Mechanically expandable shunt implant

Abstract

To provide a novel shunt for reducing left atrium pressure.SOLUTION: A shunt includes a center flow part configured to at least partially fit to the inside of an opening part of a tissue wall. The tissue wall is located between a first anatomical chamber and a second anatomical chamber. The opening part represents a blood flow path between the first anatomical camber and the second anatomical chamber. The center flow part is further configured to perform maintaining the blood flow path from the first anatomical chamber and the second anatomical chamber, preventing an internal growth of the tissue inside the opening, and extending according to extension of the tissue wall.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] Related Applications This application claims priority to U.S. Provisional Application No. 62 / 939,407, filed November 22, 2019, entitled MECHANICALLY EXPANDABLE SHUNT IMPLANT, which is incorporated herein by reference in its entirety.

[0002] The present invention relates generally to cardiac shunts and delivery systems and methods, and more particularly to shunts for reducing left atrial pressure. [Background technology]

[0003] Heart failure is a common and potentially fatal condition affecting humans, with suboptimal clinical outcomes often resulting in symptoms, morbidity, and / or mortality despite maximal treatment. Specifically, "diastolic heart failure" refers to the clinical syndrome of heart failure occurring in the presence of preserved left ventricular systolic function (ejection fraction) and the absence of major valvular disease. This condition is characterized by left ventricular stiffness, reduced compliance, and impaired relaxation, resulting in elevated end-diastolic pressure. Approximately one-third of patients with heart failure have diastolic heart failure, and few, if any, treatments have proven effective.

[0004] Symptoms of diastolic heart failure are at least in large part due to elevated left atrial pressure. Elevated left atrial pressure (LAP) is present in several 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 increase left atrial pressure. Both heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF) can exhibit elevated LAP. It has been hypothesized that lowering LAP in both HF subgroups may advantageously reduce systolic preload on the left ventricle, i.e., left ventricular end-diastolic pressure (LVEDP). This may also relieve pressure on the pulmonary circulation, reducing the risk of pulmonary edema and improving breathing and patient comfort. Summary of the Invention [Means for solving the problem]

[0005] For purposes of summarizing the present disclosure, certain aspects, advantages, and novel features will now be described. It is to be understood that not necessarily all such advantages will be achieved in accordance with any particular embodiment. Thus, the disclosed embodiments may be implemented to achieve or optimize one advantage or group of advantages taught herein without necessarily achieving other advantages that may be taught or suggested herein.

[0006] Some implementations of the present disclosure relate to a shunt including a central flow section configured to fit at least partially within an opening in a tissue wall. The tissue wall is located between a first anatomical chamber and a second anatomical chamber, and the opening represents a blood flow path between the first and second anatomical chambers. The central flow section is further configured to maintain a blood flow path from the first anatomical chamber to the second anatomical chamber, prevent tissue ingrowth within the opening, and expand in response to expansion of the tissue wall.

[0007] The shunt may further comprise one or more anchoring arms, sometimes referred to as "anchoring means," extending from the central flow section. The one or more anchoring arms may be configured to anchor to a tissue wall. In some embodiments, each of the one or more anchoring arms may include an anchoring mechanism at an end. The anchoring mechanism may comprise one or more of the group including a barb, a hook, a nail, and a screw.

[0008] In some embodiments, the central flow section comprises a network of one or more lines, each of the one or more lines configured to interweave with itself or at least one other of the one or more lines. The central flow section may comprise a network of chains, each chain of the network of chains configured to interlock with at least one other chain of the network of chains.

[0009] The central flow section may comprise a coiled line. In some embodiments, the central flow section has a constant diameter approximately equal to the diameter of the opening. A first portion of the central flow section may be configured to be positioned within the opening, and a second portion of the central flow section may be configured to extend into the first anatomical chamber. The first portion may have a first diameter, and the second portion may have a second diameter. The second diameter may be larger than the first diameter. The second portion may be configured to prevent the central flow section from becoming dislodged.

[0010] In some embodiments, the central flow section comprises one or more rings. Each of the one or more rings may have an oval shape to approximate the shape of the opening. In some embodiments, at least one of the one or more rings is coated with a polymer configured to prevent tissue in-growth. Each of the one or more rings may be composed of a shape-memory material. In some embodiments, each of the one or more rings may be configured to naturally have a first diameter. Each of the one or more rings may be configured to compress to a second diameter smaller than the first diameter to fit into the opening. In some embodiments, each of the one or more rings is configured to press against the tissue wall to hold itself in place. Each of the one or more rings may comprise an anchoring mechanism configured to anchor to the tissue wall. In some embodiments, the anchoring mechanism may include at least one of the group including spikes, screws, nails, barbs, and hooks. Each of the one or more rings may be connected by fabric.

[0011] The central flow section may comprise two or more elastic members. In some embodiments, a first elastic member of the two or more elastic members has a first diameter. A second elastic member of the two or more elastic members may have a second diameter smaller than the first diameter, and the second elastic member may be configured to fit at least partially within the central opening of the first elastic member. In some embodiments, the second elastic member is configured to move relative to the first elastic member to adjust the amount of overlap between the first elastic member and the second elastic member. The second elastic member may be configured to reduce the amount of overlap between the first elastic member and the second elastic member in response to tissue wall expansion. The first elastic member and the second elastic member may comprise one or more connection mechanisms configured to enable unidirectional movement of the second elastic member.

[0012] In some embodiments, the central flow section comprises a fabric sheet extending from the first anatomical chamber to the second anatomical chamber and configured to stretch in response to expansion of the tissue wall. The fabric sheet may be configured to form a cylindrical shape at the opening. The shunt may further comprise one or more anchoring mechanisms configured to anchor the fabric sheet to the first surface of the tissue wall. In some embodiments, the fabric sheet is configured to form a sac and at least partially cover the opening, and has one or more holes that allow blood to flow through the fabric sheet.

[0013] Some implementations of the present disclosure relate to a method including forming an opening in a tissue wall, the tissue wall being located between a first anatomical chamber and a second anatomical chamber, the opening representing a blood flow path between the first anatomical chamber and the second anatomical chamber. The method further includes placing a shunt in the opening. The shunt includes a central flow portion configured to at least partially fit within the opening in the tissue wall, maintain a blood flow path from the first anatomical chamber to the second anatomical chamber, prevent tissue ingrowth within the opening, and expand in response to expansion of the tissue wall.

[0014] Various embodiments are shown in the accompanying drawings for illustrative purposes, but these embodiments should not be construed as limiting the scope of the present invention. Furthermore, various features of different disclosed embodiments can be combined to form additional embodiments, and such additional embodiments are part of this disclosure. Reference numerals may be reused throughout the drawings to indicate correspondence between referenced elements. However, it should be understood that the use of like reference numerals in relation to multiple drawings does not necessarily imply that the associated embodiments are similar. Furthermore, it should be understood that the elements in each drawing are not necessarily drawn to scale, and that the depicted size of each element is presented for the purpose of illustrating aspects of the present invention. In general, some of the depicted elements may be relatively smaller than the elements illustrated in some embodiments or configurations. [Brief explanation of the drawings]

[0015] [Figure 1] 1A-1C illustrate several approaches for maneuvering guidewires and / or catheters within and around the heart to deploy an expandable shunt according to some embodiments. [Figure 2] 1A-1D illustrate a method for deploying an expandable shunt according to some embodiments. [Figure 3A] FIG. 10 is a side view of an opening through a tissue wall for placement of a shunt in the opening, according to some embodiments. [Figure 3B] FIG. 10 is a top view (e.g., from the left atrium) of an opening through a tissue wall for placement of a shunt in the opening, according to some embodiments. [Figure 4] 1A-1C illustrate a first expandable shunt implant according to some embodiments. [Figure 5] FIG. 1 illustrates a second expandable shunt implant according to some embodiments. [Figure 6A]1A-1C illustrate a first expandable coiled shunt implant according to some embodiments. [Figure 6B] FIG. 1 illustrates a second expandable coiled shunt implant according to some embodiments. [Figure 7] 1A-1C illustrate an expandable ring-shaped shunt implant according to some embodiments. [Figure 8] 1A-1C illustrate a retractable shunt implant according to some embodiments. [Figure 9A] FIG. 1 is a side view of a fabric shunt implant according to some embodiments. [Figure 9B] 1A illustrates a top view (eg, from the left atrium) of a fabric shunt implant according to some embodiments. [Figure 10] 1 is a flow diagram of an example process for delivering and / or anchoring an expandable shunt to a human body according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0016] The headings provided herein are for convenience of explanation only and do not necessarily affect the scope or meaning of the claimed invention.

[0017] overview In vertebrates, the heart is a hollow, muscular organ with four pumping chambers—the left and right atria and the left and right ventricles—each with its own one-way valve. Biological heart valves are identified as the aortic, mitral (or bicuspid), tricuspid, and pulmonary valves, each attached to an annulus with a dense fibrous ring attached directly or indirectly to atrial and ventricular muscle fibers. Each annulus defines a flow orifice. The four valves ensure that blood does not flow in the wrong direction during the cardiac cycle, i.e., blood does not backflow through the valves. Blood flows from the venous system and right atrium through the tricuspid valve to the right ventricle, then from the right ventricle through the pulmonary valve to the pulmonary artery and lungs. Oxygen-rich blood then flows from the left atrium through the mitral valve to the left ventricle, and finally from the left ventricle through the aortic valve to the aortic / arterial system.

[0018] Heart failure is a common and potentially fatal condition affecting humans, with suboptimal clinical outcomes often resulting in symptoms, morbidity, and / or mortality despite maximal treatment. Specifically, "diastolic heart failure" refers to the clinical syndrome of heart failure occurring in the presence of preserved left ventricular systolic function (ejection fraction) and the absence of major valvular disease. This condition is characterized by left ventricular stiffness, reduced compliance, and impaired relaxation, resulting in elevated end-diastolic pressure. Approximately one-third of patients with heart failure have diastolic heart failure, and few, if any, treatments have proven effective.

[0019] Symptoms of diastolic heart failure are at least largely due to elevated left atrial pressure. Elevated left atrial pressure (LAP) is present in several 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 increase left atrial pressure. Both heart failure with preserved ejection fraction (HFpEF) and heart failure with reduced ejection fraction (HFrEF) can exhibit elevated LAP. It has been hypothesized that lowering LAP in both HF subgroups may advantageously reduce systolic preload on the left ventricle, i.e., left ventricular end-diastolic pressure (LVEDP). This may also relieve pressure on the pulmonary circulation, reducing the risk of pulmonary edema and improving respiratory and patient comfort.

[0020] Pulmonary hypertension (PH) is defined as elevated mean pressure in the main pulmonary arteries. PH can develop due to many different causes, but all patients have been shown to have a high mortality rate. Fatal PH occurs in the very small arterial branches of the pulmonary arteries and is called pulmonary arterial hypertension (PAH). In PAH, cells inside small arteries proliferate due to injury or disease, narrowing the arterial interior surface area and thickening the arterial walls. As a result, these small pulmonary arteries narrow and stiffen, thereby restricting blood flow and increasing upstream pressure. This elevated pressure in the main pulmonary arteries is a common link between all forms of PH, regardless of the underlying cause. Despite previous attempts, improved methods are needed to reduce elevated pressure in the left atrium, as well as other affected heart chambers, such as the pulmonary artery.

[0021] The present disclosure provides methods and devices that can reduce elevated LAP by shunting blood from a first anatomical chamber (e.g., the left atrium) to a second anatomical chamber (e.g., the coronary sinus). While some embodiments herein may be described with respect to the treatment of LAP and / or similar problems, the described shunting devices and methods may be used to treat other problems, including dialysis. Some embodiments include a shunt that defines an open pathway between the left atrium and the coronary sinus. However, this method can be used to place shunts between other heart chambers, such as between the pulmonary artery and the right atrium. The terms "shunt" and / or "shunting means" are used herein in accordance with their ordinary meaning and may refer to any medical implant configured to allow and / or facilitate blood flow from one part of a patient's body to another. The shunt may be configured to prevent initial collapse of the open pathway and to prevent tissue ingrowth on at least the interior surface of the open pathway. In some embodiments, the shunt may be expandable so that it can be compressed, delivered through a low-profile sheath or tube, and removed to resume its expanded state. Some methods may involve first utilizing a deployment catheter that can create a puncture hole in the tissue wall between the left atrium and the coronary sinus.

[0022] Furthermore, in some embodiments, the shunt may be configured to expand in response to tissue wall expansion after delivery. For example, some patients, and particularly HF patients, may experience amyloidosis, a protein disorder in which amyloid deposits in the heart can harden and / or thicken the heart wall. Shunt implants with maximum tissue wall thickness specifications may not be configured to accommodate a certain level of tissue growth / expansion. For example, some shunt implants may have a wall thickness specification of approximately 4 mm. However, many amyloidosis patients may experience tissue wall thicknesses that continue to increase beyond 4 mm, thus creating patency issues for the shunt implant after implantation. While it may be possible to at least partially inhibit tissue wall growth, doing so may raise concerns about tissue damage. Therefore, it may be advantageous for the shunt implant to have the ability to expand and / or "grow" as the tissue wall thickens.

[0023] Thus, the shunt implants described herein may include a central flow section that may be configured to expand at least longitudinally as and / or in response to the tissue wall expanding (e.g., a shunt implant passing through a tissue wall may expand in the direction of the increasing thickness of the tissue wall). The central flow section may incorporate various mechanical systems to enable expansion. Details of these methods, implants, and deployment systems are described below.

[0024] 1 illustrates several access routes for maneuvering guidewires and catheters in and around the heart 1 to deploy the expandable shunt of the present application. For example, an access route may begin from above via the subclavian vein 11 or jugular vein 12 into the superior vena cava (SVC) 15, the right atrium (RA) 5, and from there into the coronary sinus (CS) 19. Alternatively, an access route may begin in the femoral artery 13 and enter the heart 1 through the inferior vena cava 14. Other access routes may also be used, each generally utilizing a percutaneous incision through which the guidewire and catheter are inserted into the vasculature, usually with a sealed introducer, from which the physician controls the distal end of the device from outside the body.

[0025] Figure 2 illustrates a method for deploying an expandable shunt as described herein, in which a guidewire is passed through a catheter 16 into the subclavian vein or carotid artery, through the SVC 15, and into the coronary sinus 19, allowing delivery of the implant device 10. After the guidewire has formed a pathway, an introducer sheath (not shown) may be advanced into the patient's vasculature along the guidewire, typically with the use of a dilator. Figure 2 illustrates the deployment catheter 16 extending from the SVC 15 to the coronary sinus 19 of the heart 1, with the deployment catheter 16 passing through the introducer sheath, which forms a hemostatic septum to prevent blood loss.

[0026] In one embodiment, the deployment catheter 16 may be approximately 30 cm in length, and the guidewire may be somewhat longer than 30 cm for ease of use. In some embodiments, the deployment catheter may serve to prepare the opening in the wall of the left atrium 2, and a separate placement or delivery catheter is used to deliver the expandable shunt. In other embodiments, the deployment catheter may be used as a full-function puncture hole preparation and shunt placement catheter. In this application, the terms "deployment catheter" or "delivery catheter" are used to refer to catheters or introducers that have one or both of these functions.

[0027] The coronary sinus 19 is primarily adjacent to and surrounds the left atrium 2, allowing for a variety of acceptable placements for the stent. The site selected for stent placement may be an area of ​​thinner or less dense tissue in a particular patient, as previously determined by non-invasive diagnostic means such as a CT scan or radiographic techniques such as fluoroscopy or intravascular ultrasound (IVUS).

[0028] Some methods for reducing LAP include utilizing a shunt through the interatrial septum between the left atrium 2 and the right atrium 5. This is an advantageous approach because the two structures are adjacent and transseptal access is a common method. However, emboli can potentially migrate from the right to the left side of the heart, creating a risk of stroke. This event is thought to occur primarily during discrete events such as coughing, sneezing, the Valsalva maneuver, or defecation, when right atrial pressure exceeds left atrial pressure. The anatomical location of the septum naturally allows emboli to move freely between the atria when a shunt is present and the pressure gradient is reversed. This is mitigated by valve or filter elements within the shunt, but emboli may still traverse it.

[0029] Shunting to the coronary sinus 19 has several notable advantages, primarily that the coronary sinus 19 is significantly less likely to harbor emboli for several reasons. First, blood leaving the coronary vasculature and flowing into the right atrium 5 has just passed through the capillaries and is therefore essentially filtered blood. Second, the mouth of the coronary sinus 19 in the right atrium 5 is often partially covered by a pseudovalve called the Thebesian valve. The Thebesian valve is not always present, and several studies have found that it is present in over 60% of hearts and acts as a biological "watchdog" for the coronary sinus, preventing emboli from entering if right atrial pressure suddenly rises. Third, the pressure gradient between the coronary sinus 19 and the right atrium 5, where emboli enter, is very low, meaning that emboli in the right atrium 5 are likely to remain lodged there. Fourth, if an embolus enters the coronary sinus 19, a much greater gradient exists between the right atrium 5 and the coronary vasculature than between the right atrium 5 and the left atrium 2. The embolus will most likely travel further along the coronary vasculature until right atrial pressure returns to normal, and then the embolus will return directly to the right atrium 5.

[0030] Some additional benefits of placing a shunt between the left atrium 2 and the coronary sinus 19 are that this anatomy is less mobile (more stable) than the septum, thus preserving the septum for later transseptal access for alternative treatments, which may provide other therapeutic benefits in some cases. By routing left atrial blood into the coronary sinus 19, sinus pressure may be slightly elevated. This allows blood in the coronary vasculature to move through the heart at a slower rate, increasing perfusion and oxygen transfer, and may also help necrotic myocardium recover through more efficient perfusion and oxygen transfer. Preserving transseptal access is also a significant advantage, as HF patients often have several other comorbidities, such as atrial fibrillation (AF) and mitral regurgitation (MR), and several therapies to treat these conditions require a transseptal approach.

[0031] Shunts may also be placed between other heart chambers, such as between the pulmonary artery and the right atrium 5. The shunt may desirably be implanted within the wall of the pulmonary artery by approaching it from above and passing a catheter through the pulmonary artery using the deployment device described herein. As discussed above, pulmonary hypertension (PH) is defined as an increase in mean pressure within the main pulmonary artery. Blood flows through the shunt in the direction from the pulmonary artery into the right atrium 5 when a pressure difference causes blood to flow in that direction, thereby attenuating pressure and reducing damage to the pulmonary artery. The purpose is to attenuate pressure spikes within the pulmonary artery. Shunts may also extend from the pulmonary artery to other heart chambers (e.g., the left atrium 2) and / or blood vessels. While not preferred or illustrated, the shunt may further include a one-way valve to prevent backflow or a check valve to only allow blood above a specified pressure. This application discloses a novel expandable shunt. In some embodiments, the expandable shunt may be at least partially flexible and / or resilient in structure, which may advantageously simplify the delivery process for the surgeon. For example, the shunts described herein may be shaped and / or shaped as desired / needed to fit into openings through tissue walls, and the openings and / or tissue walls may have various shapes and / or sizes. Furthermore, the shunts may include any of a variety of anchoring arms and / or mechanisms that may be modified as needed to effectively anchor the shunt.

[0032] FIG. 3A is a side view, and FIG. 3B is a view from above (e.g., left atrium 2) of an opening (i.e., puncture hole) 311 through a tissue wall 308 (e.g., between the coronary sinus 19 and left atrium 2) with a shunt positioned within the opening 311. As shown in FIG. 3A, a shunt deployment or delivery catheter 350 may be advanced to the tissue wall 308 between two cavities (e.g., the coronary sinus 19 and the left atrium 2). The catheter 350 may have a soft and / or tapered distal tip 352. The delivery catheter 350 may be advanced through the opening 311 in the tissue wall 308, e.g., into the left atrium 2. The opening may be formed in any of a variety of ways. One exemplary method is described below.

[0033] First, a guidewire may be advanced into the coronary sinus 19, for example, from the right atrium through the ostium or opening of the coronary sinus 19. A puncture catheter may be advanced along the guidewire. The puncture catheter may be introduced into the body through the proximal end of an introducer sheath. The introducer sheath may allow access to a specific vascular pathway (e.g., the carotid artery or subclavian vein) and may have a hemostatic valve therein. The surgeon can manipulate the puncture catheter to the implantation site while holding the introducer sheath in a fixed position. A puncture catheter having a puncture needle including a sharp tip is advanced along the catheter and punctures the wall 8, for example, into the left atrium 2. A puncture expander may be advanced along the guidewire and penetrate the tissue wall 308 into the left atrium 2. The puncture expander may be, for example, an elongated inflatable balloon. The puncture expander may expand radially outward to widen the puncture hole through the tissue wall 308.

[0034] The expandable shunt may be delivered through the lumen of the catheter 350. During delivery, the expandable shunt may be in a collapsed configuration to facilitate delivery. For example, the shunt may be rolled, bent, twisted, and / or otherwise formed to have a minimal profile to facilitate delivery through the catheter 350. The shunt may be positioned within the annular space between the inner and outer sheaths of the catheter 350. The inner sheath may be retracted to position the shunt in snug engagement with the tissue wall 308. Radiopaque markers may be provided to facilitate placement of the catheter 350 and / or shunt. By forming an opening between the left atrium 2 and the coronary sinus 19, blood can flow from the left atrium 2 (typically >8 mmHg) to the coronary sinus 19 (typically <8 mmHg). The shunt may be configured to be attached / anchored to the first surface 301 and / or second surface 303 of the tissue wall 308.

[0035] Expandable Shunt Implant FIG. 4 illustrates a first expandable shunt implant according to some embodiments. The first expandable shunt implant 400 may include a central flow section 402 composed of a mesh of lines 404, which may include wires, sutures, strings, and / or various other elongated devices. One or more lines 404 may interact with one another in a weaving / interlacing and / or knitting pattern. For example, a first line may pass over a second line, under a third line, over a fourth line, and so on. Thus, one or more lines 404 may have at least some flexibility, whereby the lines 404 may be configured to bend over and / or under other lines 404. For example, one or more lines 404 may be composed of nitinol and / or another material configured to at least partially bend and / or stretch.

[0036] The flow portion 402 may include any number of lines 404. In some embodiments, the flow portion 402 may comprise a single line 404 configured to interweave with itself. For example, the single line 404 may be configured to pass through (e.g., be entangled with) one or more devices, such as rings 406, which may be configured to be attached to and / or extend from the flow portion 402. The line 404 may pass through multiple rings 406 and / or may pass through a single ring 406 multiple times. The line 404 may enter the ring 406 at a first angle and exit the ring 406 at a second angle (e.g., approximately 45 degrees different from the first angle).

[0037] By increasing the number of lines 404 and / or the amount of interweaving of one or more lines 404, gaps between the lines 404 and / or gaps between different portions of each single line 404 may be minimized to improve the prevention and / or reduction of tissue ingrowth. Additionally, each of the lines 404 may have any thickness and may be designed to maximize the expandability of the flow portion 402 while minimizing gaps.

[0038] The flow portion 402 may include one or more rings 406 configured to be attached to and / or extend from the mesh portion of the lines 404. As shown in FIG. 4, the flow portion 402 may include a first ring 406 at a first end of the flow portion 402. For example, the first ring 406 may be located at or near a first surface 401 of the tissue wall. However, while only a single ring 406 is shown in FIG. 4, the flow portion 402 may include any number of rings 406. For example, a second ring 406 may be attached to one or more lines 404 at a second end of the flow portion 402 near a second surface 403 of the tissue wall 408. The flow portion 402 may be configured to be at least partially located within an opening in the tissue wall (see, e.g., opening 311 in FIGS. 3A and 3B). The tissue wall may have a first surface 401 and a second surface 403, and the opening may represent a gap through the tissue wall. The "thickness" of the tissue wall 408 may refer to the distance between the first surface 401 and the second surface 403 of the tissue wall 408. In other words, the "thickness" may refer to the length of the tissue wall 408 along the longitudinal axis 410. As used herein, a "longitudinal" length may refer to a length perpendicular to the surface of the tissue wall 408 (i.e., a direction into, toward, and / or away from the tissue wall). An opening through the tissue wall 408 may have a depth equal to the thickness of the tissue wall 408. In other words, the opening may extend the entire longitudinal length of the tissue wall 408. Furthermore, the opening may have various widths. For example, the opening may have a circular shape with a certain diameter (e.g., opening 311 in FIGS. 3A and 3B). The "width" of an opening may refer to the length of the opening along the lateral axis 412. As used herein, a "lateral" length may refer to a length parallel to (along) the surface of the tissue wall 408.

[0039] Upon delivery, the flow portion 402 of the first expandable shunt implant 400 may have a length (measured along the longitudinal axis 410) that is generally equal to the depth of the opening and / or the thickness of the tissue wall 408. Thus, the first end of the first ring 406 and / or flow portion 402 may be generally aligned with the first surface 401 of the tissue wall 408 along the longitudinal axis 410, and / or the second end of the second ring 406 and / or flow portion 402 may be generally aligned with the second surface 403 of the tissue wall 408 along the longitudinal axis 410. However, the first expandable shunt implant 400 may have a longitudinal length that is greater than the thickness of the tissue wall 408 (such that the first and / or second ends of the flow portion 402 extend outward from the opening) or less than the thickness of the tissue wall 408 (such that the first and / or second ends of the flow portion 402 are located within the opening).

[0040] One or more lines 404 of flow portion 402 may form a cylindrical or other shape to approximate the shape of the opening. In some embodiments, the opening may widen generally evenly in all directions from the puncture point to form a generally circular opening having a diameter. Thus, flow portion 402, including one or more rings 406 and / or interconnected lines 404, may have an at least partially round shape and / or at least a partial circle around / pertaining to longitudinal axis 410.

[0041] In some embodiments, the expandable shunt implant 400 may be in a compressed and / or otherwise expandable form during delivery. For example, during delivery, the one or more lines 404 may be positioned relatively close to one another such that gaps between the one or more lines 404 are minimized. As the tissue wall 408 expands (e.g., along the longitudinal axis 410), the one or more lines 404 may gradually separate and / or stretch to form a larger length of the expandable shunt implant 400 (along the longitudinal axis 410). In some embodiments, the one or more lines 404 may be configured to stretch in response to the expansion of the tissue wall 408. For example, during delivery, the one or more lines 404 may be in a natural, resting state and / or may be only minimally stretched. As the tissue wall 408 expands, at least some of the one or more lines 404 may stretch to form a larger length of the expandable shunt implant 400.

[0042] The expandable shunt implant 400 may include one or more anchoring arms 414, also referred to as "anchor means," configured to anchor to / within the tissue wall 408. Although the expandable shunt implant 400 is shown having seven anchoring arms 414, the expandable shunt implant 400 may have any number of anchoring arms 414. In some embodiments, the expandable shunt implant 400 may include one or more anchoring arms 414 at a first end of the expandable shunt implant 400 (e.g., configured to anchor to a first surface 401 of the tissue wall 408) and / or at or near a second end of the expandable shunt implant 400 (e.g., configured to anchor to a second surface 403 of the tissue wall 408). The anchoring arms 414 may be attached to and / or extend from the ring 406 or one or more lines 404. For example, if the expandable shunt implant 400 does not include a ring 406, the anchoring arms 414 may be attached to and / or extend from the lines 404.

[0043] Each of the anchoring arms 414 may include an anchoring mechanism 415 configured to penetrate, attach to, and / or otherwise anchor to the tissue wall 408. As shown in FIG. 4, the anchoring mechanism 415 may include a barb. However, suitable mechanisms 415 may include one or more of a hook, needle, screw, nail, and / or other device.

[0044] In some embodiments, the lines 404, the rings 406, and / or the anchoring arms 414 may each be constructed of a common material or different materials. In some embodiments, any of the lines 404, the rings 406, and / or the anchoring arms 414 may be constructed of nitinol and / or other metals, plastics, polymers, and / or other materials. In some embodiments, the rings 406 may have an at least partially rigid structure to provide some stability to the expandable shunt implant 400. For example, one or more rings 406 may be configured to retain a predetermined configuration even as the expandable shunt implant 400 expands. In this manner, the one or more rings 406 may be configured to prevent unnecessary damage to the tissue wall 408. For example, one or more anchoring arms 414 may extend from and / or be attached to the ring 406. Due at least in part to the rigid structure of the ring 406, the flow portion 402 may provide a constant level of pressure and / or form a constant orientation relative to the one or more anchoring arms 414.

[0045] Various elements of the shunt implant 400, including the central flow section 402 and / or the anchoring arms 414, described herein may apply to shunt devices described and / or shown in other figures of the present application. For example, any description regarding the shunt implant 400 shown in FIG. 4 may equally apply to the shunt implant 500 in FIG. 5, the shunt implant 600 in FIGS. 6A and / or 6B, the shunt implant in FIG. 7, the shunt implant in FIG. 8, and / or the shunt implant in FIGS. 9A and 9B described herein. Furthermore, it should be understood that other shunts shown and / or described with respect to other figures may not include the line 404 and / or ring 406 as shown in FIG. 4, although the line 404 and / or ring 406 may be added to shunts described with respect to other figures. Similarly, various elements described with respect to other figures herein may be added to the shunt implant 400 in FIG. 4 and / or other figures herein even if the shunt implant 400 is not shown and / or described with respect to each figure. Although the shunt implant 400 is shown as including both a central flow section 402 and anchoring arms 414, the shunt implant 400 may not include anchoring arms 414 in some embodiments.

[0046] FIG. 5 illustrates a second expandable shunt implant according to some embodiments. The second expandable shunt implant 500 may include a central flow section 502 made up of a mesh of chains 504, which may include wires, sutures, strings, and / or various other devices. Each chain 504 may be configured to interlock with one or more other chains 504 to form a "chainmail" pattern of chains 504. Although the chains 504 are shown in FIG. 5 as having a generally circular shape, each chain 504 may have any suitable shape and / or size. For example, the chains 504 may have a triangular, octagonal, pentagonal, rectangular, or other shape. Each chain 504 may interlock with any number of other chains 504. For example, a first chain 504 at an end of the flow section 502 (e.g., connected to the ring 506) may be interlocked with five other chains 504 (e.g., one chain 504 to the right of the first chain 504, one chain to the left of the first chain 504, and three chains below the first chain 504). In other words, the five chains 504 may pass through a hole in the first chain 504. In another example, a first chain 504 not located at an end of the flow section 502 may be connected to eight chains 504 (e.g., three chains 504 above the first chain 504, one chain 504 to the right of the first chain 504, one chain to the left of the first chain 504, and three chains below the first chain 504).

[0047] The flow portion 502 may further include one or more rings 506 configured to be attached to and / or extend from the mesh portion of the chain 504. For example, the rings 506 may pass through holes in one or more of the chains 504. As shown in FIG. 5 , the flow portion 502 may include a first ring 506 at a first end of the flow portion 502. For example, the first ring 506 may be located at or near a first surface 501 of a tissue wall 508. The flow portion 502 may be located at least partially within an opening in the tissue wall. The tissue wall 508 may have a first surface 501 and a second surface 503, and the opening may represent a gap that penetrates the tissue wall. The opening that penetrates the tissue wall 508 may have a depth equal to the thickness of the tissue wall 508. Furthermore, the opening may have various widths. For example, the opening may have a generally circular shape with a certain diameter (e.g., opening 311 in FIGS. 3A and 3B ).

[0048] Upon delivery, the flow portion 502 of the second expandable shunt implant 500 may have a longitudinal length that is generally equal to the depth of the opening and / or the thickness of the tissue wall 508. Thus, the first ring 506 and / or the first end of the flow portion 502 may be generally aligned with the first surface 501 of the tissue wall 508 along the longitudinal axis, and / or the second end of the flow portion 502 may be generally aligned with the second surface 503 of the tissue wall 508 along the longitudinal axis. However, the second expandable shunt implant 500 may have a longitudinal length that is greater than the thickness of the tissue wall 508 (such that the first and / or second ends of the flow portion 502 extend outward from the opening) or less than the thickness of the tissue wall 508 (such that the first and / or second ends of the flow portion 502 are located within the opening).

[0049] The one or more chains 504 of the flow portion 502 may form a cylinder or other shape to approximate the shape of the opening. In some embodiments, the opening may widen generally evenly in all directions from the puncture point to form a circular opening having a diameter. Thus, the flow portion 502, including one or more rings 506 and / or interconnected chains 504, may have an at least partially round shape and / or at least a partial circle about the longitudinal axis.

[0050] In some embodiments, the expandable shunt implant 500 may be in a compressed and / or possibly expandable form upon delivery. For example, upon delivery, one or more chains 504 may be positioned relatively close to one another such that separation between the one or more chains 504 is minimized. As the tissue wall 508 expands (e.g., longitudinally), the one or more chains 504 may gradually separate to form an expandable shunt implant 500 with a greater longitudinal length. In some embodiments, the one or more chains 504 may be configured to stretch in response to the expansion of the tissue wall 508. For example, upon delivery, the one or more chains 504 may be in a natural, resting state and / or may be only minimally stretched. As the tissue wall 508 expands, at least some of the one or more lines 504 may stretch to form an expandable shunt implant 500 with a greater length. In some embodiments, the flow portion 502 may comprise one or more restraining mechanisms to prevent the flow portion 502 from expanding prior to the corresponding expansion of the tissue wall 508. For example, two or more chains 504 may be held in proximity to one another by a suture, wire, or similar device. As the tissue wall 508 expands, the pressure applied to the restraining mechanism may increase to a level at which the restraining mechanism breaks and / or stretches, allowing a greater degree of separation between the two or more chains 504.

[0051] The expandable shunt implant 500 may include one or more anchoring arms 514 configured to anchor within the tissue wall 508. Although the expandable shunt implant 500 is shown having two anchoring arms 514, the expandable shunt implant 500 may have any number of anchoring arms 514. In some embodiments, the expandable shunt implant 500 may include one or more anchoring arms 514 at a first end of the expandable shunt implant 500 (e.g., configured to anchor a first surface 501 of the tissue wall 508) and / or at or near a second end of the expandable shunt implant 500 (e.g., configured to anchor a second surface 503 of the tissue wall 508). The anchoring arms 514 may be attached to and / or extend from the ring 506 or the one or more chains 504. For example, if the expandable shunt implant 500 does not include the optional ring 506 , the anchoring arms 514 may be attached to and / or extend from the chain 504 .

[0052] Each of the anchoring arms 514 may include an anchoring mechanism 515 configured to penetrate, attach to, and / or otherwise anchor to the tissue wall 508. As shown in FIG. 5, the anchoring mechanism 515 may include a barb. However, suitable mechanisms 515 may include one or more of a hook, needle, screw, nail, and / or other device.

[0053] In some embodiments, the chain 504, the rings 506, and / or the anchoring arms 514 may each be constructed of a common material or different materials. In some embodiments, any of the chain 504, the rings 506, and / or the anchoring arms 514 may be constructed of nitinol and / or other metals, plastics, polymers, and / or other materials. In some embodiments, the rings 506 may have an at least partially rigid structure to provide a level of stability to the expandable shunt implant 500. For example, one or more rings 506 may be configured to retain a predetermined configuration even as the expandable shunt implant 400 expands. In this manner, the one or more rings 506 may be configured to prevent unnecessary damage to the tissue wall 508. For example, one or more anchoring arms 514 may extend from and / or be attached to the ring 506. Due at least in part to the rigid structure of the ring 506, the flow portion 502 may provide a constant level of pressure and / or form a constant orientation relative to the one or more anchoring arms 514.

[0054] 6A and 6B illustrate an expandable coiled shunt implant according to some embodiments. The coiled shunt implant 600 may include a central flow portion 602 comprised of one or more coiled lines 604. In some embodiments, the flow portion 602 and / or the single coiled line 604 may extend from at least a first side 601 of the tissue wall 608 to a second side 603 of the tissue wall 608. The flow portion 602 may be at least partially located within an opening in the tissue wall 608.

[0055] During delivery, the flow portion 602 of the coiled shunt implant 600 may have a longitudinal length that is generally equal to the depth of the opening and / or the thickness of the tissue wall 608. Thus, the first end 620 of the flow portion 602 may be generally aligned with the first surface 601 of the tissue wall 608 along the longitudinal axis, and / or the second end 622 of the flow portion 602 may be generally aligned with the second surface 603 of the tissue wall 608 along the longitudinal axis. However, the coiled shunt implant 600 may have a longitudinal length that is greater than the thickness of the tissue wall 608 (such that the first end 620 and / or the second end 622 of the flow portion 602 extend outward from the opening) or less than the thickness of the tissue wall 608 (such that the first end 620 and / or the second end 622 of the flow portion 602 are located within the opening).

[0056] The one or more lines 604 of the flow portion 602 may form a cylindrical or other shape to approximate the shape of the opening. In some embodiments, the opening in the tissue wall 608 may widen generally evenly in all directions from the puncture point to form a circular opening having a diameter. Thus, the flow portion 602, including the one or more lines 604, may have an at least partially rounded shape and / or a circular shape about the longitudinal axis.

[0057] In some embodiments, the expandable shunt implant 600 may be in a compressed and / or otherwise expandable / unexpanded form upon delivery. For example, upon delivery, the one or more chains 604 may form a relatively tight set of coils with minimal separation between the coils of the one or more lines 604. As the tissue wall 608 expands (e.g., longitudinally), the set of coils may gradually expand / separate to form a coiled shunt implant 600 of greater longitudinal length. In some embodiments, the one or more chains 604 may have elastic characteristics such that the one or more lines 604 may naturally exert a force and return to a resting (e.g., unexpanded) state upon expansion.

[0058] The coiled shunt implant 600 may include one or more anchoring arms 614 configured to anchor within the tissue wall 508. Although the coiled shunt implant 600 is shown having four anchoring arms 614, the coiled shunt implant 600 may have any number of anchoring arms 614. In some embodiments, the coiled shunt implant 600 may include one or more anchoring arms 614 at a first end 620 of the coiled shunt implant 600 (e.g., configured to anchor a first side 601 of the tissue wall 608) and / or at or near a second end 622 of the coiled shunt implant 600 (e.g., configured to anchor a second side 603 of the tissue wall 608). The anchoring arms 614 may be attached to and / or extend from one or more lines 604.

[0059] Each anchoring arm 614 may include an anchoring mechanism 615 configured to penetrate, attach to, and / or otherwise anchor to the tissue wall 608. As shown in FIG. 6A , the anchoring mechanism 615 may include a barb. However, suitable mechanisms 615 may include one or more of a hook, needle, screw, nail, and / or other device.

[0060] In some embodiments, the lines 604 and / or the anchoring arms 614 may each be constructed from a common material or different materials. In some embodiments, either the lines 604 and / or the anchoring arms 614 may be constructed from nitinol and / or other metals, plastics, polymers, and / or other materials.

[0061] FIG. 6B illustrates a coiled shunt implant 600 in which a first portion 620 of a flow portion 602 may extend beyond a first surface 601 of a tissue wall 608 into a first anatomical chamber. A second end 622 may extend beyond a second surface 603 of the tissue wall 608 into a second anatomical chamber. For example, the first portion 621 of the flow portion 602 may extend beyond the first surface 601 of the tissue wall 608, the second portion 623 of the flow portion 602 may be within the tissue wall 608, and / or the third portion 624 may extend beyond the second surface 603 of the tissue wall 608. In some embodiments, the flow portion 602 may have a varying diameter. For example, the flow portion 602 may have a minimum and / or constant diameter at the second portion 623. The flow portion 602 may expand to a larger diameter at the first portion 621 and / or the third portion 624. In some embodiments, the diameter of flow portion 602 may gradually increase generally between first surface 601 of tissue wall 608 and first end 620 of flow portion 602. Similarly, the diameter of flow portion 602 may gradually increase generally between second surface 603 of tissue wall 608 and second end 622 of flow portion 602. However, in some embodiments, flow portion 602 may have a generally constant diameter and / or a generally maximum diameter at first portion 621 and / or third portion 624.

[0062] The diameter of the flow portion 602 at the first portion 621 and / or the third portion 624 may be larger than the diameter of the opening in the tissue wall 608. In this manner, at least a portion of the first portion 621 and / or the third portion 624 may be prevented from entering the opening in the tissue wall 608, and the flow portion 602 may be held in place by the tissue wall 608. Thus, the coiled shunt implant 600 may not include any anchoring arms 614, as the coiled shunt implant 600 may be anchored to the tissue wall 608 to prevent the flow portion 602 from dislodging without the need for anchoring arms 614.

[0063] The diameter of the second portion 623 of the flow portion 602 may be approximately equal to the diameter of the opening in the tissue wall 608. Thus, the second portion 623 of the flow portion 602 may be configured to press against the tissue wall 608 to prevent tissue ingrowth at the opening. At least the second portion 623 (and / or the first portion 621 and / or the third portion 624) may be configured to expand longitudinally in response to an increasing thickness of the tissue wall 608. As the tissue wall 608 thickens, the coils of the flow portion 602 may separate, increasing the longitudinal length of the flow portion 602. In some embodiments, the flow portion 602 may include a relatively large number of coils, such that the flow portion 602 may be configured to increase its longitudinal length without requiring a high degree of separation between each set of coils. In this manner, separation between the coils may be minimized to prevent tissue ingrowth even during expansion, thereby maintaining the shape and / or size of the opening in the tissue wall 608.

[0064] 7 illustrates an expandable ring-shaped shunt implant according to some embodiments. The ring-shaped shunt implant may include a central flow portion 702 made up of one or more rings 704. In some embodiments, the flow portion 702 may extend from at least a first side 701 of a tissue wall 708 to a second side 703 of the tissue wall 708. The flow portion 702 may be at least partially located within an opening in the tissue wall 708. While the central flow portion 702 is shown as including seven rings 704, the central flow portion 702 may include any number of rings 704.

[0065] During delivery, the flow portion 702 of the ring-shaped shunt implant may have a longitudinal length that is generally equal to the depth of the opening and / or the thickness of the tissue wall 708. Thus, the first ring 704a of the flow portion 702 may be generally aligned with the first surface 701 of the tissue wall 708 along the longitudinal axis, and / or the second ring 704b of the flow portion 702 may be generally aligned with the second surface 703 of the tissue wall 708 along the longitudinal axis. However, the ring-shaped shunt implant may have a longitudinal length that is less than the thickness of the tissue wall 708 (such that the first ring 704a and / or the second ring 704b of the flow portion 702 are located within the opening).

[0066] Each of the one or more rings 704 may have a circular and / or oval shape to approximate the shape of the opening in the tissue wall 708. The one or more rings 704 may be configured to press against and / or penetrate the inner surface of the tissue wall 708. In some embodiments, the one or more rings 704 may have spikes and / or similar elements configured to penetrate and / or be secured to the inner surface of the tissue wall 708 to hold the rings 704 in place.

[0067] In some embodiments, the ring-shaped shunt implant may be in a compressed and / or otherwise expandable / unexpanded form upon delivery. For example, upon delivery, one or more rings 704 may have a minimal separation from one another. As the tissue wall 708 expands (e.g., longitudinally), the rings may gradually separate to form a ring-shaped shunt implant of greater longitudinal length.

[0068] In some embodiments, one or more rings 704 may be connected via one or more wires, fabric, and / or similar devices. For example, a fabric or similar material having a generally cylindrical shape may surround and / or be attached to one or more rings 704. In this manner, the fabric may fill gaps between one or more rings 704 to prevent tissue ingrowth between the rings 704.

[0069] The ring-shaped shunt implant may include one or more anchoring arms configured to anchor within the tissue wall 708. For example, the ring-shaped shunt implant may include one or more anchoring arms attached to and / or extending from a first ring 704a of the ring-shaped shunt implant (e.g., configured to anchor a first surface 701 of the tissue wall 708) and / or one or more anchoring arms attached to and / or extending from a second ring 704b of the ring-shaped shunt implant (e.g., configured to anchor a second surface 703 of the tissue wall 708).

[0070] In some embodiments, each of the rings 704 may be composed of a common material or different materials. In some embodiments, any of the rings 704 may be composed of nitinol and / or other metals, plastics, polymers, and / or other materials. One or more of the rings 704 may be composed of nitinol or other shape-memory materials and may be naturally shaped to have a diameter larger than the opening in the tissue wall 708, thereby pressing against the inner surface of the opening and holding itself in place. For example, the rings 704 may include discontinuous lines that may be configured to curl in response to force. One or more of the rings 704 may be configured to compress and reduce in diameter when placed within the opening in the tissue wall 708. In some embodiments, the rings 704 and / or anchoring arms may be composed of and / or coated with a similar material (e.g., a polymer) configured to prevent and / or inhibit carbuton and / or tissue ingrowth.

[0071] FIG. 8 illustrates a telescoping shunt implant according to some embodiments. The telescoping shunt implant 800 may include a central flow section 802 comprised of one or more telescoping members 804. While the telescoping members 804 are shown in FIG. 8 as having a cylindrical shape, each telescoping member 804 may have any suitable shape and / or size. In some embodiments, the first telescoping member 804a may have a larger diameter / width than the second telescoping member 804b, such that the second telescoping member 804b may be configured to fit at least partially within a central opening / region of the first telescoping member 804a. While FIG. 8 illustrates only two telescoping members 804, the flow section 802 may include three or more telescoping members 804.

[0072] As shown in FIG. 8 , the end of the first elastic member 804a may be configured to be located at or near a first surface 801 of a tissue wall 808. The flow portion 802 may be located at least partially within an opening in the tissue wall. The tissue wall 808 may have a first surface 801 and / or a second surface 803, and the opening may represent a gap through the tissue wall. The opening through the tissue wall 808 may have a depth equal to the thickness of the tissue wall 808. Furthermore, the opening may have various widths. For example, the opening may have a circular shape with a certain diameter (see, e.g., opening 311 in FIGS. 3A and 3B ).

[0073] During delivery, the flow portion 802 of the telescoping shunt implant 800 may be configured to have a longitudinal length that is generally equal to the depth of the opening and / or the thickness of the tissue wall 808. Thus, the end of the first telescoping member 804a may be configured to be generally aligned with the first surface 801 of the tissue wall 808 along the longitudinal axis, and / or the end of the second telescoping member 804b may be configured to be generally aligned with the second surface 803 of the tissue wall 808 along the longitudinal axis. However, the telescoping shunt implant 808 may have a longitudinal length that is greater than the thickness of the tissue wall 808 (such that the first and / or second ends of the flow portion 802 may be configured to extend outward from the opening) or less than the thickness of the tissue wall 808 (such that the first and / or second ends of the flow portion 802 may be configured to lie within the opening).

[0074] The two or more elastic members 804 of the flow portion 802 may form a cylindrical or other shape to approximate the shape of the opening in the tissue wall 808. In some embodiments, they may expand generally evenly in all directions from the puncture point to form an oval (e.g., circular) opening having a certain diameter. Thus, the flow portion 802 may include two or more elastic members 804 and have an at least partially round and / or circular shape about the longitudinal axis.

[0075] The telescoping shunt implant 800 may be in a compressed and / or otherwise expandable configuration during delivery. During delivery, the two or more elastic members 804 may have a maximum amount of overlap. For example, the second elastic member 804b may be located entirely within a central (e.g., at least partially hollow) region of the first elastic member 804a. As the tissue wall 808 expands (e.g., longitudinally), the amount of overlap between the two or more elastic members 804 may gradually decrease to form a telescoping shunt implant 800 with a greater longitudinal length. For example, the first elastic member 804a may be configured to move relative to the second elastic member 804b and / or the second elastic member 804b may be configured to move relative to the first elastic member 804a to adjust the amount of overlap between the elastic members 804.

[0076] In some embodiments, each elastic member 804 may be attached to and / or extend from at least one other elastic member. For example, a first elastic member 804a may be attached to a second elastic member 804b. In some embodiments, the attachment may be a slidable attachment. For example, the first elastic member 804a may include a guide track configured to fit into a peg, notch, or similar feature. The second elastic member 804b may include a peg, notch, or similar feature configured to fit into / over the guide track of the first elastic member 804a. Thus, the second elastic member 804b may be configured to slide relative to the first elastic member 804a, and the first elastic member 804a may be configured to slide relative to the second elastic member 804b. In some embodiments, the slidable attachment between the multiple elastic members 804 may include the use of various stops (e.g., cords, pegs, notches, teeth, etc.) configured to at least temporarily prevent and / or temporarily resist movement of the elastic members 804 relative to one another. For example, the second elastic member 804b may be configured to slide along a guide track of the first elastic member 804a and may interact with one or more stops while sliding along the guide track. The stops may be configured to stop and / or slow the second elastic member 804b temporarily and / or until sufficient force is applied for the second elastic member 804b to break and / or push out the stops. In this manner, the longitudinal expansion of the first portion 802 may be controlled and / or divided into stages to match and / or approximate the expansion of the flow portion 802 to the increasing thickness of the tissue wall 808. Additionally, the telescoping member 804 may include other attachment mechanisms in addition to and / or in place of the guide tracks and / or corresponding pegs / notches.For example, the first telescoping member 804a may comprise a round and / or linear gear including teeth configured to interact with one or more pawls or similar features of the second telescoping member 804b to form a ratchet connection between the telescoping members 804. One or more teeth of the gear and / or rack may be asymmetrical and / or have a first edge that is partially sloped and a second edge that is more steeply sloped. In this manner, the pawl or similar feature of the second telescoping member 804b may be configured to move more easily in one direction (e.g., a direction that decreases the overlap between the first telescoping member 804a and the second telescoping member 804b) than in a second direction (e.g., a direction that increases the overlap between the first telescoping member 804a and the second telescoping member 804b).

[0077] The elastic members 804 may be configured to move in response to the expansion of the tissue wall 808. In some embodiments, the flow portion 802 may include one or more connecting / restraining mechanisms to prevent the flow portion 802 from expanding prior to the corresponding expansion of the tissue wall 808. For example, the two or more elastic members 804 may be held together by sutures, clamps, or similar devices to maximize overlap. As the tissue wall 808 expands, pressure applied against the restraining mechanisms may increase to a level where the restraining mechanisms break and / or stretch, thereby allowing the flow portion 802 to extend and reducing the amount of overlap between the two or more elastic members 804.

[0078] In some embodiments, the telescoping shunt implant 800 may include one or more pegs, notches, and / or similar features to allow the flow portion 802 to expand in stages. For example, the first telescoping member 804a may include one or more notches configured for corresponding pegs extending from the second telescoping member 804b. During delivery, a first peg extending from the second telescoping member 804b may reside within the first notch of the first telescoping member 804a. As the tissue wall 808 expands, the first peg may slide along the first telescoping member 804a and nest within the second notch of the first telescoping member 804a. When a peg (or similar feature) on the second elastic member 804b interacts with a notch (or similar feature) on the first elastic member 804a, a resistive force may be exerted that prevents movement of the second elastic member 804b relative to the first elastic member 804a until sufficient force (e.g., expansion of the tissue wall 808) is applied to the second elastic member 804b and / or the first elastic member 804a. In some embodiments, each feature may be configured to allow unidirectional movement of the elastic member 804 (i.e., movement in only one direction), similar to a ratchet.

[0079] The telescoping shunt implant 800 may include one or more anchoring arms 814 configured to anchor within the tissue wall 808. Although the telescoping shunt implant 800 is shown having two anchoring arms 814, the telescoping shunt implant 800 may have any number of anchoring arms 814. In some embodiments, the telescoping shunt implant 800 may include one or more anchoring arms 814 at a first end of the telescoping shunt implant 800 (e.g., configured to anchor a first surface 801 of the tissue wall 808) and / or at or near a second end of the telescoping shunt implant 800 (e.g., configured to anchor a second surface 803 of the tissue wall 808). The anchoring arms 814 may be attached to and / or extend from two or more telescoping members 804.

[0080] Each of the anchoring arms 814 may include an anchoring mechanism 815 configured to penetrate, attach to, and / or otherwise anchor to the tissue wall 808. As shown in FIG. 8 , the anchoring mechanism 815 may include a barb. However, suitable mechanisms 815 may include one or more of a hook, needle, screw, nail, and / or other device.

[0081] In some embodiments, the elastic members 804 and / or the anchoring arms 814 may each be constructed from a common material or different materials. In some embodiments, either the elastic members 804 and / or the anchoring arms 814 may be constructed from Nitinol and / or other metals, plastics, polymers, and / or other materials.

[0082] 9A and 9B illustrate a fabric shunt implant 900 according to some embodiments. FIG. 9A illustrates a side view of the fabric shunt implant 900. The fabric shunt implant 900 may comprise a central flow section 902 (having a first section 920, a second section 922, and / or a third section 924) comprised of a single continuous sheet of fabric or one or more discontinuous sheets of fabric. As used herein, "fabric" may refer to any elastic and / or flexible material that can be stretched, molded, and / or shaped in response to various forces. The central flow section 902 may comprise a piece of fabric in the form of a sack, tube, bag, or sheet. For example, the central flow section 902 may comprise a sack, where the central flow section 902 has a continuous structure without edges, corners, etc. The fabric may be comprised of an elastic material, such that the fabric stretches in response to force and / or returns to a predetermined shape when the force is removed. In some embodiments, the central flow portion 902 may have an at least partially hollow interior or may be completely surrounded by fabric. The central flow portion 902 may be at least partially amorphous, such that the central flow portion 902 may be shaped to form various shapes and / or elongated to have various sizes. The central flow portion 902 may be configured to elongate longitudinally (i.e., the distance between the first portion 920 and the third portion 924 increases) in response to expansion and / or growth of the tissue wall 908.

[0083] 9A , the first portion 920 of the flow portion 902 may be configured to be located at or near the first surface 901 of the tissue wall 908, the second portion 922 of the flow portion 902 may be configured to be located within an opening in the tissue wall 908, and the third portion 924 of the flow portion 902 may be configured to be located at or near the second surface 903 of the tissue wall 908. In some embodiments, the flow portion 902 may be configured to at least partially cover the opening in the tissue wall. For example, the first portion 920 may be configured to at least partially cover the opening in the first surface 901 of the tissue wall 908 and / or the third portion 924 may be configured to at least partially cover the opening in the second surface 903 of the tissue wall 908. The first portion 920 and / or the third portion 924 may be configured to at least partially cover the opening in a resting state and / or may be configured to stretch to a sufficient extent to cover the opening.

[0084] In some embodiments, the fabric shunt implant 900 may be configured to define and / or maintain a flow path through the tissue wall 908. The central flow portion 902 (e.g., first portion 920 and / or third portion 924) may be constructed of a material having a breathable structure, which may allow flow through the central flow portion 902. For example, the central flow portion 902 may be constructed of a material including a plurality of woven fibers with small gaps between the fibers. Thus, blood may be able to flow through the central flow portion 902. In some embodiments, the flow portion 902 (e.g., first portion 920 and / or third portion 924) may have one or more holes 925 configured to allow blood to flow through the flow portion 902. Each of the holes 925 may have a size sufficient to allow blood flow. The flow portion 902 may have any number of holes 925, and / or the holes 925 may have any size and / or shape. The holes 925 may be located at points in the first portion 920 and / or third portion 924 configured to align with openings through the tissue wall 908. Thus, blood flow through the holes 925 may pass through the central flow portion 902 and through the openings.

[0085] FIG. 9B shows an overhead view (e.g., as viewed from the left atrium) of the fabric shunt implant 900 on the first surface 901 of the tissue wall 908. As shown in FIG. 9B, an opening 911 may be formed in the tissue wall 908. The opening 911 is shown in FIG. 9B as a dotted line to represent the placement of the opening 911 relative to the central flow portion 902. The opening 911 may be at least partially covered by the central flow portion 902 (e.g., by the first portion 920) and may not be visible through the central flow portion 902, but is shown here for illustrative purposes. In some embodiments, the opening 911 may have an elliptical (e.g., circular) shape. The first portion 920 of the flow portion 902 may be configured to at least partially cover the opening 911 in the tissue wall 908 at the first surface 901 of the tissue wall 908. In some embodiments, the first portion 920 may form an elliptical (e.g., circular) shape around the opening 911. The first portion 920 may be secured to the tissue wall 908 (e.g., at the first surface 901) by using one or more anchoring mechanisms 914. In some embodiments, the anchoring mechanisms 914 may include nails, screws, hooks, barbs, and / or other devices configured to penetrate and / or otherwise attach to the surface of the tissue wall 908. Additionally, the anchoring mechanisms 914 may pass through the flow portion 902 to press the flow portion 902 against the tissue wall 908. Although four anchoring mechanisms 914 are shown anchoring the first portion 920 of the flow portion 902 to the first surface 901 of the tissue wall, any number of anchoring mechanisms 914 may be used. Additional anchoring mechanisms 914 may be used to anchor the flow portion 902 (e.g., the third portion 924) to the second surface 903 of the tissue wall 908.

[0086] At least a portion of second portion 922 may be configured to be disposed within the opening in tissue wall 908. Second portion 922 may have a generally cylindrical / tubular shape and / or may be configured to be shaped into a generally cylindrical / tubular shape, where the size and / or shape of second portion 922 approximates the size and / or shape of the opening in tissue wall 908. Second portion 922 may be configured to establish a barrier against the inner surface of opening 911 in tissue wall 908 to prevent tissue ingrowth after forming opening 911. In some embodiments, second portion 922 may be configured to press against the inner surface of opening 911. Each of first portion, second portion, and / or third portion 924 may be a separate piece of fabric and / or may form a continuous piece of fabric.

[0087] During delivery, the flow portion 902 of the fabric shunt implant 900 may have a longitudinal length and / or may be configured to extend a longitudinal length approximately equal to the depth of the opening and / or the thickness of the tissue wall 908. Thus, a first end of the flow portion 902 (e.g., first portion 920) may be approximately aligned with a first surface 901 of the tissue wall 908 along the longitudinal axis, and / or a second end of the flow portion 902 (e.g., third portion 924) may be approximately aligned with a second surface 903 of the tissue wall 908 along the longitudinal axis. The flow portion 902 may be configured to stretch as the thickness of the tissue wall 908 increases, such that the first portion 920 remains generally aligned with and / or attached to the first surface 901 of the tissue wall 908, and / or the third portion 924 remains generally aligned with and / or attached to the second surface 903 of the tissue wall 908.

[0088] The textile shunt implant 900 may be in a compressed and / or otherwise expandable form during delivery. For example, the textile shunt implant 900 may be rolled, twisted, loosened, and / or otherwise compressed to fit onto a catheter and / or to allow the textile shunt implant 900 to stretch to fit through the opening 911 in the tissue wall 908. After delivery of the textile shunt implant 900, as the tissue wall 908 expands (e.g., longitudinally), the flow portion 902 (e.g., second portion 922) may stretch to form a textile shunt implant 900 with a greater longitudinal length. In some embodiments, the flow portion 902 may have an at least partially elastic structure and / or may resist stretching until a sufficient force is applied (e.g., expansion of the tissue wall 908).

[0089] Delivery Process 10 is a flow diagram of an example process 1000 for delivering and / or anchoring an expandable shunt to a human body according to some embodiments. Process 1000 includes, at block 1002, forming an opening in a tissue wall. As described herein, the opening may be formed by using one or more of a guidewire, a puncture catheter, an introducer sheath, a puncture sheath, and / or a puncture expander. The opening may form a blood flow path between two anatomical chambers (e.g., the left atrium and the coronary sinus).

[0090] Process 1000 includes attaching an expandable shunt to a delivery catheter at block 1004. The expandable shunt may be located within a lumen of the delivery catheter and / or may be in a collapsed state during delivery. Process 1000 includes advancing the delivery catheter to and / or near the opening at block 1006.

[0091] Process 1000 includes placing an expandable shunt within and / or around the opening at block 1008. For example, the shunt may include a flow portion configured to be positioned within the opening and / or one or more anchoring mechanisms configured to anchor the flow portion to a portion of the tissue wall outside the opening. Process 1000 includes anchoring the expandable shunt to the tissue wall at block 1010.

[0092] Additional Embodiments Depending on the embodiment, some acts, events, or functions of any of the processes or algorithms described herein may be performed in a different sequence, added, combined, or omitted entirely. Thus, in some embodiments, not all described acts or events are required to implement a process.

[0093] In particular, conditional terms used herein, such as "can," "could," "may," "may," "for example," and the like, are intended to have their ordinary meaning unless otherwise indicated or understood otherwise within the context in which they are used, and are generally intended to indicate that some embodiments include certain features, elements, and / or steps, and other embodiments do not include those features, elements, and / or steps. Thus, such conditional terms generally do not imply that features, elements, and / or steps are required for one or more embodiments, nor do they imply that one or more embodiments necessarily include logic for determining, with or without authorial input or direction, whether those features, elements, and / or steps are included in any particular embodiment or whether those features, elements, and / or steps should be performed in any particular embodiment. Terms such as "comprise," "include," "have," and the like are synonymous and used in their ordinary sense, and are used in an open-ended, inclusive manner and do not exclude additional elements, features, acts, operations, etc. Furthermore, the term "or" is used in an inclusive sense (and not an exclusive sense), whereby when the term is used, for example, to connect a list of elements, the term "or" means one, some, or all of the elements in the list. Connective language such as "at least one of X, Y, or Z" is understood to be used within the context of its general use to indicate that an item, term, element, etc., can be either X, Y, or Z, unless otherwise indicated. Thus, such connective language does not generally imply that a particular embodiment requires that at least one X, at least one Y, and at least one Z each be present.

[0094] In the foregoing description of embodiments, it should be appreciated that various features may be grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure and aiding in the understanding of one or more of the various inventive aspects. However, this method of disclosure should not be interpreted as reflecting an intention that any claim requires more features than are expressly recited in that claim. Moreover, any component, feature, or step illustrated and / or described in a particular embodiment herein may be applied to or used in conjunction with any other embodiment. Furthermore, no component, feature, step, or group of components, features, or steps is necessary or essential to each embodiment. Accordingly, the scope of the invention as disclosed herein and claimed below is not intended to be limited by the specific embodiments described above, but rather should be determined solely by a fair reading of the following claims.

[0095] It should be understood that some ordinal numbers (e.g., "first" or "second") are provided for ease of reference and do not necessarily imply physical characteristics or order. Thus, herein, ordinal numbers (e.g., "first," "second," "third," etc.) used to modify an element, such as a structure, component, or operation, do not necessarily indicate a priority or order of that element relative to any other elements, but generally distinguish that element from another element having a similar or identical name (for the purposes of using the ordinal number). Furthermore, herein, indefinite articles ("a" and "an") may indicate "one or more" rather than "one." Furthermore, an action performed "based on" a condition or event may be performed based on one or more other conditions or events not explicitly stated.

[0096] Unless otherwise specified, all terms (including scientific and technical terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the exemplary embodiments belong. Terms as defined in commonly used dictionaries should be understood to have a meaning consistent with the meaning of the term in the context of the relevant art, and should not be construed in an idealized or overly formal sense unless explicitly defined.

[0097] Although several preferred embodiments and examples are disclosed below, the subject matter of the present invention extends beyond the explicitly disclosed embodiments to other alternative embodiments and / or alternative uses, as well as modifications and equivalents thereof. Accordingly, the scope of claims that may arise from the above embodiments is not limited by any of the specific embodiments described below. For example, in any method or process disclosed herein, the acts or operations of the method or process may be performed in any suitable sequence and are not necessarily limited to any particular sequence disclosed. Although various operations may be described as multiple discrete operations as may be useful in understanding some embodiments, the order of description should not be construed to imply that these operations are order dependent. Furthermore, structures, systems, and / or devices described herein may be embodied as integrated components or as separate components. For purposes of comparing various embodiments, several aspects and advantages of these embodiments will be discussed. It is not necessarily the case that all such aspects or advantages are achieved by any particular embodiment. Thus, for example, various embodiments may be implemented to achieve or optimize one advantage or group of advantages taught herein without necessarily achieving other aspects or advantages that may also be taught or suggested herein.

[0098] Spatially relative terms such as "outside," "inside," "top," "bottom," "lower," "upper," "vertical," "horizontal," and similar terms may be used herein for ease of description when describing the relationship between one element or component and another element or component illustrated in the figures. It should be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation, as well as the orientation shown in the figures. For example, if a device illustrated in the figures were turned over, a device positioned "below" or "below" another device might be positioned "above" the other device. Thus, the exemplary term "below" may include both a lower position and an upper position. Devices may be oriented in other directions, and thus the spatially relative terms may be interpreted differently depending on the orientation.

[0099] Unless expressly stated otherwise, comparison and / or quantitative terms such as "less," "more," "greater than," etc. are intended to encompass the concept of equivalence. For example, "less" can mean "less than" in the strictest mathematical sense as well as "less than or equal to."

[0100] The delivery systems described herein may be used to position catheter tips and / or catheters in various regions of the human heart. For example, the catheter tip and / or catheter may be configured to travel from the right atrium to the coronary sinus. However, the description may also refer to or generally apply to positioning the catheter tip and / or catheter from a first body cavity or lumen to a second body cavity or lumen, with the understanding that the catheter tip and / or catheter may be bent as it is positioned from the first body cavity or lumen into the second body cavity or lumen. A body cavity or lumen may refer to any of several fluid channels, blood vessels, and / or organ cavities (e.g., heart chambers). Furthermore, references herein to a “catheter,” “tube,” “sheath,” “steerable sheath,” and / or “steerable catheter” may refer to or generally apply to any type of elongated tubular delivery device with an inner lumen configured to slidably receive an instrument, such as an elongated tubular delivery device for placement within the atrium or coronary sinus, including, for example, a delivery catheter and / or cannula. It will be appreciated that other types of medical implant devices and / or procedures can be delivered to the coronary sinus using the delivery systems described herein, including, for example, ablation therapy, drug delivery, and / or coronary sinus lead placement. The subject matter of the present invention is also provided in the following sections. [Section 1] 1. A shunt comprising a central flow section, the central flow section comprising: fitting at least partially within an opening in a tissue wall, the tissue wall being located between a first anatomical chamber and a second anatomical chamber, the opening representing a blood flow path between the first anatomical chamber and the second anatomical chamber; maintaining the blood flow path from the first anatomical chamber to the second anatomical chamber; preventing tissue ingrowth within the opening; and and expanding in response to expansion of the tissue wall. [Section 2] Item 1. The shunt described in item 1, further comprising one or more anchoring arms extending from the central flow section, the one or more anchoring arms configured to anchor to the tissue wall. [Section 3] Item 3. The shunt described in item 2, wherein each of the one or more anchoring arms includes an anchoring mechanism at an end thereof. [Section 4] Item 4. The shunt of item 3, wherein the fixation mechanism comprises one or more of the group including barbs, hooks, nails, and screws. [Section 5] A shunt described in any one of paragraphs 1 to 4, wherein the central flow section comprises a mesh of one or more lines, each of which is configured to interweave with itself or at least one other of the one or more lines. [Section 6] 6. A shunt as described in any one of paragraphs 1 to 5, wherein the central flow section comprises a network of chains, each chain of the network of chains configured to interlock with at least one other chain of the network of chains. [Section 7] 7. The shunt of any one of paragraphs 1 to 6, wherein the central flow section comprises a coiled line. [Section 8] Item 8. The shunt described in item 7, wherein the central flow section has a constant diameter approximately equal to the diameter of the opening. [Section 9] a first portion of the central flow section configured to be located within the opening; a second portion of the central flow section configured to extend into the first anatomical chamber; the first portion has a first diameter and the second portion has a second diameter; Item 9. The shunt of item 7 or 8, wherein the second diameter is greater than the first diameter. [Section 10] Item 10. The shunt of item 9, wherein the second portion is configured to prevent the central flow portion from becoming dislodged. [Section 11] 11. A shunt as described in any one of paragraphs 1 to 10, wherein the central flow section comprises one or more rings, each of which has an elliptical shape to approximate the shape of the opening. [Section 12] Item 12. The shunt of item 11, wherein at least one of the one or more rings is coated with a polymer configured to prevent tissue in-growth. [Section 13] each of the one or more rings is comprised of a shape memory material; each of the one or more rings is naturally configured to have a first diameter; each of the one or more rings is configured to be compressed to a second diameter smaller than the first diameter to fit within the opening; Item 13. The shunt of item 11 or 12, wherein each of the one or more rings is configured to press against the tissue wall to hold itself in place. [Section 14] 14. The shunt of any one of paragraphs 11 to 13, wherein each of the one or more rings comprises an anchoring mechanism configured to anchor to the tissue wall. [Section 15] Item 15. The shunt of item 14, wherein the fixation mechanism is at least one of the group including spikes, screws, nails, barbs, and hooks. [Section 16] 16. A shunt according to any one of paragraphs 11 to 15, wherein each of the one or more rings is connected by a cloth. [Section 17] the central flow section comprises two or more elastic members; a first telescopic member of the two or more telescopic members having a first diameter; a second telescopic member of the two or more telescopic members having a second diameter smaller than the first diameter; 17. The shunt of any one of paragraphs 1 to 16, wherein the second elastic member is configured to fit at least partially within the central opening of the first elastic member. [Section 18] Item 18. The shunt described in item 17, wherein the second elastic member is configured to move relative to the first elastic member to adjust the amount of overlap between the first elastic member and the second elastic member. [Section 19] Item 19. The shunt described in item 18, wherein the second elastic member is configured to reduce the amount of overlap between the first elastic member and the second elastic member in response to expansion of the tissue wall. [Section 20] Item 20. The shunt described in item 19, wherein the first elastic member and the second elastic member include one or more connection mechanisms configured to allow unidirectional movement of the second elastic member. [Section 21] 21. The shunt of any one of paragraphs 1 to 20, wherein the central flow section extends from the first anatomical chamber to the second anatomical chamber and comprises a fabric sheet configured to stretch in response to expansion of the tissue wall. [Section 22] Item 22. The shunt of item 21, wherein the fabric sheet is configured to form a cylindrical shape at the opening. [Section 23] 23. The shunt of paragraph 21 or 22, further comprising one or more anchoring mechanisms configured to anchor the fabric sheet to the first surface of the tissue wall. [Section 24] Item 24. The shunt of item 23, wherein the fabric sheet is configured to form a sac and at least partially cover the opening, and has one or more holes that allow blood to flow through the fabric sheet. [Section 25] forming an opening in the tissue wall, the tissue wall is located between a first anatomical chamber and a second anatomical chamber; the opening representing a blood flow path between the first anatomical chamber and the second anatomical chamber; placing a shunt in the opening, the shunt comprising a central flow section, the central flow section comprising: fitting at least partially within the opening in the tissue wall; maintaining the blood flow path from the first anatomical chamber to the second anatomical chamber; preventing tissue ingrowth within the opening; and and expanding in response to the expansion of the tissue wall. [Section 26] 26. The method of claim 25, further comprising one or more anchoring arms extending from the central flow section, the one or more anchoring arms configured to anchor to the tissue wall. [Section 27] 27. The method of claim 25 or 26, wherein the central flow section comprises a network of one or more lines, each of the one or more lines being configured to interweave with itself or with at least one other of the one or more lines. [Section 28] 28. The method of any one of clauses 25 to 27, wherein the central flow section comprises a network of chains, each chain of the network of chains configured to interlock with at least one other chain of the network of chains. [Section 29] 29. The method of any one of paragraphs 25 to 28, wherein the central flow section comprises a coiled line. [Section 30] 30. The method of any one of paragraphs 25 to 29, wherein the central flow section comprises one or more rings, each of which has an elliptical shape to approximate the shape of the opening. [Section 31] the central flow section comprises two or more elastic members; a first telescopic member of the two or more telescopic members having a first diameter; a second telescopic member of the two or more telescopic members having a second diameter smaller than the first diameter; 31. The method of any one of clauses 25 to 30, wherein the second elastic member is configured to fit at least partially within a central opening of the first elastic member. [Section 32] 32. The method of any one of clauses 25 to 31, wherein the central flow section extends from the first anatomical chamber to the second anatomical chamber and comprises a fabric sheet configured to stretch in response to expansion of the tissue wall. [Explanation of symbols]

[0101] 1. Heart 2 left atrium 5 Right atrium 10 Implant Devices 11 Subclavian vein 12 carotid artery 13 femoral vein 14. Inferior vena cava 15 Superior vena cava 16 Catheter 19 Coronary sinus 301 First Side 303 Second Side 308 Organization Wall 311 Opening 350 Delivery Catheter 352 Distal tip 400 First Expandable Shunt Implant 401 First Side 402 Central flow section 403 Second Side 404 Line 406 Ring 408 Organization Wall 410 Longitudinal Axis 412 Horizontal axis 414 Fixed Arm 415 Fixing mechanism 500 Shunt Implants 501 First Side 502 Flow Section 503 Second Side 504 Chain 506 Ring 508 Organization Wall 514 Fixed arm 515 Fixing mechanism 600 Shunt Implants 601 First Side 602 Flow Section 603 Second Side 604 Coiled Line 608 Organization Wall 614 Fixed Arm 615 Fixing mechanism 620 first end 621 First Part 622 Second End 623 Second Part 624 Third Part 701 First Side 702 Central flow section 703 Second Side 704 Ring 704a First Ring 704b Second Ring 708 Organization Wall 800 Telescopic Shunt Implant 801 First Side 802 Central flow section 803 Second Side 804 Elastic member 804a First elastic member 804b Second elastic member 808 Organization Wall 814 Fixed arm 815 Fixing mechanism 900 Fabric Shunt Implant 901 First Side 902 Central flow section 903 Second Side 908 Organization Wall 911 Opening 914 Fixing mechanism 920 First Part 922 Second Part 924 Third Part 925 holes

Claims

1. A shunt for enabling blood flow through a tissue wall, wherein the shunt is A central flow portion, sized to fit at least partially into the opening of the tissue wall, wherein the tissue wall is located between a first anatomical chamber and a second anatomical chamber, and the opening forms and maintains a blood flow path between the first anatomical chamber and the second anatomical chamber, A first set of one or more fixing arms connected to the central flow portion at their respective bases, each of the first set of one or more fixing arms configured to be fixed to the first end of the central flow portion, extending from the central flow portion and penetrating the first surface of the tissue wall, A second set of one or more fixing arms connected to the central flow portion at their respective bases, wherein each of the second set of one or more fixing arms is configured to be fixed to the second end of the central flow portion, extending from the central flow portion and penetrating the second surface of the tissue wall, Equipped with, The aforementioned central flow section is Extending from the first anatomical chamber to the second anatomical chamber, inhibiting tissue growth within the opening, A shunt that extends in one direction together with the tissue wall and is configured to increase the distance between the base of a first set of one or more anchoring arms and the base of a second set of one or more anchoring arms in accordance with the growth of the tissue wall.

2. A shunt according to Claim 1, wherein the first end of the central flow portion is configurable to align with a first surface of the tissue wall, the second end of the central flow portion is configurable to align with a second surface of the tissue wall, and the central flow portion is configured to expand to adapt to the growth of the tissue wall, in order to maintain the first end of the central flow portion and the second end of the central flow portion align with the first surface of the tissue wall and the second surface of the tissue wall, respectively.

3. A shunt according to Claim 1, wherein the central flow portion is configured to expand in one direction together with the tissue wall and in accordance with the growth of the tissue wall, without affecting the flow of blood passing through the flow path and flowing out therefrom.

4. The shunt according to claim 1, The central flow section comprises two or more expandable members, The first of the two or more expandable members has a first diameter. The second of the two or more expandable members has a second diameter smaller than the first diameter. A shunt in which the second expandable member is sized to fit at least partially into the central opening of the first expandable member.

5. A shunt according to claim 4, wherein the second expandable member is sized to move relative to the first expandable member to adjust the amount of overlap between the first expandable member and the second expandable member, the outlet channel of the central flow section is not affected by the relative positions of the first expandable member and the second expandable member, and when the central flow section is located within the opening, only a single flow path is maintained through the opening in the tissue wall, and the blood flow passing through the opening must pass through a lumen defined by the central flow section.

6. A shunt according to claim 5, wherein the second expandable member is arranged to reduce the amount of overlap between the first expandable member and the second expandable member in response to the expansion of the tissue wall.

7. A shunt according to claim 6, wherein the first telescopic member and the second telescopic member are provided with one or more connecting mechanisms arranged to enable unidirectional movement of the second telescopic member.

8. A shunt for enabling blood flow through a tissue wall, wherein the shunt is A central flow portion having a size that forms a blood flow path passing through the opening in the tissue wall and penetrating the tissue wall, wherein the central flow portion is configured to expand together with the tissue wall and in accordance with the growth of the tissue wall without affecting the blood flow through the blood flow path, A first set of one or more fixing arms extends from the central flow portion at the first end of the central flow portion and is fixed to and embedded in the first surface of the tissue wall, A second set of one or more fixing arms extends from the central flow portion at the second end of the central flow portion and is fixed to and embedded in the second surface of the tissue wall, A shunt equipped with a shunt.

9. The shunt according to claim 8, The central flow section comprises two or more expandable members, The first of the two or more expandable members has a first diameter. The second of the two or more expandable members has a second diameter smaller than the first diameter. A shunt in which the second expandable member is sized to fit at least partially into the central opening of the first expandable member.

10. A shunt according to claim 9, wherein the second expandable member is sized to move relative to the first expandable member to adjust the amount of overlap between the first expandable member and the second expandable member.

11. A shunt according to claim 10, wherein the second expandable member is arranged to reduce the amount of overlap between the first expandable member and the second expandable member in response to the expansion of the tissue wall.

12. A shunt according to claim 11, wherein the first telescopic member and the second telescopic member are provided with one or more connecting mechanisms arranged to allow the second telescopic member to move in one direction.

13. A shunt according to claim 8, wherein the length of the central flow portion is substantially equal to or greater than the width of the tissue wall.

14. A shunt according to claim 8, wherein the central flow portion has a cylindrical shape.

15. A shunt for enabling blood flow through a tissue wall, wherein the shunt is A central flow tube having a cylindrical shape and sized to fit at least partially into an opening in the tissue wall to form a blood flow channel through the tissue wall, wherein the central flow tube is configured to expand axially in response to the growth of the tissue wall, A first set of one or more fixing arms connected to the central flow tube by their respective bases, each of the first set of one or more fixing arms extending from the central flow tube at a first end of the central flow tube, penetrating a first surface of the tissue wall and fixing thereto, A second set of one or more fixing arms connected to the central flow tube by their respective bases, each of the second set of one or more fixing arms extending from the central flow tube at the second end of the central flow tube, penetrating the second surface of the tissue wall and fixing thereto, Equipped with, A shunt in which the central flow tube is configured to expand to increase the distance between the base of a first set of one or more fixing arms and the base of a second set of one or more fixing arms.

16. A shunt according to claim 15, wherein the central flow tube is configured to expand in one direction together with the tissue wall and in accordance with the growth of the tissue wall, without affecting the flow of blood passing through the flow path and exiting therefrom.

17. The shunt according to claim 15, The central flow tube comprises two or more expandable members, The first of the two or more expandable members has a first diameter that is sized to abut against the edge of the opening in the tissue wall. The second of the two or more expandable members has a second diameter smaller than the first diameter. A shunt in which the second expandable member is sized to fit at least partially into the central opening of the first expandable member.

18. A shunt according to claim 17, wherein the second expandable member is sized to move relative to the first expandable member to adjust the amount of overlap between the first expandable member and the second expandable member.

19. A shunt according to claim 18, wherein the second expandable member is arranged to reduce the amount of overlap between the first expandable member and the second expandable member in response to the expansion of the tissue wall.

20. A shunt according to claim 19, wherein the first telescopic member and the second telescopic member are provided with one or more connecting mechanisms arranged to allow the second telescopic member to move in one direction.

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