Valved stent and delivery system for in situ replacement of a dysfunctional heart valve

Abstract

A valved stent for implantation at a dysfunctional or diseased atrioventricular valve annulus is disclosed. The valved stent is expandable from a collapsed shape to an expanded shape for minimally invasive delivery and has a low profile in the atrial or superior aspect to achieve improved hemodynamics and provide the ability to manufacture replacement valves with large diameters. The invention also includes a delivery apparatus uniquely designed for implantation of the valved stent and provides the possibility of controlled and precise placement of the valved stent at the atrioventricular valve annulus. The invention also includes methods for the above devices and for the treatment of a diseased atrioventricular valve.

Description

[0001] Related applications

[0002] This application is a divisional application of Chinese Patent Application No. 201880033944.5, filed on May 14, 2018, entitled "Valve stent and delivery system for in-situ replacement of dysfunctional heart valves". Technical Field

[0003] This invention discloses a valved stent for replacing and restoring function of defective heart valves, and a specific system for delivery and deployment under controlled conditions. More specifically, the invention discloses preferred geometry and key dimensions of the prosthetic valve structure when anchored to an autologous valve ring to improve the hydrodynamics through the prosthetic valve and adjacent vascular system. The invention also includes an endovascular delivery system that uses optimal positioning to deploy the replacement valve to ensure proper attachment and subsequent function while minimizing surgical complications. Background Technology

[0004] The four valves found in normal heart valves—pulmonary valves, aortic valves, tricuspid valves, and mitral valves—have specific forms and functions. The primary function of all four valves is to maintain unidirectional blood flow by opening and closing at coordinated and specific times during the beating heart cycle. In this way, blood is collected from all tissues of the body, and blood returns to the right side of the heart via veins through the right atrium (RA) and passes through the tricuspid valve. The aortic and pulmonary valves are found as the entrance gates of the heart and as part of a physiological structure that is a continuum of the valvular annulus (poorly defined histologically), attached to three leaflets of different shapes without free edges. The edges of the tricuspid valve are attached to chordae tendineae, which are attached to the myocardial layer or the wall of the myocardium opposite or on the distal side. These components work together to maintain the proper function and structural configuration of the valve during opening and closing.

[0005] As the ventricles pump blood forward, the chordae tendineae protect the valvular leaflets from rupture or regenerate, thus preventing valve failure, which would result in insufficient blood reaching the lungs. Therefore, when the right ventricle contracts and propels blood forward, the tricuspid valve must close behind the blood flow to maintain its capacity, ensuring that most of the blood in the ventricles is propelled through the pulmonary valves to the lungs for oxygenation.

[0006] Continuing in a unidirectional flow, the oxygenated blood then enters the left side of the heart through the left atrium and subsequently through another atrioventricular valve called the mitral valve into the left ventricle. Similar to the tricuspid valve, the leaflets of the mitral valve attach to the valvular annulus on the atrial side and the chordae tendineae on the ventricular side, which attach to the myocardium of the left ventricle (LV) in the same manner as the tricuspid valve. When the mitral valve closes, the left ventricle then contracts to propel oxygenated blood through the aorta to every tissue in the body. To provide oxygen flow throughout the body, the pumping action of the left ventricle must be significantly greater than that of the RV, as can be seen from the difference in the magnitude of the instantaneous ventricular pressure, which can be mathematically expressed as the change in pressure over time (dp / dt). The left ventricular dp / dt of a seated person at normal rest is approximately 1600 mmHg / s, and the pressure is applied at the mitral valve when it closes. On the other hand, when the heart closes, the tricuspid valve on the right side experiences only about one-fifth of the instantaneous pressure experienced by the mitral valve, with dp / dt being approximately 350 mmHg / second.

[0007] Although both the tricuspid and mitral valves are atrioventricular valves, the tricuspid valve differs in size, structure, position, and shape. Most importantly, the size requirements for the tricuspid valve differ from those for the mitral valve. The specially designed replacement valve prosthesis for the tricuspid valve is different from that for the mitral valve.

[0008] Valve replacement may be necessary due to disease, injury, or simply aging. For decades, surgical methods for valve repair or replacement have required open-heart surgery, stopping the heart, attaching a cardiopulmonary bypass machine, and surgically opening the heart to access the diseased valve. Even in successful cases, the surgery involved lengthy hospital stays and the risk of many often fatal complications. These drawbacks led researchers and clinicians to search for a less invasive method of heart valve replacement. Catheter-based interventional procedures, such as placing stents to dilate blocked arteries, were well-known as minimally invasive procedures in cardiology at the time, and researchers began to investigate the possibility of replacing defective heart valves using catheter-based delivery systems.

[0009] Andersen first successfully implanted a prosthetic valve using a catheter in an animal model in 1989. The ability to use catheter-based delivery systems enabled valve replacement surgery for a large number of patients who would otherwise die due to comorbidities that put them at high risk of death during cardiopulmonary bypass. Over the years, other advances have improved valve replacement surgery. In September 2000, A glutaraldehyde-preserved bovine jugular vein valve was implanted into a porcine bioprosthetic within a catheter of a dysfunctional pulmonary artery in an 11-year-old child using a platinum-iridium stent to support the valve at the distal end of a 6mm catheter. This was the first catheter-guided valve implanted in a human. Cribier subsequently implanted the valve in the aortic region in 2002 using balloon dilation replacement, the valve being made of animal tissue housed within a stainless steel stent support structure.

[0010] Over the next decade, a range of replacement valves for the semilunar, pulmonary, and aortic valves utilized stent-supported designs, until the use of these types of replacement valves and the minimally invasive procedures for their delivery became routine and were used worldwide to replace defective autologous valves. Stent-supported designs for valves that allow blood to flow in and out of the heart, including aortic and pulmonary valves, are now available in many different designs, with new developments in interventricular or atrioventricular valves, mitral valves, and tricuspid valves currently under testing.

[0011] Minimally invasive catheter-based techniques are used to access different valves in either direction relative to blood flow—either retrograde (advanced) by advancing the catheter in the opposite direction to blood flow or antegrade (advanced) by advancing the catheter in the same direction as blood flow. Access to the tricuspid valve is antegrade, whether intracavitary or transatrial (heart-beating surgery).

[0012] When the tricuspid valve becomes dysfunctional and fails to close properly, the heart loses its ability to provide sufficient unidirectional blood flow. While the right ventricle (RV) pumps a certain amount of blood to the lungs, some of this blood flows backward and back to the right atrium (RA), causing blood to flow retrogradely through the inferior vena cava (IVC) to the liver, kidneys, and lower limbs, and through the superior vena cava (SVC) to the brain. The severity of regurgitation can be graded from mild to severe. Severe regurgitation is a serious condition that also leads to insufficient blood flow back to the heart. The liver suffers and develops what is known as cardiogenic cirrhosis (which is actually cirrhosis), systemic edema and ascites, the accumulation of serous fluid in the abdominal cavity, also known as abdominal or peritoneal edema or ascites. The reduced venous blood flow also reduces oxygenated blood flow from the lungs to the heart, and as a result, all tissues in the body are damaged.

[0013] Like other valves, tricuspid valve insufficiency cannot repair itself, and without proper treatment, its inevitable progression leads to weakness and death. (Refer to this article.) Figure 3A , Figure 3B and Figure 4Published literature (Nath J et al., JACC 2004 43(3):405-409) indicates that the prognosis of tricuspid regurgitation is very poor, with a one-year mortality rate of 9.7% for mild tricuspid regurgitation, 21.1% for moderate tricuspid regurgitation, and 36.1% for severe tricuspid regurgitation. As Vahanian et al. (Eur Heart J 2012 33(19):2451-2396) show, most patients do not undergo cardiac surgery because they are considered inoperable (at high risk of death) due to a one-year mortality rate of approximately 37%. In its severe stage, patients with TR have few treatment options to correct their condition. In the United States, studies estimate that 1.9 million patients develop moderate to severe tricuspid regurgitation (TR) each year, with fewer than 8,000 receiving surgical treatment annually that could potentially extend their lives. In Europe, the numbers are likely significantly higher. Stuge O., Liddicoat J., et al. JTCS 2006; 132:1258-61 (see also...) Figure 3A Bernal JM, et al. J Thorac. Cardiovasc Surg. 2005; 130:498-503; Taramasso M, et al. J Am Coll Cardiol. 2012; 59:703-710).

[0014] Because the condition is age-related, it is estimated that millions of people worldwide suffer from advanced tricuspid regurgitation (TR), and the number is growing. TR patients are considered inoperable or “high-risk” for surgery that carries a mortality risk of over 35%–40%. Current treatments consist of diuretics found in blood pressure medications, which are ineffective because the problem is caused by valvular dysfunction. In the long term, these patients tend to develop right heart failure (RHF), severe ascites, bilateral pleural effusion, and severe peripheral edema, and often require monthly thoracentesis for diuresis and thoracentesis, as well as treatment for tricuspid regurgitation, leading to progressive weakness, cardiac cachexia, congestive liver disease, renal insufficiency, refractory ascites, and pleural effusion. At this point, these patients have a very poor quality of life and a depressing prognosis.

[0015] When considering catheter-based repair or replacement, both mitral and tricuspid valves present numerous challenges due to their location and their complex structure relative to the other two valves in the heart. Navigation within the vascular system using a valve replacement delivery device with a sufficiently large diameter to accommodate the replacement valve is possible if the profile of the delivery device can be reduced to approximately the size of the narrowest vessel the device must traverse to deliver the prosthetic valve to its target location within the heart without requiring open surgery. Even though the replacement valve can be designed to collapse to a smaller diameter to fit the catheter-based delivery device used during percutaneous replacement, there are limitations on the minimum possible diameter that the replacement valve can produce. These delivery catheters must also be able to bend to form sharp angles, as these are necessary to reach the target site for some defective heart valves.

[0016] Furthermore, when the distal end of the delivery device containing the replacement valve reaches the target location for valve replacement, the delivery catheter and the replacement valve stent, then in a contracted or collapsed state within the delivery system, must be able to approach the plane of the original valve in such a configuration that the approach direction of the replacement valve is perpendicular to and coaxial with the plane of the defective valve. A suitable delivery mechanism to achieve this orientation must be part of the delivery device to ensure maximum compatibility with the replacement valve in both form and function.

[0017] One of the major challenges in creating a properly fitted tricuspid valve is the absolute size of the bioprosthetic replacement valve. In individuals without valvular disease, the normal tricuspid valve diameter has a very specific range. The diameter of aortic valves in normal adults varies between approximately 18 mm and approximately 27-29 mm, and pulmonary or pulmonary artery valves are typically smaller, ranging from approximately 17 mm to approximately 25 mm in diameter. Atrioventricular valves (the mitral valve on the left side of the heart) vary from 25 to 30 or 31 mm, but the tricuspid valve is generally larger than the mitral valve and typically has a diameter of approximately 27 to approximately 33 mm.

[0018] The design of replacement valves exacerbates this problem because valve size is significantly affected by disease or aging. Furthermore, aging and disease cause material buildup within the valve tissue, hardening the valve and reducing its size by decreasing the diameter of the fluid passage. This condition, known as stenosis, reduces the effective size of the valve orifice, requiring greater ventricular force to pump blood through the smaller orifice. Increased pressure is needed to pump blood effectively, and the pressure gradient between the atria and ventricles becomes increasingly undesirable. With this increasing pressure gradient, even with increasing cardiac output, reduced blood flow is an inevitable consequence.

[0019] Currently, in contrast to “repair” devices used for tricuspid valve placement, various researchers have begun exploring valve replacement methods. However, viable replacement valves must address the condition of tricuspid regurgitation by surrounding and capturing the wide diameter of the dysfunctional tricuspid valve annulus. Atrioventricular regurgitation, particularly functional tricuspid regurgitation (FTR), is common in dilated cardiomyopathy (DCM). Although the valve leaflets remain unaffected, the enlarged diameter of the valve annulus hinders the leaflets' ability to adhere to each other, resulting in “co-dilation” to provide closure to stop retrograde flow. Researchers have found that for most bioprosthetic valves used for aortic, pulmonary, and mitral valve replacements, it is not possible to implant bioprosthetics in situ into diseased, abnormally dilated, and regurgitated autologous human valves because their conformation and size cannot surround the dilated valve annulus and restore valve function.

[0020] For this condition, major treatment advancements have focused on implanting smaller cylindrical bioprosthetics with valvular stents into previously implanted, failed surgically implanted pig or pericardial bioprosthetics or annuloplasty rings—so-called intravalvular (VIV) implantations. Examples include the Sapien transcatheter aortic bioprosthetic (cylindrical in size, 21 mm to 29 mm) and Melody transcatheter pulmonary bioprosthetic valve (cylindrical in size, 14 mm to 22 mm), both of which have been relatively successfully implanted into failed mitral and tricuspid bioprosthetics. When tricuspid regurgitation cannot be corrected, additional efforts are made to mitigate its many adverse effects, such as cirrhosis, renal failure, peripheral edema, and ascites, using implants with valvular stents placed in both the inferior and superior vena cava to prevent retrograde flow and pressure in the two veins that can transmit to all these organs.

[0021] Currently, no known prosthetic valve design can surround, hold, and maintain hemodynamic flow when the size of the atrioventricular valve annulus is significantly increased. Furthermore, the deposition of large valves with an average diameter of approximately 49 mm, and some with diameters below 60 mm, necessitates careful control of valve guidance and release during deployment, ensuring the valve enters coaxially with the center of the tricuspid valve plane and resulting in the replacement valve being held and secured to the dilated valve annulus. Therefore, a special catheter with an articulated structure allows for a change of direction upon reaching a point in the right atrium, oriented towards the distal orifice of the replacement valve towards the center of the tricuspid valve leaflet junction.

[0022] Additionally, when such a catheter has been inserted into a dysfunctional tricuspid valve, it will allow for the initial, fully controlled release of the distal orifice of the valvular stent, enabling specific features of the stent to unfold and initiate engagement of the soft portion of the leaflet without damaging or disrupting the chordae tendineae attached to the floating edge of the leaflet. A special device must be manufactured that will allow for the release of the proximal structure of the valvular stent, capable of fully controlled truncation of the leaflet connector and valve annulus from the atrial side, entirely guided by the operator's hand and visual navigation. The sequence must be performed with extreme care to ensure that the atrioventricular stent is properly positioned without tilting or angle, so that after the valvular stent is released, there is no leakage, a perfect fit with the inappropriate tricuspid valve device, and no blood flow around the peripheral inner chamber (ventricle to atrium or retrograde). Furthermore, as described, it is extremely important to perform these procedures, and it is crucial to remember that the proximal orifice of the stent has components that must be kept away from adjacent conduction system parts of the heart to prevent cardiac blockage, which is a disturbance of the conduction system that interrupts the heart's electrical activity—the energy that powers the heart's contractions and relaxations—leading to cardiac arrest and the pumping of blood—a fatal consequence unless rhythmic pacing is employed. Additionally, it should be noted that tricuspid regurgitation can be caused by pacemaker leads that restrict the function of the valvular leaflets, and this condition is present in a large number of patients.

[0023] Therefore, it is desirable to provide a prosthetic valve with design parameters capable of replacing dysfunctional valves using valve design, which achieves robust anchoring at the target site and improved hemodynamic properties through the valve and in the surrounding vascular system. The prosthetic valve should restore function similar to that of an autologous valve and should not extend into either chamber, thereby causing disturbances and flow patterns (turbulence) known to lead to thrombosis and thromboembolism.

[0024] A delivery system is also desired that allows minimally invasive surgery to grasp the dilated annulus of a tricuspid valve by unfolding the prosthetic valve, thereby anchoring the replacement valve to the target site on the patient's heart and surrounding the entire blood flow path to form a stable and effective replacement valve. Ideally, the delivery system can be used in either retrograde or antegrade manner to deliver the valve through controlled release and precise placement at the target location. Compared to existing devices, delivery systems, and open-heart surgery, the controlled release and secure placement of the bioprosthetic heart valve will minimize trauma, avoid the risks and trauma of using a cardiopulmonary bypass machine, shorten operation time, and lead to better long-term outcomes. Summary of the Invention

[0025] This invention relates to restoring the function of cardiovascular valves, including repairing and replacing any one of the four heart valves, but particularly to the placement of prosthetic replacements for atrioventricular valves. The invention also includes apparatus and methods using an integrated system comprising a replacement valve and a delivery system specifically designed for the replacement valve of this invention. The system comprises both a valve-bearing stent specifically for a target valve (e.g., a tricuspid or mitral valve) and a delivery system also specifically for the target valve. Thus, the invention consists of each of two separate devices, complemented by a complementary combination of separate means.

[0026] The method of the present invention includes techniques for controlled deployment of prosthetic valves achieved through a unique design of the delivery system and the valve. Specifically, these mechanisms enable the prosthetic valve to be deployed and released in a controlled manner, allowing the surgeon to carefully control the placement of the valve during delivery, instruct the rate of expansion of the replacement prosthesis during delivery, and ensure that the valve-supported stent lands in the appropriate area during implantation.

[0027] Specifically, the present invention provides a valved stent for implantation at an autologous valve annulus (preferably an atrioventricular valve), comprising: a support structure, wherein the support structure is expandable from a collapsed shape to an expanded shape; a tissue valve having at least one leaflet, the tissue valve being connected to the support structure; and upper and lower (upper and lower) devices for securing and stabilizing the stent-bearing valve to the valve annulus, wherein the devices for securing and stabilizing the valved stent are located at the outer circumference of the support structure. The securing and stabilizing of the valved stent at the autologous valve annulus can also be described as having a securing and stabilizing structure relative to the autologous valve annulus in the atrium (upper) or ventricle (lower). Crucially, the securing and stabilizing devices provide a carefully controlled profile for the overall dimensions of the prosthesis, including the relative dimensions of height and width, which are controlled by the hydrodynamics of both the orifice of the replacement valve and the proximal and distal regions of the valve, where the hydrodynamics and relative fluid flow affect the long-term patency, thrombotic properties, and durability of the replacement valve.

[0028] In another embodiment, the support structure of the stented valve is self-expanding to a predetermined size, selected to match the diameter of the valve annulus of the dysfunctional valve. In some embodiments, the measurement of the size of the atrioventricular valve replacement device takes into account that the valve annulus, along with the valve leaflet material, will be captured by anchoring, fixing, and stabilizing elements of the stented valve, which becomes dysfunctional due to the expansion of its valve annulus. Functionally, these elements use a pair or several sets of structures, each unfolding from a first position to a second position, to grasp the tissue surrounding the autologous valve annulus. The unfolding occurs substantially at the limits of the structure's range of motion and can be consistent with the overall structure of the stented valve, which moves from a collapsed or constrained configuration to an expanded configuration to ultimately place the autologous valve annulus. The unfolding can also be consistent with a change from a first temperature to a second temperature, which can activate a structural change in the shape memory elements of the stented valve prosthesis.

[0029] Due to the unique strain-stress relationship caused by increased strain or temperature changes, temperature memory alloys exhibit unique mechanical properties resulting from solid-state phase transformations. This stress-responsiveness is known as "superelasticity," referring to the alloy's ability to yield to applied stress by altering its molecular crystal structure—that is, undergoing a phase transformation from austenite to martensite—with reversible elastic deformation up to 10%. Thermal response, or "shape memory," is due to phase transformations caused by changes in material temperature.

[0030] In another embodiment, when the distal restrictive seal of the catheter with a valved stent is retracted and the distal or ventricular outflow orifice appears at ambient (blood) temperature, the angle of the first gripping element at or near the distal orifice or flow inlet portion of the support structure swings from a first position to a second position, and the distal tip of the first tissue-engaging element unfolds radially at an angle of about 40° to 50° (preferably about 42° to about 46°) with respect to the surface and is exposed to both body temperatures. The tips of the ventricular cusps are positioned spaced apart between adjacent chordae tendineae. The space formed by the tissue-engaging area and the outer circumference of the stent support structure becomes a cavity in which portions of the edge of the valvular leaflet between the chordae tendineae are captured. Similarly, as the operator further retracts the distal seal, the end of the proximal or atrial gripping element in the form of a winglet is now cylindrically curled to expose to ambient (blood) temperature, at which point the engagement element unfolds radially at a predetermined angle toward the distal inflow orifice. The angle is between 80° and 95°, preferably about 90° (see [reference]). Figure 5CFor a given size of dysfunctional valve and valve-supported stent, the final clearance between the upper (atrial) and lower gripping elements adequately accommodates the leaflets, leaflet joints, and autologous valve annulus, thereby providing anchorage and maximum restraint around the interventricular orifice. Atrial cusps form an annular skirt that rests on or near the floor of the atrioventricular ventricle and applies the gripping function thereon.

[0031] In another embodiment, the valve expands from a collapsed structure to an expanded structure according to a different temperature gradient having a first temperature for the gripping element between about 0°C and 8°C, preferably between about 4°C and 16°C, and a second temperature for the expanded structure, wherein the second temperature for the gripping element is between about 20°C and 45°C, preferably between about 35°C and 40°C.

[0032] Another object of the present invention is to provide a method for delivering a stent valve to a target autologous valve location adjacent to a valve annulus via a blood vessel, comprising the steps of: advancing a stent-supported valve having a tissue valve having at least one leaflet and a support structure, the tissue valve being connected to the support structure, the support structure being expandable from a collapsed shape to an expanded shape, wherein the support structure has a stent frame and includes a gripping device for securing and stabilizing the stent valve on the valve annulus when the gripping device includes a first device for engaging an upper portion of the autologous valve annulus and a second device for engaging a lower portion of the autologous valve annulus; passing the support structure through the blood vessel, the support structure being in a collapsed shape; expanding the stent valve to a desired valve location near the valve annulus, wherein the support structure is in the expanded shape; and anchoring the stent valve to the valve annulus using the gripping device, wherein the gripping function is provided by the first structure for engaging the upper portion of the autologous valve annulus and the second structure for engaging the lower portion of the autologous valve annulus.

[0033] In one embodiment, the support structure of the valve-supported stent is made of shape memory metal (such as nitinol) or shape memory polymer, wherein the gripping device comprises two sets of spaced-apart elements that engage tissue adjacent to the autologous valve annulus when the entire prosthesis unfolds and transitions from a collapsed configuration to an expanded configuration. The unfolding of the device functionally anchors the prosthesis at a target site on the autologous valve annulus. In one embodiment, the gripping function is performed by structural elements engaging tissue adjacent to the autologous valve annulus as the valve-supported stent expands from a first position at a first temperature to a second position at a second temperature. Preferably, the valve-supported stent forms a cavity between the outer circumference of the device and the tissue. The cavity considered in a cross-sectional perspective view of the autologous valve annulus can be viewed as being generated in the form of a capital letter "J," thus creating an annular cavity for capturing dysfunctional leaflet fragments, leaflet joints, and the valve annulus.

[0034] The valved stent of the present invention has specific and predetermined dimensions to generate favorable hemodynamic flow parameters after implantation through the orifice of the replacement valve and the atrial and ventricular spaces near the valve. As described above, the desired and undesired specific flow conditions are a direct result of the size, shape, and overall construction of the prosthetic valve, and in particular a direct result of the width and height of the device as a discrete function of the different sizes of the stent valve device.

[0035] In another embodiment, the method of the present invention includes unfolding a valved stent from a collapsed configuration constrained at the distal end of a delivery catheter to a partially expanded configuration, wherein the valved stent presents a partially or fully expanded configuration, and then maintaining the unfolded configuration, wherein the valved stent achieves a substantially fully expanded configuration while being held attached by sutures or threads unfolded from the delivery system, and then completing the unfolding, with the valved stent reaching its desired configuration and the delivery system in a position for removal.

[0036] In a preferred embodiment, the internal dimensions have absolute and relative values ​​designed for optimal hemodynamics. The tissue valve diameter is selected based on the size of the diseased autologous valve ring in the patient, and the valve-supported stent has a series of absolute and relative dimensions, including but not limited to total valve height, tissue valve height, coronal diameter, and tissue separation distance, which are proportional to or remain constant according to the tissue valve diameter. As described further in detail below, the invention includes predetermined limitations on the dimensions or size proportions of selected measurements of key valve structures.

[0037] In another embodiment, the deployment step is performed by expanding the valved stent support structure from a collapsed shape to an expanded shape or by using an expandable airbag.

[0038] In another embodiment, the vessel through which the valve stent passes is one or more of the internal jugular vein, superior vena cava or inferior vena cava, axillary vein or subclavian vein, femoral vein and iliac vein.

[0039] This application focuses particularly on a technique for implanting atrioventricular valves, which can be retracted or folded within a delivery system or cannula for delivery to a desired location, particularly the right atrium, via a minimally invasive intercostal perforation. Subsequently, the constricted or coiled valve is released, dilated, detached from the delivery system, and secured to the desired location using an anchoring mechanism that does not excessively alter adjacent structures, such as tearing or puncturing, and that the constricted or coiled valve can withstand continuous impacts from blood closing the leaflets at considerable pressure without being advanced or displaced from its intended position.

[0040] The delivery system is designed to house the valved stent in a collapsed position for delivery. The valved stent is encapsulated at the distal end of the device and has a profile diameter OD of approximately 35F. This larger profile diameter is carefully designed due to considerations including, but not limited to, ensuring surgical safety, accurate and consistent device delivery, safe, accurate, and consistent reception of the bioprosthetic in a controlled manner, and preventing misalignment of the valved stent that could result from undesirable rapid spring effects of the shape memory metal during release from the collapsed to the expanded state. Operator-controlled slow release minimizes the reaction forces resulting from the rapid expansion of the valved stent to the predetermined and selected diameter due to compression and constraint. Attached Figure Description

[0041] Figure 1A and Figure 1B A portion of the heart is shown to illustrate blood flow characterizing the right side of the heart. Figure 1A The internal structure of the normal path. Figure 1B The disordered tricuspid valve is shown, which allows blood to flow back into the right atrium, thus indicating surgical intervention.

[0042] Figure 2A and Figure 2B It shows including Figure 2B The defective valve is an abnormally dilated tricuspid valve with an abnormally large valvular annulus. Specifically, Figure 2A A photograph of a human tricuspid valve is shown, which is defective due to over-dilation and the resulting inability of the leaflets to engage, thus failing to close completely to prevent retrograde flow. Figure 2B The use of a precision occlusion ring is illustrated, which illustrates the abnormal dilation of a valve to a diameter of 48 mm, a size that excludes normal cardiac function.

[0043] Figure 3A The prevalence of tricuspid regurgitation in the U.S. population is graphically presented, showing the extent to which the condition is undertreated.

[0044] Figure 3B The relationship between selected forms of tricuspid valve dysfunction (insufficiency or regurgitation) and increased mortality in the short to medium term is illustrated graphically. Specifically, Figure 3B It showed a rapid increase in mortality in patients with tricuspid regurgitation (60% mortality rate within three years).

[0045] Figure 4This demonstrates the efficacy of conventional surgical repair rather than complete replacement for tricuspid valve insufficiency. Data indicate a high failure rate for conventional valve repair surgery. FR = Free Repair: sutures that bring the leaflets together and facilitate open-heart surgery; RR = Ring Repair: sutures + valve annulation rings; Kay = Specially placed sutures within the valve to allow the leaflets to expand together; Et-E+Kay = Valve margins with sutures at the junction – the two margins are close together. These lines indicate year-over-year repair failure, suggesting a high failure rate for both open-heart and catheter-guided repairs.

[0046] Figures 5A to 5C It is a valve-supported frame structure used to support the valve mechanism of the bioprosthetic valve-supported stent of the present invention, preferably for replacing dysfunctional atrioventricular valves via percutaneous minimally invasive surgery. Figure 5A It shows the result of Figure 5B The general support geometry indicated by the supporting structure is shown as follows: Figure 5B The various configurations, distances, angles, and absolute and relative parameters are shown. Figure 5C These geometries and their relationships are further illustrated in Table I.

[0047] Figures 6A to 6B Several embodiments of percutaneous valves are shown, in which the valve assembly has been placed within a truncated conical stent. Due to the geometry, the stent with valve can be manufactured by those skilled in the art, and its size is typically twice the size of a normal tricuspid valve, reaching and exceeding the valve annulus diameter found in patients with TR, greater than 48 mm and entering the 60 mm range.

[0048] Figures 7A to 7B This is an embodiment of the valved stent of the present invention placed in the valve annulus of an autologous valve, showing a position, for example, relative to the atrial skirt, in which the position is placed near the bottom of the left atrium and has chordae tendineae located between the ventricular cusps of the valved stent.

[0049] Figures 8A to 8C An embodiment of a delivery catheter distal end is shown, the delivery catheter being used to deliver and deploy a balloon-shaped expandable valved stent having a cap, a positioning pin, and a nasal cone.

[0050] Figure 9A and Figure 9B The tab retainer for the tissue release filament located at the distal end of the delivery catheter facilitates directional control of the distal end of the delivery catheter and controlled release of the valved stent.

[0051] Figure 10 The present invention is a delivery system, showing a handle that is selectively manipulated by a surgeon to operate the delivery system for delivering a valved stent as described herein.

[0052] Figures 11A to 11B Details of the casing and related components of the delivery system of the present invention, including the distal nasal cone, are shown. Detailed Implementation

[0053] Other objects and features of the invention will become more apparent when read with reference to the accompanying drawings, and the invention itself will be better understood from the following detailed description.

[0054] Referring to Figures 1 through 11, a valve-supported stent and delivery system are illustrated for the repair and replacement of atrioventricular heart valves. While the valve design of this invention offers advantages even in open cardiac surgery, the valve is specifically designed for introduction via a minimally invasive procedure, either retrogradely or antegradely, through a blood vessel. This minimally invasive procedure includes transvascular, laparoscopic, or percutaneous surgery, utilizing the delivery system to facilitate the surgical placement of the valve-supported stent as a prosthetic heart valve replacement.

[0055] Tricuspid regurgitation, or tricuspid insufficiency, is a disease of the right atrioventricular valves of the heart, characterized by the valve's inability to close during cardiac systole. Instead, the right ventricle contracts to pump blood from the chambers towards the pulmonary valves and lungs. The valve orifice remains open for most of the time, allowing reverse flow at the level of the tricuspid valve. In effect, the right ventricle can only eject a small amount of blood, which necessitates a significant increase in ventricular volume (enlargement) and pressure through the orifice.

[0056] The prosthetic heart valve of the present invention can be described as a valve-supported assembly because it has a desired set of structures: 1) a synthetic valve portion that extends substantially across the entire diameter of the support structure; 2) a scaffold-like support structure that surrounds and maintains the integrity of the valve prosthesis; 3) a pre-cut polymer mesh material 23 that substantially covers the entire inner surface of the support structure; and 4) a tissue-engaging structure that performs the function of grasping the tissue of the autologous valve annulus to firmly anchor the replacement bioprosthesis upon deployment. The term "valve-supported assembly" may be used herein to describe the properties uniquely derived from the foregoing combination of structures, but is generally interchangeable with the term "valve-supported stent" as used throughout the document.

[0057] The prosthetic valve-supported stent assembly comprises a valve portion made of autologous or synthetic tissue and has at least two leaflets joined at commissures. If the autologous valve has three leaflets, the leaflets are preferably formed of continuous, substantially equal size and shape and geometrically oriented across the entire circumference of the valve-supported stent. The valve prosthesis is attached to the support structural frame of the valve-supported stent at adjacent joining edges of the leaflets at a dedicated vertical structure integral with the structural frame. The valve leaflets are made from suitable synthetic or non-human pericardial tissue, typically harvested from sheep, goats, cattle, or horses, and are chemically treated with a low concentration (0.25%) of glutaraldehyde and a buffer solution of glutaraldehyde derivatives, which allows the valve-supported stent to be sterilized and packaged without an accompanying storage solution. The valve-supported stent leaflet material forms the assembled valve prosthesis such that the individual leaflets do not directly contact the structural support members of the stent, but only contact a microfiber cloth covering the inner circumference of the structural support members of the stent. Although the precise dimensions of the valve-supported stent are given below in several discrete diameters, the size of the valve-supported stent can be manufactured to extend to at least 64 mm and up to 70 mm, with equivalent dimensions as described herein for valves with smaller diameters.

[0058] The stent has a structural frame support 11, which is preferably made of nitinol or other similar shape-memory metals or polymers. The stent configuration is preferably laser-cut from an 8mm or 10mm thiocyanate tube, and its shape is thermomechanically set to a predetermined orientation, as shown in Figures 5 and 6. Connecting rods 30, 31, and 32 are also made of nitinol and support the valve suture by being attached along the length of the connecting rods to the valve suture. Figures 6A to 6B In one embodiment, the three connecting rods 30, 31, and 32 are spaced 120° apart to accommodate a trilobal valve structure.

[0059] The pre-cut polymeric fiber mesh material 23 is preferably microfiber polyester fabric, laser-cut to conform to and substantially match the size of the inner circumference of the valve-supported structure, and covers the entire inner surface of the stent before valve installation. In a preferred embodiment, the individual pre-cut annular segments of the mesh material 23 are designed to cover either or both of the upper or lower surfaces of the annular atrial skirt, and are constructed to have an area at least equal to the entire length of the atrial cusps forming the annular skirt. The biocompatible material mesh layer 23 can be synthetic, such as polyester (e.g., ...). (Invista, Wichita, Kans.), woven velvet, polyurethane, PTFE, ePTFE, (WLGore & Associates, Flagstaff, Ariz.) or heparin-coated fabric. Alternatively, the layer may be a biological material, such as bovine, goat, horse, and / or porcine pericardium, peritoneal tissue, pleura, submucosal tissue, dura mater, allogeneic graft, allogeneic graft, patient graft, or cell-inoculated tissue.

[0060] The pre-cut mesh layer 23 can be attached individually around the entire circumference of the valve-supported stent 10, or it can be attached in segments or discontinuous sections to allow the expandable support member to expand and contract more easily. Figure 6B As shown, for example, all or part of the annular skirt may be covered by the pre-cut mesh layer 23. The pre-cut mesh layer 23 may also be attached to the stent support structure at the midpoint along the height of the stent support structure, and may comprise a single layer formed only on the inner circumference of the valve stent support structure.

[0061] Preferably, the structure performing the gripping function to anchor the bioprosthetic valve in place includes two separate tissue-engaging structures spaced apart along the height of the support structure, such that the atrial or inflow portion and the ventricular or outflow portion of the valve stent assembly are respectively secured to both sides of the autologous valve ring. In one embodiment, the upper and lower tissue-engaging structures consist of atrial and ventricular cusps. The atrial cusps may be formed to collectively create a ring structure that rotates into place as the valve stent expands from a collapsed configuration to an expanded configuration. The atrial and ventricular tissue-engaging elements are preferably cut from a hypotube used to manufacture the stent structure support elements. When rotated to the expanded configuration, the atrial ring tissue-engaging structure has a substantially flat upper and lower surface that extends radially at approximately 90° relative to the linear central vertical axis of the valve stent and rotates to form a ring or annular "skirt" to engage the tissue of the autologous valve ring on the atrial side. The atrial cusps can be formed by individual inverted V-shaped winglets, which are evenly spaced and arranged with a low-profile coronal portion around the inflow. Once unfolded, the lower surface of the annular skirt rests on the atrial side of the autologous valve annulus. The atrial cusps, together with the ventricular cusps, form an external space that will capture the autologous dysfunctional valve leaflets and autologous valve annulus.

[0062] In the exemplary embodiments of Figures 5 and 6, twelve ventricular cusps are intended to grasp three tricuspid valve leaflets from the ventricular side. Like the rest of the support structure, the ventricular cusps are shaped to extend outwards from the body of the valve support. The number of cusps is not critical, as long as it is sufficient to perform the tissue engagement function as described herein, such that the grasping force is sufficient to secure the autologous valve leaflets and prevent valve movement.

[0063] In one aspect, implanting a bioprosthetic valve using the valved stent of the present invention to replace a dysfunctional autologous atrioventricular valve (tricuspid or mitral valve) does not involve the removal of the autologous leaflet or the autologous valve, as is done in open-heart surgery. Instead, the attached prosthetic heart valve includes a gripping function that anchors the valved stent within the autologous valve annulus, causing the autologous valve to permanently retract against the wall of the autologous valve annulus. The gripping function includes retracting the autologous leaflet, stably anchoring the prosthesis in place, and performing the gripping function through a plurality of structurally secure engagements without puncturing or penetrating tissue at or near the autologous valve annulus. In cases where pacemaker or automated external defibrillator (AICD) leads pass through the autologous tricuspid valve, as often occurs in patients with severe tricuspid regurgitation, the leads must be pushed against the valve annulus and autologous leaflet by the stent without damaging the leads or interfering with their function. The design of the support structure allows the lead to fall into the area between the joint structures (such as the ventricular cusps described below), so that the lead can be positioned between them and pressed against the autologous tissue without damage.

[0064] For the purposes of this invention, references to the positional aspects of the invention will be defined relative to the directional flow vector of blood flow through the implantable device. Therefore, the term "proximal" is used to indicate the inflow or upstream flow side of the device, while "distal" is used to indicate the outflow or downstream flow side of the device. Regarding the delivery device described herein, the term "proximal" is used to indicate the operator and handle end closer to the delivery device, while the term "distal" is used to indicate the terminal or device-bearing end facing the delivery device. In the case of atrioventricular valves, atrial direction refers to the volumetric displacement of a portion of the prosthetic valve in the left or right atrium, and ventricular direction refers to the volumetric displacement of a portion of the prosthetic valve in the left or right ventricle.

[0065] The present invention includes a method for delivering a stent valve via the jugular vein, subclavian vein, or femoral vein, comprising the steps of: (a) advancing a tissue valve having at least one leaflet and a supporting stent structure through a portion of the patient's vascular system, wherein the supporting stent structure is expandable from a collapsed configuration to an expanded configuration, wherein the outer circumference of the supporting stent structure has at least a pair of spaced-apart structures for grasping cardiac tissue adjacent to the autologous valve ring and for restraining leaflets on the ventricular side of the valve ring or leaflets of the valve ring; (b) unfolding a prosthetic valve at the autologous valve ring of the dysfunctional valve by expanding the stent with the valve from the collapsed configuration to the expanded configuration; and (c) securing the stent with the valve to the autologous valve ring by expanding the stent with the valve to a nominal size based on a preselected size corresponding to the size of the orifice of the diseased autologous valve, and having ventricular and atrial grasping elements to prevent dislocation and movement, while providing a sealing function for peripheral leakage along either direction of the bioprosthetic valve.

[0066] In one embodiment, the fixation step is achieved by grasping the cardiac tissue adjacent to the autologous valve annulus, and the valve stent component includes an upper and / or lower element configured to pivot to form a horizontally tilted “U”, “C”, or “J” configuration receiver for receiving and retaining the valve annulus and leaflet fragment.

[0067] In one embodiment of antegrade percutaneous valve implantation, i.e., the tricuspid valve is implanted along the direction of blood flow at different stages of device delivery, demonstrating that the dysfunctional tricuspid valve can be approached antegradely. In one embodiment, a delivery device with a valved stent retracted within a distal segment of the delivery device is percutaneously introduced via the axillary vein and subclavian vein. Once it has passed through the superior ventricular vein and is close to the approximate center of the right atrium and ventricle, the distal end of the catheter carrying the encapsulated valved stent is guided to the tricuspid valve annular plane or the tricuspid valve site, the distal segment being positioned within the tricuspid valve. The catheter sheath is then slowly withdrawn to release the valved stent from the distal segment. In one embodiment, the stent support structure is self-expanding, meaning the stent valve expands as it is released from the catheter sheath. As described above, by raising the temperature from a first temperature to a second temperature, the gripping device undergoes the following stages: a pre-deployed valve, a partially deployed valve with a swinging distal gripping element, and a fully deployed valve with two gripping elements positioned accordingly.

[0068] Percutaneous valve implantation in an antegrade manner begins with a valved stent retracted within the distal segment of the delivery device, and is percutaneously introduced via a vein, passing through the superior or inferior vena cava. Once it has passed through the right atrium of the heart and is close to the target atrioventricular valve (tricuspid valve) site, the distal segment is properly positioned within the valve annulus facing the right atrium. The catheter sheath is slowly withdrawn to release the valved stent from the distal segment. In one embodiment, the stent support structure is self-expanding. Therefore, the stent valve will expand as it is released from the catheter sheath. As described above, the gripping device undergoes the following stages—pre-deployed valve, partially deployed valve, swinging distal gripping element, and fully deployed valve with two swinging gripping elements—as the temperature is raised from a first temperature to a second temperature by body temperature: pre-deployed valve, partially deployed valve, swinging distal gripping element, and fully deployed valve with two swinging gripping elements.

[0069] During any step of the procedure, any imaging modality can be inserted or utilized to visualize the surgical area. Imaging modalities may include transesophageal echo, transthoracic echo, 3D echo imaging, or radiopaque injectable dyes. Dynamic fluoroscopy may also be used. In one embodiment, some imaging systems may be delivered to the surgical area via a cannula or catheter. Imaging systems are well known to those skilled in the art.

[0070] refer to Figure 1A and Figure 1BThe heart has four valves, two of which connect the heart to the vascular system, which supplies blood to and from the heart. (Reference) Figure 1A Blood enters the right side of the heart through two large veins (the inferior vena cava and the superior vena cava), delivering deoxygenated blood from the venous system to the right atrium. As the right atrium contracts and the right ventricle relaxes, blood flows from the right atrium into the right ventricle through the open tricuspid valve. When the ventricle is full, the tricuspid valve closes. This prevents blood from flowing back into the atrium during ventricular contraction. As the ventricle contracts, blood leaves the heart through the pulmonary valves into the pulmonary artery, and then into the oxygenated lungs.

[0071] The tricuspid and aortic valves respectively act as the entrance and exit gates between the heart and the vascular system, and provide oxygenated blood flow to the rest of the body. In their normal, disease-free state, these valves regulate the continuity of unidirectional blood flow through the heart. When an abnormality or disease causes one of the four valves to malfunction, the result is either incomplete blood flow from the body into the heart and complete blood flow within the heart and between the heart and lung systems, or incomplete oxygenated blood flow from the left ventricle of the heart to the arterial system.

[0072] refer to Figure 1B A defective or dysfunctional tricuspid valve, sometimes referred to as a "dysfunctional" tricuspid valve, allows blood to flow abnormally back into the right atrium.

[0073] refer to Figure 2A and Figure 2B The abnormal physiology of the tricuspid valve is shown to include: Figure 2B The size of the defective valve annulus. Specifically, Figure 2A The image shows a human tricuspid valve that is defective due to overdilation and the resulting inability of the leaflets to engage along their commissures, thus failing to close completely to prevent retrograde closure. This condition is commonly associated with a heart condition called dilated cardiomyopathy (DCM). Figure 2B This demonstrates the use of precision occlusion rings to... Figure 2A The measurements of the valve shown illustrate an abnormally dilated valve diameter of 48 mm, an abnormal size that excludes normal cardiac function.

[0074] refer to Figure 3A This shows the prevalence of tricuspid regurgitation in the US population and the extent of inadequate treatment of the condition. Figure 3B The study showed the relationship between these specific forms of valvular heart dysfunction and increased short- to medium-term mortality. Specifically, regarding... Figure 3BData shows a rapid decrease in the number of patients with tricuspid regurgitation, with a three-year mortality rate of 60%. As can be clearly seen from the attached chart, the number of patients with this condition continues to decline until death, and there is no stabilization or recovery, as this condition is not self-repairing.

[0075] refer to Figure 4 Data has been collected to evaluate the efficacy of conventional surgical repair rather than complete replacement for tricuspid valve insufficiency. The data indicate a high failure rate for conventional valve repair surgery. Based on this data, valve repair surgery may be considered suboptimal, and catheter-guided replacement devices and methods for complete tricuspid valve replacement will contribute to improving the approach.

[0076] refer to Figures 5A to 5C The valve-supported stent 10 has a structural frame support 11, which serves as the structural foundation of the assembly structure and accommodates the valve mechanism of the valve-supported stent 10 of the present invention (see also below). Figures 6A to 6B This device is used to replace dysfunctional atrioventricular valves via percutaneous minimally invasive delivery. The geometry of the valved stent 10 is specially designed such that when the valved stent 10 is in an expanded configuration, it forms a truncated cone profile, such that the upper flow inlet or upper proximal orifice or atrial portion of the structural frame support 11 of the valved stent 10 has a minimum height dimension, a profile very low relative to the diameter of the valve prosthesis, and a diameter smaller than that of the lower, lower, or ventricular exit flow inlet or distal orifice.

[0077] The specific design of the components of the valved stent 10 is based on a low-profile configuration of the structural frame support 11 relative to the diameter of the valve prosthesis. This low-profile configuration originates from and depends on predetermined distances, distance ratios, angles, and mold references of the structural elements of the structural frame support 11. As blood flows through the valved stent and experiences a pressure differential on both sides of the valved stent 10, the structural elements generate excellent flow dynamics. Specifically, the device has a low ratio of the total height of the structural elements of the valved stent to the diameter of the tissue portion of the valve prosthesis, resulting in reduced pressure differential and turbulence both proximal to the valved stent 10 (i.e., in the atrial space immediately adjacent to the valved stent 10) and distal to the valved stent 10 (i.e., in the ventricular space immediately adjacent to the valved stent 10).

[0078] In addition to providing a central truncated cone support structure for the valve elements of the prosthesis, the structural elements of the structural frame support 11 also provide support for a first tissue engagement element and a second tissue engagement element, which grip tissue on both the atrial and ventricular sides of the autologous valve annulus and form a cavity therebetween. When the valve-supported stent 10 is fully deployed to the expanded configuration, the final positions of the paired tissue engagement structures and the outer circumferential region of the valve-supported stent frame form an annular cavity that surrounds the autologous valve leaflet and aligns the entire valve-supported stent assembly 10 with the inner annular circumference of the autologous valve annulus.

[0079] The valved stent assembly 10 includes a stent structure frame 11 having individual rhomboid sub-units 12 that are generally arranged in overlapping rows and made of shape memory tubular material. A predetermined and pre-designed amount of material has been removed from the shape memory tubular material along its length, thereby allowing the support provided by the stent structure frame 11 to change from a collapsed tubular or shape to an expanded configuration, such that the proximal / atrium or inflow orifice is smaller than the distal / ventricle or outflow orifice.

[0080] Due to the heat-set shape memory properties of the material used to manufacture the structural frame support 11, the individual struts 13 of the structural frame exhibit a predetermined configuration. Each strut 13 can be joined along its length at a joint 14, which is equidistant from each strut 13 along the length of each rhomboid unit 12 forming the structural frame support 11. In the atrial or upper / superior dimension of the sub-unit 12 of the structural frame support 11, each strut 13 joins at an upper hub 15, which is also preferably joined to a plurality of atrial cusps 19 circumferentially positioned substantially around the entire upper inner surface of the valve-supported stent 10. Figure 5A In one embodiment, the atrial cusps can be manufactured to define an inverted V-shaped structure similar to that forming the coronary portion 20, and can rotate about the circumferential axis of the structural frame support 11 such that when the valved stent 10 is in a collapsed configuration and rotated in an expanded configuration to radially expand outward at an angle between approximately 80° and 100°, preferably approximately 90°, relative to the vertical central axis of the valved stent 10, the annular skirt 19 formed by the plurality of atrial cusps and the entire structure of the coronary portion 20 are substantially collinear with the other structures of the structural frame support 11. Reference Figure 5A and Figure 5C Table I below, which specifies dimensions, relative dimensions, and angles, illustrates a preferred embodiment of the valved stent assembly 10 in its deployed state, wherein the aforementioned dimensions, angles, and proportions are defined by the structural frame support 11 in both deployed and assumed fully expanded configurations.

[0081] At the upper end of the structural frame support 11, the coronary portion 20 extends above the circumferentially extending annular atrial skirt 19 after deployment. The annular atrial skirt 19 serves as a first tissue engagement structure, which, in the expanded configuration with the valve stent 10 after deployment, preferably rests on the atrial base. The coronary portion 20 comprises a series of coronary subunits 21, each having a damage-resistant tip 22 at its uppermost end, such that the entire coronary portion 20 maintains a low profile defined by dimension F, such that substantially no structure extends into the right atrium. The plurality of coronary subunits 20 include coronary struts 21, which define a space between the damage-resistant tip 22 and the remainder of the structural frame support 11, the space including openings through which release sutures can pass and engage (see below). Figures 8A to 8C (See Figure 9). The maximum height of the coronary portion 20 above the atrium skirt 19 is described in Table I.

[0082] In the lower / lower stage or ventricular portion of the valved stent assembly 10, ventricular cusps 18 are integrally formed with a lower hub 17, which engages individual struts 13 distal to the structural frame support 11 or in the ventricular portion. The lower hub 17 may have an opening 16 extending through the body of the lower hub 17 and may receive sutures or other attachment structures (not shown). The ventricular cusps 18 are preferably linear barbs attached to the lower hub 17, and extend radially away from the lower hub 17 as the valved stent 10 expands from a collapsed configuration to an expanded configuration during deployment. Each ventricular cusp acts as a second tissue engagement structure extending away from the stent structural frame support 11 to engage tissue of the autologous valve annulus, thereby anchoring the valved stent assembly 10 in place.

[0083] Preferably, a plurality of ventricular cusps 18 are formed by a plurality of equal lower hub portions 17 to form a set of ventricular cusps 18, which, upon unfolding, performs a gripping function that anchors and secures the valved stent assembly to the ventricular portion of the valve annulus. The combination of atrial and ventricular cusps 18 forming an annular atrial skirt 19 forms a pair of tissue-engaging structures that engage two tissue regions adjacent to the autologous valve annulus and perform a gripping function in two directions. This gripping function is annular in construction, at least partially relative to fix and anchor the valved stent 10. The gap between the tips of the cusps 18 and the outer circumferential surface of the valved stent, as well as the underside of the annular atrial skirt, forms a curved annular chamber, which is filled with autologous leaflets and annular tissue, simultaneously securing the valved stent assembly 10, such that the valved stent establishes a fluid-tight interface between the atrium and ventricle, thereby providing interventricular sealing and preventing migration.

[0084] As described above, the relative dimensions of the valve stent assembly 10 establish a low-profile configuration with a large valve tissue diameter relative to the height dimension, to generate excellent hydrodynamics when blood flows through the body of the structural frame support 11, provided that the valve mechanism (not shown) is disposed therein. Figure 5B As shown, several dimensions are defined to specify the size, size range, and size ratio or proportion, which provide excellent hydrodynamics for a particular valve prosthesis, in which case a valve stent assembly 10 is selected for a patient who requires a 48mm replacement valve for their autologous valve ring.

[0085] As described below, the numerous relative dimensions of the valve-supported stent assembly 10 are aspects of the present invention and produce a unique dimensional profile and excellent hemodynamics; however, the overall diameter of the valve prosthesis is determined by the individual pathology of the patient. For each patient, the overall valve size or tissue annulus diameter (TAD) is obtained by computed tomography angiography (CT scan) and transesophageal echocardiography (TEE) or real-time three-dimensional echocardiography (RT3DE) obtained from the patient. The severity of valve dysfunction is analyzed in the area and circumference of the valve annulus, thereby obtaining the valve annulus size. The diameter is matched to the nearest, distal, or maximum diameter of the valve-supported stent. The tissue annulus diameter size falling within the discrete diameters provided for the individual size of the valve-supported stent of the present invention is optimally adapted to the next lower size of the valve-supported stent, thereby avoiding excessive size affecting the aortic valve sinus and impacting the cardiac electrical system, which could lead to potential arrhythmias or cardiac block. Valve annulus size in patients with diseased autologous valves. The inflow diameter B defines the atrial opening or orifice for blood flow through the valve-supported stent assembly 10. The coronal diameter C is the inner diameter of the annular atrial skirt 19. The total height D is the sum of the height F from the ventricular floor to the annular atrial ring 19 plus the height F of the coronary 20.

[0086] In addition, due to Figure 6A The height of the tissue component comprising the valve leaflets (e.g., valve leaflets 26a, 26b, 26c) is substantially equal to the total height of dimension D, so dimension D also provides a measure of the total height of the tissue component of the valve leaflets. As described above, since the entire diameter of the valve-supported assembly 10 is composed of the tissue component of the valve element, the diameter, dimension A, and dimension B also correspond to the total diameter of the tissue component of the valve-supported assembly 10. The height H of the ventricular cusp 18 extends from the bottom of the ventricular ring to the tip of the ventricular cusp 18, as it extends away from the lower hub 17. Dimension H thus defines the height of the engagement structure protruding from the ventricular portion of the valve-supported assembly 10. As described above, together with the atrial coronal 20 having a height F above the atrial cusp 19, the atrial coronal 20 and the ventricular cusp 18 exert a paired gripping function on the tissue on the atrial and ventricular sides of the autologous valve ring.

[0087] Size I is the distance between the atrial-oriented tissue bonding device and the ventricular-oriented tissue bonding device, and provides a capture size for the valve stent 10 to surround the autologous leaflet and the autologous valve annulus. Size I ranges between 5.5 mm and 9 mm, and the size of the mitral valve prosthesis is preferably between 5.5 and 8 mm, the size of the tricuspid valve prosthesis is preferably between 6.5 and 9 mm, and the size of the tricuspid valve prosthesis is substantially about 7-8 mm. Figure 5A and Figure 5C In this embodiment, dimension I is the distance between the annular atrial skirt 19 and the plane formed by the uppermost tips of the plurality of ventricular cusps 18. Therefore, the distance of dimension I can be measured between the plane of the annular portion of the atrial skirt 19 and the average distance from the uppermost tips of the ventricular cusps 18, which are considered to be located in a single plane. As described herein, dimension I preferably ranges between 5.5 mm and 9 mm, with the range being 5.5–8 mm for mitral valve prostheses and 6.5–9.0 mm for tricuspid valve prostheses.

[0088] For valved stents with dimensions of 36mm, 40mm, 44mm, 48mm, and 52mm, these distances, dimensions, and relative and absolute proportions can be summarized as follows:

[0089] Table I

[0090]

[0091] The valved stent 10 of the present invention can be manufactured to have any predetermined diameter, but is conveniently provided in sizes between 36 mm and 52 mm and up to about 64 mm, while maintaining the height restrictions and relative proportions as described in Table I. To achieve the benefits of a low-profile design, the valved stent assembly 10 has a total height of less than 25 mm and generally between 10 and 22 mm, consistent with the predetermined geometry and dimensions described herein. It is evident from the values ​​in Table I that the ratio of the size of the atrium or inlet orifice, size B, to the size of the ventricle or outlet orifice, size A, is between 0.60 and 0.90, preferably between 0.70 and 0.85. An embodiment of the invention with a relative proportion of 0.75 can be used as a guide for manufacturing valves with the dimensions described herein, the guide having any size in diameter between 30 mm and up to 70 mm, consistent with the other design parameters and size restrictions described herein. In addition to the specific quantitative values ​​in Table I, the disclosure of this invention includes all incremental values ​​between them, as well as percentage ratios of deviations from the stated values ​​of 95%, 90%, 85%, 80%, and 75%, consistent with the general teachings of this invention. In a particularly preferred embodiment, the valve-supported stent assembly has a predetermined diameter, namely dimension A, between 36 mm and 54 mm, a ratio of dimension B to dimension A between 0.70 and 0.85, a total height dimension D less than 0.25 mm, and a dimension I including the gap between the upper and lower tissue junction structures between 5.5 mm and 9 mm.

[0092] refer to Figure 5C The diagram shows the relative angle of the length of the ventricular cusp 18 with respect to the adjacent elements of the structural frame support 11. The taper angle of the overall height of the device is shown as 19°. The overall taper is preferably less than 20° and greater than 1°, such that the overall dimension of the support structure is non-cylindrical and has a finite taper along the entire height dimension D.

[0093] Figures 6A to 6B These are top and side perspective views of a valve-supported stent assembly 10, which has gripping devices for securing and stabilizing the heart valve device on the valve annulus. As described above, the valve device of the present invention includes a tissue valve 25, which is secured to a structural frame support 11 and has leaflets 26a, 26b, and 26c. The leaflets substantially comprise the stent structural frame along the above... Figure 5AThe entire height and diameter of dimension E are determined without relying on additional support structures or attachment rings inside or outside the structural frame support 11. Therefore, the stent structure frame is directly attached to the autologous valve tissue around the outer surface and the tissue component of the valve prosthesis at the inner circumference without additional material. This configuration maximizes the working diameter of the valve prosthesis while maintaining a low profile for the overall height dimension D of the valve stent assembly 10.

[0094] In one particular embodiment, the support structure also includes structures for grasping tissue adjacent to the autologous valve ring, and... Figure 5A In an exemplary embodiment, the coronary portion 20 and atrial cusps 19 are gripping devices for securing and stabilizing the heart valve device onto the autologous valve ring. Key elements of the gripping function are provided by structures spaced apart along the body of the gripping device, comprising multiple pairs of lower and upper tissue engagements spaced apart and located on the outer circumferential surfaces of the upper atrium and lower ventricle of the stent structure frame 11, and configured to pivot to form generally “J,” “U,” or “C” shaped receivers (outwardly) for receiving and retaining the valve ring.

[0095] In another embodiment, the stent surface portion 24 of the "C"-shaped receiver 23 is uniformly lined with a certain fabric material. The lining material on the inner stent surface supports the pericardial wall of the valved stent and seals the space between the atrial cusps and the area near the outer surface of the valved stent 10 and the edge of the autologous valve ring to prevent blood leakage or enhance local blood clotting, thereby maintaining the separation of the upper (atrial) chamber and the lower (ventricular) chamber of the heart. The lining material is typically hydrophilic and can be selected from the group consisting of: ethylene, silicone, polyurethane, hydrogels, polymers of fabrics, and microfibers of esters of other polymers.

[0096] Preferably, the gripping function is achieved when the atrial cusp 19 extends to a position substantially perpendicular to the axial straight line through the blood flow axis of the valve 25 (first position). This is because when the valve device is in its collapsed configuration during the delivery phase, the atrial cusp 19 is coiled within the distal catheter sheath. Figure 7A As shown, when the valved stent is allowed to fully unfold from the cover 50 (see Figures 8 and 11), the atrial cusps 19 forming the annular skirt rotate approximately 90° to achieve a radially extended structure and engage the atrial side of the autologous valve ring.

[0097] The gross radial expansion of the ventricular cusps can be aided by exposure to a second temperature, namely normal body or blood temperature. The ventricular elements can pivot outward from the outer surface of the stent at an angle ranging from approximately 39° to approximately 44°.

[0098] During deployment, the atrial skirt 19 and ventricular cusps 18 apply paired gripping forces to the annular tissue of the autologous valve annulus to anchor the valved stent 10 in place by engaging the valve annulus at two locations and from two different directions. As described below, this deployment or actuation of the atrial skirt 19 and ventricular cusps 18 can be a discrete step in the deployment method of the present invention, which facilitates precise and controlled placement of the valved stent 10 at the target, dysfunctional autologous valve annulus. In one embodiment, a first temperature is between about 1°C and 35°C, preferably between about 4°C and 20°C. In another embodiment, a second temperature is between about 20°C and 45°C, preferably between 35°C and 40°C.

[0099] refer to Figure 7A and Figure 7B An embodiment of the valved stent of the present invention is placed in the valve annulus of an autologous valve, for example, showing the overall position of the valved stent 10 relative to the valve annulus and chordae tendineae 40, which in turn are connected to the wall of the ventricle 41. Figure 7A In the left panel, the valve-supported stent 10 is shown in the expanded position and its size relative to the autologous valve ring is shown. As described herein, the valve-supported stent 10 of the present invention is selected and matched in size based on measurements of the size of the dysfunctional valve in the patient. Figure 7A The right panel shows a valved stent 10 after replacement of a dysfunctional valve. In this example, the atrial skirt 19 engages the base of the right atrium, while the ventricular cusps 18 engage the ventricular side of the autologous valve annulus, such that the chordae tendineae fall between adjacent ventricular cusps.

[0100] When placed within the autologous valve annulus, the valve-supported stent 10 has a minimal upper profile extending into the atrium to provide excellent hemodynamics and minimize the possibility of damaging the contact between the bioprosthetic and the atrial wall during contraction. The only structure extending above the atrial skirt 19 is the tip of the coronary portion 20, which has an inverted “V” shape and is formed by the upper portion of the rhomboid strut 13 after expansion. The uppermost structure of the valve is the damage-resistant tip 22, which defines the height of the coronary portion 20 above the annular atrial skirt 19. As described above, attachment to the autologous valve annulus occurs both in the upper atrium of the bioprosthetic, i.e., proximal to the blood flow, via the first tissue-engaging structure (the annular atrial skirt 19 in this example), and in the lower ventricle, i.e., distal to the blood flow, via the second tissue-engaging structure (the ventricular cusp in this example). With this construction, the gripping function of the valved stent 10 at the autologous valve annulus is facilitated by two tissue-attachment structures: one with atrial placement and the other with ventricular placement, and both having discrete heights (defined as dimension I above) for securing the autologous valve leaflets against the autologous valve annulus to seal the valved stent 10. Therefore, the tapered size of the structural frame support 11, the upper / atrial and lower / ventricular attachment structures of the device, and the overall size of the device facilitate a secure attachment of the valved stent 10 to the autologous valve annulus, ensuring a firm fit within the annulus and anchorage at the target location.

[0101] refer to Figure 7B A detailed view of the valve stent 10 attached to the autologous valve annulus shows the tight engagement of the annular atrial skirt 19 and the positioning of the chordae tendineae between the ventricular cusps 18. Individual subunits of the structural frame support 11 are shown as having a rhomboid structure formed by individual struts 13 terminating at the upper hub 15 and lower hub 17. The unfolding of the ventricular cusps is shown as passing between the chordae tendineae to engage the ventricular aspect of the autologous valve annulus.

[0102] refer to Figures 8A to 8C The distal end of the delivery system 39 is shown, with a portion of the structural frame support 11 provided to demonstrate engagement of the structural frame support 11 with a release mechanism at the distal end of the delivery system. The steerable conduit 40 comprises a hollow lumen 44 terminating at a distal conduit hub 41, through which a pair of locating pins 43 traverse. Although... Figure 8AThe embodiment shows a pair of locating pins 43, but any number of pins can be envisioned as long as steerability is provided. The pair of locating pins 43 allows deflection of the distal end of the steerable catheter 40 and a single plane, and the ability to rotate the steerable catheter 40 allows the operator to change the axial arrangement of the distal end of the delivery system to orient the valve-bearing stent 10 toward the plane of the autologous valve ring in a vertical manner. Port 42 provides fluid communication to a fluid conduit (not shown) that extends along the length of the lumen 44 of the steerable catheter 40. The delivery system is a housing 50 positioned between the distal hub 41 and the nasal cone 55. During delivery of the valve-bearing stent, the valve-bearing stent is contained in a collapsed configuration within the housing 50 until the distal end of the delivery system 39 approaches the target site. A valve-supported stent is held in place by a nasal cone that can be axially moved relative to a steerable catheter 40 by manipulating a flexible hypotube 51 that traverses the lumen 44 of the steerable catheter 40 and can be manipulated by the user, such as in combination. Figure 10 As described, the filament 51 traverses the valved stent by passing through the leaflet and is integrally formed with the nasal cone 55 by attaching at attachment point 54. The nasal cone 55 has a blunt distal end 53, which is undamaged when the distal end of the delivery system 39 traverses the vascular system to position the valved stent at the target location. Figure 8A In the example, the valve will be partially expanded, wherein the structural frame support 11 is in a partially expanded configuration, with its central ventricular portion and ventricular cusps 18 facing the expanded configuration, while the atrial portion including the atrial skirt 19 is at least partially collapsed and can be maintained within the main body of the cap 50.

[0103] refer to Figure 8B The attachment / release mechanism of the valved stent is shown as a single component of the structural frame support 11, which has a release wire 56 that loops through the coronal portion of the valved stent and engages the tab retainer 69 to maintain the collapsed configuration of the atrial portion of the valved stent while ensuring secure positioning at the target location. The cover 50 is withdrawn axially and proximally relative to the valved stent to expose the tab retainer 60 and the locking wire 56 located at the distal point of the lumen 44 of the steerable catheter 40.

[0104] refer to Figure 8CThe distal end of the steerable delivery catheter 40 is shown as having four loops formed by release threads 56 traversing the coronal portion 20 with a valved stent. Each release thread 56 engages a tab 68 at the distal end of the delivery catheter 40. Each release thread 56 can be manipulated by a surgeon to release the engagement of the release thread 56 at the tab retainer 67, allowing the release thread 56 to disengage from the tab 68. When the release thread 56 disengages from the tab 68, the release thread 56 can be pulled through the coronal portion 20 with the valved stent, thereby releasing the valved stent from the distal end of the steerable delivery catheter 40. Figure 8C In this embodiment, four wire loops engage the valved stent 10 at 90° opposite positions around the coronal portion 20. While the number of engagement points of the release wire 56 with the coronal portion 20 of the valved stent is not critical, it is preferred at least for the engagement points with the coronal portion 20 to enhance the ability to control the deployment of the valved stent 10 by manipulating the release wire 56. The tab retainer 60 has an outer circumferential surface 69 that maintains close engagement with the inner surface of the delivery catheter lumen 44. The close engagement between the outer circumference of the tab retainer 60 and the lumen 44 of the steerable catheter 40 ensures that the tab retainer remains concentrically oriented with respect to the distal opening of the steerable delivery catheter 40 for precise positioning of the valved stent 10. Actuation of the release wire 56 occurs after the proximal retraction of the cover 50 to allow the release wire 56 to be released from the tab 68. The release wire 56 traverses the body of the tab retainer 60 through a dedicated wire opening as described below with reference to FIG. 9. The diameter of the nasal cone 52 is necessarily smaller than the diameter of the ventricular portion of the valved stent 10, so that after the release wire 56 is released, the valved stent 10 can be deployed, and the nasal cone 52 retracts proximally through the interior of the valved stent 10 toward the tab retainer 60. The nasal cone 52 preferably has a curved outer portion 55 that tapers gradually along its length to allow the structure to traverse the leaflets of the valved stent 10 without damage.

[0105] refer to Figures 9A to 9B , Figure 9A The lower side of the tab holder 60 at the distal end of the delivery system is shown, and how the release wire 56 is oriented around the central axis of the flexible hyaluronic acid tube 51 and the spacing of the port 61 for the release wire 56 away from the attachment point for the positioning pin 43 are shown. Figure 9BA tab 68 is also shown, which engages a release filament 56 until it is released to deploy the valved stent 10. A release filament port 61 traverses the body of the tab retainer 60, and the body of the tab retainer 60 has an attachment fixation device 65 for attaching a positioning pin 43. A flexible hypo tube 51, connected to the anterior cone 52, traverses the central port 63. The proximal side of the tab retainer 60 has a recessed portion 62 to provide a release mechanism capable of controlling the deployment of the valved stent 10, allowing for careful control by a surgeon of the expansion from a collapsed configuration to an expanded configuration.

[0106] The delivery system includes a distal tip assembly, a steerable catheter, and a handle assembly that houses a cap 50, a nose cone 52, a positioning pin 43, and a control device for a release thread 56. Figure 10 The entire delivery system is shown, including a proximal control device that enables manipulation of the steerable delivery catheter 40. As described above, the nasal cone 52 and the shroud 50 housing a valved stent (not shown) in a collapsed configuration are located at the distal end of the entire delivery system and are connected to the manual control device via the steerable catheter. The manual control device is housed in a multi-functional handle 71, which includes a flushing port 70 and a control device for manipulating the steerable catheter 40 by rotating a retaining device that provides relative movement to a positioning pin 43. In a two-pin embodiment, either pin is shortened to guide the nasal cone toward the shortened pin and allows the nasal cone 52 to deflect at least 90°. The handle also preferably has a control device for axial movement of the shroud 59. For example, rotation of the shroud control knob 73 pulls the shroud 50 proximally to facilitate deployment of the valved stent. Separately, the control handle 71 has a retaining device for controlling the release of the filament 56. For example, a knob that can rotate about the axis of the handle 71 releases the release wire 56 to allow the deployment of the valved stent.

[0107] refer to Figure 11A and Figure 11BThe relative orientation of the sash 50, the hypotube 51, the positioning pin 43, and the release wire 56 illustrates how the sash can be manipulated using the positioning pin while maintaining the ability to pull the sash 50 proximally to deploy the valved stent (not shown). As described above with respect to the positioning pin 43, shortening the length of one positioning pin 43 relative to the other results in the deflection of the sash and the ability to manipulate the sash 50 containing the valved stent for deployment. As can be seen from the construction of the delivery system, the deflection of the sash 50 is possible without altering the functionality of the hypotube 51 or the integrity of the sash 50, allowing the sash 50 to be retracted without affecting its orientation relative to the axial length of the steerable catheter 40 or the tension maintained on the release wire 56. Thus, the sash 50 can be partially retracted to deploy the ventricular cusp 18 while the release wire 56 retains the atrial end of the valved stent attached to the tab retainer 60. In this configuration, the individual movement of the cap 50 and the actuation of the release thread 56 provide for the individual deployment of the ventricular cusps from the annular atrial skirt 19. The result of this configuration is that the valved stent 10 can be deployed in a stepwise manner, allowing the second tissue-engaging structure, the ventricular cusps 18, to first deploy to the ventricular portion of the autologous valve annulus to position the ventricular cusps 18 between the autologous chordae tendineae, thereby ensuring a firm engagement of the ventricular end of the valved stent while the atrial end of the valved stent remains captured by the release thread 56. Once the ventricular cusps 18 are correctly positioned, ensuring the overall construction of the valved stent 10 and the still at least partially collapsed atrial coronary 20, the atrial portion of the valved stent 10 can be individually released to complete the deployment.

[0108] General methods of delivery of catheter-based valve devices are known in the art. The foregoing description should be considered as modifications of commonly known procedures. Catheter devices for the delivery of cardiac valve bioprosthetics and their use are well known to those skilled in the art. For example, Tu et al. disclosed a catheter and a method for delivering a stentless bioprosthetic in a body passage in U.S. Patent No. 6,682,558 (the entire contents of which are incorporated herein by reference), the method comprising percutaneously introducing the catheter into the body passage, wherein the catheter accommodates a stentless bioprosthetic in a retracted state; and disengaging the stentless bioprosthetic from the distal opening of the catheter by a pulling mechanism associated with the catheter structure.

[0109] Therefore, due to its unique design, the valved stent 10 is maintained within the cylindrical housing of the enclosure 50 until the distal or ventricular end of the valved stent 10 begins to be exposed from the enclosure, causing the lower or ventricular cusps to radially expand to an outward position (second position) away from the peripheral surface of the valved stent 10. The expansion of the valved stent 10 from the delivery system can be achieved through several modes that allow or cause the valved stent 10 to expand from a collapsed configuration to an expanded configuration. The overall profile of the valved stent 10 can be limited by housing the valved stent 10 within a hollow portion of the housing (such as a pre-formed lumen 44 at the distal end of the delivery catheter 40). The distal end of the delivery catheter 40 can be a simple hollow space or housing for accommodating the collapsed valved stent 10, or it can be formed by a variety of other structures to facilitate the expansion step. In accordance with other known implantable medical devices, the valved stent 10 can be pushed from the distal end of a delivery catheter by a pusher or other mechanical means, which advances against the structural frame support 11 of the valved stent 10. Alternatively, a spindle can hold the stent assembly 10 in place while retracting the outer lumen along the length of the valved stent 10 to allow for its expansion.

[0110] In a preferred embodiment, such as Figure 10The described delivery system is provided with a steerable delivery catheter 40, which includes: a catheter having an inner lumen 44 composed of a braided PTFE tube and a PTFE liner, and may have an outer diameter less than about 24F and a length of at least 41 cm; a distal steerable region including a cap 50 and a nasal cone 52, and capable of directional control and a deflection angle of at least 75°, preferably 90° or greater, by manipulating a steering mechanism. The steering mechanism may include any mechanical means operable from the handle of the delivery system and steering the distal end of the delivery catheter 40. In the embodiments of Figures 8 and 11, the steering mechanism includes a locating pin 43. However, the locating pin 43 may be replaced by a steerable guidewire or other equivalent to reduce the overall diameter of the capping element constrained by the necessary diameter dimension A of the valve stent 10. The length of the steerable region is approximately 25 mm. A stainless steel cable (not shown) may be embedded in the steerable catheter 40 for navigation control. The controlled release wire 56 is preferably made of nitinol coated with polytetrafluoroethylene, enabling controlled release of the valved stent. The combination of retaining tabs 68 on the tab retainer 60 forms a release mechanism including a releasable attachment to the coronal portion 20 or the small wing unit 21, which has an opening through which the release wire 56 traverses. Thus, the release wire 56 extends from the control mechanism 74 across the lumen 40, through the divertible catheter 40, across the small wing unit 21 of the coronal portion 20, and engages the tab retainer 60 at the tab 68. Once the surgeon has confirmed that the valved stent 10 is correctly positioned, the distal end of the release wire 56 can be released from the tab 68 by simply increasing its length, thus releasing the atrial portion of the valved stent 10.

[0111] The delivery system handle 71 includes a manipulator control knob 72 for directional navigation of the distal end of the steerable catheter 40. The steering control has a torque limiter to prevent damage due to potential oversteering. A sealing control knob 73 controls the initial partial release of the ventricular portion of the valved stent by retracting the sealing 50, resulting in at least partial expansion of the ventricular aspect of the valved stent 10 as the length of the structural frame support 11 is exposed during the retraction of the sealing 50. The handle also includes a control mechanism for releasing the release cord 65, which releases the release cord for controlled deployment of the atrial portion of the valved stent 10 and ultimately releases the entire prosthesis at the target site. A safety pin (not shown) may be added to the release cord control mechanism to prevent accidental release of the valved stent from the distal end of the delivery catheter 40.

[0112] Echo and fluorescence imaging are used for navigation, and any structural features of the valved stent 10 or the distal portion of the delivery system can have additional elements for detection during imaging. The distal tip of the delivery device can be guided into the desired configuration of the autologous dysfunctional valve annulus by rotating the steering control knob and rotating the entire handle 71. Deployment of the valved stent 10 is achieved stepwise by first advancing the nasal cone 53 a short distance from the dysfunctional autologous valve under fluoroscopic guidance. Next, the sealing control mechanism 73 is actuated, for example, by rotating the knob clockwise. By locking the sealing control mechanism 73 in place, a safety feature can fix the position of the sealing shell after the initial release of the ventricular portion of the valved stent 10, preventing further rotation and axial movement of the sealing shell 50 relative to the axis of the steerable catheter 40. This causes the sealing shell to retract and expose the ventricular or outflow aspect of the implant. At this point, the distal, ventricular outflow portion of the valved stent 10 is in a substantially open configuration, while the proximal atrial inflow portion of the valved stent 10 is restricted, for example, to a diameter substantially equal to the inflow diameter dimension B, by maintaining tension on the release cable 56. A final adjustment is made to the position of the valved stent 10 within the autologous valve annulus, and then the controlled release knob 74 is rotated to advance the controlled release cable 56. This action slowly expands the atrial inflow portion of the valved stent until the coronary portion 20 is fully expanded within the atrial skirt 19, rotating approximately 90° into a fully expanded configuration. Further manipulation of the valved stent can be performed by gently pushing or pulling the delivery system to ensure the valved stent is properly positioned within the tricuspid valve annulus.

[0113] Next, pull the safety pin while simultaneously rotating the sealing control mechanism 73 knob counterclockwise, which further retracts the sealing shell 50. Next, the release wire control mechanism 74 is actuated, for example by rotating counterclockwise, to retract the release wire 56 into the lumen 44 of the delivery system catheter 40. The nasal cone 52 is retracted by pulling the guidewire 51, for example, when the guidewire extends proximally to the handle at the attachment point, by retracting the proximal portion 76 of the guidewire. The Tuohy Borst adapter 75 is secured to the guidewire catheter 51, which locks the nasal cone 52 in the retracted position. At this point, the delivery system catheter 40 can be safely withdrawn.

[0114] In a preferred embodiment, the valved stent 10 is stored in an expanded configuration and then compressed and loaded into the delivery catheter 40 as described above by lowering the temperature of the valved stent 10 before use. The compression loading system may consist of the following components: a valved stent support and fixation device with an ice bath; a compression cone preferably made of Ultem; a transfer cap preferably made of Ultem; a pusher preferably made of Ultem; and a standby compliant balloon with a syringe.

Claims

1. A system for atrioventricular valve replacement, comprising: Biological prosthetic atrioventricular valves, including: A valve stent assembly includes a structural frame support that is expandable from a collapsed shape to an expanded shape and has an atrial inlet orifice and a ventricular outlet orifice, and a tapering dimension along the height of the structural frame support, wherein the atrial inlet orifice has a smaller diameter than the ventricular outlet orifice. A pre-cut mesh layer covers the inner surface of the structural frame support from the atrial inflow orifice to the ventricular outflow orifice; A tissue valve having at least two leaflets and fixed around the inner surface of the structural frame support, and having a height and diameter approximately the same as the height and diameter of the structural frame support; and A first tissue-joining structure and a second tissue-joining structure, the first tissue-joining structure extending from a portion of the structural frame support near the atrial inlet orifice, and the second tissue-joining structure extending from a portion of the structural frame support near the ventricular outlet orifice, for holding tissue at both the atrium and ventricle of the autologous valve annulus; and Delivery system, which includes: A cap, located at the distal end of the steerable catheter, accommodates the bioprosthetic atrioventricular valve. The nasal cone, which is located distal to the sealing shell and is fixed to a filament that traverses the length of the tissue valve and the steerable catheter; A tab retainer is located near the distal end of the steerable conduit and defines a tab fixing device; Multiple release threads, which cross: The length of the steerable conduit, The coronal portion of the bioprosthetic atrioventricular valve is used to maintain the bioprosthetic atrioventricular valve in a collapsed configuration, and The tab retainer forms a ring to engage the tab fixing device; and The proximal stem houses control mechanisms for each of the following: manipulating the distal end of the steerable catheter, axially sliding the cap to deploy the bioprosthetic valve, and controlling the tension in the plurality of release filaments.

2. The system of claim 1, wherein the first tissue engagement structure is located in an annular atrial skirt, the annular atrial skirt extending radially from the structural frame support at an angle between 85° and 95°.

3. The system of claim 1, wherein the second tissue engagement structure is a plurality of ventricular cusps extending radially away from a plurality of hubs circumferentially positioned around the ventricular outflow orifice.

4. The system of claim 1, wherein the distance between the first tissue-joining structure and the second tissue-joining structure is between 5.5 mm and 9.0 mm.

5. The system of claim 4, wherein the distance between the first tissue-joining structure and the second tissue-joining structure is between 7.0 mm and 8.0 mm.

6. The system of claim 1, wherein the total height of the structural frame support is less than 25 mm.

7. The system of claim 6, wherein the ratio of the diameter of the atrial inflow orifice to the diameter of the ventricular outflow orifice is between 0.60 and 0.

90.

8. The system of claim 7, wherein the ratio of the diameter of the atrial inflow orifice to the diameter of the ventricular outflow orifice is between 0.70 and 0.

85.

9. The system of claim 1, wherein the diameter of the ventricular outflow orifice is greater than 30 mm.

10. The system of claim 1, wherein the first tissue-jointing structure is covered with a mesh layer, the mesh layer covering a portion of its annular structure, including an upper surface, a lower surface, or a combination thereof.

11. The system of claim 1, wherein the proximal stalk further includes a flushing port having a fluid communication path that traverses the steerable catheter and terminates near the cap that houses the collapsed bioprosthetic valve of claim 1.

12. The system of claim 1, further comprising a locating pin extending through the steerable conduit and secured to the housing, such that selective orientation of the locating pin steers the distal end of the delivery system.

13. The system of claim 1, wherein the bioprosthetic valve has a total height of less than 25 mm for the structural frame support, the ratio of the diameter of the atrial inlet to the diameter of the ventricular outlet is between 0.60 and 0.90, and the diameter of the ventricular outlet is greater than 30 mm.

14. The system of claim 1, wherein the proximal stem, the steerable catheter, the tissue valve, and the sealing shell are traversed by a guidewire attached to the distal nasal cone.

15. A delivery system for a biological prosthetic tricuspid valve, the delivery system comprising: A cap, located at the distal end of the steerable catheter, accommodates the bioprosthetic tricuspid valve. The nasal cone, located distal to the sealing shell and secured to a filament that traverses the length of the bioprosthetic tricuspid valve and the steerable conduit; A tab retainer is located near the distal end of the steerable conduit and defines a tab fixing device; Multiple release threads, which cross: The length of the steerable conduit, The coronal portion of the prosthetic tricuspid valve is used to maintain the prosthetic tricuspid valve in its collapsed structure, and The tab retainer is configured to form a ring to engage the tab fixing device; as well as The proximal handle portion houses the control mechanism for the following: The axial sliding of the cap expands the bioprosthetic tricuspid valve, and Control the tension in the plurality of release threads.

16. The delivery system of claim 15, wherein the proximal stalk further includes a flushing port having a fluid communication path that traverses the steerable catheter and terminates near the suffix containing the bioprosthetic tricuspid valve.

17. The delivery system of claim 15, further comprising a locating pin extending through the steerable conduit and secured to the housing, such that selective orientation of the locating pin steers the distal end of the delivery system.

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