WO2007081820A1

WO2007081820A1 - Transcatheter delivery of a replacement heart valve

Info

Publication number: WO2007081820A1
Application number: PCT/US2007/000315
Authority: WO
Inventors: Alan Nugent; James Bieloski; James E. Lock
Original assignee: Children's Medical Center Corporation
Priority date: 2006-01-09
Filing date: 2007-01-09
Publication date: 2007-07-19

Abstract

Disclosed is a replacement valve apparatus including a docking station (30) , a self -expanding member (32) , and a valve frame (40) . The valve frame is adapted to be positioned within the docking station, whereas the self-expanding member is adapted to be associated with an outer wall of the docking station. The valve frame generally includes a substantially cylindrical body defining a lumen and a plurality of curved support structures attached to the substantially cylindrical body. The valve frame further can have a plurality of leaflets. Each leaflet can be attached to a respective inner curved support structure and can extend over a respective outer curved support structure, so as to position the body of the leaflet within the lumen of the valve frame.

Description

TRANSCATHETER DELIVERY OF A REPLACEMENT HEART VALVE

TECHNICAL FIELD

[0001] The present teachings generally relate to the treatment of heart valve dysfunctions with minimally invasive systems and methods for replacing such heart valves.

BACKGROUND

[0002] The heart has four chambers and is located in the middle of the chest with a slight tilt toward the left side. Deoxygenated blood (containing low oxygen) returns from the entire body via the superior and inferior branches of the vena cava emptying into the right atrium. During diastole, or the relaxation phase of the cardiac cycle, pressure in the right ventricle falls from between about 20 mm Hg and about 30 mm Hg to between about 5 mm Hg and about 10 mm Hg. The pressure gradient formed between the right atrium and right ventricle, plus the contraction of the atrium, causes forward flow of blood through the tricuspid valve into the right ventricle. The flow of blood through the tricuspid valve thereby fills the right ventricle with blood. During systole, the pumping phase of the cycle, the right ventricle starts to contract, increasing intraventricular pressure. This causes the tricuspid valve to snap shut and the cusps of the pulmonary valve to open. Blood then flows out of the right ventricle through the pulmonary artery into the lungs where oxygenation occurs and carbon dioxide is removed. [0003] The cycle of blood flow starts again with relaxation of the right ventricle. Because the diastolic pressure (e.g., less than about 5 mm Hg) in the right ventricle is lower than the pulmonary artery pressure (e.g., about 10 mm Hg) the pulmonary- valve closes and prevents regurgitation. Simultaneously with the fall in the pressure in the right ventricle, the tricuspid valve opens and again fills the right ventricle.

[0004] Once the blood has been oxygenated, it flows into the left side of the heart via the pulmonary veins into the left atrium. It is during diastole that blood flows through the mitral valve into the left ventricle. During systole, the pressure in the left ventricle causes the mitral valve leaflets to close and the aortic valve to open. The blood flows out of the aorta for circulation throughout the body.

[0005] The geometry and circuitry of the two sides of the heart are similar; however the function of each is different. The right side pumps blood only to the lungs for gas exchange. The left side pumps blood to the entire body. The left side generates pressures three to four times greater than the right side.

[0006] As discussed, there are four valves within the human heart, located at the exit of each chamber. In order of blood flow, they are the tricuspid (right atrium), pulmonary (right ventricle), mitral (left atrium) and aortic valves (left ventricle). Due to the higher-pressure gradient, the mitral and aortic valves are subject to greater fatigue and/or risk of disease. The aortic and pulmonary valves are similar anatomically and are referred to as semi-lunar valves, named because of the partial moon-like shape of their three cusps. [0007] The three cusps are soft tissue structures attached to a wall of the valve in an area designated as the annulus. In the case of the pulmonary valve, the three cusps are pushed back against the wall of the pulmonary trunk during systole, thereby allowing blood to flow through. During diastole, the right ventricular pressure falls and when the pressure is below the relaxation pressure of the pulmonary artery, the pulmonary valve closes (the three cusps fall away from the wall and close), thereby eliminating backward flow of the blood.

[0008] Tetrology of Fallot is a congenital heart defect often discovered at birth, in which a baby appears blue as a result of an obstruction affecting the proper functioning of the pulmonary valve of the heart. The obstruction is often surgically removed at an early age to improve the chances that the baby will survive. The surgical procedure typically results in subsequent leaking (i.e., regurgitation) of blood through the pulmonary valve. Over the life of the patient, the regurgitation may become more severe and result in further dysfunction of the heart valve due to, for example, dilation of the heart chamber and heart valve by the body to compensate for the increased regurgitation.

[0009] Treatment of congenital heart disease including tetralogy of Fallot requires surgical intervention, such as "open-heart" surgery during which the thoracic cavity is opened and the heart, arteries/veins and/or associated valves are repaired or otherwise treated. Postoperative complications that may appear during short and long-term patient follow-up include heart valve dysfunctions such as pulmonary regurgitation. [0010] Pulmonary regurgitation occurs when the heart valve in the main pulmonary artery between the heart and the lungs, is unable to completely prevent the backflow of blood to the right ventricle of the heart. The dysfunction of this heart valve leads to a volume load on the right ventricle and causes right ventricular dilation, which can lead to right ventricular dysfunction which is thought to contribute to ventricular tachycardia and sudden death.

[0011] Due to the long-term deleterious effects of severe pulmonary regurgitation, surgical pulmonary valve replacement is performed for patients with severe regurgitation, symptoms of exercise intolerance and/or progressive right ventricular dilation and dysfunction.

[0012] Cardiologists typically defer the valve replacement procedure as long as possible because of the need for a repeat open-heart surgery, the risks of surgery and cardiopulmonary bypass, and the limited lifespan of all available surgically- implanted valves. The risks associated with surgical valve replacement are particularly acute with respect to pediatric patients in that the replacement valves do not grow with the patient and thus require more frequent replacement.

[0013] Prosthetic heart valves used to replace diseased or abnormal natural heart valves are typically mechanical devices with, for example, a rigid orifice ring and rigid hinged leaflets or ball-and-cage assemblies. Prosthetic heart valves are, more recently, bioprosthetic devices that combine a mechanical assembly with biological material (e.g., human, porcine, bovine, or biopolymer leaflets). Many bioprosthetic valves include an additional support structure, such as a stent, to support the leaflets of the valve. The stent also absorbs the stresses, which would otherwise be borne by the leaflets, from the hemodynamic pressure exerted during normal heart operation.

[0014] Heart valve replacement, typically, involves the surgical implantation of the valve prosthesis during open heart surgery and requires the use of a heart and lung machine for external circulation of the blood as the heart is stopped and the artificial valve prosthesis is sewn in. Valve replacement surgery is thus very demanding on the patient's body and may, therefore, not be a viable technique for patients that are physically weak due to age or illness. Accordingly, it is desirable.to develop a heart valve replacement apparatus and procedure that is minimally invasive and does not have the morbidity of a re-operation.

[0015] One minimally invasive procedure that is currently available is catheterization. Prosthetic heart valves designed for transcatheter (or percutaneous) delivery must possess certain size and mechanical characteristics that are not essential for surgically implantable replacement heart valves. For example, to allow transcatheter delivery, the heart valve replacement assembly must be able to collapse to a small diameter when crimped and loaded, and to expand to a larger diameter when deployed.

[0016] Despite recent developments in percutaneous heart valve designs, there remain several barriers to the widespread use of percutaneous heart valve replacement. For example, a well-documented problem that remains to be solved is the lack of percutaneous replacement heart valve apparatus and methods that can be used with patients who have aneurysmal or large (e.g., over about 25 mm in diameter) outflow tract. As previously mentioned, a great majority of the patients requiring pulmonary valve replacement suffer from regurgitation, which is a heart valve dysfunction that often creates aneurysmal regions in the right ventricular outflow tract. Unfortunately, current percutaneous replacement heart valve designs do not permit anchorage of the replacement device in such aneurysmal regions, partially due to limitations on device sizes imposed by transcatheter delivery. The failure to address this long felt need effectively prevents a significant portion of the patient population from taking advantage of percutaneous valve replacement procedures.

SUMMARY [0017] The present teachings solved the above -identified problem by providing replacement valves and supporting structures that can be delivered to and anchored in anatomical lumens or cavities of various diameters and dimensions by minimally invasive procedures. In particular, the present teachings enable transcatheter procedures involving replacement heart valves and supporting structures to be performed on patients with aneurysmal or large outflow tracts that are not possible with existing apparatus and procedures. Methods of making and using these replacement valves and supporting structures are within the scope of the present teachings.

[0018] Although replacement heart valves, and specifically replacement pulmonary valves, are herein described in detail for illustrative purposes, it will be possible to use a valve prosthesis according to the present teachings to replace or supplement the functions of other natural valves in the body including, but not limited to, valves in the veins, valves in the esophagus and at the stomach, valves in the ureter and/or the vesica, valves in the biliary passages, valves in the lymphatic system, and valves in the intestines.

[0019] In one aspect, the present teachings provide a replacement valve apparatus that can be delivered via a cathether. The replacement valve apparatus can include a docking station and a valve frame adapted to be positioned within the docking station. The docking station is adapted to receive the valve frame and can be deployable within an anatomical lumen via an introducing catheter prior to the docking station receiving and supporting the valve frame.

[0020] The replacement valve apparatus can be adapted to replace or supplement the functions of a natural heart valve. For such applications, the docking station can have a barrel or sinus shape when opened so as to mimic the physiological shape of a human heart valve. A balloon catheter can be used to expand the docking station once it is withdrawn from the introducing catheter. Alternatively, the docking station can self-expand once it is withdrawn from the introducing catheter.

[0021] In some embodiments, a docking station made in accordance with the disclosed technology can enable the transcatheter delivery of a valve frame. The docking station can include a plurality of securing structures or materials (e.g., sutures or adhesive), where each such securing structure or material can be adapted to receive and support one of a plurality of valve frames.

[0022] The two-part methodology discussed above, where the docking station is deployed first and the valve frame is deployed and affixed to the docking station second, can enable the introducing catheter to be a relatively small French size and reduce the distortion of the replacement heart valve during implantation. The docking station also can enable multiple valve frame replacements without replacing the docking station and maintains precise valve frame alignment relative to the docking station when deployed within the anatomical lumen.

[0023] To provide improved anchorage over existing valve prostheses, the replacement valve apparatus can further include a self-expanding member. The self- expanding member can be adapted to be associated with the outer wall of the docking station. The self-expanding member can be made of a self-expanding material that can expand and shape to securely engage the replacement valve apparatus in a relatively large anatomical lumen or cavity.

[0024] The self-expanding material is preferably biocompatible but nonbiodegradable. The self-expanding material can expand upon contact with a fluid, for example, a bodily fluid such as blood. The self-expanding material can be a foam, a sponge, or a hydrogel, and can be composed of one or more natural or synthetic polymers selected from polyvinyl alcohol, polyurethane, polyethylene, polypropylene, polytetrafluoroethylene, polyacrylate, polymethacrylate, polystyrene, polylactide, polycaprolactone, silicone, collagen, and copolymers thereof. The self- expanding material can be collagen sponge.

[0025] A self-expanding member made of any of the above-listed polymeric self-expanding materials can be attached to the outer wall of the docking station by gluing, stitching, or other methods known in the art. Alternatively, the self- expanding member can be securely associated with the outer wall of the docking station without any direct physical or chemical attachment. For example, the self- expanding member can be formed into a sleeve into which the docking station can be tightly fitted.

[0026] In other embodiments, the self-expanding material can be a shape memory alloy such as nitinol. For example, the self-expanding member can be a nitinol mesh attached to the outer wall of the docking station by gluing, stitching. welding, or other methods known in the art.

[0027] A valve frame of the present teachings can be adapted to be positioned within the docking station described above. It can be adapted to alter the flow of blood through a blood vessel, e.g., a blood vessel of a heart. In some embodiments, the valve frame can have a substantially cylindrical body defining a lumen and a plurality of curved support structures attached at one end of the substantially cylindrical body. Each curved support structure can include an inner curved support structure and an outer curved support structure. The valve frame can further include a plurality of leaflets, each of which can include a leaflet body and a leaflet projection. To position the body of the leaflet within the lumen of the valve frame, the leaflet projection can be attached to the inner curved support structure while the leaflet body can extend over the outer curved support structure. Additionally, one end of the substantially cylindrical body of the valve frame can have a serpentine edge to which the curved support structures are attached. In some embodiments, the inner curved support structure can be attached to a vertex of the serpentine edge while the outer curved support structure can be attached to a trough of the serpentine edge. The valve frame can include a radiopaque marker at each end. [0028] The inner curved support structure and the outer curved support structure individually can resemble a pocket in shape. In some embodiments, each of the inner curved support structure and the outer curved support structure can include a wire. In other embodiments, the outer curved support structure can include two wires while the inner curved support structure can have one wire. The two wires of the outer curved support structure can be separated along a portion of their lengths by a distance of about a suture or stitch diameter.

[0029] In another aspect, the present teachings provide a method of replacing a heart valve with a replacement valve. The method can involve introducing the various components of the replacement valve assembly described above into a heart through a catheter. In some embodiments, the docking station can be introduced into the heart simultaneously with the self-expanding member. For example, the self-expanding member may have been attached to the outer wall of the docking station prior to the introduction of the docking station into the body. Subsequently, a valve frame can be introduced into the docking station through either the same or a different catheter. The valve frame can then be positioned within the docking station and finally released therewithin. The method can further include contacting the self-expanding member with a fluid so as to trigger the self-expanding member to expand. The expansion of the self-expanding member can help to anchor the docking station securely in an anatomical lumen of the heart.

[0030] In other embodiments, the method can involve the use of a self- expanding member formed into a sleeve. The self-expanding member can include an outer wall, an inner wall, and a lumen defined by the inner wall that is adapted to receive the docking station in its compressed state. The method can include introducing the self-expanding member via a catheter into a pre-selected location of the heart, contacting the self-expanding member with a fluid, and introducing the docking station into the lumen of the self-expanding member via the same or a different catheter. The docking station can then be deployed. Finally, the valve frame can be introduced into the lumen of the docking station and released inside the docking station.

[0031] The methods described above also can include introducing a balloon into the docking station and inflating the balloon, thereby expanding the docking station to a predetermined configuration and size. Additionally, the methods can include partially deploying the valve frame within the docking station, determining the position of the valve frame within the docking station under fluoroscopy using radiopaque markers at the ends of the valve frame, and retracting and redeploying the valve frame within the docking station in response to the determination of the position of the valve frame.

[0032] These and other objects, along with the features of the present teachings herein disclosed, will become apparent through reference to the following description, the accompanying drawings, and the claims. Furthermore, it is to be understood that the features of the various embodiments described herein are not mutually exclusive and can exist in various combinations and permutations.

1

BRIEF DESCRIPTION OF DRAWINGS

[0033] In the drawings, like reference characters generally refer to the same parts throughout the different views. Also, the drawings are not necessarily to scale, emphasis generally being placed upon illustrating the principles of the present teachings. In the following description, various embodiments of the present teachings are described with reference to the following drawings, in which:

[0034] FIG. IA is a top-view of an embodiment of an expanded docking station according to the present teachings.

[0035] FIG. IB is a side-view of the docking station of FIG. IA.

[0036] FIG. 1C is a cross-sectional view of an embodiment of the present teachings which includes a continuous layer of a self-expanding material associated with the outer wall of an expanded docking station according to the present teachings.

[0037] FIG. ID is a side-view of another embodiment of the present teachings which includes a plurality of self-expanding members in the form of annular rings associated with the outer wall of an unexpanded docking station according to the present teachings.

[0038] FIG IE is a side-view of yet another embodiment of the present teachings which includes a plurality of self-expanding members in the form of longitudinal strips associated with the outer wall of an unexpanded docking station according to the present teachings.

[0039] FIG. IF is a side-view of a further embodiment of the present teachings which includes a plurality of self-expanding beads associated with the outer wall of an unexpanded docking station according to the present teachings. [0040] FIG. 2 A is a top-view of an embodiment of a valve frame according to the present teachings.

[0041] FIG. 2B is a side-view of the valve frame of FIG. 2 A

[0042] FIG. 3 A is a top-view of the valve frame of FIG. 2 A located within a lumen of the docking station of FIG. IA.

[0043] FIG. 3B is a side-view of the valve frame and docking station of FIG. 3A.

[0044] FIG. 3 C is a top-view of the valve frame and docking station of FIG. 3 A with the members of the valve frame covered with a cover material and free ends of the cover material located away from the wall of the docking station.

[0045] FIG. 3D ^"is a cross-sectional view of the valve frame and docking station of FIG. 3C.

[0046] ^■ FIG. 3E is a top-view of the valve frame and docking station of FIG. 3C with the free ends of the cover material located towards the wall of the docking station.

[0047] FIG. 3F is a cross-sectional view of the valve frame and docking station of FIG. 3E.

[0048] FIG. 4 is a partially hroken-away view of a heart subsequent to insertion of an introducing catheter into the heart. [0049] FIG. 5 is a partially broken-away view of the heart of FIG. 4 subsequent to placement of a docking station and a balloon in a predetermined location of an anatomical lumen of the heart.

[0050] FIG. 6 is a partially broken-away view of the heart of FIGS. 4 and 5 subsequent to expansion of the self-expanding material on the docking station of FIG. 5.

[0051] FIG. 7 is a partially broken-away view of the heart of FIGS. 4-6 subsequent to balloon inflation of the docking station.

[0052] FIG. 8 is a partially broken-away view of the heart of FIGS. 4-7 subsequent to the withdrawal of the balloon of FIG. 7.

[0053] FIG. 9 is a partially broken-away view of the heart of FIGS. 4-8 illustrating a valve frame being introduced into the introducing catheter.

[0054] FIG. 10 is a partially broken-away view of the heart of FIGS. 4-9 subsequent to the deployment of the valve frame within the docking station.

[0055] FIG. 11 A is a top-view of an embodiment of a valve assembly according to the present teachings.

[0056] FIG. 1 IB is a side-view of the valve assembly of FIG. 1 IA.

[0057] FIG. 11 C is a cross-sectional view of the valve assembly of FIG. 1 IB with a cover material applied to the valve assembly. [0058] FIG. 12A is a side-view of an embodiment of a valve assembly according to the present teachings.

[0059] FIG. 12B is a cross-sectional view of the valve assembly of FIG. 12A with a cover material applied to the valve assembly.

[0060] FIG. 13 A is a top view of a digital image of a model of a valve frame, such as the valve frame of FIG. 3C.

[0061] FIG. 13B is a side-view of a digital image of a model of a valve frame, such as the valve frame of FIG. 3D.

[0062] FIG. 14A is a top view of a digital image of a model of a valve assembly, such as the valve assembly of FIG. 1 IA.

[0063] FIG. 14B is a side-view of a digital image of a model of a valve assembly, such as the valve assembly of FIG. 1 IB.

[0064] FIG. 15A is a top view of a digital image of a model of a valve assembly, such as the valve assembly of FIG. 12 A.

[0065] FIG. 15B is a side view of a digital image of a model of a valve assembly, such as the valve assembly of FIG. 12B.

[0066] FIG. 16 is a side-view of a docking station in accordance with one embodiment of the present teachings.

[0067] FIG. 17 is a side-view of a valve frame in accordance with one embodiment of the present teachings. [0068] FIGS. 18A-18E are side-views of a valve frame being deployed by catheter into the docking station of FIG. 16 in accordance with one embodiment of the present teachings.

[0069] FIGS. 19A-19E are side-views of docking stations for receiving medical devices or drugs.

[0070] FIGS.20A-20F are side-views of docking stations inserted into the body at various locations.

[0071] FIG. 21 is a side view of an embodiment of the docking station and the valve frame (without leaflets) of the present teachings.

[0072] FIG. 22 is an opened view of a portion of another embodiment of the valve frame (without leaflets) of the present teachings.

[0073] FIG 23 is a plan view of the embodiment of the valve frame of FIG. 21 with leaflets attached.

[0074] FIG. 24 is a plan view of a leaflet.

[0075] FIG. 25 is a cross-sectional view through line AA' of FIG. 23 showing the attachment of the leaflet to the inner curved support structure and the placement of the leaflet over the outer curved support structure.

[0076] FIG. 26 is an opened view of a portion of yet another embodiment of the valve frame (without leaflets) of the present teachings. [0077] FIG. 27 is a plan view of the embodiment of the valve frame of FIG. 26 with leaflets attached.

[0078] FIG. 28 is a cross-sectional view through BB' of FIG. 27 showing the attachment of the leaflet to the inner curved support structure and the placement of the leaflet over and between the outer curved support structure.

[0079] FIG. 29 is an opened view of a portion of another embodiment of the valve frame (without leaflets) of the present teachings.

DETAILED DESCRIPTION

[0080] The disclosed technology can mitigate the potential complications of invasive surgery by applying minimally invasive techniques to, for example, replace a damaged natural heart valve with a replacement heart valve. In some embodiments, a supporting structure, such as a docking station, a stent or a scaffold, can be deployed at a preselected position within an anatomical lumen of the heart via an introducing catheter. The phrase "docking station" is herein used to broadly refer to all types of supporting structures including stents. The replacement heart valve can then be inserted into the deployed stent docking station using the same catheter or, alternatively, a second catheter. The docking station and/or valve assembly can include attachment means (e.g., sutures or adhesive) to hold securely the valve assembly in a desired orientation and alignment relative to the docking station. The two-part deployment of the docking station and the heart valve can enable the use of smaller catheters because the inner diameter of the catheter need not accommodate, at the same point in time of the procedure, the compressed volume of both a docking station and a valve assembly. [0081] Throughout the description, where compositions are described as having, including, or comprising specific components, or where processes are described as having, including, or comprising specific process steps, it is contemplated that compositions of the present teachings also consist essentially of, or consist of, the recited components, and that the processes of the present teachings also consist essentially of, or consist of, the recited processing steps.

[0082] It also should be understood that the order of steps or order for performing certain actions is immaterial so long as the method or process remains operable. Moreover, two or more steps or actions can be conducted simultaneously.

[0083] As shown in FIGS. IA and IB, one embodiment of a docking station 30 according to the present teachings is made of a shape memory material. The docking station 30 defines a generally cylindrical body that has a wall 34 that is constructed from a mesh 32. The wall 34 defines a lumen 36. The mesh 32 is constructed from, for example, wires or strips of a shape memory material. By way of example, the shape memory material can be nickel-titanium wire sold under the product name nitinol. The nickel-titanium wire, when properly manufactured, can exhibit elastic properties that allow the wire to be manipulated (e.g., bent) by an operator and then returned to, substantially, the same shape the wire possessed prior to it being manipulated. The wire can return to substantially its original shape when the operator heats the wire or, alternatively, when the operator removes the forces applied to bend the wire. In this embodiment, the docking station 30 can approximate the form of a cloverleaf to closely conform to the cloverleaf-Iike shape (associated with the three sinuses of a natural heart valve) of the location in a heart where a defective heart valve has been surgically removed.

[0084] The docking station 30 can, alternatively, be any geometric shape (e.g., cylindrical, conical, spherical or barrel-like) that is compatible with the placement of the docking station 30 within, for example, a lumen of the heart. The docking station 30 can be manufactured using alternative materials (e.g., stainless steel alloys, molybdenum alloys or pyrolitic carbon) that are compatible with placement in the body, that possess desirable material wear properties and/or that have a minimal risk of causing infection in the body of the patient.

[0085] In certain embodiments, a docking station of the present teachings can be dimensioned to fit in a catheter having a diameter no larger than about 22 Fr (7.3 mm). For example, the docking station can have a diameter of about 5 mm or less when crimped. When expanded, the widest portion of the docking station can have a diameter of about 30 mm, and the narrowest portion can have a diameter of about 25 mm.

[0086] These size limitations that allow transcatheter delivery of the docking station have previously disadvantaged patients with aneurysmal or large outflow tracts, making them ineligible for percutaneous valve replacement procedures. To expand the patient inclusion criteria for percutaneous valve replacement, the replacement valve apparatus of the present teachings preferably can include a self- expanding member that is adapted to be associated with the outer wall of the docking station. The self-expanding member can be made of a biocompatible, self- expanding material that can expand and shape to securely engage the replacement valve assembly in a relatively large anatomical lumen or cavity.

[0087] In some embodiments, the self-expanding member can expand upon contact with fluids, including body fluids such as blood. Self-expanding materials, such as foam, sponges, or hydrogels which typically expand upon contact with fluids, can be utilized. In certain embodiments, the self-expanding material can be non-biodegradable or can biodegrade very slowly (e.g., at least after one year). Additionally, the self-expanding material can be both resilient and deformable such that in an expanded state, it not only exerts pressure against the lumen wall, fills the cavity and holds the replacement valve assembly in place, but does so in a manner that minimizes risks of tissue trauma and enables the gradual size reduction of the lumen or cavity over the course of treatment. For example, an aneurysmal region in the right ventricular outflow tract due to pulmonary regurgitation is expected to reduce in size after the natural pulmonary valve has been replaced with a valve prosthesis.

[0088] Exemplary self-expanding materials can include, but are not limited to, shape memory alloys (e.g., nitinol) and foams, sponges, and hydrogels made from natural or synthetic polymers that are biocompatible. Examples of biocompatible, non-biodegradable polymers can include, but are not limited to, polyvinyl alcohols, polyurethanes, polyethylenes, polypropylenes, polytetrafluoroethylenes, polyacrylates, polymethacrylates, polystyrene, silicones, and copolymers thereof. Examples of biocompatible polymers that slowly biodegrade (in months to years) can include, but are not limited to, collagen, elastin, gelatin, polylactides and polycaprolactones. Foam, sponges, and hydrogels made from biodegradable polymers can be strengthened, thus slowing down the biodegradation rate, by crossiinking (e.g., with various crosslinking agents known in the art including glutaraldehyde) or by introducing woven fabric made from non-biodegradable polymers (e.g., polytetrafluoroethylenes). A plant protein made from the root stalk of a seaweed known as laminaria japonica also can be used. As described in U.S. Patent No. 4,624,258, the vegetable stalk laminaria japonica is known to expand radially by a factor of 200 to 300 percent upon absorption of fluids over a period of several hours.

[0089] In some embodiments, the self-expanding material can include collagen sponge and/or a superabsorbent polymer (SAP) composed of a sodium acrylate and vinyl alcohol copolymer (Osuga et al. (2002), J. Vase. Interv. Radiol, 13: 1125- 1133). As described in the literature, the SAP material is nontoxic and nonbiodegradable. It absorbs fluids and swells within several minutes. Specifically, Osuga et al. reported that a microsphere made from the material swelled in human serum to 3.5 times larger than its original size in dry state. After absorbing fluids, the swollen particle was reported to remain soft and deformable while maintaining a spherical shape as it enlarged.

[0090] A self-expanding member comprising sponges made from proteins such as collagen and elastin can be prepared by first dispersing the purified protein in an aqueous medium to form a slurry, then dehydrating the gel-like dispersion either by Iyophilization or extraction with organic solvents (see, e.g., Chvapil (1977), J. Biomed. Mater. Res., 11: 721-741). Crosslinking agents and/or polymeric fibers can be incorporated to stabilize and/or enhance the mechanical properties of the proteineous sponge (see, e.g.,.Magr et al. (2003), Tissue Engineering, 9(6): 1101- 1112).

[0091] In some embodiments, the self-expanding member can be attached to the outer wall of the docking station using various methods known in the art, including but not limited to gluing, stitching, welding, crimping, and dip molding. For instance, the self-expanding member can be a nitinol mesh welded to the outer wall of the docking station. Alternatively, the self-expanding member can be a collagen sponge glued to the outer wall of the docking station. The docking station also can be introduced into the casting mold, inside which the collagen sponge will eventually form such that upon lyophilization, the collagen slurry becomes a tubular sponge matrix that encapsulates the docking station. In other embodiments, a self- expanding material can be deposited as a coating on the outer wall of the docking station to form the self-expanding member. In yet other embodiments, a plurality of self-expanding members can be embedded, or otherwise incorporated, in selected locations along the body of the docking station.

[0092] In other embodiments, the self-expanding member can be securely associated with the outer wall of the docking station without any direct physical or chemical attachment. For example, the self-expanding member can be molded into a tubular shape (such as a sleeve) with a lumen sized to receive the docking station in its compressed state. In use, the tubular sponge matrix may be deployed at the anatomical site and allowed to swell prior to the introduction of the docking station and the valve assembly as described in more detail below. [0093] Referring to FIGS. 1C-1E, the self-expanding member 39 can take various shapes. As illustrated in FIG. 1C, it can form a continuous layer on the outer wall 34 of the docking station 30. With reference to FIGS. ID and IE, the self-expanding member 39 can form a discontinuous layer on the outer wall 34 of the docking station 30, for example, in annular shape (shown in FIG. ID), or in longitudinal strips (shown in FIG. IE). In these embodiments, a plurality of self- expanding members 39 can be sparsely attached to the outer wall 34 of the docking station 30. For example, depending on the swelling capacity and mechanical strength of the material, as few as two rings or strips of the self-expanding material can be used.

[0094] In other embodiments, the self-expanding member can be in the shape of beads, spheres, rods, or discs. With reference to FIG. IF, self-expanding members 39 of any of such shapes, can be embedded, or otherwise incorporated, in selected locations along the body of the docking station 30. For example, the wire mesh 32 forming the outer wall 34 of the docking station 30 can include a plurality of self- expanding beads 39.

[0095] FIGS. 2 A and 2B illustrate one embodiment of a valve frame 40 in deployed form (i.e., not constrained by the wall of a catheter used to introduce the valve frame 40 into the body). The valve frame 40 can be deployed within a docking station, such as the docking station 30 of FIG. 1C. The valve frame 40 can be made of a shape memory material. The valve frame 40 can define a generally cylindrical body that can be constructed from a mesh 42. The mesh 42 can be constructed from wires or strips of a shape memory material. The valve frame 40 also can have three valve members 44a, 44b and 44c. The valve members 44a, 44b and 44c each can have a free end 48a, 48b and 48c, respectively. The valve frame 40 can, alternatively, be of any geometric shape (e.g., cylindrical, conical, spherical or barrel-like) that is compatible with the placement of the valve frame 40 within a docking station, such as the docking station 30 of FIG. 1C.

[0096] As shown in FIGS. 3 A and 3B, the valve frame 40 can be deployed within the lumen 36 of the docking station 30 thereby creating a valve assembly 50. In some embodiments, the valve assembly 50 can be deployed within a human heart to replace a natural heart valve that may not function properly. The valve frame 40 would be manufactured to ensure that the valve frame 40 would maintain a desired (e.g., fixed) placement with respect to the docking station 30 when the valve frame 40 and the docking station 30 are located within the heart of a patient and subjected to the flow of blood through the valve assembly 50. Referring now to FIGS. 3C and 3D, the valve members 44a, 44b and 44c can be coated, typically, with a cover material 56 (e.g., a biocompatible material such as silicon rubber or bovine, porcine or human tissue that is chemically treated to minimize the likelihood of rejection by the patient's immune system). The coated valve members 44a, 44b and 44c can imitate the function of the three cusps of a natural heart valve (e.g., a pulmonary valve or an aortic valve). The cover material 56 can be a bio-engineered material that is capable of being applied to the valve members 44a, 44b and 44c. The cover material 56 can be applied to the valve frame 40 prior to deployment of the valve frame 40 into the body. The cover material 56 can have three free ends 46a, 46b and 46c corresponding to valve members 44a, 44b and 44c, respectively. The free ends 46a, 46b and 46c also are herein referred to as leaflets. After placement of the valve W

frame 40 within the docking station 30 (located within the body) the cover material 56 applied to the valve members 44a, 44b and 44c can, generally, obstruct the flow of blood in the negative direction along the X-axis. The free ends 46a, 46b and 46c can move away from the inner wall 34 of the docking station 30, thereby limiting the 5 flow of blood in the negative direction along the X-axis.

[0097] However, as blood flows in the positive direction along the X-axis, referring now to FIGS. 3E and 3F, the free ends 46a, 46b and 46c of the cover material 56 can move towards the inner wall 34 of the docking station 30. The free ends 46a, 46b and 46c, thereby can substantially restrict the flow of blood through 0 the valve assembly 50. In this manner, the valve assembly 50 can approximate the functioning of a natural heart valve of the body by allowing blood to flow in the positive direction along the X-axis.

[0098] FIGS. 13A and 13B are digital images of a model 130 of a valve frame, such as the valve frame 40 of FIGS. 3C and 3D. For clarity of illustration purposes 5 the valve frame model 130 can be constructed from a tube 132 and a silicon rubber cover material 134. The valve frame model 130, referring now to FIG. 1 IB, can be cylindrical in shape. The valve frame model 130, alternatively, can be any geometric shape as described previously herein.

[0099] In more detail and with reference to FIG. 4, method steps associated with 0 introducing an embodiment of the present teachings are described. An introducing catheter 61 is delivered via a femoral vessel to the inferior vena cava 63 by means of a guidewire 62 to a preselected position 68 in an anatomical lumen 65 of the heart. The preselected position 68 can be in proximity to the original location of a natural heart valve. The introducing catheter 61 can have an inner wall 69 that defines a lumen 64 through which the guidewire 62 can pass. The introducing catheter 61 can have an opening 66 out of which the guidewire 62 can be extended. In some embodiments, the leaflets of the natural heart valve can be removed prior to the insertion of the introducing catheter 61 into the heart by resecting the leaflets intravenously (e.g., by inserting a cutting and grasping device via a catheter to cut and remove the leaflets).

[0100] In other embodiments, the natural heart valve can remain within the heart. With reference also to FIG. 5, a docking station/balloon combination 71 can be inserted into the introducing catheter 61 and can be guided to the preselected position 68 using the guidewire 62. The combination 71 can then be deployed from the confines of the introducing catheter 61 and can be located within the anatomical lumen 65. The docking station/balloon combination 71 can include a balloon 73 located within a lumen 75 of a docking station 77. The docking station/balloon combination 71 can be positioned within the introducing catheter 61 prior to inserting the introducing catheter 61 into the anatomical lumen 65. Alternatively, the docking station/balloon combination 71 can be inserted into the introducing catheter 61 after the opening 66 of the introducing catheter 61 has been located at the preselected position 68. In some embodiments, the preselected position 68 can correspond to the sinus-shaped region of the anatomical lumen 65. In other embodiments, the preselected position 68 can correspond to a region within the anatomical lumen 65 that is in substantial proximity to the original position of the natural heart valve. For example, the preselected position 68 can correspond to an aneurysmal region 67 within the anatomical lumen 65. [0101] In alternative embodiments, the docking station 77 can be made of a shape memory material, such as a nickel-titanium wire, and can self-expand when it is removed from the confines of the introducing catheter 61. Subsequent to deploying the docking station 77 from the introducing catheter 61 the docking station 77 can expand to a predetermined size and shape because there are no longer any constraining forces (e.g., by the inner wall 69 of the introducing catheter 61) applied to the docking station 77.

[0102] In certain embodiments, the replacement valve assembly can include a self-expanding member 79 associated with the outer wall of the docking station 77. Any of the configurations described hereinbefore can be used, including the configurations shown in FIGS. 1C, ID, IE, and IF. Such embodiments can be used when the docking station/balloon combination 71 or the docking station 77 by itself needs to be placed in a region within the anatomical lumen 65 that is wider than the docking station 77 when fully expanded.

[0103] FIG. 6 shows a deployed docking station/balloon combination 71 that lacks sufficient width even when fully expanded to be securely anchored in an aneurysmal region 67 within the anatomical lumen 65 (as shown in FIG. 7). The self-expanding member 79, upon contact with fluids (in this case, blood), begins to expand. Once the self-expanding member 79 has expanded to a desired dimension, the balloon 73 of the deployed docking station/balloon combination 71 can then be inflated, referring now to FIG. 7, thereby expanding the docking station 77 to a predetermined configuration and size and compressing the self-expanding member 79 firmly against the wall of the anatomical lumen to ensure stability of the docking station 77. After the docking station 77 is fully expanded, the balloon 73 can be deflated immediately to prevent unduly occluding the blood flow. The balloon can then be withdrawn. As shown in FIG. 7, the expanded self-expanding member 79 can conform to the sinus-shaped region of the anatomical lumen 65 and can anchor the docking station 77 in a substantially fixed position and orientation in the aneurysmal region 67. In some embodiments and with reference to FIG. 8, an optional second balloon 74 can be introduced and deployed to further shape the docking station in preparation for the deployment of the valve frame 91.

[0104] Referring now to FIG. 9, a valve frame 91 can be compressed and inserted into the introducing catheter 61 and the valve frame 91 can be guided to the catheter orifice 66 and deployed into the lumen 75 of the expanded docking station 77.' By way of example, in one embodiment the valve frame 91 can be the valve frame 40 of FIG. 3C. The valve frame 91 can expand upon being deployed from the introducing catheter 61 and can assume substantially the same size and shape as the lumen 75 of the expanded docking station 77. The docking station 77 and/or valve frame 91 can have attachment means that serve to align and fix the valve frame 91 in the predetermined position 68 within and with respect to the docking station 77. Referring now to FIG. 10, the introducing catheter 61 can then be removed from the anatomical lumen 65 and the operation of the replacement valve can be subsequently monitored. Over time, the aneurysmal region 67 can be expected to reduce in size with the use of a competent replacement valve. [0105] For self-expanding materials that can be formed into a tubular shape (e.g. a collagen sponge), it is also possible to introduce the self-expanding member separately prior to the introduction of the docking station and the valve frame. In these embodiments, the self-expanding member can have an outer wall, an inner wall, and a lumen defined by the inner wall. The self-expanding member can be characterized by the compression strength of its walls such that the diameter of the lumen can increase or decrease depending on the pressure exerted against the inner wall.

[0106] In use, the self-expanding member can be first introduced via an introducing catheter to the aneurysmal region. Upon contact with blood, the self- expanding member can swell and anchor against the wall of the anatomical cavity. The docking station can then be inserted into the lumen of the self-expanding member and deployed. Optionally, a balloon can be used to expand and/or shape the docking station to a desirable configuration and size. The docking station, in its expanded state, should exert sufficient pressure against the lumen of the self- expanding member to secure itself immovably within the self-expanding member. The expansion of the docking station can also press the inner wall of the self- expanding member against the outer wall of the self-expanding member, thereby further securing the swollen self-expanding member in the aneurysmal region. Finally, the valve frame can be introduced into the lumen of the docking station and deployed as described above. [0107] In another embodiment, as illustrated in FIGS. 1 IA and I IB, a valve assembly 110 according to the present teachings is a unitary body that comprises the functionality of both a docking station, such as the docking station 30 of any of FIGS. IA and IB, and a valve frame, such as the valve frame 40 of any of FIGS. 2A and 2B. The valve assembly 110 can be constructed from a mesh 112. The mesh 112 can be constructed from, for example, wires or strips of shape memory material as previously described herein. In certain embodiments, an outer wall of the valve assembly 110 can be associated with one or more self-expanding members (not shown). These self-expanding members can be made from various self-expanding materials such, as the ones previously listed. The one or more self-expanding members can be associated with the outer wall of the valve assembly in a variety of configurations, including but not limited to the configurations shown in FIGS. 1C, ID, IE, and IF. The expansion of the self-expanding members can be triggered by contact with a fluid such as blood, which then can help to anchor the valve assembly in an aneurysmal region.

[0108] Referring now to FIGS. 1 IA, 1 IB and 11C, the valve assembly 110 can have three valve gaps I l ia, 111b and 11 1c, each of which can act as a hinge point for a cover material, for example, the cover material 56 of FIG. 3C. Valve gap 111b is shown in hidden view in FIG. 1 IB for clarity of illustration purposes.

[0109] The cover material 56 can be a biocompatible material such as silicon rubber or bovine, porcine or human tissue that is chemically treated to minimize the likelihood of rejection by the patient's immune system. The cover material 56 is not shown in FIG. 1 IB for clarity of illustration purposes. The cover material 56 can be applied to the valve assembly 110 prior to deployment of the valve assembly 1 10 into the body. The cover material can be, for example, sutured to the valve assembly 110 in a location 118a, 118b and 118c (1 18b is not shown for clarity of illustration purposes). Subsequent to placement of the valve assembly 1 10 within the body, the cover material 56 is capable of, generally, permitting the flow of blood in the positive direction along the X-axis, as previously described herein.

[0110] The valve assembly 110 is capable of being compressed as described previously herein and loaded into an introducing catheter, such as the introducing catheter 61 of FIG. 6. Subsequent to insertion of the introducing catheter 61 into the heart of a patient and locating the introducing catheter 61 in a desirable location, an operator can deploy the valve assembly 110 from the introducing catheter 61. The valve assembly 110 can then expand because the introducing catheter 61 no longer applies a constraining force to the valve assembly 110. Alternatively, a balloon, such as the balloon 73 of FIG. 7 can be used, as described previously herein, to expand the valve assembly 110.

[0111] The valve assembly 110, alternatively, can be expanded by heating the shape memory material once the valve assembly 1 10 is located in a desirable location in the heart. The valve assembly can warm due to contact with, for example, heart tissue or blood of the patient.

[0112] However, as blood flows in the negative direction along the X-axis the free ends 119a, 119b and 119c (the free end 119b is not shown for clarity of illustration purposes) of the cover material 56 can move away from an inner wall 115 of the valve assembly 110. The cover material 56, thereby, can restrict the flow of blood through the valve assembly 1 10. In this manner, the valve assembly 110 can approximate the functioning of a natural heart valve of the body by preventing the flow of blood along the negative direction along the X-axis.

[0113] The valve gaps I l ia, 11 1b and 111c can be of any suitable shape (e.g., leaf shaped, oval shaped or generally polygonal shaped) and any number (e.g., three, four or six) such that depending upon the direction of the flow of blood, the flow of blood can be either adequately blocked or permitted by the presence of the cover material 56 located on the valve assembly 110. Additionally, the alternative shapes and number of valve gaps should allow the valve assembly to be loaded into and unloaded from an introducing catheter, such as the introducing catheter 61 of FIG. 6.

[0114] FIGS. 14A and 14B are digital images of a model 140 of a valve assembly, such as the valve assembly 110 of FIGS. 1 IA and 1 IB, respectively. For clarity of illustration purposes the valve assembly model 140 can be constructed from a tube 142 and a silicon rubber cover material 144. The valve assembly model 140, referring now to FIG. 14B, can be cylindrical in shape. The valve assembly model 140, alternatively, can be any geometric shape as described previously herein.

[0115] In another embodiment, now referring to FIGS. 12A and 12B, a valve assembly 120 can have three valve gaps I l ia, 111b and 111c (the valve gap 11 Ib is not shown for clarity of illustration purposes). The valve assembly 120 also can have three openings 121a, 121b and 121c (the opening 121b is not shown for clarity of illustration purposes). The openings 121a, 121b and 121c, for example, can represent openings in the valve assembly 120 that are in fluid communication with three coronary arteries in the heart. In some embodiments, the valve assembly 120 can only have two openings, one for the right main coronary artery and one for the left main coronary artery. Due to the presence of the valve openings, less material is required to fabricate the valve assembly 120. As such, it can be possible to use a smaller diameter, introducing catheter, such as the introducing catheter 61 of FIG. 4 to introduce the valve assembly 120 into the heart of the patient.

[0116] FIGS. 15A and 15B are digital images of a model 150 of a valve assembly, such as the valve assembly 120 of FIGS. 12A and 12B. For clarity of illustration purposes the valve assembly model 150 can be constructed from a tube 152 and a silicon rubber cover material 154. The valve assembly model 150, referring now to FIG. 15B, can be cylindrical in shape. The valve assembly model 150, alternatively, can be any geometric shape as described previously herein.

[0117] As shown in FIG. 16, another embodiment of a docking station 30 is illustrated. In this embodiment, the docking station 30 can approximate the form of a cloverleaf to closely conform, for example, to the cloverleaf-like shape (associated with the three sinuses of a natural heart valve) of the location in a heart where a defective heart valve has been surgically removed. The docking station 30 can define a generally cylindrical, elongated body that has a wall 34 that is constructed from a mesh 32. The wall 34 defines a lumen 36. The mesh 32 can be constructed from, for example, wires or strips of shape memory material or other alternative materials as earlier described. A self-expanding member 39 can be associated with the outer wall of the docking station 30 as described earlier. [01 18] Referring again to FIG. 16, the lumen 36 of the docking station 30 can include a neck portion 37 that can accommodate a partially deployed valve frame 40 (a valve frame 40 is illustrated in FIG. 17). The docking station 30 also can include a tapered portion 38 extending from a distal end 31 of the docking station 30 and a bulbous portion 35 extending from a proximal end 33 of the docking station 30.

[0119] Enabling a valve frame 40 to partially, deploy within the docking station 30 can be beneficial, since the valve frame 40 can be repositioned in the docking station 30 prior to being fully deployed in the docking station 30. Repositioning the valve frame 40 can be necessary, for instance, to ensure a proper alignment of the valve frame 40 within the lumen 36 of the stentdocking station 30 so that movement of the valve frame 40 with respect to the docking station 30 is minimal once the valve frame 40 is fully deployed.

[0120] FIG. 17 illustrates one embodiment of a valve frame 40 in deployed form (i.e., not constrained by a wall of a catheter used to introduce the valve frame 40 into the body). The valve frame 40 can be deployed within a docking station, such as the docking station 30 of FIG. 16 and can be constructed as described earlier with reference to FIGS. 2 A and 2B.

[0121] As earlier described, the valve frame 40 can be deployed within the lumen 36 of the docking station 30 thereby creating a valve assembly 50 (FIG. 18E). In one embodiment, the valve assembly 50 can be deployed within a human heart to replace a natural heart valve that is not functioning properly. The valve frame 40 and the docking station 30 can be manufactured to ensure that the valve frame 40 maintains a desired (e.g., fixed) placement with respect to the docking station 30 when the valve frame 40 and the docking station 30 are located within the heart of a patient and subjected to the flow of blood through the valve assembly 50.

[0122] In more detail and with reference to FIGS. 18A-18E, method steps associated with introducing an embodiment of the present teachings into an anatomical lumen are described. As an initial step, with the aid of a fluoroscope, an introducing catheter 61 is delivered via a vessel to the heart by means of a guide wire 62 to a preselected position in an anatomical lumen of the heart. The preselected position can be, for instance, in proximity to the original location of a natural heart valve. The introducing catheter 61 can have an inner wall 69 that defines a lumen 64 through which the guidewire 62 can pass. The introducing catheter 61 can have an opening 66 out of which the guidewire 62 can be extended. In an alternative embodiment, a catheter can be inserted and maneuvered within a patient without the use of a guidewire 62.

[0123] With reference to FIG. 18A, the docking station 30 can be compressed and inserted into the introducing catheter 61, and the docking station 30 can be guided in a distal direction to the catheter orifice 66 over the guidewire 62. Alternatively, the guidewire 62 can be removed, and the docking station 30 can be guided through the introducing catheter 61 to the catheter orifice 66 using the walls 69 of the introducing catheter 61 as a guide.

[0124] Once the docking station 30 reaches the catheter orifice 66, the docking station 30 can be guided through the orifice and into the body. The docking station 30 can be expanded to a predetermined configuration and size, using methods previously described. The expanded configuration of the docking station 30 can conform to a region of the anatomical lumen (not shown) and in one embodiment, the size and shape of the docking station 30 can be sufficient to hold the docking station 30 in a substantially fixed position and orientation within the anatomical lumen. In other embodiments, the docking station 30 can include elements (e.g., sutures, hooks, spikes or tack tips) that attach to the interior walls of the anatomical lumen so as to more rigidly hold the docking station 30 in a fixed position. In alternative embodiments, the expanded configuration of the docking station 30 by itself may not be sufficiently wide to be secured in a region of the anatomical lumen, for example, an aneurysmal region of an outflow tract of the heart. For such applications, the replacement valve assembly can include a self-expanding member 39 attached to the outer wall of the docking station, which upon expansion (for example, after contact with and/or absorption of blood) can conform to the aneurysmal region.

[0125] Referring to FIG. 18B, after the docking station 30 is inserted into the body, the valve frame 40 can be compressed and inserted into the introducing catheter 61. Like the docking station 30, the valve frame 40 can be guided in a distal direction to the catheter orifice 66 over the guide wire. Alternatively, the guidewire 62 can be removed, and the valve frame 40 can be guided through the introducing catheter 61 to the catheter orifice 66 using the walls 69 of the introducing catheter 61 as a guide.

[0126] Referring to FIG. 18C, once the valve frame 40 reaches the catheter orifice 66, the valve frame 40 can be partially deployed into the neck portion 37 of the elongated lumen 36 of the expanded docking station 30. The elongated docking station 30 and the elongated body of the valve frame 40 can enable the valve frame 40 to be partially deployed in the docking station 30. In the partially deployed state, the valve frame 40 can still be retracted into the introducing catheter 61, and repositioned within the docking station 30 if necessary. Upon being partially deployed, a distal end 47 of the valve frame 40 can expand and assume substantially the same size and shape as the lumen 36 of the expanded docking station30. A determination is then made, for example, using fluoroscopy, as to whether the valve frame 40 is properly positioned within the docking station 30. To be properly positioned, the distal end 47 of the valve frame should align as shown in FIG. 18C with the tapered portion 38 of the docking station 30. If a determination is made that the docking station 30 and the valve frame 40 are not in proper alignment, the valve frame 40 can be retracted into the introducing catheter 61, and then re-deployed at the proper location within the docking station 30.

[0127] Once the valve frame 40 is properly aligned with the docking station 30, the medical practitioner can fully release the valve frame 40 into the docking station 30, and withdraw the catheter 61 (FIGS. 18D-18E). When the valve frame 40 is fully deployed within the docking station 30, the valve frame 40 can expand and adjust to substantially correspond with the shape of the docking station 30, such that the outer surfaces of the valve frame 40 mate with the inner surfaces of the docking station 30. The mating surfaces of the valve frame 40 and the docking station 30 can maintain the positioning of the valve frame 40 within the docking station 30. For example, the distal end 47 of the valve frame 40 can engage with the tapered portion 38 of the docking station 30, and the valve members 44a, 44b, and 44c can expand to engage the bulbous portion 35 of the docking station 30. [0128] Referring to FIGS. 19A-19E, in other embodiments, the docking station 130 can be any geometric shape (e.g., cylindrical, conical, spherical or barrel-like) that is compatible with the placement of the docking station 130 within, for example, a lumen of the heart or in a ureter. The illustrated docking stations 130 can be made from the docking station materials described earlier. One or more of the self- expanding members 39 described earlier can be present in association with the outer wall of these docking stations. The docking stations 130 when inserted into the body can hold a variety of devices in addition to valves, such as the valve frame 40 of FIG. 3C (as shown in FIG. 19B). For example, referring to FIG. 19A, the docking station 130 can include a pocket that receives a capsule of medicine 135. The capsule 135 can be held in place by frictional engagement with the docking station 130. For example, dimples can protrude inwardly from the inner surface of the docking station 130 to engage the capsule. Referring to FIG. 19C, in another embodiment, the docking station 130 can include an external annular ring 131 that can hold a pressure-responsive valve and/or sphincter 132 to reduce the flow of fluids in a body cavity. In another embodiment as illustrated in FIG. 19D, the docking station 130 can include a recessed surface or cavity 133 that can hold a monitoring device 137, such as a video camera, a blood pressure monitor, a heart rate monitor, an electroencephalogram (EEG) device, or an elctrocardiogram (ECG or EKG) sensor. Referring to FIG. 19E, the docking station 130, in one embodiment, can form a closed body to receive a medical device, drug, or radiation source 139. In one embodiment, the drug can be a slow-release medication formulation. The closed end 134 of the docking station 130 can be coupled to a mounting device 136 that can be used to secure the docking station 130 in the body. [0129] Referring to FIGS 20A-20F, the docking station 130 is shown inserted into various locations of the body including a blood vessel (FIG. 20A), the brain (FIG. 20B), a ureter (FIG. 20C)₃ the stomach (FIG. 20D), the colon (FIG. 20E), and the heart (FIG. 20F). In general, the docking station 130 can be inserted into any cavity, organ, vessel, valve, sphincter, or lumen of the body. The docking station 130 can be inserted through a catheter, as described above with reference to FIGS. 18A-18E. Once the docking station 130 is placed in the body, the docking station 130 can receive medical devices that either temporarily or permanently couple with the docking station 130 as described above. As an example, as illustrated in FIG. 2OB, a drug/radiation source 139 can be inserted into a docking station 130 located in the brain to treat a seizure focus, a malignancy, or to repair damaged tissue. Alternatively, referring to FIGS. 2OC and 2OD, a docking station 130 mounted in the stomach or a ureter can couple to a pressure-responsive valve and/or sphincter (FIG. 19C) to prevent reflux. Referring to FIG. 2OE, in another embodiment, a docking station 130 similar to the docking station 130 illustrated in FIG. 19D can be inserted into the colon. The docking station 130 can then receive a monitoring device to provide feedback to care providers. Referring to FIG. 2OF, as another example, a heart rate monitor, an electrocardiogram sensor, or a pacemaker can be coupled to a docking station 130 implanted in the heart. One advantage of the apparatus disclosed herein is that if a medical device or a drug is no longer required, the medical device or drug can be removed from the docking station 130, with the docking station 130 remaining in place within the body for future use with another medical device or drug. [0130] In another embodiment (FIG. 21 ) the replacement valve assembly 310 can include a docking station 330, a self-expanding member 339, and a valve frame 340. The docking station 330 can be expandable between a first compressed state (shown) and a second expanded state (not shown). The docking station 330 can have a cylindrical body constructed from a plurality of serpentine wires (generally 331). Each of the serpentine curves of a first wire 331 can be attached at the vertices 333 to each of the serpentine curves of an adjacent wire 331. In one embodiment the wires 331 can be constructed of stainless steel. At each end of the docking station 330 can be an additional serpentine shaped end wire (generally 334) having serpentine curves of smaller radius. Several of the vertices of each of these serpentine end wires 334 can be attached to several of the vertices 336 other serpentine wires 331 of the body. The self-expanding member 339 can be adapted to be associated with the outer wall of the cylindrical body of the do'cking station 330 in one of the manners described earlier in accordance with self-expanding member 39 and docking station 30.

[0131] Referring also to FIG. 22, the valve frame 340 can include a substantially cylindrical body portion 341, a plurality of valve attachment pairs 346, and a plurality of standoffs 350 attached to one or more exterior serpentine wire rings 353. In some embodiments, and as shown in FIG. 26, the plurality of standoffs 350 and the one or more exterior serpentine wire rings 353 can be absent.

[0132] The substantially cylindrical body portion 341 of the valve frame 340 can be constructed of a plurality of serpentine curved wires 352. Each of the vertices 356 of the serpentine curves of a first wire 352 can be attached at the vertices 356 to each of the vertices of the serpentine curves of an adjacent wire 352. In one embodiment the wires 352 can be constructed of nitinol. Again the substantially cylindrical body portion 341 can be expandable between a first compressed state (not shown) and a second expanded state (shown). It should be noted that when the terms "vertex" or "trough" are used, the convention is that the term "trough" is a bend in the wire that points in the direction of blood flow (i.e., in the positive direction of X shown in FIG. 22) and a "vertex" is a bend that points in a direction opposite blood flow (i.e., in the negative direction of X shown in FIG. 22).

[0133] At one end of the cylindrical body 341 of the valve frame 340 are three sets of valve attachment pairs 346 for attaching valve leaflets 390. Each valve attachment pair 346 can include an inner curved support structure 358 and an outer curved support structure 360. Each curved support structure 358, 360 can be attached either to a vertex 362, 364 (respectively as shown in FIG. 21) or to a trough 372 and vertex 370 (respectively as shown in FIG. 22). In some embodiments (as shown in FIGS. 22 and 26), the space S between the inner curved support structure 358 and the outer curved support structure 360 can be constant. The space S, for example, can be in the range of about 2-3 mm. The inner curved support structure 358 and the outer curved support structure 360, as well as the space S therebetween, can be substantially parabolic in shape (as shown in FIG. 22) or can resemble a pocket, i.e., a partial rectangle with rounded corners (as shown in FIG. 26).

[0134] By placing the attachment of the outer 360 and inner 358 curved support structures to the body 341 of the valve frame 340, at adjacent vertices 370 and troughs 372, the distance between the inner 358 and outer 360 curved support structures can be substantially assured. As a result, the movement of the valve leaflets 390 does not cause the curved support structures 358, 360 to touch, thereby preventing damage to the leaflets 390.

[0135] In some embodiments, the inner curved support structure 358 and the outer curved support structure 360 each can include one piece of wire only (shown in FIG. 22). In other embodiments, the inner curved support structure 358 can have one piece of wire, while the outer curved support structure 360 can have two or more pieces of wire (shown in FIG. 26). It is preferred that the two or more pieces of wire of the outer curved support structure 360 can be spaced as closely as possible but still permit passage of the chosen cover material 396 (shown in FIGS. 27 and 28). For example, the cover material can have a thickness of 0.4 mm to about 1.0 mm, and the space between the wires of the outer curved support structure can be within the range of about 0.5 mm to about 1.0 mm.

[0136] More details of the leaflet 390 are shown in FIG. 24. With reference to FIGS. 23, 24, 25, 27 and 28, a leaflet 390 can be attached to each valve attachment pair 346. Each leaflet 390 can have a leaflet body 396 and a plurality of leaflet projections 392. When attached to the valve frame 340, the leaflet body 396 can be located within the lumen of the valve frame 340.

[0137] Referring to FIG. 25, the leaflet 390 can be positioned such that the portion of the leaflet body 396 nearest the projections 392 can be pulled over the outer curved support structure 360 and the leaflet projections 392 can be curved over the inner curved support structure 358. Each leaflet projection 392 can be attached by sutures 394 to itself. This can anchor the leaflet projections 392 to the inner curved support structure 358 and permit the leaflet body 396 to be secured and maintain its shape within the lumen of the valve frame 340. This configuration can prevent the sutures 394 from being exposed to blood passing through the valve and provide free motion of the leaflet body without any contact to prosthetic materials thereby preventing damage to the leaflet.

[0138] In the embodiment shown in FIG. 28, the two wires of the outer curved support structure 360 can be placed very close to each other. Similar to the embodiment shown in FIG. 25, the leaflet 390 can be positioned such that the portion of the leaflet body 396 nearest the projections 392 can be pulled over the outermost wire of the outer curved support structure 360. Each of the leaflet projections 392 can then pass through the space between the two wires of the outer curved support structure 360. Because the space between these two wires is designed to barely allow passage of the cover material 396, displacement of the leaflet between the docking station and the valve frame is minimized, in addition to the other advantages described in accordance with the embodiment shown in FIG. 25. Each of the leaflet projections 392 can then wrap over the inner curved support structure 358 and can be attached by sutures 394 to itself as in the other embodiment.

[0139] FIG. 29 depicts a similar valve frame but one in which the inner 358 and outer 360 curved support structures are attached to the same location 404 on vertices of wire 352 of the cylindrical body 352. Additionally, a plurality of standoffs 350 can hold one or more exterior serpentine rings 353 at a distance away from the outer curved support structure 360 to provide extra support to the valve frame 340. At several locations on the exterior serpentine ring(s) 353 are located platinum markers 400. In some embodiments (shown) platinum wire can be wrapped about the exterior serpentine ring(s) 353 in several locations. These locations can then serve as radiopaque markers 400 to help position the valve frame 340 within the docking station 330. hi other embodiments, the platinum markers can also be positioned on the opposite end of the valve frame so that both ends of the valve frame 340 can be seen clearly under fluoroscopy as the valve frame 340 is positioned within the docking station 330. Each standoff 350 should be long enough so that when the valve frame 340 is compressed to fit within a catheter, the leaflet 396 which is turned over the outer support structure 360 does not contact the exterior serpentine ring 353 thereby potentially causing damage to the leaflet 390. Similar platinum markers can be positioned on one or both ends of any of the valve frames described hereinabove, including the valve frames shown in FIGS. 22 and 26.

[0140] In use, the docking station 330 can be inserted into position in the heart through a catheter as described previously with respect to other embodiments. An optional self-expanding member 339 (not shown), if present, can be allowed to expand to help anchor the docking station 330 in a large anatomical lumen. An elongated balloon can be introduced through a catheter into the lumen of the docking station 330. The balloon can be inflated within the docking station 330 and the docking station 330 can expand radially and substantially uniformly along its length. Then a second balloon that is substantially spherical in shape can be introduced into the middle of the expanded docking station 330 and inflated. This additional inflation causes the center region of the docking station 330 to expand further causing the docking station 330 to take on a barrel shape. [0141] Next the compressed valve frame 340 with attached leaflets 396 can be introduced into the docking station 330 through a catheter and permitted to expand. The tapered ends of the barrel shape of the docking station 330 can hold the valve frame 340 in place even when the closed valve results in pressure being placed on the valve frame 340 due to the stopped blood flow.

[0142] Other embodiments incorporating the concepts disclosed herein can be used without departing from the spirit and scope of the present teachings. The described embodiments are to be considered in all respects as only illustrative and not restrictive.

[0143] What is claimed is:

Claims

1. A replacement valve apparatus comprising: a docking station; a valve frame positioned within the docking station; and a self-expanding member comprising a self-expanding material, wherein the self-expanding member is associated with an outer wall of the docking station.

2. The replacement valve apparatus of claim 1, wherein the self-expanding member is attached to the outer wall of the docking station.

3. The replacement valve apparatus of claim 1 or 2, wherein the self- expanding material is non-biodegradable.

4. The replacement valve apparatus of any one of claims 1-3, wherein the self-expanding material expands upon contact with a fluid.

5. The replacement valve apparatus of claim 4, wherein the fluid is blood.

6. The replacement valve apparatus of any one of claims 1-5, wherein the self-expanding member comprises a foam, a sponge, or a hydrogel.

7. The replacement valve apparatus of any one of claims 1-5, wherein the self-expanding member comprises one or more natural or synthetic polymers selected from polyvinyl alcohol, polyurethane, polyethylene, polypropylene, polytetrafluoroethylene, polyacrylate, polymethacrylate, polystyrene, polylactide, polycaprolactone, silicone, collagen, elastin, and copolymers thereof.

8. The replacement valve apparatus of claim 6, wherein the self-expanding member comprises a collagen sponge.

9. The replacement valve apparatus of any one of claims 1-3, wherein the self-expanding member comprises a nitinol mesh.

10. The replacement valve apparatus of any one of claims 1-8, wherein the self-expanding member forms a continuous layer attached to the outer wall of the docking station.

1 1. The replacement valve apparatus of any one of claims 1-10, wherein the self-expanding member is attached to the outer wall of the docking station by gluing, stitching, or welding.

12. The replacement valve apparatus of any one of claims 1-11, wherein the valve frame comprises a substantially cylindrical body defining a lumen and a plurality of curved support structures attached to the substantially cylindrical body, the valve frame further comprising a plurality of leaflets, each leaflet comprising a leaflet body and a leaflet projection, the leaflet projection attached to a respective inner curved support structure and the leaflet body extending over a respective outer curved support structure, so as to position the body of the leaflet within the lumen of the valve frame.

13. The replacement valve apparatus of claim 12 wherein the inner curved support structure and the outer curved support structure individually resemble a pocket in shape.

14. The replacement valve apparatus of claim '12 or 13 wherein the outer curved support structure comprises two wires.

15. The replacement valve apparatus of claim 14 wherein the wires are separated along a portion of their lengths by a distance of about a suture or stitch diameter.

16. The replacement valve apparatus of any one of claims 12-15 wherein one end of the valve frame has a serpentine edge and wherein the inner curved support structure is attached to a vertex of the serpentine edge and the outer curved support structure is attached to a trough of the serpentine edge.

17. The replacement valve apparatus of any one of claims 1-16 further comprising a radiopaque marker at each end of the valve frame.

18. A method of replacing a heart valve with a replacement valve, the method comprising: providing a replacement valve assembly, the replacement valve assembly comprising a docking station, a self-expanding member, and a valve frame, wherein the self-expanding member is associated with an outer wall of the docking station; introducing the docking station into a heart through a catheter; contacting the self-expanding member with a fluid; introducing a valve frame into the docking station through a catheter; positioning the valve frame within the docking station; and releasing the valve frame within the docking station.

19. The method of claim 18, wherein the self-expanding member is attached to the outer wall.

20. The method of claim 18 or 19, wherein the self-expanding member comprises a collagen sponge.