such as radiofrequency (RF) ablation via an ablation assembly to selectively treat target regions inside of the airway wall (e.g., anatomical features in the stromas) and / or target areas that run to the lung along the outside of the bronchus, while protecting superficial tissues such as the surface of the airway wall. For example, the mucous glands can be damaged to reduce mucus production enough to prevent the accumulation of mucus that causes increased air flow resistance while preserving enough mucus production to maintain effective mucociliary transport, if needed or desired. Nerve branches / fibers passing through the airway wall or other anatomical features in the airway wall can also be destroyed. Specially designed catheters allow for the introduction of an ablation assembly, generally comprising one or more collapsible electrodes or energy emitters, coupled to an expandable member, such as a balloon, into the airway of a patient via a delivery device. The delivery device can be a guide tube, a delivery sheath, a bronchoscope, or an endoscope and can include one or more viewing devices, such as optical viewing devices (e.g., cameras), optical trains (e.g., a set of lenses), optical fibers, charge-coupled device (CCD) chips, and the like. Once positioned in the desired region of the airway, such as the left and / or right main bronchi, the expandable member is expanded to position the one or more electrodes in contact with the airway wall.

[0011] Energy, such as RF energy, is supplied to the energy emitter to ablate the targeted tissue, causing a lesion to form, therefore temporarily or permanently damaging the targeted tissue, and affecting, e.g., attenuating nerve signals to or from, portions of the lungs associated with the targeted tissue. Simultaneously, a coolant is supplied through the catheter and is directed to the one or more electrodes and into the expandable member or balloon. This allows for cooling of the superficial tissue in contact with the electrode, as well as the adjacent tissues. The size, shape, and depth of the lesions are determined by the flow rate and temperature of the coolant, and the energy supplied to the energy emitter(s).

[0012] Devices, systems, and methods of targeted lung denervation are described in, for example, one or more of U.S. Pat. Nos. 8,088,127 and 9,649,153 toMayse et al., while esophageal protection during ablation procedures is described in U.S. Pat. No. 10,575,893 to Mayse, all of which are commonly assigned to the assignee of the present application and the disclosures of which are hereby incorporated by reference in their entireties.

[0013] Before targeted lung denervation and prior to the advent of effective asthma medications, an asthma treatment performed was a surgical sympathectomy of the posterior pulmonary nerve plexus. Although the surgery was very morbid, typically requiring severing large muscle groups and manipulating the ribs, pleura and lungs, it was in some cases effective.

[0014] There exists, in addition to the posterior pulmonary nerve plexus, an anterior pulmonary nerve plexus. Historically, the anterior pulmonary nerve plexus was never approached surgically due to its proximity to the heart and the great vessels. It is theorized that these nerves are also involved in airway constriction associated with asthma and other pulmonary diseases. There are several complicating factors to performing a denervation of these nerves from within the body. The nerves of interest run along the outside of the anterior trachea and bronchi, and the posterior plexus runs along the posterior, along and within the junction between the trachea and the esophagus. Damage to the esophagus or the branches of the vagus nerve that run along the outside of the esophagus and continue into the abdomen may be especially traumatic to a patient, and because of such difficulties there has historically been minimal interest in targeting the posterior and / or anterior pulmonary nerve plexus to treat pulmonary diseases.

[0015] Relatedly, negative effects of ablation performed near the esophagus have been observed in association with cardiac ablation therapies, such as atrial fibrillation ablation therapies. These effects include esophageal fistulae, acute pyloric spasm, gastroparesis, and temperature-related damage to the esophageal walls. Possible causes of these complications may be attributed to direct thermal energy delivered to esophageal tissue, injury to esophageal blood supply, late effects of an acidic environment within the esophagus, injury to the vagus nerve and / or pulmonary nerve plexi, and / or excessive heat release to the esophageal tissue from the direct thermal energy.

[0016] Efforts to reduce the risk of esophageal injury during ablation procedures include esophageal temperature monitoring (ETM) in which a temperature probe is positioned in the esophagus during the ablation procedure. For example, during cardiac ablation procedures, if a rise in temperature is observed while energy is applied to the posterior wall of the atrium, the power or the duration of the individual ablations is reduced to have less effect on esophageal temperature. However, one weakness of temperature monitoring is not knowing whether the placement of the probe is resting near the ablation zone.

[0017] Another example of such efforts includes esophageal retraction or moving the esophagus away from the ablation zone using a retractors. However, physicians prefer to protect the esophagus while leaving it in its natural position rather than physical manipulating the esophagus. Most recently, some physicians have been using esophageal cooling as a tool for esophageal protection during ablation procedures to treat atrial fibrillation. The physician may first to a transesophageal echocardiogram (TEE) to rule out thrombus formation in the left atrium. After a clear TEE, an esophageal cooling device is placed in the esophagus, typically by anesthesia staff, and a heat exchanger connected to the cooling device cools a heat transfer medium that is supplied to the device. Often, the heat exchange runs for the remainder of the procedure, including during vascular access and mapping before the ablation itself, which can sometimes be around 2-2.5 hours. However, this can lead to excessive cooling of a subject’s core temperature which causes the procedure to be paused until the core temperature is increased.

[0018] In view of the risks of esophageal injury observed in cardiac ablation therapies, it would be advantageous if other procedures, such as, but not limited to, pulmonary-related or cariac- related ablation procedures, could be performed near the esophagus without similar risks of injury, including temperature-related damage to esophageal tissue. Preferably, such procedures would not only avoid injury to the esophagus directly, but injury to the peri-esophageal branches of the vagus nerve that run along or outside of the esophagus, while not significantly changing a core temperature of the subject.

[0019] SUMMARY

[0020] In general, embodiments of the disclosure are directed to devices and methods for transferring heat, e.g. cooling, in the esophagus (or other lumen) while performing procedures near the esophagus, such as, but not limited to, ablation therapy somewhere else in the body (e.g., the airway) thus protecting the esophagus from injury. Embodiments of the disclosure may effectuate cooling of the esophagus by circulating a heat transfer medium, such as a cooled gas or fluid (e.g., water, saline, etc.) through a dual-lumen device including an outer (i.e., external) shaft or tube and an inner (i.e., internal) shaft or tube positioned at least partially within the outer shaft. Circulating a cooled gas or fluid through a dual-lumen tube located in the esophagus can be accomplished, for example, by coaxial flow, i.e. introducing the medium from an external source through the outer shaft along its length and back through the internal shaft to return it to the external source or to be disposed. This advantageously helps to reduce, or eliminate entirely, temperature-related injuries to the esophagus.

[0021] The terms “procedure” and “therapy” used throughout the application can be any of a variety of medical or other procedures or therapies in which heat may be generated and / or injury to the esophagus may be a risk associated with the procedure or therapy. For example, procedures and therapies can include protecting the esophagus during energy delivery to nearby structures can include, but are not limited to, pulmonary ablation procedures including radio-frequency (RF) ablation in the airway for targeted lung denervation, cardiac ablation procedures including RF ablation in the heart for treating arrhythmia such as atrial fibrillation, and tumor ablation in areas of the neck or chest including lungs, liver, thyroid, etc., radiation therapy in the neck or chest. Alternative energy delivery from RF can include ultrasound, microwave, cryoenergy, and combinations thereof. Other examples of procedures and therapies in which the heat transfer device can be incorporated can include protecting the colon during energy delivery in nearby structures, such as, energy delivery to the prostate, vagina, uterus, or bladder, and tumor ablation in the abdomen area including kidneys, liver, bones, breasts, pancreas, etc. Yet other examples of procedures and therapies in which the heat transfer device can be incorporated can include protecting other tissue susceptible to collateral damage during energy delivery to adjacent tissues. For sake of efficiency, the esophagus and ablation procedures are discussed going forward, although any of a variety of these procedures may be substituted in any of the embodiments described herein, and the embodiments are not limited to esophageal cooling or protection.

[0022] According to embodiments, actively cooling the esophagus during a procedure such as pulmonary ablation therapy can reduce or avoid the occurrence of damage to the esophagus. In such embodiments, the dual-lumen heat transfer device can be placed within the esophagus. In particular embodiments, a dual-lumen heat transfer device designed as a catheter can be placed in the esophagus proximate the treatment site in the bronchus. A coolant in the form of a gas or a liquid can be circulated within the catheter to lower the temperature of tissue within and around the esophagus near the treatment site in the airway. This cooling approach counteracts the potentially damaging heat created by an ablation treatment or other heat-generating treatment. Additionally, the device can be of a desired length such that it is designed to transfer heat only proximate the area of treatment. For example, the device does not extend into the stomach, and / or a minimal length extends external to a subject’s oral cavity. Additionally, the device can include an insulating portion such that an active heat transfer portion is minimized to allow localized heat transfer or cooling. In an example, insulation such as an insulating sleeve, is positioned within the exterior shaft. Alternatively, the exterior shaft thickness can be increased in the insulating portion compared to the heat transfer portion, or an air gap can be introduced internally in the insulating portion. Additionally or alternatively, by having a reduced profile in combination with insulation to minimize the heat transfer area, a subject’s core temperature is not significantly affected, thereby minimizing the need to stop or pause the procedure to avoid hypothermia or other negative cooling effects. In one non-limiting example, a subject’s core temperature changes 2 degrees C or less during continuous circulation of a heat transfer medium during a procedure lasting around 120-150 minutes or more.

[0023] Additionally, a contrast media, cooled or not cooled, can be circulated through the catheter, and imaged so that the location of the esophagus relative to the treatment site is known either prior to and / or throughout the ablation treatment. In the event the esophagus is determined to be too close to safely deliver energy to the treatment site in the airway, delivering ablation therapy in the vicinity can be avoided, and risk of injury to the esophagus is minimized.

[0024] Additionally, the temperature of the esophagus can be monitored during the procedure and the procedure can be halted as necessary to prevent or minimize esophageal damage. In such embodiments, a temperature of one or more portions of the esophagus and / or the surrounding tissue can be monitored with a temperature probe placed in or around the esophagus near the treatment site during ablation treatment. In the event the observed temperature rises to an unacceptable or undesirable level, the power output may be reduced, cooling increased, or treatment may be halted altogether. This advantageously helps maintain optimal levels of temperature, power output, and cooling without excessive physician intervention during the procedure.

[0025] Injuries and damage to the esophagus can thereby be reduced, substantially limited, or eliminated entirely while performing ablation therapy somewhere else in the body. Additional features such as imaging to determine the location of the esophagus relative to an ablation treatment site and measuring the temperature of the esophagus during pulmonary ablation therapy can advantageously improve treatment outcomes for patients undergoing ablation procedures.

[0026] The above summary is not intended to describe each illustrated embodiment or every implementation of the subject matter hereof. The figures and the detailed description that follow more particularly exemplify various embodiments.

[0027] BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Subject matter hereof may be more completely understood in consideration of the following detailed description of various embodiments in connection with the accompanying figures, in which:

[0029] FIG. 1 depicts a perspective view of an esophageal heat transfer device, according to an embodiment of the disclosure.

[0030] FIG. 2 depicts an exploded view of an esophageal heat transfer device, according to an embodiment of the disclosure. FIG. 3 depicts a detailed view of an esophageal heat transfer device, according to an embodiment of the disclosure.

[0031] FIG. 4 depicts a detailed view of an esophageal heat transfer device, according to an embodiment of the disclosure.

[0032] FIG. 5 depicts a detailed view of an esophageal heat transfer device, according to an embodiment of the disclosure.

[0033] FIG. 6 depicts a detailed view of an esophageal heat transfer device, according to an embodiment of the disclosure.

[0034] FIG. 7 depicts a view of fluid flow through an esophageal heat transfer device, according to an embodiment of the disclosure.

[0035] FIG. 8 depicts a thermoelectric system including a console and heat transfer device, according to an embodiment of the disclosure.

[0036] While various embodiments are amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the claimed inventions to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the subject matter as defined by the claims.

[0037] DETAILED DESCRIPTION OF THE DRAWINGS

[0038] The following detailed description should be read with reference to the drawings in which similar elements in different drawings are numbered the same. The drawings, which are not necessarily to scale, depict illustrative embodiments and are not intended to limit the scope of the disclosure.

[0039] The embodiments, features, systems, devices, materials, methods, and techniques described in the attached disclosure may, in certain embodiments, be applied to or used in connection with any one or more of the embodiments, features, systems, devices, materials, methods, and techniques disclosed in the previously mentioned patents incorporated by reference herein.

[0040] Referring generally to FIGS. 1-6, an esophageal heat transfer device 100 is shown according to embodiments of the disclosure. Esophageal heat transfer device 100 can be placed into the esophagus while performing ablation therapy somewhere else in the body to enable cooling of or heat transfer in the esophagus, thereby substantially limiting or preventing entirely injury or damage to the esophagus and the nerves that run along the outside of the esophagus. Esophageal heat transfer device 100 can include a distal tip 102, an outer shaft body 104, a strain relief coupling 106, atube coupling 108, extension tubes 113, 113’, extension couplings 114, 114’, an inner shaft body 116, and an insulation member 118 (collectively, “components”). It is noted that esophageal heat transfer device 100 can have one or more of the aforementioned components as necessitated by a particular therapy or procedure. In embodiments, inner shaft body 116 and outer shaft body 104 are of a coaxial arrangement such that a fluid enters outer shaft body 104, flows along its length, and flows into inner shaft body 116 and out of the esophageal heat transfer device. In alternative embodiments, the flow of fluid may be reversed as desired. In one embodiment, inner shaft body 116 is substantially centered within outer shaft body 104 along a longitudinal axis. In another embodiment (not shown), the inner shaft body can be offset from a center of the outer shaft body.

[0041] According to embodiments, and with reference to FIGs. 4 and 7, distal tip 102 can be characterized as having a first tip portion 103a and a second portion 103b extending upward from tip portion 103a. First tip portion 103a may comprise a cap having a hemispherical shape with an inner flattened surface coupled to, integrated with, or formed into, an outer surface of second tip portion 103b, thereby forming an operationally connected unitary piece. Other shapes of first tip portion 103a are contemplated for different embodiments of distal tip 102, including triangular, square, pentagonal, hexagonal, and other similar multi-sided shapes. Second tip portion 103b may have a cylindrical shape with a longitudinal cutout section 105 extending partially or fully through a center region, the center region defined by a longitudinal axis extending through a midpoint. The cutout section 105 of second tip portion 103b, illustrated as having a slotted cross-section in FIG. 4, can be configured to receive and couple to shaft body 116, thereby operationally connecting distal tip 102 with shaft body 116, and in centering inner shaft body 116 within outer shaft body 104. Other geometries of second tip portion 103b are contemplated for different embodiments of distal tip 102, including spherical, conical, cubical, prismatic, and other similar three-dimensional geometries. Cutout section 105 is configured to allow fluid to pass from outer shaft body 104 into inner shaft body 116 (as seen in FIG. 7) or vice versa.

[0042] In other embodiments, second tip portion 103b does not include a cutout section and instead receives and couples to shaft body 116 using a different connection method known to one skilled in the art, such as fastening, welding, gluing with an adhesive (e.g., an ultraviolet adhesive; adhesion with a bond tensile strength greater than one pound-force), or another similar connecting process. First tip portion 103a and second tip portion 103b can be manufactured from a variety of materials known to one skilled in the art, including polymers, metals, ceramics, composites, or combinations thereof. First tip portion 103 a and second tip portion 103b can be coupled, integrated, and / or formed together using any suitable method, including fastening, welding, gluing with an adhesive, or another similar connecting process. In this embodiment, fluid may flow from shaft body 104 to inner body 116 (or vice versa) via one or more holes formed near a distal end of inner body 116.

[0043] Generally, second tip portion 103b is entirely enclosed by outer shaft body 104 while the inner-facing flattened surface of first tip portion 103a coincides or mates with an end surface of outer shaft body 104. As illustrated by FIG. 1, this allows first tip portion 103a and outer shaft body 104 to be coupled together by any suitable connection method (e.g., adhesion with a bond tensile strength greater than ten pound-force).

[0044] According to embodiments and referring to FIG. 2, outer shaft body 104 can be characterized as having a cylindrical, hollow, tube-like geometry along a longitudinal axis extending through a midpoint, such that shaft body 104 includes an inner surface having an inner diameter and an outer surface having an outer diameter. According to embodiments, insulation member 118 can be characterized as having a cylindrical, hollow, tube-like geometry along a longitudinal axis extending through a midpoint, such that insulation member 118 includes an inner surface having an inner diameter and an outer surface having an outer diameter equal to, slightly less than (e.g., within approximately 0.5% to approximately 5%), or less than (e.g., greater than 5%) the inner diameter of outer shaft body 104. According to embodiments, inner shaft body 116 can be characterized as having a cylindrical hollow geometry with an outer surface having an outer diameter equal to, slightly less than, or less than the inner diameter of insulation member 118. Other geometries of outer shaft body 104, insulation member 118, and inner shaft body 116 are contemplated by the disclosure, including spherical, conical, cubical, prismatic, and other similar three-dimensional geometries.

[0045] In embodiments, outer shaft body 104 and inner shaft body 116 are non-inflatable or nonexpandable. In alternative embodiments, outer shaft body 104, inner shaft body 116, or both are expandable or inflatable and expand upon introduction of the heat transfer medium.

[0046] Outer shaft body 104 can be configured to receive insulation member 118 along a portion of a length of shaft body 104, specifically at a proximal portion away from distal tip 102, such that insulation member 118 is within and concentric with outer shaft body 104. Outer shaft body 104 can be configured to receive inner shaft body 116 along substantially all of the length of outer shaft body 104, such that inner shaft body 116 is nested within and concentric with outer shaft body 104, and nested within insulation member 118. In other embodiments, insulation member 118 and / or inner shaft body 116 may be offset from the longitudinal axis of outer shaft body 104.

[0047] Outer shaft body 104 may have a length greater than, equal to, or slightly less than a length of inner shaft body 116. For example, outer shaft body 104 can have a length equal to approximately 40 centimeters, approximately 60 centimeters, or any suitable value greater than, less than, or between approximately 40 and 60 centimeters. Insulation member 118 generally has a length less than outer shaft body 104 and inner shaft body 1 16 so as to define in upper insultation portion 101 of device 100 and an active heat transfer portion 103 of device 100. For example, insulation member 118 can have a length equal to approximately 10-30 centimeters, approximately 13-23 centimeters, or approximately 20 centimeters, or any suitable value greater than, or less than. In some embodiments, a surface area of heat transfer portion 103 can be 100 cm2or less to minimize effects or changes to a subject’s core temperature and to protect the skin or other nontarget areas of the subject, while adequately protecting the esophagus from injury. In some embodiments, heat transfer portion 103 has a surface area equal to or less than a surface area of insulation portion 101. In other embodiments, heat transfer portion 103 has a surface area equal to or more than a surface area of insulation portion 101.

[0048] In alternative embodiments (not shown), in addition to or as an alternative to insulation member 118, the wall of the outer shaft body 104 can be thicker in the insulation portion 101, thereby acting as the insulating member. In yet another alternative embodiment, an air gap between the outer wall and inner wall of outer shaft 104 can be added in the insulation portion 101, which would also be visible via intracardiac echocardiograph (ICE) so as to assist or determine positioning of insulating portion 101 and active portion 103 of device 100. In yet other embodiments, in addition to or as an alternative to insulation internal to shaft 104, insulation can be external to shaft. For example, strain relief 106 can serve as an insulating bite block for the subject, and / or an additional insulating sleeve can be positioned external to shaft 104 around the subject’s mouth and face to protect the mouth, throat, and skin around the mouth. Further, it has been observed that by insulating device 100 proximate the throat, further unwanted subject cooling may be reduced.

[0049] Outer shaft body 104 and inner shaft body 116 can be manufactured from a variety of materials known to one skilled in the art, such as polymers, metals, ceramics, composites, or combinations thereof, and can be coupled, integrated, and / or formed together using any suitable method, including fastening, welding, gluing with an adhesive, or another similar connecting process. Insulation member 118 is generally manufactured from a material having high insulative capabilities, such as plastics, fiberglass, combinations thereof, or another suitable insulative material known to one skilled in the art. In embodiments, insulation member 118 may be integrally formed along the inner surface of outer shaft body 104 to collectively form a single unitary part during manufacturing. In an embodiment, at least outer shaft body 104 is formed of a material that is resistant to gastric fluid, such as, for example, silicon, polyurethane, or other suitable materials.

[0050] In one embodiment, at least a portion of outer shaft body 104 is visible or detectable via ICE, x-ray, ultrasound, electromagnetic navigation, or other imaging technology, to assist in placement of esophageal heat transfer device 100 within the esophagus. For example, at least a portion of outer shaft body 104 includes a radiocontrast or radiopaque material, such as barium sulfate, air bubbles formed within the wall of outer shafter 104 which are detectable via ultrasound, and / or sensors for electromagnetic (EM) navigation. Other materials or devices can be incorporated such that device 100 is detectable via any of a variety of imaging modalities or combinations thereof. In some embodiments, the entire length of outer shaft body 104 incorporates the visible material, while in other embodiments, only the active heat transfer region 103 incorporates the visible material, or only the insulating region 101 incorporates the visible material. In yet other embodiments, the inner lumen 116 incorporates the visible material.

[0051] In embodiments, in addition to or as an alternative to the visible or detectable shaft body 104, a radioopaque marker band can be included on shaft body 104 (external or internal) to delineate insulating portion 101 from active heat transfer portion 103. For example, such marker band can be formed of a stainless-steel tape with holes in it, or air bubbles formed within the wall and around the circumference of outer shaft body 104. Other such materials can be considered that are detectable under other imaging modalities, as described above with respect to outer shaft 104. Other markings or indications can also be considered, for example, flow rate maximums or other warnings, indications, instructions, graphics, branding, or the like.

[0052] In yet another embodiment, a radiocontrast material, such as barium sulfate, can be added to the heat transfer fluid and circulated throughout the device.

[0053] As illustrated particularly by FIGS. 1, 5 and 6, esophageal heat transfer device 100 can include a coupling 108 that allows inner shaft body 116 (which as noted can be connected to each of distal tip 102, shaft body 104, and insulation member 118) to fluidly couple to extension tubes 113, 113’ for supplying a fluid to or from inner shaft body 116 and extension tube 113, 113’ for supplying a fluid to or from outer shaft body 104. Tube coupling 108 can include one or more coupling portions 109 coupled and / or integrally formed together, such as first coupling portion 109a, second coupling portion 109b, third coupling portion 109c, fourth coupling portion 109d, and fifth coupling portion 109e. Generally, the one or more portions 109 can be characterized as having cylindrical geometries as shown by way of example in FIGS. 5 and 6, though other three- dimensional geometries are contemplated. Tube coupling 108 and one or more portions 109 can be manufactured from a variety of materials known to one skilled in the art, such as polymers, metals, ceramics, composites, or combinations thereof.

[0054] In embodiments, first coupling portion 109a can have a first end surface with an aperture for receiving a segment of shaft body 1 16. The aperture generally extends from the first end surface to a second end surface that, for example, can have a chamfered or filleted perimeter edge. As shown in FIG. 6, first coupling portion 109a can fluidly couple to shaft body 104 using any suitable connection method (e.g., adhesion with a bond tensile strength greater than one pound-force). In other embodiments, a gap is formed between first coupling portion 109a and shaft body 104 as shown by way of example in FIG. 5. The chamfered or filleted perimeter edges can be helpful to accommodate differently sized extension tubes 113, 113’.

[0055] The second end surface of first coupling portion 109a can be connected to a first end surface of second coupling portion 109b using any suitable connection method, including fastening, welding, gluing with an adhesive, or another similar connecting process. As with first coupling portion 109a, second coupling portion 109b can have an aperture defined within the first end surface that extends to a second end surface that, for example, can have a chamfered or filleted perimeter edge. The aperture of second coupling portion 109b is generally concentric with the aperture of first coupling portion 109a and is also configured to receive a segment of shaft body 116 which can extend through first coupling portion 109a. In embodiments, second coupling portion 109b has an outer diameter equal to, slightly less than, or less than an inner diameter of first coupling portion 109a.

[0056] The second end surface of second coupling portion 109b can be connected to a first end surface of third coupling portion 109c using any suitable connection method. Third coupling portion 109c generally has a threaded outer surface with an aperture defined within the first end surface that extends to a second end surface of third coupling portion 109c, the aperture being configured to receive a segment of a tube structure such as extension tube 113 and / or shaft body 116.

[0057] Fourth coupling portion 109d can be coupled to and / or integrally formed with an outer surface of second coupling portion 109b as shown by way of example in FIGS. 5 and 6. Generally, fourth coupling portion 109d extends outward at an angle relative to a longitudinal axis extending through a midpoint of second coupling portion 109b. Fourth coupling portion 109d can have an aperture defined within a first end surface that extends to a second end surface, the aperture configured to receive a segment of a tube structure such as extension shaft 112, extension tube 113, and / or shaft body 116. The first end surface of fourth coupling portion 109d can be connected to the outer surface of second coupling portion 109b using any suitable connection method, including fastening, welding, gluing with an adhesive, or another similar connecting process.

[0058] The second end surface of fourth coupling portion 109d can be connected to a first end surface of fifth coupling portion 109e using any suitable connection method. Fifth coupling portion 109e generally has a threaded outer surface, similar or identical to third coupling portion 109c, with an aperture defined within the first end surface that extends to a second end surface of fifth coupling portion 109e. The aperture can be configured to receive and couple to a segment of a tube structure such extension tube 113 and / or inner shaft body 116 (e.g., adhesion with a bond tensile strength greater than ten pound-force).

[0059] In embodiments, tube coupling 108 can include one or more struts 110 to provide, for example, support for the connection between second coupling portion 109b and fourth coupling portion 109c. The one or more struts 110 can be placed at any suitable location along outer surfaces of the one or more coupling portions 109 as needed. The one or more struts 110 can be manufactured from the same material as tube coupling 108, or from a different material.

[0060] It is noted that one or more portions 109 of tube coupling 108 can be separate, independent structures coupled together using any suitable connection method, or integrally formed together during manufacturing as a single, unitary piece. It is also noted that tube coupling 108 can include additional coupling portions 109 beyond those described in this disclosure, including, for example, multiple fourth coupling portions 109d coupled to the outer surface of second coupling portion 109b to provide additional inlets extending from outer shaft body 104.

[0061] Esophageal heat transfer device 100 can include a strain relief coupling 106 that can connect outer shaft body 104 to the first end surface of first coupling portion 109a (e.g., adhesion with a bond tensile strength greater than one pound-force). Strain relief coupling 106 can be characterized as having a cylindrical geometry as shown by way of example in FIGS. 1, 2, and 6, though other three-dimensional geometries are contemplated. In embodiments, there can be a gap between strain relief coupling 106 and first coupling portion 109a as shown by way of example in FIG. 6. Strain relief coupling 106 can be manufactured from a variety of materials known to one skilled in the art, such as polymers, metals, ceramics, composites, or combinations thereof. In some embodiments, strain relief coupling 106 can be formed of a material that is sufficiently soft or pliable to be used as a bite block for the subject’s mouth, and more preferably, an insulating material such that the bite block is insulated, thereby protecting the subject’s mouth and throat from frost bite or excessive cooling.

[0062] According to embodiments, extension tubes 113, 113’ can be characterized as having a cylindrical, tube-like geometry with a cutout extending along a longitudinal axis extending through a midpoint, such that extension tube 113 includes an inner surface having an inner diameter and an outer surface having an outer diameter, the outer diameter of extension tube 113 being equal to, slightly less than, or less than the inner diameter of outer shaft body 104. Other geometries of extension tubes 113, 113’ are contemplated by the disclosure, including spherical, conical, cubical, prismatic, and other similar three-dimensional geometries. Extension tubes 113, 113’ can be manufactured from a variety of materials known to one skilled in the art, such as polymers, metals, ceramics, composites, or combinations thereof, and can be coupled, integrated, and / or formed together using any suitable method, including fastening, welding, gluing with an adhesive, or another similar connecting process.

[0063] Generally, third coupling portion 109c and fifth coupling portion 109e are entirely enclosed by (and thus coupled to) separate extension tubes 113, 113’ as shown by way of example in FIG. 1 (e.g., adhesion with a barb tensile strength greater than five pound-force). Additionally, third coupling portion 109c and fifth coupling portion 109e generally receive separate extension tubes 113, 113’ with respective apertures defined at respective second end surfaces, as described previously and shown by way of example in FIGS. 5 and 6.

[0064] Esophageal heat transfer device 100 can also include, for each extension tube 113, 113’ combination, an extension coupling 114 partially received within the cutout of the extension shaft 112 (and thus coupled to extension shaft 112 using, for example, adhesion with barb tensile strength greater than five pound-force). Extension coupling 114 can include an inlet portion connected to both a middle portion and a threaded portion. The threaded portion of extension coupling 114 is configured to receive a segment of an extension tube 113 or 113, specifically from extension coupling 114 to extension tube 113 and through tube coupling 108 to the combination of shaft body 116 and shaft body 104 which can be positioned in the esophagus of a patient.

[0065] Extension couplings can easily and quickly connect to fluid inlet or outlet of an external heating or cooling unit. In embodiments, extension couplings 114 can be quick connectors, such as commercially available quick connect and disconnect connectors from CPC Global headquartered in Arden Hills, Minnesota. Extension couplings 114 can optionally include a valve which can be closed when connecting or disconnecting from the external unit, and then opened in use to allow fluid to allow the heat transfer fluid to be circulated throughout esophageal heat transfer device 100. The valves help protect against leaks when connecting or disconnecting device 100 from the external unit. Couplings 114 (and optionally additional adapters) can be compatible with the external unit, such as a commercially available unit like the Blanketrol® III Hyper-Hypothermia System heater-cooler available from Gentherm of Northville, Michigan. Other heater-cooler systems can also be contemplated, such as discussed in more detail infra.

[0066] Device 100 can optionally include one or more additional features. For example, device 100 can include vacuum suction through a distal end thereof so as to pull the wall of the esophagus or other lumen in which device 100 is placed against and in contact with device 100 forcing cooling contact. Temperature sensors may also be incorporated into device 100. For example, one o or more temperature sensors or thermocouples can be placed proximate or in the center of active transfer region 103 to measure temperature of the esophagus (and / or heat transfer fluid) near the treatment site. Additional sensors could be used to monitor a temperature of the heat transfer fluid at the inlet and / or outlet of device 100, and / or at the reservoir of the external unit. One or more microchip cameras can be coupled to outer shaft body 104 that can be coupled to an external monitor or other imaging device to allow for real-time visual inspection of the esophagus during placement, the procedure, or afterward the procedure to determine whether there is any damage to the esophagus.

[0067] Referring now to FIG. 8, a system 800 includes a thermoelectric unit 802 and device 100 coupleable to system 800 via extension tubes 113 and couplers 114 (described above) and umbilical cords (coaxial or multiple ribbon umbilical cords) as desired, such as, for power, connection to an internet source, etc. In an embodiment, thermoelectric unit 802 can comprises a fluid reservoir 804 containing the heat transfer fluid, a heat exchanger 806 including a thermal plate coupled to a cooling device 808, a disposable fluid cartridge (not shown) coupled to the thermal plate, and a peristaltic pump 810 for circulating the fluid from reservoir 804 through cartridge 808, through device 100, and back to reservoir 804 or disposed. In an embodiment, such thermoelectric unit 802 and heat exchanger 806 including the disposal cartridge is described in U.S. Pat. No. 10,368,937, incorporated herein by reference in its entirety.

[0068] As mentioned above, unit 802 may further include a pump 810 to supply and / or circulate a volume of fluid to the patient or subject S. At least one controller 812 may be coupled to cooling device 808 and pump 810 for regulating the amount heat transfer and fluid volume and pressure to supply to the subject S. System 800 may also include a supply path and a return path, which may include a series of lines or tubes or fluid pathways. The supply path originates at fluid reservoir 804 where the fluid is traversed through the heat exchanger cartridge (not shown) of heat exchange 806 for chilling the fluid, and then traversed to treatment device 100 in the subject S for cooling at a treatment site. The return path originates at treatment device 100 in the subject S, and then the return path may traverse back to fluid reservoir 804 for continuous circulation of the fluid through system 800. Thus, fluid reservoir 804, the supply and return tubes, a fluid channel of the cartridge, and treatment device 100 are all in fluid communication with each other. Accordingly, cooling device 808 chills the fluid that pump 810 circulates throughout system 800 during treatment of the subject S.

[0069] As can be appreciated in any aspect of the present disclosure, the fluid cooling supply system 800 may be a closed loop system or an open loop system. In a closed loop system, the fluid is continuously supplied from and returned to fluid reservoir 804 for recirculation. In an open loop system, the fluid is supplied from fluid reservoir 804 to treatment device 100 and then discarded after circulation through the treatment device (waste).

[0070] In embodiments, thermoelectric unit 802 is a standalone unit and is configured to collect and monitor one or more of fluid inlet temperature, fluid outlet temperature, reservoir temperature, and flow rate. Unit 802 can also be configured to calculate heat transfer wattage. Temperature monitoring can be accomplished via thermocouples in disposable components (e.g. connectors of device 100), and / or a reusable temperature probe. Optionally, a thermochromic label can be incorporated on unit 802 and / or device 100 in which it visually indicates, such as by turning a blue color, that demonstrates that the fluid is at an appropriate temperature based on a predetermined setting. Unit 802 can incorporate leak detection throughout the loop. Additionally or alternatively, a small volume reservoir can be selected to reduce leak risks, i.e. in the event unit 802 and / or device 100 leaks, the effect would be minimal.

[0071] Unit 802 can further include a graphic user interface to display the monitored temperature(s), including data from temperature sensor positioned on the device 100, and optionally use visual and / or audible warning indicators if the temperature data is out of a predetermined range or value, if a leak is detected, and / or if there are other system failures.

[0072] In embodiments, one or more components of system 800 are disposable (one-time use) to reduce the need to clean components after each use. For example, in an embodiment, any composition of device 100, cartridge 808, reservoir 804, extension tubes 113, couplers 114, and umbilical cords (not shown) are disposable. In an embodiment, system 800 is sized such that unit 802 is coupled to a portable tower or card or can be hung from an IV pole or other type device, such that unit 802 can be easily moved or transported from room to room or within a room.

[0073] In an embodiment, system 800 can provide a flow through device 100 that is synchronized with software used for a procedure, such as a targeted lung denervation (TLD) procedure. For example, unit 802 can be configured to initiate or stop fluid flow depending on signals received from the TLD energy delivery unit, such as fluid flow through device 100 is only initiated when protection is needed, e.g. ablation is being performed proximate the esophagus, so as to further reduce unwanted patient cooling.

[0074] In operation, esophageal heat transfer device 100 is first connected to the external unit, as described previously, via connectors and connecting hoses. The external unit is then powered on. A predetermined fluid temperature and flow rate are selected, such as, for example, a temperature in a range of about 0C to about 90C, and a flow rate of about 1 - 300 L / hr. Fluid flow is initiated through device 100 to determine whether any leaks exist and to remove air from device 100. The fluid flow is then paused. Optionally, a water-soluble lubricant is applied to device 100 to aid in insertion. Device 100 is then positioned inside the esophagus of a patient with distal tip 102 and outer shaft body 104 located internal to the patient. For example, device 100 is inserted, distal tip 102 first, posteriorly and downwardly through the mouth, past the oropharynx and into the esophagus until a desired length of shaft 104 is within the esophagus and heat transfer region 103 is positioned proximate an ablation or procedure zone. Remaining shaft 104 with insulating member 118 and coupling 108 and tubes 113, 113’ remain outside of the patient and may be secured by a securement device such as tape. Strain relief coupling 116 may remain in the patient’ s mouth if being utilized as a bite block. Optionally, further insulating material can be placed around shaft 104 that remains outside of the patient. A position of device 100 is monitored and confirmed by imaging or fluoroscopy, such as, for example, ICE, x-ray, ultrasound, or any of a variety of imaging modalities corresponding to the imaging material incorporated into device 100.

[0075] The fluid flow is then restarted and the heat transfer fluid (e.g., water, saline, etc.) is transported from a fluid source connected to extension coupling 114 through extension tube 113 fluidly coupled to the outer shaft body 104. The cooled fluid moves through extension tube 113 and into a junction formed by tube coupling 108 which has one or more portions 109 each connected to a separate extension tube 113. The cooled fluid can then be transported through outer shaft body 104 into and through inner shaft body 116, returning to the external unit via extension tube 113 coupled to inner shaft body 116. The circulation of heat transfer, i.e. cooled, fluid through esophageal heat transfer device 100 protects the esophagus by providing active cooling or heat transfer while the patient receives a heat generating or ablation therapy somewhere else in the body (e g., the airway). Accordingly, injury or damage to the esophagus is substantially limited or prevented entirely, thus leading to improved patient outcomes from ablation therapy procedures. Once the procedure is completed, device 100 can be removed by pulling upwardly through the mouth. Device 100 can then be disposed.

[0076] As mentioned, in embodiments, esophageal heat transfer device 100 can have a shaft body 104 with a length of approximately 60 centimeters and an insulation member 118 with a length of approximately 13 centimeters, which creates a heat transfer section of approximately 50 centimeters in length along shaft body 104. In other embodiments, esophageal heat transfer device 100 can have a shaft body 104 with a length of approximately 40 centimeters and an insulation member 118 with a length of approximately 20 centimeters, which creates a heat transfer section approximately 20 centimeters in length along shaft body 104. As mentioned above, a variety of lengths and dimensions can be considered depending on its desired use.

[0077] By carefully selecting the dimensions of device 100 including the dimensions of outer and inner shaft bodies 104, 116 in relation to insulating member 118, active heat transfer region 103 is tailored to transfer heat only in a localized manner so as to not significantly change a core temperature of the subject. In embodiments, a core temperature of the subject changes 4 degrees Celsius or less with continuous flow in a range from about 120 minutes to 150 minutes, and more specifically, 2 degrees Celsius or less with continuous flow in a range from about 120 minutes to 150 minutes. This allows for a procedure, such as a cardiac or pulmonary ablation procedure, to be performed without having to pause the procedure due to excessive patient cooling.

[0078] Further advantages of the heat transfer device as described herein include its shorter length compared to other such devices such that it does not extend beyond the esophagus and into the stomach, and the length that extends beyond the subject’s mouth is minimized resulting in greater control of the device, and reduced risk of injury to the subject’s mouth, skin, and throat. The non- traumatic distal tip as described herein allows for easier insertion because it is of sufficient rigidity such that it does not flop or get caught upon insertion. Further, the stability and column strength of the outer shaft and in combination with the insulating member which adds thickness to the outer wall reduces or prevents buckling of the device upon insertion.

[0079] Various embodiments of systems, devices, and methods have been described herein. These embodiments are given only by way of example and are not intended to limit the scope of the claimed inventions. It should be appreciated, moreover, that the various features of the embodiments that have been described may be combined in various ways to produce numerous additional embodiments. Moreover, while various materials, dimensions, shapes, configurations, and locations, etc. have been described for use with disclosed embodiments, others besides those disclosed may be utilized without exceeding the scope of the claimed inventions.

[0080] Persons of ordinary skill in the relevant arts will recognize that the subject matter hereof may comprise fewer features than illustrated in any individual embodiment described above. The embodiments described herein are not meant to be an exhaustive presentation of the ways in which the various features of the subject matter hereof may be combined. Accordingly, the embodiments are not mutually exclusive combinations of features; rather, the various embodiments can comprise a combination of different individual features selected from different individual embodiments, as understood by persons of ordinary skill in the art. Moreover, elements described with respect to one embodiment can be implemented in other embodiments even when not described in such embodiments unless otherwise noted.

[0081] Although a dependent claim may refer in the claims to a specific combination with one or more other claims, other embodiments can also include a combination of the dependent claim with the subject matter of each other dependent claim or a combination of one or more features with other dependent or independent claims. Such combinations are proposed herein unless it is stated that a specific combination is not intended.

[0082] Any incorporation by reference of documents above is limited such that no subject matter is incorporated that is contrary to the explicit disclosure herein. Any incorporation by reference of documents above is further limited such that no claims included in the documents are incorporated by reference herein. Any incorporation by reference of documents above is yet further limited such that any definitions provided in the documents are not incorporated by reference herein unless expressly included herein.

[0083] For purposes of interpreting the claims, it is expressly intended that the provisions of 35

[0084] U.S.C. § 112(f) are not to be invoked unless the specific terms “means for” or “step for” are recited in a claim.

Claims

CLAIMS1. A transfer device configured for circulating a heat transfer medium therethrough comprising: a longitudinal outer shaft; a longitudinal inner shaft positioned within the outer inflow shaft; and a distal tip portion connecting the outer shaft to the inner shaft, wherein the distal tip portion includes structure defining a fluid opening such that the outer shaft is in fluid communication with the inner shaft; and an insulating member positioned along a portion of an inner surface of the outer shaft, wherein the insulating member has a longitudinal length less than a longitudinal length of the outer shaft, thereby defining an insulating portion and an active heat transfer portion of the delivery device.

2. The device of claim 1, wherein the insulating member comprises a sleeve positioned proximate the inner surface of the outer shaft.

3. The device of claim 1, wherein the insulating member comprises an increased wall thickness of the outer shaft along the insulating portion compared to a wall thickness of the outer shaft along the active heat transfer region.

4. The device of claim 1, wherein the insulating member comprises a second shaft wall spaced apart from an inner surface of outer shaft and defining an air gap therebetween along theinsulating portion of the delivery device.

5. The device of claim 1, wherein at least a portion of the outer shaft includes a visual indicator material detectable by an imaging modality.

6. The device of claim 5, wherein the visual indicator material comprises a radiopaque material.

7. The device of claim 6, wherein the radiopaque material comprises barium sulfate.

8. The device of claim 5, wherein the visual indicator material comprises air bubbles formed within a wall of the outer shaft, the air bubble being detectable via ultrasound.

9. The device of claim 1, wherein a radiopaque marker band is formed about at least a portion of a circumference of the outer shaft to delineate the active heat transfer portion and the insulating portion.

10. The device of claim 1, wherein a surface area of the insulating portion is equal to or greater than a surface area of the active heat transfer region.

11. The device of claim 1, wherein the outer shaft is configured to be fluidly coupled to a fluid inlet and the inner shaft is configured to be fluidly coupled to a fluid outlet such that theheat transfer medium is configured to flow from the fluid inlet into and through the outer shaft to the distal tip and then into and through the inner shaft to the fluid outlet.

12. A system for protecting an esophagus during a medical procedure, the system comprising: the device of claim 1 ; and a portable heat exchanger unit, the heat exchanger unit comprising a heat exchanger, a peristaltic pump, and a fluid reservoir, wherein the heat transfer fluid is pumped from the fluid reservoir, through the heat exchanger, through the outer shaft of the device to the distal tip and then into and through the inner shaft, back to the reservoir.

13. The system of claim 12, wherein the heat exchanger comprises a thermal plate and a removable cartridge coupleable to the thermal plate.

14. The system of claim 12, wherein the portable heat exchanger unit is configured to be coupled to a wheeled frame or an IV pole.

15. A method of protecting an esophagus of a subject using a heat transfer device during a ablation procedure, the method comprising: positioning a heat transfer device within the esophagus of a subject, wherein the heat transfer device includes a longitudinal outer shaft, a longitudinal inner shaft positioned within the outer inflow shaft and in fluid communication with the outer shaft, and an insulating member positioned along a portion of an inner surface of the outer shaft, whereinthe insulating member has a longitudinal length less than a longitudinal length of the outer shaft, thereby defining an insulating portion and an active heat transfer portion of the delivery device; circulating a heat transfer fluid through the outer shaft and into and through the inner shaft, wherein a temperature of only a portion of the esophagus proximate to the active heat transfer portion is affected; and stopping the circulation of the heat transfer fluid open completion of the ablation procedure.

16. The method of claim 15, wherein a core temperature of the subject changes two degrees Celsius or less during the ablation procedure when the heat transfer fluid is circulated continuously during the duration of the ablation procedure.

17. The method of claim 15, wherein the at least a portion of the outer shaft includes a visual indicator material detectable by an imaging modality, and the method further comprises imaging the esophagus after positioning the heat transfer device within the esophagus to confirm that the active heat transfer region is proximate an ablation zone.

18. The method of claim 17, wherein the visual indicator material comprises a radiopaque material.

19. The method of claim 18, wherein the radiopaque material comprises barium sulfate.

20. The method of claim 17, wherein the visual indicator material comprises air bubbles formed within a wall of the outer shaft, the air bubble being detectable via ultrasound.

21. The method of claim 15, wherein a radiopaque marker band is formed about at least a portion of a circumference of the outer shaft to delineate the active heat transfer portion and the insulating portion.

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