Guidewire delivery catheter with expandable anchoring mechanism for use in the coronary sinus

Abstract

We provide delivery devices such as catheters for medical procedures involving the coronary sinus. [Solution] A mechanism (400) for fixing a catheter in place is disclosed to facilitate puncturing a hole through the blood vessel wall. The fixing mechanism (400) includes an expansion member (402) that expands when activated and presses against the blood vessel wall (e.g., the coronary sinus wall (30)). Activation of the fixing mechanism (400) occurs by removing a restraint (e.g., a cover (401)) or by pushing or pulling a wire. The expansion member (402) may self-expand or expand by a spring within a mesh structure. The fixing mechanism, activated by pushing or pulling a wire, expands as a result of the movement of the wire itself or of components attached to the wire and anchor member.

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application claims priority based on U.S. Provisional Patent Application No. 63 / 180,602, filed on April 27, 2021, entitled "SECURING A GUIDEWIRE DELIVERY CATHETER IN THE CORONARY SINUS USING MATERIAL OR ADVANCEMENT MECHANISMS", the entire disclosure of which is incorporated herein by reference in its entirety.

Background Art

[0002] The present invention generally relates to the field of delivery devices, such as catheters, for medical procedures involving the coronary sinus.

[0003] (Description of Related Technologies) Heart failure is a common and potentially life - threatening condition that affects humans, and despite maximum treatment, sub - optimal clinical outcomes often result in symptoms, morbidity, and / or mortality. In particular, "diastolic heart failure" refers to a clinical syndrome of heart failure that occurs in the presence of preserved left ventricular systolic function (ejection fraction) and in the absence of major valvular disease. This condition is characterized by a stiff left ventricle with decreased compliance and impaired relaxation, which leads to an increase in end - diastolic pressure.

[0004] The symptoms of diastolic heart failure are, at least in large part, due to an increase in left atrial pressure. Left atrial pressure elevation (LAP) exists in several abnormal cardiac conditions, including heart failure (HF). In addition to diastolic heart failure, several other medical conditions, including left ventricular systolic dysfunction and valvular disease, can result in an increase in pressure in the left atrium. Both heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF) may exhibit an elevation in LAP.

[0005] Reducing the pressure increase in the left atrium may be beneficial. One way to do this is to shunt blood from the left atrium to the coronary sinus. By creating an opening between the left atrium and the coronary sinus, blood flows from the higher-pressure left atrium to the lower-pressure coronary sinus. An example of a method for shunting blood from the left atrium to the coronary sinus is described in U.S. Patent No. 9,789,294, entitled "Expandable cardiac Shunt," the entire contents of which are incorporated herein by reference.

[0006] Using a catheter-based instrument, the surgeon creates a puncture site between the left atrium and the coronary sinus and places a dilatable shunt within the puncture site. To do this, one or more catheters are used to create the puncture site, deliver the dilatable shunt along a guidewire, and deploy the dilatable shunt within the puncture site. Once expanded, the shunt defines a blood flow channel that allows blood to flow from the left atrium to the coronary sinus when the LAP rises. [Overview of the project]

[0007] For the purpose of summarizing this disclosure, specific aspects, advantages, and novel features are described herein. It should be understood that not all such advantages can necessarily be achieved according to any particular embodiment. Accordingly, the disclosed embodiments may be implemented in a manner that achieves or optimizes one or more advantages as taught herein, without necessarily achieving other advantages that can be taught or suggested herein. [Means for solving the problem]

[0008] Partial implementation of this disclosure relates to a guidewire delivery catheter used to implant a shunt between the coronary sinus and the left atrium, wherein the catheter includes a fixation mechanism. The fixation mechanism includes a removable cover connected to a wire or hypotube. The fixation mechanism includes an expansion member activated by the removal of the removable cover, the removable cover being pulled by the wire or hypotube to expose the expansion member, which expands the expansion member out of the catheter, thereby fixing the distal end of the catheter in a predetermined position within the coronary sinus.

[0009] In some embodiments, the expansion member comprises a mesh structure. In some embodiments, the expansion member comprises an adaptive wire material. In some embodiments, the expansion member comprises a self-expanding bubble.

[0010] In some embodiments, the expansion member includes a spring-loaded bubble. In further embodiments, the spring is held in a compressed state by a cover, and by removing the cover, the spring can be extended, thereby expanding the spring-loaded bubble to form a dome shape.

[0011] In some embodiments, the expansion member is configured to retract by re-advancing a removable cover over the expansion member. In some embodiments, the activation of the expansion member presses the expansion member against the vessel wall, providing wall alignment to the catheter to facilitate puncture of the vessel wall.

[0012] Partial implementation of this disclosure relates to a guidewire delivery catheter used to implant a shunt between the coronary sinus and the left atrium, wherein the catheter includes a fixation mechanism. The fixation mechanism includes an activation member comprising a wire or hypotube. The fixation mechanism includes an expansion member activated by the activation member, the proximal end of which is connected to the distal end of the activation member, and the expansion member is configured to expand out of the catheter in response to the activation member advancing distally, thereby fixing the distal end of the catheter in a predetermined position within the coronary sinus.

[0013] In some embodiments, the expansion member comprises a mesh structure. In some embodiments, the expansion member comprises an adaptable wire material. In some embodiments, the expansion member is configured to retract by pulling the activation member proximal. In some embodiments, the distal portion of the expansion member is fixed to the catheter. In some embodiments, activation of the expansion member presses the expansion member against the vessel wall, providing wall alignment to the catheter to facilitate puncture of the vessel wall. In some embodiments, the expansion member comprises a fabric cover that restrains the distal portion of the activation member, such that as the activation member advances distally, the distal portion of the activation member curves within the fabric cover, causing the fabric cover to form a dome shape.

[0014] Partial implementation of this disclosure relates to a guidewire delivery catheter used to implant a shunt between the coronary sinus and the left atrium, wherein the catheter includes an fixation mechanism. The fixation mechanism includes an activation member comprising a wire or hypotube connected to a movable distal structure. The fixation mechanism includes an expansion member activated by the activation member, the expansion member comprising a fixed proximal structure and a movable distal structure having a flexible material that forms a wall attached to the fixed proximal structure and the movable distal structure, such that pulling the activation member moves the movable distal structure toward the fixed proximal structure, causing its wall to expand outward, thereby fixing the distal end of the catheter in a predetermined position within the coronary sinus.

[0015] In some embodiments, the wall comprises an adaptable wire material. In some embodiments, the expansion member is configured to retract by pushing the activation member distally. In some embodiments, activation of the expansion member presses the expansion member against the vessel wall, providing wall alignment to the catheter to facilitate puncture of the vessel wall. In some embodiments, the activation member comprises a wire extending through a hypotube, which is surrounded by a fixed proximal structure. [Brief explanation of the drawing]

[0016] Various embodiments are shown in the accompanying drawings for illustrative purposes and should not be construed as limiting the scope of the invention. In addition, various features of different disclosed embodiments may be combined to form additional embodiments which are part of this disclosure. Throughout the drawings, reference numerals may be reused to indicate correspondences between reference elements. However, it should be understood that the use of similar reference numerals in relation to multiple drawings does not necessarily imply similarity between the respective embodiments relating thereto. Furthermore, it should be understood that features in each drawing are not necessarily drawn to scale, and their illustrated sizes are presented for illustrative purposes to illustrate aspects of the invention. In general, some illustrated features may be relatively smaller than those illustrated in some embodiments or configurations.

[0017] [Figure 1] Figure 1 shows several access routes for manipulating the guidewire and / or catheter within and around the heart in order to deploy the shunt. [Figure 2] Figure 2 illustrates one approach to deploying an expandable shunt, in which a guidewire is introduced into the coronary sinus via the subclavian or jugular vein and then the superior vena cava. [Figure 3] Figures 3A, 3B, 3C, and 3D show schematic diagrams of the process of creating a puncture hole through the wall of the coronary sinus, with the posterior surface facing downwards and a portion of the heart viewed from above. [Figure 4] Figures 4A, 4B, and 4C show a first exemplary fixing mechanism including a self-expanding bubble and cover. [Figure 5] Figures 5A, 5B, and 5C show a second exemplary fastening mechanism including a spring-loaded bubble and cover. [Figure 6] Figures 6A, 6B, and 6C show a third exemplary fastening mechanism, which includes a mesh structure and a wire that can be pushed to expand the mesh structure. [Figure 7]Figures 7A, 7B, and 7C show a fourth exemplary fixation mechanism that includes a compliant wall that expands when a wire is pulled for proximal movement of a distal movable structure relative to a proximal fixed structure.

BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The headings provided herein are for convenience only and do not necessarily affect the scope or meaning of the claimed invention.

[0019] Abstract The symptoms of diastolic heart failure result from an increase in left atrial pressure, or an increase in left atrial pressure (LAP). Other cardiac conditions may also exhibit an increase in LAP. To reduce the pressure in the left atrium, a pathway can be created between the left atrium and the coronary sinus. This allows blood to flow from the higher-pressure left atrium to the lower-pressure coronary sinus. The pathway can be created by puncturing a hole between the left atrium and the coronary sinus. Once the hole is created, a shunt can be placed in the hole to keep the hole open.

[0020] For example, a catheter-based device can be used to create the hole and deliver and deploy the shunt into the puncture hole. The catheter may be referred to as a guide wire delivery catheter (GDC) and can be used to puncture through the coronary sinus into the left atrium to place a guide wire in the left atrium. To puncture through tissue, the catheter has a wall juxtaposition for directly capturing the needle against the coronary sinus-left atrial wall. Previous GDCs used an "anchor balloon" (saline-inflated balloon) to fix the catheter when creating the puncture hole. The anchor balloon solution can rupture or dislodge from position, which can be harmful to the patient.

[0021] Therefore, materials and mechanisms for fixing the GDC in place to allow the GDC to puncture the wall from the coronary sinus to the left atrium are described herein. These materials and mechanisms function as an alternative to the anchor balloon.

[0022] The term "catheter" is used herein in its broad and ordinary sense and can include any tube, sheath, steerable sheath, steerable catheter, and / or any other type of elongated tubular delivery device having an inner lumen configured to slidably receive an instrument, for example, for positioning within the atrium or coronary sinus, including, for example, a delivery catheter and / or cannula. The term "hypotube" is used herein in its broad and ordinary sense and can include small diameter tubes typically made of stainless steel or nitinol, typically used in medical devices such as catheters, stents, etc. As used herein, a wire can be used as a general term to denote an elongated, flexible structure that can include a hypotube.

[0023] In some cases, the fixation mechanism may be composed of a shape memory alloy (e.g., nitinol) and / or may have a predefined shape and / or structure. The fixation mechanism can be configured to be shaped and / or compressed to fit within and / or around the catheter. In some cases, the fixation mechanism may have an elongated shape that extends at least partially along the catheter in a delivery configuration and changes shape to provide wall juxtaposition in a deployed configuration.

[0024] Some embodiments described herein provide a method and / or system for fixing a guidewire delivery catheter or other similar delivery device to provide wall juxtaposition for piercing a blood vessel wall. Some embodiments may be directed to fixing a catheter within the coronary sinus to pierce the wall between the coronary sinus and the left atrium, but the devices described herein may be applicable to other regions of the body. For example, some of the devices described herein can be advantageously configured to fix a catheter to a blood vessel other than the coronary sinus.

[0025] The following includes a general description of methods for delivering a guidewire delivery catheter to a target location in the coronary sinus. Figure 1 shows several access routes for manipulating the guidewire and / or catheter within and around the heart to deploy a shunt. For example, access can be obtained from above via either the subclavian or jugular vein to the superior vena cava (SVC), into the right atrium (RA), and from there into the coronary sinus (CS). Alternatively, the access route may begin in the femoral vein, pass through the inferior vena cava (IVC), and enter the heart. Other access routes may also be used, each typically utilizing a percutaneous incision through which the guidewire and catheter are inserted into the vascular system, usually through a sealed introducer, from which the physician controls the distal end of the device from outside the body.

[0026] Figure 2 illustrates one approach to deploying an expandable shunt, in which a guidewire 10 is introduced into the coronary sinus via the subclavian or jugular vein and the superior vena cava (SVC). Once the guidewire provides the pathway, an introducer sheath (not shown) can be routed along the guidewire into the patient's vascular system, typically by the use of a dilator. Figure 2 shows a deployment catheter 12 extending from the SVC into the coronary sinus of the heart, passing through an introducer sheath that provides a hemostatic valve to prevent blood loss.

[0027] In some embodiments, the deployment catheter 12 may be about 30 cm in length, and the guidewire 10 may be somewhat longer for ease of use. In certain embodiments, the deployment catheter 12 may function to form and prepare an opening in the wall of the left atrium, and a separate placement or delivery catheter may be used for delivery of an expandable shunt. In various embodiments, the deployment catheter may be used for puncture preparation and may also function as a fully functional shunt placement catheter. In this application, the terms “deployment catheter” and “delivery catheter” may be used to describe a catheter or introducer that provides one or both of these functions.

[0028] Because the coronary sinuses are largely continuous around the left atrium, there are a variety of possible and acceptable placements for stents. The site chosen for stent placement may be within an area where the tissue of a particular patient is thin or low-density, as predetermined by non-invasive diagnostic methods such as fluoroscopy or intravascular ultrasound (IVUS), such as CT scans or X-rays.

[0029] Figures 3A–3D show schematic diagrams of the process of creating a puncture hole through the wall of the coronary sinus, viewed from above with the posterior surface facing downwards and a portion of the heart. First, Figure 3A shows the guidewire 20 advancing from the right atrium through its small hole or opening into the coronary sinus. Next, the puncture catheter 22 advances above the guidewire 20, as shown in Figure 3B. The puncture catheter 22 is introduced into the body through the proximal end of an introducer sheath (not shown). Conventionally, the introducer sheath provides access to a specific vascular pathway (e.g., the jugular vein or subclavian vein) and may have a hemostatic valve within it. While holding the introducer sheath in a fixed position, the surgeon manipulates the puncture catheter 22 to the implantation site.

[0030] In some embodiments, the distal end of the puncture catheter 22 has a built-in slight curvature, with radially inward and radially outward directions, to conform to the curvature of the coronary sinus. The fixation mechanism 24 is exposed along the radially outward direction of the catheter 22, adjacent to the distal segment 25, which may be thinner than the proximal range of the catheter 22 or tapered and narrower from the proximal range of the catheter 22. Radiopaque markers 26 on the catheter 22 may be used to help the surgeon determine the precise advancement distance for the desired placement of the fixation mechanism 24 in the coronary sinus. Preferably, the radiopaque markers 26 are C-shaped bands located on the sides of the proximal and distal ends of the fixation mechanism 24.

[0031] Figure 3C shows the outward deployment of the fixation mechanism 24, which is considered a general structure that can be replaced by any of the fixation mechanisms disclosed herein and described with reference to Figures 4A–7C. The deployment of the fixation mechanism 24 presses the radially medial curve of the catheter against the luminal wall of the coronary sinus, providing wall juxtaposition. Here again, the fixation mechanism 24 is located adjacent to the distal segment 25 of the puncture catheter 22. In some embodiments, the fixation mechanism 24 extends to the opposite side of the needle port 28 formed on the radially medial wall of the catheter 22. As a result, the needle port 28 abuts against the luminal wall and faces the tissue wall 30 between the coronary sinus and the left atrium. Guided by visualization of radiopaque markers 26, the surgeon prefers to advance the catheter 22 so that the needle port 28 is located within approximately 2–4 cm of the coronary artery orifice. This ensures that the subsequent puncture is positioned approximately above the "P2" portion of the posterior leaflet of the mitral valve (as shown in Figure 3B, when viewed from the inflow side of the valve, the posterior leaflet has P1-P2-P3 leaflets in the CCW direction). The fixation mechanism 24 may be centered diametrically across the catheter 22 from the needle port 28, or it may be offset proximal to the needle port 28 to improve the lever action, as shown, or it may be offset distal to the needle port 28.

[0032] The curvature of the distal end of the puncture catheter 22 aligns with the anatomical structure within the coronary sinus, "fitting along" it and orienting the needle port 28 inward, while the fixation mechanism 24 holds the catheter 22 in place relative to the coronary sinus. Then, as shown in Figure 3D, the puncture sheath 32, with a puncture needle 34 having a sharp tip, advances along the catheter 22, exiting the needle port 28 at an angle from the longitudinal direction of the catheter 22 and puncturing into the left atrium through the wall 30. The puncture sheath 32 has an inherent curvature at its end, "aligning" with the curvature of the anatomical structure to ensure that the needle 34 is oriented inward toward the left atrium. The fixation mechanism 24 provides rigidity to the system and holds the needle port 28 against the wall 30 (e.g., the fixation mechanism provides wall juxtaposition). The puncture needle 34 has a flattened structure that forms a straight cut and is preferably attached to the distal end of an elongated wire or flexible rod (not shown) that passes through the lumen of the puncture sheath 32.

[0033] Fixing mechanism Mechanisms for fixing a catheter within a blood vessel are described herein to facilitate puncturing the blood vessel wall using a needle extending from the catheter. The fixation mechanisms described herein can be implemented in catheters such as catheter 22 described herein with respect to Figures 3A-3D. In addition, the fixation mechanisms described herein provide the functionality of the general fixation mechanism 24 described herein with respect to Figures 3A-3D. In other words, the fixation mechanisms described below can be used in place of the fixation mechanism 24 described herein with respect to Figures 3A-3D.

[0034] The disclosed fixation mechanism is a variation of fixation mechanism 24 used to fix a guidewire delivery catheter in place, enabling puncture of the wall between the coronary sinus and the left atrium. In particular, the embodiment represents an improvement over saline-filled anchor balloons because it eliminates the risk of balloon rupture and offers the possibility of better catheter fixation. With balloon procedures, if the balloon ruptures before the needle is deployed, the needle may deploy into the wrong space, potentially causing severe injury to the patient. Furthermore, a ruptured balloon can lead to embolism in the patient. The disclosed embodiment eliminates this risk by not using a saline-filled balloon or other elements that require inflation using liquid or gas. In addition, the disclosed embodiment eliminates the need to deflate the balloon, thereby providing a more streamlined procedure.

[0035] The disclosed fixation mechanism may include a bubble, mesh, flap, or similar feature that expands when activated and presses against the wall of the coronary sinus. This force fixes the distal end of the guidewire delivery catheter, allowing the needle to puncture the wall of the coronary sinus. Activation of the disclosed fixation mechanism may occur by removing a restraint (e.g., a cover) or by pushing or pulling the wire. The disclosed fixation mechanism material may be a mesh made from an elastic and adaptable wire material and / or a shape memory material or a self-expanding material. Exemplary materials may be nickel-titanium alloys such as nitinol, but other materials may also be used. A fixation mechanism activated by removal of a restraint may self-expand or expand by a spring within the mesh structure. A fixation mechanism activated by pushing or pulling the wire expands as a result of movement of the wire itself or as a result of movement of components attached to the wire and anchor member.

[0036] The disclosed fixation mechanism is configured for use with a catheter, such as a guidewire delivery catheter described herein. Also disclosed herein is a guidewire delivery catheter having a fixation mechanism (or anchor member) comprising an activation member and an expansion member activated by the activation member. The fixation mechanism is located on the side of the catheter opposite the needle port or similar feature and can provide wall alignment when puncturing through a blood vessel wall.

[0037] A first exemplary fixation mechanism includes a cover that is removed to allow a self-expanding bubble to expand outward from the side of the catheter. A second exemplary fixation mechanism includes a cover that is removed to allow a spring-loaded bubble to expand outward from the side of the catheter. A third exemplary fixation mechanism includes a wire that is compressed and bundled, causing a mesh structure to expand outward from the side of the catheter. A fourth exemplary fixation mechanism has an expansion member that includes a fixed proximal structure, a movable distal structure, and strips attached to the proximal and distal structures, wherein pulling the wire moves the distal structure toward the proximal structure and inflates the strips outward. The expansion members of the disclosed fixation mechanisms are configured to be activated without the use of liquid or gas as an inflation means. That is, the disclosed fixation mechanisms are not activated by inflation using liquid or gas.

[0038] Figures 4A–4C illustrate a first exemplary fixation mechanism 400. The first exemplary fixation mechanism 400 includes a self-expanding bubble 402 that is restrained by a cover 401 or other similar restraint, as shown in Figure 4A. The fixation mechanism 400 can be guided as part of the catheter 22 to a fixed position, for example, where the needle 34 will puncture the wall of the coronary sinus 30. The bubble 402 is restrained during delivery using a restraint structure such as the cover 401. As shown in Figure 4B, once in position, the cover 401 can be removed. As shown in Figure 4C, removal of the cover 401 allows the self-expanding bubble structure 402 to expand out of the catheter 22, thereby fixing the distal end of the guidewire delivery catheter 22 in a fixed position against the wall 30. In the expanded or deployed state, the bubble 402 provides wall juxtaposition to the coronary sinus wall 30 for the needle 34 to puncture the opposite coronary sinus wall 30.

[0039] In some embodiments, the bubble 402 may be located inside the catheter 22. In some embodiments, the cover 401 may be part of the outer wall of the catheter 22. In these embodiments, the fixation mechanism 400 is housed inside the catheter 22 during delivery. In certain embodiments, the bubble 402 and the cover 401 are attached to the outer surface of the catheter 22. In various embodiments, the cover 401 is located outside the catheter 22, and the bubble 402 is at least partially housed inside the catheter 22.

[0040] The self-expanding bubble 402 can be made from a bundled material such as a stretchable and adaptable wire material. The material can be, for example, nitinol. The self-expanding bubble 402 can be a mesh material that allows fluid to flow through it, as opposed to a balloon that contains a fluid (e.g., saline solution) used to inflate it. Beneficially, this allows fluid to flow through the container during the puncture procedure.

[0041] The self-expanding bubble 402 can be shaped so that when expanded, it forms a dome shape. In some embodiments, the self-expanding bubble 402 is configured to expand rapidly when the cover 401 is removed. The self-expanding bubble 402 can be pulled back into the catheter 22 using a pull wire or hypotube to draw the self-expanding bubble 402 into the catheter 22. Once the self-expanding bubble retracts, the cover 401 can be advanced again to cover the self-expanding bubble 402. The cover 401 advantageously keeps the self-expanding bubble 402 within a restraining area, preventing the self-expanding bubble 402 from deploying before the cover is removed, thus reducing the risk of damage during insertion.

[0042] Figures 5A–5C illustrate a second exemplary fixation mechanism 500. The second exemplary fixation mechanism 500 includes a spring-loaded bubble 502 that expands when the restraint 501 is removed, as shown in Figure 5A, and the expansion is caused by a spring 503 contained within the bubble 502. The fixation mechanism 500 can be guided as part of the catheter 22 to a fixed position, for example, where the needle 34 will puncture the wall of the coronary sinus 30. As shown in Figure 5B, once in position, the restraint 501 can be removed. As shown in Figure 5C, the removal of the restraint 501 allows the compressed spring 503 within the bubble 502 to extend, expanding the mesh bubble 502 out of the catheter 22, thereby fixing the distal end of the guidewire delivery catheter 22 in a fixed position against the wall 30. In the expanded or deployed state, the bubble 502 provides wall juxtaposition to the coronary sinus wall 30 for the needle 34 to puncture the opposite coronary sinus wall 30. Bubble 502 can be a mesh material such as a stretchable and adaptable wire material. Beneficially, this allows fluid to flow through the container during the puncture procedure.

[0043] In some embodiments, the bubble 502 may be located inside the catheter 22. In some embodiments, the restraint 501 may be part of the outer wall of the catheter 22. In these embodiments, the fixation mechanism 500 is housed inside the catheter 22 during delivery. In certain embodiments, the bubble 502 and the restraint 501 are attached to the outer surface of the catheter 22. In various embodiments, the restraint 501 is located outside the catheter 22, and the bubble 502 is at least partially housed inside the catheter 22.

[0044] The spring-loaded bubble 502 is initially covered during delivery, and the restraint 501 is configured to keep the spring 503 compressed. Therefore, the restraint 501 is sufficiently elastic to maintain the spring 503 in a compressed state. The restraint 501 may be connected to a pull wire, hypotube, or other similar mechanism to pull out the restraint 501 when the catheter 22 is in a fixed position at the desired location. When the restraint 501 is removed, the spring 503 expands, thereby expanding the mesh or bubble 502. When the bubble 502 is expanded by the spring 503, it forms a dome-shaped shape rather than a cylindrical shape, and conforms more closely to the spring 503. Therefore, the material of the bubble 502 is sufficiently rigid to form a target dome-shaped shape, while being sufficiently adaptable to be compressed by the restraint 501.

[0045] Figures 6A–6C illustrate a third exemplary fixation mechanism 600. The third exemplary fixation mechanism 600 includes a mesh structure 601 having a proximal end attached to a wire 602, as shown in Figure 6A. The fixation mechanism 600 can be guided as part of the catheter 22 to a fixed position, i.e., where the needle 34 will puncture the wall 30 of the coronary sinus. Once in position, the wire 602 can be pushed to expand the mesh structure 601, as shown in Figure 6B. Similarly, the mesh structure 601 can be retracted by pulling the wire 602, as shown in Figure 6B. By pushing the wire 602, the mesh structure 601 is bundled and expanded outward from the catheter 22, thereby fixing the distal end of the guidewire delivery catheter 22 in a fixed position against the wall 30 of the coronary sinus. This provides wall juxtaposition for the needle 34 to puncture the wall 30 of the coronary sinus. The mesh structure 601 may be a mesh material, such as a flexible and adaptable wire material. Beneficial, this allows fluid to flow through the container during the puncture procedure. The distal portion of the mesh structure 601 can be attached to the catheter 22. This can be done to facilitate bundling the mesh structure 601 as the wire 602 advances (e.g., is pushed distally). In some embodiments, the mesh structure 601 is partially or completely housed within the catheter 22 during delivery. In certain embodiments, the mesh structure 601 forms part of the outer wall of the catheter 22.

[0046] In some embodiments, the mesh structure 601 includes a cloth covering a wire that advances and forms a dome shape. In such embodiments, the cloth is expanded by the wire, which is then constricted within the cloth, thereby influencing the shape of the wire. This interaction between the cloth cover and the wire forms a dome shape, which is pressed against the coronary sinus wall 30 to provide juxtaposition with respect to the needle 34.

[0047] The wire 602 may extend from the proximal end of the mesh structure 601 to the proximal end of the catheter 22. In some embodiments, the wire 602 may be attached to the mesh structure 601 using a ring around the wire 601. In such embodiments, the ring has sliding ability. In some embodiments, the wire 601 is a hypotube that can advance and retract independently of the guidewire of the catheter 22. Thus, when the catheter 22 is in position, the hypotube can be pushed to expand the mesh structure 601, facilitating puncture of the wall 30, and after puncture of the wall 30, the hypotube can be pulled to retract the mesh structure 601.

[0048] Figures 7A–7C illustrate a fourth exemplary fixation mechanism 700. The fourth exemplary fixation mechanism 700 includes a flap, strip, or wall (continuous or discontinuous) 703 having a proximal end attached to a fixed proximal structure 701 (e.g., a cylinder) and a distal end attached to a movable distal structure 702 (e.g., a cylinder), as shown in Figure 7A, and a wire 704 that passes through the fixed proximal structure 701 and is attached to the movable distal structure 702. The fixation mechanism 700 can be guided as part of the catheter 22 to a fixed position, i.e., the location where the needle 34 will puncture the wall 30 of the coronary sinus. Once in position, the wire 704 can be pulled. By pulling the wire 704, the distal structure 702 moves proximal toward the fixed proximal structure 701, as shown in Figure 7B. This relative movement causes the flap or wall 703 to expand outward away from the catheter 22, as shown in Figure 7C, thereby fixing the distal end of the guidewire delivery catheter 22 in place against the wall 30 of the coronary sinus. The flap or wall 703 can be any suitable material, such as a flexible and adaptable wire material. In some embodiments, a wire 704 extends through a hypotube, and the wire 704 and hypotube are surrounded by a proximal structure 701 and a wall 703.

[0049] Each of the fixation mechanisms 400, 500, 600, and 700 may include a radiopaque marker band to indicate the position of the fixation mechanism when visualized using fluoroscopy. In such embodiments, the marker band may be on the opposite side of the needle 34 to ensure that the needle is in the desired position before extending the needle to puncture the wall 30.

[0050] Additional Embodiments Depending on the embodiment, any particular action, event, or function of any process or algorithm described herein may be performed in a different order, added, merged, or completely excluded. Therefore, in a particular embodiment, not all described actions or events are necessary for the practice of the process.

[0051] In particular, conditional statements used herein, such as “can,” “could,” “might,” “may,” and “e.g.,” are intended in their ordinary sense unless otherwise stated or understood differently in the context in which they are used, and are generally intended to convey that certain features, elements, and / or steps are included in certain embodiments but not in other embodiments. Therefore, such conditional statements are not generally intended to imply that features, elements, and / or steps are required in any way in one or more embodiments, or that one or more embodiments necessarily include, with or without input or prompting by the author, logic for determining whether these features, elements, and / or steps are included or performed in any particular embodiment. Terms such as “comprising,” “including,” and “having” are synonymous and are used in their ordinary sense, comprehensively and non-restrictively, without precluding additional elements, features, actions, or functions. Furthermore, the term "or" is used in its inclusive sense (and not its exclusive sense), and therefore, for example, when used to connect a list of elements, the term "or" means one, some, or all of the elements in the list. Connecting phrases such as "at least one of X, Y, and Z" are generally understood in context to be used to convey that an item, term, element, etc., may be one of X, Y, or Z, unless otherwise specified. Thus, such connecting phrases are not generally intended to imply that a particular embodiment requires the presence of at least one of X, at least one of Y, and at least one of Z, respectively.

[0052] In the above-described embodiments, it should be understood that various features may be grouped together in a single embodiment, figure, or description for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various embodiments of the invention. However, this method of disclosure should not be construed as reflecting an intention that any claim requires more features than those explicitly enumerated in that claim. Furthermore, any components, features, or steps illustrated and / or described in a particular embodiment of this specification may be applied to or used in conjunction with any other embodiment. Moreover, there are no components, features, steps, or groups of components, features, or steps that are necessarily required or essential to each embodiment. Accordingly, the scope of the invention of this specification disclosed and claimed below should not be limited by the particular embodiments described above, but should be determined solely by a fair reading of the following claims.

[0053] It should be understood that certain sequential terms (e.g., "first" or "second") may be provided for ease of reference and do not necessarily imply any physical characteristics or order. Therefore, when used herein, sequential terms (e.g., "first," "second," "third," etc.) used to modify elements such as structure, components, and actions do not necessarily indicate the priority or order of the element relative to any other element, but rather may schematically distinguish the element from other elements having similar or identical names (other than the use of sequential terms). In addition, when used herein, the indefinite articles ("a" and "an") may indicate "one or more" rather than "one." Furthermore, actions performed "on the basis" of a condition or event may also be performed on the basis of one or more other conditions or events not explicitly listed.

[0054] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as they are generally understood by those skilled in the art to which the exemplary embodiments belong. Furthermore, terms such as those defined in commonly used dictionaries should be interpreted as having the meaning consistent with their meaning in the context of the relevant art, and should not be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0055] While certain preferred embodiments and examples are disclosed below, the subject matter of the invention extends beyond the specifically disclosed embodiments to other alternative embodiments and / or uses, as well as their modifications and equivalents. Therefore, the claims that may arise from this specification are not limited by any of the specific embodiments described below. For example, in any method or process disclosed herein, the action or operation of the method or process may be performed in any preferred order, and is not necessarily limited to any specific disclosed order. Various operations may be described sequentially as a plurality of distinct operations in a manner that may be useful for understanding a particular embodiment, but the order of description should not be interpreted as implying that these operations are order-dependent. In addition, structures, systems, and / or apparatus described herein may be embodied as integrated components or as separate components. For the purpose of comparing various embodiments, specific aspects and advantages of these embodiments are described. Not all such aspects or advantages are necessarily achieved by any particular embodiment. Therefore, for example, various embodiments may be implemented in a manner that achieves or optimizes one or a set of advantages as taught herein, without necessarily achieving other embodiments or advantages that may similarly be taught or suggested herein.

[0056] The spatially relative terms “outside,” “inside,” “top,” “bottom,” “down,” “up,” “vertical,” and “horizontal,” and similar terms, may be used herein to facilitate explanation and to describe the relationship between one element or component and another, as illustrated in the drawings. It should be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the drawings. For example, if the device shown in the drawings is turned over, a device positioned “below” or “directly below” another device may be positioned “above” the other device. Thus, the illustrative term “below” may include both the lower and upper positions. The device may also be oriented in other directions, and therefore, the spatially relative terms may have different interpretations depending on the orientation.

[0057] Unless otherwise explicitly stated, comparative and / or quantitative terms such as "less," "more," and "greater" are intended to encompass the concept of equality. For example, "less" can mean not only "less" in the strict mathematical sense, but also "less than or equal to."

[0058] The delivery systems described herein may be used to position a catheter tip and / or catheter in various regions of the human heart. For example, the catheter tip and / or catheter may be configured to pass from the right atrium into the coronary sinus. However, the description may refer to, or generally apply to, positioning the catheter tip and / or catheter from a first body chamber or lumen to a second body chamber or lumen, where the catheter tip and / or catheter may be bent when positioned within the second body chamber or lumen from the first body chamber or lumen. The body chamber or lumen may refer to any one of numerous fluid channels, blood vessels, and / or organ chambers (e.g., cardiac chambers). Furthermore, the references herein to “catheter,” “tube,” “sheath,” “transportable sheath,” and / or “transportable catheter” may generally refer to or apply to any type of elongated tubular delivery device, including, for example, a delivery catheter and / or cannula, which includes an inner lumen configured to slidably receive the instrument, such as for positioning within the atrium or coronary sinus. It will be understood that other types of medical implant devices and / or procedures can be delivered to the coronary sinus using the delivery systems described herein, for example, including ablation procedures, drug delivery and / or placement of coronary sinus leads.

Claims

[Claim 1] A guidewire delivery catheter used to implant a shunt between the coronary sinus and the left atrium, wherein the catheter is A removable cover connected to a wire, A catheter comprising a fixing mechanism, the fixing mechanism comprising an expansion member which is activated by the removal of the removable cover, and is configured to be pulled by the wire to expose the expansion member, expand the expansion member out of the catheter, and fix the distal end of the catheter in a predetermined position within the coronary sinus.

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