Compliable introducer

Abstract

An introducer (200) includes a hub (202) and a tubular body (204) coupled to the hub. The tubular body defines a lumen sized to receive a medical device. The tubular body is formed from a single material. The tubular body is configured to be percutaneously inserted into the body of a patient. The tubular body is configured to be advanced toward a target site within the body through a vasculature of the patient. The tubular body is configured to elastically deform to conform to a vessel shape at a constriction in the vasculature of the body.

Description

COMPLIABLE INTRODUCER

[0001] This application claims the benefit of U.S. Provisional Patent Application Serial No. 63 / 586.883, filed September 29, 2023, the entire content of which is incorporated herein by reference.TECHNICAL FIELD

[0002] This disclosure relates generally to medical devices, and, more particularly, to systems for delivering medical devices.BACKGROUND

[0003] Implantable medical devices (IMDs) are typically implanted via surgical procedures. In some examples, a medical device delivery system may include an introducer configured to provide access for an IMD into the body and / or a pathway for the IMD to a target site within the body. An introducer may include a sheath configured to be inserted through an access site into the patient. The introducer may interact with additional components of an IMD delivery system, such as a dilator or guide wire, which may aid in the advancement of the introducer. In some examples, the IMD is carried by and / or delivered via a catheter, which may be advanceable through a lumen of the introducer. An introducer may decrease tissue trauma and increase the precision and safety of IMD placement, e.g., using a catheter. Examples of medical devices that may benefit from an introducer include catheters, stents, and other implantable devices.SUMMARY

[0004] In some examples, an introducer includes: a hub; a tubular body coupled to the hub, wherein the tubular body defines a lumen sized to receive a medical device, wherein the tubular body is formed from a single material, and wherein the tubular body is configured to: be percutaneously inserted into the body of a patient; be advanced toward a target site within the body through a vasculature of the patient; and elastically deform to conform to a vessel shape at a constriction in the vasculature of the body.

[0005] In some examples, a system includes: a medical device; and an introducer including: a hub; a tubular body coupled to the hub, wherein the tubular body defines alumen sized to receive a medical device, wherein the tubular body is formed from a single material, and wherein the tubular body is configured to: be percutaneously inserted into the body of a patient; be advanced toward a target site within the body through a vasculature of the patient; and elastically deform to conform to a vessel shape at a constriction in the vasculature of the body.

[0006] In some examples, a method includes: percutaneously inserting an introducer into the body of a patient, wherein the introducer includes: a hub; and a tubular body coupled to the hub, wherein the tubular body defines a lumen sized to receive a medical device, and wherein the tubular body is formed from a single material; and advancing the introducer toward a target site within the body through a vasculature of the patient, wherein the tubular body is configured to elastically deform to conform to a vessel shape at a constriction in the vasculature of the body.

[0007] This summary is intended to provide an overview of the subject matter described in this disclosure. It is not intended to provide an exclusive or exhaustive explanation of the apparatus and methods described in detail within the accompanying drawings and description below. Further details of one or more examples are set forth in the accompanying drawings and the description below.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is a conceptual drawing illustrating portions of patient anatomy including potential target sites for an implantable medical device (IMD).

[0009] FIG. 2A-2D are perspective drawings illustrating an example IMD delivery system including a compliable introducer.

[0010] FIG. 3 is a flow diagram illustrating an example technique for using a medical device system.DETAILED DESCRIPTION

[0011] In general, this disclosure describes a medical device delivery system (“delivery system”) configured to deliver an implantable medical device (IMD) to a target site, such as the triangle of Koch (TOK), a coronary sinus ostium, right atrium, a left bundle branch, a right ventricular apex, an intraventricular septum, etc. Although described herein primarily in the context of targeting certain areas of the heart, thedelivery system may be used to deliver an IMD to any target site, including tissue from other parts of the body.

[0012] An introducer for a delivery system may be configured to help guide and position IMD within the body. The introducer may serve as a guiding sheath or tube that is inserted into the body through a small incision or puncture. Once the introducer is in place, devices (e.g., a delivery catheter, a medical device loaded in a delivery catheter, etc.) can be passed through the introducer and guided to the targeted location within the body. This may reduce trauma and damage to surrounding tissues, while improving the accuracy and precision of the procedure.

[0013] In general, a smaller outer diameter introducer may improve the safety, efficacy, and comfort of an implantation procedures. For example, a smaller diameter introducer may help with navigating through a human vasculature that has constrictions (e.g., a narrow region along the path from the jugular access in the neck to the heart). Additionally, it may be desirable for the introducer to be compliant (e.g., able to conform to a vessel shape) while still having enough column strength to allow for insertion and removal of various devices, such as a delivery catheter, a dilator, etc.

[0014] In accordance with techniques of this disclosure, an introducer may be configured to be compliant (e.g., easy to deform), small (e.g., small outer diameter and thin sidewall thickness), and smooth (e.g., low coefficient of friction, such as less than about 0.1). For example, the introducer may be formed from a material that deforms under an applied load or force, and returns to its original shape when the load is removed. In other words, the introducer may be configured to undergo elastic deformation without being permanently deformed or damaged.

[0015] The introducer may have relatively high elasticity, low stiffness, and / or high ductility such that the introducer is flexible and conformable to blood vessels. The compliance of the introducer may be based in part on the thickness of the sidewalls of the introducer. For example, the sidewalls may be relatively thin when compared to traditional introducers for allowing vascular access to advance a delivery system to the heart (reducing the outer diameter of the introducer) and consequently easier to deform. As a result, the introducer may be pushed through a constriction (resulting in temporary deformation of the introducer) without causing tissue trauma as the introducer may change shape once the dilator is removed.

[0016] In some examples, the inner surface and the outer surface of the introducer may be relatively smooth. For example, the inner surfaces and the outer surfaces may have a uniform, flat, and consistent texture with a low degree of roughness or irregularity. The smoothness of the surfaces of the introducer may reduce friction, which may facilitate insertion and removal of the introducer into and from a patient’s body, and insertion and removal of a device into and from the introducer.

[0017] FIG. 1 is a conceptual diagram illustrating a portion of an example medical device system 10 configured to implant a relatively compact implantable medical device 100 (“IMD 100”) at a target site. In some examples, as illustrated in FIG. 1, the target site 107 may include an appendage or triangle of Koch region of a right atrium (RA) of the heart 104 of a patient. In some examples, as illustrated in FIG. 1, the target site 107 may include a coronary sinus ostium (not shown in FIG. 1), or to a left bundle branch (not shown in FIG. 1) on a right septal sidewall of a patient’s heart. In some examples, target site may include other portions of heart 104, such as an interventricular septum, right ventricular apex, or other locations within a body of the patient. Medical device system 10 may include a delivery catheter 170 configured to house and controllably deploy IMD 100. Delivery catheter 170 may include a catheter body extending from a proximal end to a distal end. A clinician may maneuver IMD 100 to target site. For example, with IMD 100 loaded within a cup 180 disposed at a distal end of the catheter body of the delivery catheter 170, the clinician may guide delivery catheter up through the inferior vena cava (IVC) and into the RA of heart 104, and place a tip 172 of cup 180 against the septum of the heart 104. In some examples, other pathways or techniques may be used to guide delivery catheter into other target sites within the body of the patient. For example, the superior vena cava (SVC) may be used to gain access to the heart.

[0018] FIG. 2A is a conceptual diagram of an introducer 200. In general, introducer 200 may be used in various medical procedures, such as in interventional cardiology, radiology, and vascular surgery. Introducer 200 may facilitate the introduction and placement of other medical devices (e.g., catheters, dilators, stents, etc.), such as a dilator 206 into the body's blood vessels or other anatomical structures.

[0019] Introducer 200 may include a hub 202 and a tubular body 204 coupled to hub 202. Tubular body 204 may be a flexible tube configured for smooth insertion into a blood vessel (e.g., through an incision made in the skin). Hub 202 may remain outside the bodyof the patient, providing access for a clinician to insert and maneuver a medical device (e.g., dilator 206, a delivery catheter, etc.) through introducer 200. Tubular body 204 may define a lumen sized to receive the medical device and / or other components of a delivery system (e.g., delivery catheter 170 of FIG. 1). In some examples, tubular body 204 may have an inner diameter of about 0.365 inches and an outer diameter of 0.380 inches (such that the sidewall thickness of tubular body 204 is about 0.0075 inches). A traditional sidewall of an introducer may have a thickness that is significantly larger than 0.0075 inches, such as 0.015 inches.

[0020] Tubular body 204 may be formed from a single material (e.g., such as polytetrafluoroethylene (PTFE)), and in some examples, the composition of tubular body 204 may be homogenous (e.g., uniform), example materials may include PTFE, perfluoroalkoxy (PFA), ethylene tetrafluoroethylene (ETFE), polyamide, polyether block amide (PEBA), other fluoropolymers etc. Fluoropolymers such as PTFE may naturally have a low coefficient of friction, while PEBA may require lubricious additives such as Mobilize, Propell, Siloxane, etc., or an externally applied silicone lubricant. In any case, the material may be extruded to form tubular body 204.

[0021] The sidewall of tubular body 204 may have sufficient column strength to facilitate insertion and removal of a dilator, delivery catheter, or other medical device. For example, tubular body 204 may have sufficient column strength to reduce the extent or likelihood of tubular body 204 bunching up or folding over when inserting / removing dilator 206. Additionally, tubular body 204 may be sized such that there is relatively little clearance when inserting dilator 206 through tubular body 204 (e.g., less than about 0.01 inches of clearance). This close fit between tubular body and dilator 206, along with the sufficient column strength, may allow tubular body 204 to not bunch up as dilator 206 is inserted into the vasculature. The low coefficient of friction of an inner surface of tubular body 204 may also facilitate insertion and removal of dilator 206 (or other device) through tubular body 204.

[0022] Tubular body 204 may be configured to be percutaneously inserted into the body of a patient and advanced to a target site (e.g., a vascular location within, near, or on a path to heart 104) within the body of the patient. For example, prior to insertion into the patient’s body, dilator 206 may be inserted through tubular body 204 and, with a distal end of dilator 206 leading the way, tubular body 204 may advance through vasculature of thepatient’s body. In some examples, dilator 206 may be mechanically coupled to hub 202 (e.g., via threads on the proximal end of hub 202 and threads on the mating portion of dilator 206) to help keep introducer 200 and dilator 206 attached during insertion into the patient’s body.

[0023] Tubular body 204 may be navigated proximate (but not necessarily adjacent to) a target site. For example, tubular body 204 may be advanced such that a distal end of tubular body 204 is just inside the heart of the patient. Tubular body 204 may be configured to elastically deform to conform to a vessel shape at a constriction in vasculature of the body. For example, dilator 206 may be removed from tubular body 204 after tubular body 204 is proximate the target site, and tubular body 204 may change shape to accommodate the patient’s vasculature (promoting patient comfort).

[0024] After tubular body 204 conforms to the patient’s vasculature, a delivery catheter carrying a medical device may be inserted into introducer 200. As the delivery catheter advances through tubular body 204, tubular body 204 may temporarily ‘open up,’ allowing passage of the delivery catheter. Tubular body 204 may be sized to allow passage of the largest outer diameter of the delivery catheter (e.g., the outer diameter of the distal cup of the delivery catheter). In this way, introducer 200 may protect the vessels and facilitate delivery catheter insertion.

[0025] FIG. 2B is a conceptual diagram of tubular body 204 defining a lumen 208. In some examples, an inner surface 210 of tubular body 204 may have a coefficient of friction less than or equal to 0.25 to facilitate passage of a medical device. Similarly, an outer surface 212 of tubular body 204 may have a coefficient of friction less than or equal to 0.25 to facilitate insertion of tubular body 204 into vasculature of the patient. The low coefficient of friction on inner surface 210 of tubular body 204 may allow for smooth insertion of a medical device. The low coefficient of friction of outer surface 212 of tubular body 204 may reduce the risk of any damage or irritation to surrounding structures during insertion of tubular body 204 into vasculature of the patient.

[0026] Tubular body 204 may have a relatively small outer diameter (e.g., from about 0.360 to about 0.385 inches). In general, the outer diameter of tubular body 204 may be sized to allow for an inner diameter that provides just enough clearance for IMD 100 (e.g., an IMD having a 0.30 inch outer diameter as well as any associated delivery catheter cup). The relatively small outer diameter of tubular body 204 may decrease tissue trauma by, forexample, preserving the integrity of blood vessels or delicate tissues. For example, tubular body 204 may cause less stretching or pressure on the blood vessels or tissues during insertion and removal, leading to improved patient comfort during and after the procedure. That said, the inner diameter of tubular body 204 may be sized to allow passage of any medical device required for a procedure.

[0027] FIG. 2C is a conceptual diagram of tubular body 204 having a sidewall 214. As shown in FIG. 2C, tubular body 204 may have a relatively thin sidewall thickness (e.g., from about 0.0025 inches to about 0.0100 inches). Tubular body 204 having a relatively thin sidewall thickness may contribute to tubular body 204 having a relatively small outer diameter. The relatively thin sidewall thickness of tubular body 204 may smoothen the transition as a medical device exits a distal end of tubular body 204. In some examples, a ratio of a sidewall thickness of tubular body 204 to an outer diameter of tubular body 204 may be less than or equal to 0.01.

[0028] In general, tubular body 204 is elastically deformable (e.g., compliant). That is, tubular body 204 may be configured to deform or change shape in response to an applied force or load (e.g., exerted by a blood vessel). As a result, tubular body 204 may be flexible and adaptable to the anatomical structures of a patient’ s vasculature, facilitating insertion of tubular body 204 and reducing any trauma.

[0029] FIG. 2D is a conceptual diagram of tubular body 204. As shown in FIG. 2D, sidewall 214 may define a secondary lumen 216. Secondary lumen 216 may be configured to receive a medical device such as a guidewire 218. Guidewire 218 may serve as a navigational tool that helps facilitate the placement of tubular body 204, as well as other medical instruments, within the body’s blood vessels or other anatomical structures. For example, while positioned in secondary lumen 216, guidewire 218 may be advanced to a desired location under fluoroscopic or other imaging guidance and act as a marker (e.g., guidewire 218 may mark the location of the coronary sinus). Guidewire 218 may also provide support and stability during the insertion of tubular body.

[0030] FIG. 3 is a flow diagram illustrating an example technique for operating an introducer according to aspects of this disclosure. The example technique of FIG. 3 is described in the context of introducer 200 of FIG. 2 but may be applicable to other embodiments of introducer 200 disclosed herein, or to other medical devices.

[0031] During an implant procedure, a clinician may advance tubular body 204 of introducer 200 through an access site (e.g., an incision) and toward a target site, such as the TOK (300). In some examples, the clinician may advance guidewire 218 to the target site first. Guidewire 218 may serve as a pathway for introducer 200 to follow. Introducer 200 may be inserted over guidewire 218, with guidewire 218 positioned in secondary lumen 216. Dilator 206 may be inserted through tubular body 204 and, with a distal end of dilator 206 leading the way, tubular body 204 may advance through vasculature of the patient’s body.

[0032] Tubular body 204 may be inserted smoothly and gradually (e.g., due to the low coefficient of friction of outer surface 212 of tubular body 204). Due to the compliance of tubular body 204, tubular body 204 may deform to navigate through constrictions while reducing trauma to patients. In some examples, imaging techniques, such as fluoroscopy or ultrasound, may be used to confirm the correct placement of introducer 200 in the desired location.

[0033] Once introducer 200 is in place and the dilator is removed, the clinician may use introducer 200 as the access point for other medical instruments, such as catheters, stents, etc. (302). For example, the clinician may advance a delivery catheter carrying IMD 100 through introducer 200 to the target site. After completing the procedure, the clinician may remove the medical device from introducer 200 and remove introducer 200 from the patient’s body (304).

[0034] The following examples are illustrative of the techniques described herein.

[0035] Example 1: An introducer includes: a hub; a tubular body coupled to the hub, wherein the tubular body defines a lumen sized to receive a medical device, wherein the tubular body is formed from a single material, and wherein the tubular body is configured to: be percutaneously inserted into the body of a patient; be advanced toward a target site within the body through a vasculature of the patient; and elastically deform to conform to a vessel shape at a constriction in the vasculature of the body.

[0036] Example 2: The introducer of example 1, wherein a composition of the tubular body is homogenous.

[0037] Example 3: The introducer of example 1 or 2, wherein an inner surface of the tubular body has a coefficient of friction less than or equal to 0.25.

[0038] Example 4: The introducer of any of examples 1 to 3, wherein an outer surface of the tubular body has a coefficient of friction less than or equal to 0.25.

[0039] Example 5: The introducer of any of examples 1 to 4, wherein a ratio of a sidewall thickness of the tubular body to an outer diameter of the tubular body is less than or equal to 0.01.

[0040] Example 6 : The introducer of any of examples 1 to 5, wherein the medical device is a catheter, a dilator, a guidewire, or a stent.

[0041] Example 7 : The introducer of any of examples 1 to 6, wherein the target site the heart of the patient.

[0042] Example 8: The introducer of any of examples 1 to 7, wherein a sidewall of the introducer defines a secondary lumen configured to receive a guidewire.

[0043] Example 9: The introducer of example 8, wherein the guidewire is configured to mark a location of the coronary sinus of the patient.

[0044] Example 10: A system includes: a medical device; and an introducer including: a hub; a tubular body coupled to the hub, wherein the tubular body defines a lumen sized to receive a medical device, wherein the tubular body is formed from a single material, and wherein the tubular body is configured to: be percutaneously inserted into the body of a patient; be advanced toward a target site within the body through a vasculature of the patient; and elastically deform to conform to a vessel shape at a constriction in the vasculature of the body.

[0045] Example 11: The system of example 10, wherein a composition of the tubular body is homogenous.

[0046] Example 12: The system of example 10 or 11, wherein an inner surface of the tubular body has a coefficient of friction less than or equal to 0.25.

[0047] Example 13: The system of any of examples 10 to 12, wherein an outer surface of the tubular body has a coefficient of friction less than or equal to 0.25.

[0048] Example 14: The system of any of examples 10 to 13, wherein a ratio of a sidewall thickness of the tubular body to an outer diameter of the tubular body is less than or equal to 0.01.

[0049] Example 15: The system of any of examples 10 to 14, wherein the medical device is a catheter, a dilator, a guidewire, or a stent.

[0050] Example 16: The system of any of examples 10 to 15, wherein the target site the heart of the patient.

[0051] Example 17: The system of any of examples 10 to 16, wherein a sidewall of the introducer defines a secondary lumen configured to receive a guidewire.

[0052] Example 18: The system of example 17, wherein the guidewire is configured to mark a location of the coronary sinus of the patient.

[0053] Example 19: A method includes: percutaneously inserting an introducer into the body of a patient, wherein the introducer includes: a hub; and a tubular body coupled to the hub, wherein the tubular body defines a lumen sized to receive a medical device, and wherein the tubular body is formed from a single material; and advancing the introducer toward a target site within the body through a vasculature of the patient, wherein the tubular body is configured to elastically deform to conform to a vessel shape at a constriction in the vasculature of the body.

[0054] Example 20: The method of example 19, wherein a ratio of a sidewall thickness of the tubular body to an outer diameter of the tubular body is less than or equal to 0.01.

[0055] Various aspects of the disclosure have been described. These and other aspects are within the scope of the following claims.

Claims

WHAT IS CLAIMED IS:

1. An introducer comprising: a hub; a tubular body coupled to the hub, wherein the tubular body defines a lumen sized to receive a medical device, wherein the tubular body is formed from a single material, and wherein the tubular body is configured to: be percutaneously inserted into the body of a patient; be advanced toward a target site within the body through a vasculature of the patient; and elastically deform to conform to a vessel shape at a constriction in the vasculature of the body.

2. The introducer of claim 1, wherein a composition of the tubular body is homogenous.

3. The introducer of claim 1 or 2, wherein an inner surface of the tubular body has a coefficient of friction less than or equal to 0.25.

4. The introducer of any of claims 1 to 3, wherein an outer surface of the tubular body has a coefficient of friction less than or equal to 0.25.

5. The introducer of any of claims 1 to 4, wherein a ratio of a sidewall thickness of the tubular body to an outer diameter of the tubular body is less than or equal to 0.01.

6. The introducer of any of claims 1 to 5, wherein the medical device is a catheter, a dilator, a guidewire, or a stent.

7. The introducer of any of claims 1 to 6, wherein the target site the heart of the patient.

8. The introducer of any of claims 1 to 7, wherein a sidewall of the introducer defines a secondary lumen configured to receive a guidewire.

9. The introducer of claim 8, wherein the guidewire is configured to mark a location of the coronary sinus of the patient.

10. A system comprising: a medical device; and an introducer comprising: a hub; a tubular body coupled to the hub, wherein the tubular body defines a lumen sized to receive a medical device, wherein the tubular body is formed from a single material, and wherein the tubular body is configured to: be percutaneously inserted into the body of a patient; be advanced toward a target site within the body through a vasculature of the patient; and elastically deform to conform to a vessel shape at a constriction in the vasculature of the body.

11. The system of claim 10, wherein a composition of the tubular body is homogenous.

12. The system of claim 10 or 11, wherein an inner surface of the tubular body has a coefficient of friction less than or equal to 0.25.

13. The system of any of claims 10 to 12, wherein an outer surface of the tubular body has a coefficient of friction less than or equal to 0.25.

14. The system of any of claims 10 to 13, wherein a ratio of a sidewall thickness of the tubular body to an outer diameter of the tubular body is less than or equal to 0.01.

15. The system of any of claims 10 to 14, wherein the medical device is a catheter, a dilator, a guidewire, or a stent.

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