US20060025857A1

US20060025857A1 - Implantable prosthetic valve

Info

Publication number: US20060025857A1
Application number: US11/112,757
Authority: US
Inventors: Bjarne Bergheim; Keith Meyers; Jeff DuMontelle; Christine Nguyen
Original assignee: Bjarne Bergheim; Meyers Keith E; Dumontelle Jeff; Christine Nguyen
Current assignee: Medtronic 3F Therapeutics Inc
Priority date: 2004-04-23
Filing date: 2005-04-22
Publication date: 2006-02-02
Also published as: JP2010188140A; US20070270944A1; JP5290573B2; BRPI0510107A; AU2005234793A1; WO2005102015A3; US9775704B2; AU2005234793B2; JP2007534381A; EP1753374A2; CN101052359A; EP1753374A4; JP2013066772A; WO2005102015A2; US20180036122A1

Abstract

The present invention provides valve prostheses adapted to be initially crimped in a narrow configuration suitable for catheterization through body ducts to a target location and adapted to be deployed by exerting substantially radial forces from within by means of a deployment device to a deployed state in the target location.

Description

This application claims the benefit of U.S. Provisional Application No. 60/565,118, filed Apr. 23, 2004.

FIELD OF THE INVENTION

The present invention relates to implantable devices. More specifically, the present invention relates to heart valve prosthetic devices for cardiac implantation. The present invention may also be utilized in other body cavities, vessels, or ducts.

BACKGROUND OF THE INVENTION

The transport of vital fluids in the human body is largely regulated by valves. Physiological valves are designed to prevent the backflow of bodily fluids, such as blood, lymph, urine, bile, etc., thereby keeping the body's fluid dynamics unidirectional for proper homeostasis. For example, venous valves maintain the upward flow of blood, particularly from the lower extremities, back toward the heart, while lymphatic valves prevent the backflow of lymph within the lymph vessels, particularly those of the limbs.
Because of their common function, valves share certain anatomical features despite variations in relative size. The cardiac valves are among the largest valves in the body with diameters that may exceed 30 mm, while valves of the smaller veins may have diameters no larger than a fraction of a millimeter. Regardless of their size, however, many physiological valves are situated in specialized anatomical structures known as sinuses. Valve sinuses can be described as dilations or bulges in the vessel wall that houses the valve. The geometry of the sinus has a function in the operation and fluid dynamics of the valve. One function is to guide fluid flow so as to create eddy currents that prevent the valve leaflets from adhering to the wall of the vessel at the peak of flow velocity, such as during systole. Another function of the sinus geometry is to generate currents that facilitate the precise closing of the leaflets at the beginning of backflow pressure. The sinus geometry is also important in reducing the stress exerted by differential fluid flow pressure on the valve leaflets or cusps as they open and close.
Thus, for example, the eddy currents occurring within the sinuses of Valsalva in the natural aortic root have been shown to be important in creating smooth, gradual and gentle closure of the aortic valve at the end of systole. Blood is permitted to travel along the curved contour of the sinus and onto the valve leaflets to effect their closure, thereby reducing the pressure that would otherwise be exerted by direct fluid flow onto the valve leaflets. The sinuses of Valsalva also contain the coronary ostia, which are outflow openings of the arteries that feed the heart muscle. When valve sinuses contain such outflow openings, they serve the additional purpose of providing blood flow to such vessels throughout the cardiac cycle.
When valves exhibit abnormal anatomy and function as a result of valve disease or injury, the unidirectional flow of the physiological fluid they are designed to regulate is disrupted, resulting in increased hydrostatic pressure. For example, venous valvular dysfunction leads to blood flowing back and pooling in the lower legs, resulting in pain, swelling and edema, changes in skin color, and skin ulcerations that can be extremely difficult to treat. Lymphatic valve insufficiency can result in lymphedema with tissue fibrosis and gross distention of the affected body part. Cardiac valvular disease may lead to pulmonary hypertension and edema, atrial fibrillation, and right heart failure in the case of mitral and tricuspid valve stenosis; or pulmonary congestion, left ventricular contractile impairment and congestive heart failure in the case of mitral regurgitation and aortic stenosis. Regardless of their etiology, all valvular diseases result in either stenosis, in which the valve does not open properly, impeding fluid flow across it and causing a rise in fluid pressure, or insufficiency/regurgitation, in which the valve does not close properly and the fluid leaks back across the valve, creating backflow. Some valves are afflicted with both stenosis and insufficiency, in which case the valve neither opens fully nor closes completely.
Because of the potential severity of the clinical consequences of valve disease, valve replacement surgery is becoming a widely used medical procedure, described and illustrated in numerous books and articles. When replacement of a valve is necessary, the diseased or abnormal valve is typically cut out and replaced with either a mechanical or tissue valve. A conventional heart valve replacement surgery involves accessing the heart in a patient's thoracic cavity through a longitudinal incision in the chest. For example, a median sternotomy requires cutting through the sternum and forcing the two opposite halves of the rib cage to be spread apart, allowing access to the thoracic cavity and the heart within. The patient is then placed on cardiopulmonary bypass, which involves stopping the heart to permit access to the internal chambers. Such open heart surgery is particularly invasive and involves a lengthy and difficult recovery period. Reducing or eliminating the time a patient spends in surgery is thus a goal of foremost clinical priority.
One strategy for reducing the time spent in surgery is to eliminate or reduce the need for suturing a replacement valve into position. Toward this end, valve assemblies that allow implantation with minimal or no sutures would be greatly advantageous. Attaching a valve such as a tissue valve to a support structure such as a stent may enable a valve assembly that allows implantation with minimal or no sutures. It is important that such valve constructs are configured such that the tissue leaflets or the support valve don't come into contact with the support structure, either during the collapsed or expanded state, or both in order to prevent abrasion. Such contact is capable of contributing undesired stress on the valve leaflet. Moreover, it is advantageous that such support structures are configured to properly support a tissue valve having a scalloped inflow annulus such as that disclosed in the U.S. patent application Ser. No. 09/772,526 which is incorporated by reference herein in its entirety.
Accordingly, there is a need for a valve replacement system comprising a collapsible and expandable valve assembly that is capable of being secured into position with minimal or no suturing; facilitating an anatomically optimal position of the valve; maintaining an open pathway for other vessel openings of vessels that may be located in the valvular sinuses; and minimizing or reducing stress to the tissue valve leaflets. The valves of the present invention may comprise a plurality of joined leaflets with a corresponding number of commissural tabs. Generally, however, the desired valve will contain two to four leaflets and commissural tabs. Examples of other suitable valves are disclosed in U.S. patent application Ser. Nos. 09/772,526, 09/853,463, 09/924,970, 10/121,208, 10/122,035, 10/153,286, 10/153,290, the disclosures of all of which are incorporated by reference in their entirety herein. Likewise, the systems and methods disclosed in U.S. patent application Ser. No. 10/831,770, filed Apr. 23, 2004, are fully incorporated by reference herein.
As mentioned above, an open-heart valve replacement is a long tedious procedure. For implantation of a bioprosthetic valve in the aortic position, a surgeon typically opens the aorta and excises the native valve. The surgeon then inserts the prosthetic valve through the opening in the aortic wall and secures the prosthesis at the junction of the aorta and the left ventricle. The inflow annulus of the valve faces the left ventricle and, relative to the surgeon's perspective, may be termed the distal annulus, while the outflow annulus of the valve faces the aorta and may be termed the proximal annulus.
An alternative procedure for approaching the left atrium and the aortic or mitral valve is by intravascular catherization from a femoral vein through the cardiac septum, which separates the right atrium and the left atrium. Yet another alternative for approaching the left atrium and the aortic or mitral valve is by intravascular catherization from a femoral artery up through aortic valve.
Andersen et al. in U.S. Pat. No. 6,582,462, entire contents of which are incorporated herein by reference, discloses a valve prosthesis for implantation in a body channel having an inner wall, the prosthesis comprising a radially collapsible and expandable cylindrical stent, the stent including a cylindrical support means having a cylinder surface; and a collapsible and expandable valve having commissural points, the valve mounted to the stent at the commissural points, wherein the stent and valve are configured to be implanted in the body by way of catheterization. It is one aspect of the present invention to utilize a balloon expandable stent coupled with a tissue valve. An alternative embodiment in the present invention to utilizing a balloon expandable stent is to utilize a self-expandable stent. Yet another alternative embodiment of the present invention to utilizing a balloon expandable stent is to utilize a stent that may be expanded with mechanical means.
Sterman et al. in U.S. Pat. No. 6,283,127, entire contents of which are incorporated herein by reference, discloses a device system and methods facilitating intervention within the heart or great vessels without the need for a median sternotomy or other form of gross thoracotomy, substantially reducing trauma, risk of complication, recovery time, and pain for the patient. Using the device systems and methods of the invention, surgical procedures may be performed through percutaneous penetrations within intercostal spaces of the patient's rib cage, without cutting, removing, or significantly displacing any of the patient's ribs or sternum. The device systems and methods are particularly well adapted for heart valve repair and replacement, facilitating visualization within the patient's thoracic cavity, repair or removal of the patient's natural valve, and, if necessary, attachment of a replacement valve in the natural valve position.
Haluck in U.S. Pat. No. 6,685,724, entire contents of which are incorporated herein by reference, discloses a surgical instrument for use in performing endoscopic procedures having a handle and an elongate tubular member having a proximal end coupled with the handle for being disposed externally of the anatomical cavity and a distal end for being disposed within the anatomical cavity. The distal end further includes a pair of opposed, relatively movable jaws that form a grasping portion operable by manipulation of the handle to releasably grasp a releasable trocar. The releasable trocar has a complementarily shaped shank, a relatively sharp tip and may include a pair of blunt-edge tissue separators that project outwardly from the outer surface of the trocar.
Endoscopic and minimally invasive medical procedures, such as laparoscopy, have become widely accepted for surgery and illness diagnosis. This is due to reduced trauma to the patient and reduced hospitalization time. Other techniques exist for creating a working space within the body cavity. At the beginning of most laparoscopic cases, a small incision is made, followed by a small (about 1 cm) port in the remaining layers of the tissue wall so as to gain access to the cavity.
Hunsberger in U.S. Pat. No. 6,613,063, entire contents of which are incorporated herein by reference, discloses a trocar assembly which includes a shank having a distal end and a proximal end, and a planar piercing blade having two substantially flat faces and a cutting contour, where the piercing blade is integrally attached to the distal end of the shank. The shank tapers inwardly towards the opposed flat faces of the piercing blade.
Further, McFarlane in U.S. Pat. No. 6,478,806, entire contents of which are incorporated herein by reference, discloses a tissue penetrating instrument of the type used in the medical field and which may or may not be embodied in the form of an obturator associated with a trocar assembly, wherein the instrument includes an elongated shaft having a penetrating tip mounted on one end thereof. The penetrating tip includes a base secured to the one end of the shaft and a distal extremity spaced longitudinally outward from the base and formed into an apex which may be defined by a point or other configuration specifically structured to facilitate penetration or puncturing of bodily tissue.
Spenser et al. disclose in U.S. patent application Ser. Nos. 09/975,750, 10/270,252, and 10/637,882, entire contents of which are incorporated herein by reference, disclose and implantable prosthetic valve that comprises a support sent to be initially crimped in a narrow configuration suitable for catherization through the body duct to a target location.
Key features of any valve where sutures to hold the replacement valve into position are to be eliminated or reduced are: durability, low-pressure gradient across the valve, sufficient seal around the valve to prevent perivalvular leak, and prevent migration. Therefore, it would be desirable to provide an implantable valve that with features that aim to increase durability, reduce pressure gradient across the valve, and provide an adequate seal around the valve and prevent migration.

SUMMARY OF THE INVENTION

The present invention provides a valve prosthesis that in one embodiment comprises a support stent, comprised of a deployable construction adapted to be initially crimped in a narrow configuration suitable for catherization through the body ducts to a target location and adapted to be deployed by exerting substantially radial forces from within by means of a deployment device to a deployed state in the target location, the support stent provided with a plurality of longitudinally rigid support beams of fixed length; and a valve assembly comprising a flexible conduit having an inlet end and an outlet, made of pliant material attached to the support beams providing collapsible slack portions of the conduit at the outlet, whereby when flow is allowed to pass through the valve prosthesis device from the inlet to the outlet the valve assembly is kept in an open position whereas a reverse flow is prevented as the collapsible slack portions of the valve assembly collapse inwardly providing blockage to the reverse flow.
In another embodiment of the present invention, the support stent comprises an annular frame.
In yet another embodiment of the present invention, the support stent is made out of stainless steel.
In yet another embodiment of the present invention, said valve assembly has a tricuspid configuration.
In yet another embodiment of the present invention, said valve assemblyis made from biocompatible material.
In yet another embodiment of the present invention, the valve assembly is made from pericardial tissue, or other biological tissue.
In yet another embodiment of the present invention, said valve assembly is made from biocompatible polymers.
In yet another embodiment of the present invention, the valve assembly is made from materials selected from the group consisting of polyurethane and polyethylene terphthalane.
In yet another embodiment of the present invention, the valve assembly comprises a main body made from polyethylene terphthalane and leaflets made from polyurethane.
In yet another embodiment of the present invention, said support stent is made from nickel titanium alloys.
In yet another embodiment of the present invention, the support beams are substantially equidistant and substantially parallel so as to provide anchorage for the valve assembly.
In yet another embodiment of the present invention, the support beams are provided with bores so as to allow stitching or tying of the valve assembly to the beams.
In yet another embodiment of the present invention, the support beams are not provided with bores so as to allow extra rigidity to the valve support structures.
In yet another embodiment of the present invention, the support beams are chemically adhered to the support stent.
In yet another embodiment of the present invention, said valve assembly is riveted to the support beams.
In yet another embodiment of the present invention, said beams are manufactured by injection using a mold, or by machining.
In yet another embodiment of the present invention, said valve assembly is rolled over the support stent at the inlet.
In yet another embodiment of the present invention, said valve device is manufactured using forging or dipping techniques.
In yet another embodiment of the present invention, said valve assembly leaflets are longer than needed to exactly close the outlet, thus when they are in the collapsed state substantial portions of the leaflets fall on each other creating better sealing.
In yet another embodiment of the present invention, said valve assembly is made from coils of a polymer, coated by a coating layer of same polymer.
In yet another embodiment of the present invention, said polymer is polyurethane.
In yet another embodiment of the present invention, the support stent is provided with heavy metal markers so as to enable tracking and determining the valve device position and orientation.
In yet another embodiment of the present invention, the heavy metal markers are selected from gold, platinum, iridium, tantalum, cobalt, chrome, and titanium alloys.
In yet another embodiment of the present invention, the valve assembly leaflets are provided with radio-opaque materials at the outlet so as to help tracking the valve device operation in vivo.
In yet another embodiment of the present invention, said radio0opque material comprises gold thread.
In yet another embodiment of the present invention, the diameter of said support stent when fully deployed is in the range of from about 15 to about 33 mm.
In yet another embodiment of the present invention, the diameter of said support stent may be expanded from about 4 to about 25 mm.
In yet another embodiment of the present invention, the diameter of said support stent may be expanded from about 10 mm to about 25 mm.
In yet another embodiment of the present invention, the support beams are provided with bores and wherein the valve assembly is attached to the support beams by means of U-shaped rigid members that are fastened to the valve assembly and that are provided with extruding portions that fit into matching bores on the support beams.
In yet another embodiment of the present invention, the support beams comprise rigid support beams in the form of frame construction, and the valve assembly pliant material is inserted through a gap in the frame and a fastening rod is inserted through a pocket formed between the pliant material and the frame and holds the valve in position.
In yet another embodiment of the present invention, the main body of the valve assembly is made from coiled wire coated with coating material.
In yet another embodiment of the present invention, the coiled wire and the coating material is made from polyurethane.
In yet another embodiment of the present invention, a strengthening wire is interlaced in the valve assembly at the outlet of the conduit so as to define a fault line about which the collapsible slack portion of the valve assembly may flap.
In yet another embodiment of the present invention, the strengthening wire is made from nickel titanium alloy.
In yet another embodiment of the present invention, there is provided a valve prosthesis device suitable for implantation in body ducts, the device comprising a main conduit body having an inlet and an outlet and pliant leaflets attached at the outlet so that when a flow passes through the conduit from the inlet to the outlet the leaflets are in an open position allowing the flow to exit the outlet, and when the flow is reversed the leaflets collapse so as to block the outlet, wherein the main body is made from polyethylene terphtalate and collapsible leaflets are made from polyurethane.
In yet another embodiment of the present invention, support beams made from polyurethane are provided on the main body and wherein the leaflets are attached to the main body at the support beams.
In yet another embodiment of the present invention, said support beams are chemically adhered to the main body.
In yet another embodiment of the present invention, there is provided a valve prosthesis device suitable for implantation in body ducts, the device comprising:
A support stent, comprised of a deployable construction adapted to be initially crimped in a narrow configuration suitable for catherization through the body duct to a target location and adapted to be deployed by exerting substantially radial force from within by means of a deployment device to a deployed state in the target location, the support stent provided with a plurality of longitudinally rigid support beams of fixed length;

- A valve assembly comprising a flexible conduit having an inlet and an outlet, made of pliant material attached to the support beams providing collapsible slack portions of the conduit at the outlet; and
- Substantially equidistant rigid support beams interlaced or attached to the slack portion of the valve assembly material, arranged longitudinally

In yet another embodiment of the present invention, the multiple plates are adapted to move simultaneously by means of a lever and transmission.
In yet another embodiment of the present invention, there is provided a method for deploying an implantable prosthesis valve device at the natural aortic valve position at the entrance to the left ventricle of a myocardium of a patient, the method comprising the steps of:

- (a) providing a balloon catheter having a proximal end and a distal end, having a first and second independently inflatable portions, the first inflatable portion located at the distal end of the catheter and the second inflatable portion adjacently behind the first inflatable portion;
- (b) providing a guiding tool for guiding the balloon catheter in the vasculature of the patient;
- (c) providing a deployable implantable valve prosthesis device adapted to be mounted on the second inflatable portion of the balloon catheter;
- (d) guiding the balloon catheter through the patient's aorta using the guiding tool, the valve device mounted over the second inflatable portion of the balloon catheter until the first inflatable portion of the balloon catheter is inserted into the left ventricle, whereas the second inflatable portion of the balloon catheter is positioned at the natural aortic valve position;
- (e) inflating the first inflatable portion of the balloon catheter so as to substantially block blood flow through the natural aortic valve and anchor the distal end of the balloon catheter in position;
- (f) inflating the second inflatable portion of the balloon catheter so as to deploy the implantable prosthesis valve device in position at the natural aortic valve positions;
- (g) deflating the first and second inflatable portions of the balloon catheter; and
- (h) retracting the balloon catheter and removing it from the patient's body.

In yet another embodiment of the present invention, the guiding tool compromises a guide wire.
In some further embodiments, the present invention provides a method for deploying an implantable prosthesis valve device at the natural aortic valve position at the entrance to the left ventricle of the myocardium of a patient, the method comprising the steps of:

- (a) providing a balloon catheter having a proximal end a distal end, having a first and second independently inflatable portions, the first inflatable portion located at the distal end of the catheter and the second inflatable portion adjacently behind the first inflatable portion;
- (b) providing a guiding tool for guiding the balloon catheter in the vasculature of the patient;
- providing a deployable implantable valve prosthesis device adapted to be mounted on the first inflatable portion of the balloon catheter, and a deployable annular stent device adapted to be mounted over the second inflatable portion of the balloon catheter, the deployable implantable valve prosthesis device and the deployable annular stent kept at a predetermined distance apart;
- (d) guiding the balloon catheter through the patient's aorta using the guiding tool, the valve device mounted over the first inflatable portion of the balloon catheter and the deployable annular stent mounted over the second inflatable portion of the balloon catheter, until the first inflatable portion of the balloon catheter is positioned at the natural aortic valve position;
- (e) inflating the second inflatable portion of the balloon catheter so that the deployable stent device is deployed within the aorta thus anchoring the deployable annular stent and the coupled valve device in position;
- (f) inflating the first inflatable portion of the balloon catheter so as to deploy the implantable prosthesis valve device in position at the natural aortic valve position;
- (g) deflating the first and second inflatable portions of the balloon catheter; and
- (h) retracting the balloon catheter and removing it from the patient's body.

It is one object of the valve device described in the present invention to presents a novel means of attaching a tissue valve to a support structure. The means of attaching the valve to the support structure may increase the durability of the valve, reduce the pressure gradient across the valve, provide a seal around the valve to prevent perivalvular leak, and prevent migration. The valves of the present invention may comprise a plurality of joined leaflets with a corresponding number of commissural tabs. Generally, however, the desired valve will contain two to four leaflets and commissural tabs.
In an embodiment of the present invention, the valves are similar to the valves disclosed in U.S. patent application Ser. Nos. 09/772,526, 09/853,463, 09/924,970, 10/121,208, 10/122,035, 10/153,286, 10/153,290, the disclosures of all of which are incorporated by reference in their entirety herein. The diameter of the valves described in these applications may be equal or less than the orifice diameter of the support structure of the valve.
In yet another embodiment of the present invention, the valves described in U.S. patent application Ser. Nos. 09/772,526, 09/853,463, 09/924,970, 10/121,208, 10/122,035, 10/153,286, 10/153,290, the valves are sized such that the effective valve diameter is 1-5 mm less than the diameter of the orifice of the support structures of the valve. This size will help prevent the valve leaflets from hitting the support structure.
In yet another embodiment of the present invention, the valves are made of equine pericardium.
In yet another embodiment of the present invention, a cuff (e.g. cloth) portion of the valve assembly is wrapped around the support stent at the inlet. This may enhance stability of the stent, but further, the cuff portion described in the current invention may be used for attaching sutures. Most importantly, the cuff portion of the present invention is intended to reduce perivalvular leak around the valve. Using such a cuff to create a seal between the valve structure and the aorta prevents perivalvular leak and is especially important in patients whose annulus (or landing zone for the valve) is calcified or irregular. The cuff may also prevent migration of the valve as the friction between the valve device and the surrounding is increased. Utilizing a cloth cuff may also induce tissue ingrowth. The cloth may initially clot when it is exposed to blood. The cloth may further induce endothelial and fibroblast, and hence tissue ingrowth into the cloth cuff.
In yet another embodiment of the present invention the cloth cuff creates a step between a thin cloth covering around the inlet portion of the valve assembly that moves up to a much thicker cloth cuff slightly further downstream in the assembly. Such a “lip” or “step” may help position and secure the valve prosthesis at the correct position.
In yet other embodiments of the present invention, the scalloped inflow edge described in U.S. application Ser. Nos. 09/772,526, 09/853,463, 09/924,970, 10/121,208, 10/122,035, 10/153,286, 10/153,290, is sutured onto the cuff portion of the valve assembly described above. Another use of the cuff is thus to allow a valve with a scalloped inflow edge to be attached to a non-scalloped stent.
In yet other embodiments of the present invention, the support beams of the stent are extended at the inflow portion to accommodate the length of longer valves such as the ones described in U.S. application Ser. Nos. 09/772,526, 09/853,463, 09/924,970, 10/121,208, 10/122,035, 10/153,286, 10/153,290.
In yet another embodiment of the present invention, the support beams form eyelets at the outflow edge that the tabs of the valves described in U.S. application Ser. Nos. 09/772,526, 09/853,463, 09/924,970, 10/121,208, 10/122,035, 10/153,286, 10/153,290 may be attached to. The valve tabs may be sutured to the eyelets around the perimeter of the eyelet. Such a configuration helps distribute the stress around the tabs and reduce the wear and tear on the commissural posts of the valve.
In yet another embodiment of the present invention, the support beam eyelets described above are covered with cloth. Covering the eyelets and tabs with cloth may help induce tissue ingrowth.
In yet another embodiment of the present invention, the valve device is made such that it cannot be crimped down beyond the diameter of a typical femoral artery or a femoral vein (where the catheter can typically be no more than 8 mm). In other words, the valve device is made such that it cannot be implanted through the femoral artery or femoral vein.
In yet another embodiment of the present invention, the valve device is crimped just after it has been manufactured, and shipped from the manufacturer in the crimped state to the hospital or where it is to be implanted.
In yet another embodiment of the present invention, the stent is made out of a memory shaped metal or a memory shaped polymer.
In yet another embodiment of the present invention, the stent of the valve device is made to be balloon expandable.
In yet another embodiment of the present invention, the stent of the valve device is made to be self-expandable.
The present invention provides systems and devices for the replacement of physiological valves. In one embodiment of the present invention, the replacement valve assemblies are adapted to fit substantially within the valve sinuses. Because the devices and procedures provided by the present invention eliminate or reduce the need for suturing, time spent in surgery is significantly decreased, and the risks associated with surgery are minimized. Further, the devices of the present invention are suitable for delivery by cannula or catheter.
In yet another embodiment of the present invention, the stent of the valve device is made such as to expand into the sinus regions during balloon expansion.
In yet another embodiment of the present invention, the stent of the valve devices is made such as to expand into the sinus region during self-expansion.
In one embodiment of the present invention a valve anchoring structure is provided that is dimensioned to be placed substantially within the valve sinus. In this embodiment, the valve anchoring structure extends substantially across the length of the valve sinus region.
In another embodiment of the present invention a valve assembly is provided, comprising a valve and anchoring structure, in which the valve comprises a body having a proximal end and a distal end, an inlet at the proximal end, and an outlet at the distal end. The inlet comprises an inflow annulus, with either a scalloped or straight edge. The outlet comprises a plurality of tabs that are supported by the anchoring means at the distal end. In an embodiment of the invention, the plurality of tabs is spaced evenly around the circumference of the valve.
In yet another embodiment of the present invention, a valve assembly is provided in which there is minimal or no contact between the valve and anchoring structure.
In still another embodiment of the present invention, a valve assembly is provided in which the valve is capable of achieving full opening and full closure without contacting the anchoring structure.
In yet another embodiment of the present invention, a valve assembly is provided in which the vertical components of the anchoring structure are limited to the commissural posts between sinus cavities, thereby minimizing contact between mechanical components and fluid, as well as providing flow to vessels located in the valve sinus.
In still another embodiment of the present invention, a valve is provided that firmly attaches to the valve sinus, obviating the need for suturing to secure the valve placement.
In a further embodiment of the present invention, a valve assembly is provided in which the anchoring structure may be collapsed to at least fifty percent of its maximum diameter.
In still a further embodiment of the present invention, an expansion and contraction device is provided to facilitate implantation of the valve and anchoring structure.
In another embodiment, the present invention provides adhesive means for securing the valve assembly in a valve sinus.
In yet another embodiment of the present invention, a valve sizing apparatus is provided for the noninvasive determination of native valve size.

BRIEF DESCRIPTION OF THE DRAWINGS

To better understand the present invention and appreciate its practical applications, the following Figures are provided and referenced hereafter. It should be noted that the Figures are given as examples only and in no way limit the scope of the invention.
FIG. 1 shows the valve structure, stent, or frame seen from the side.
FIG. 2 shows the valve structure, stent, or frame seen from the side.
FIG. 3 shows the valve structure, stent, or frame seen from an isometric view.
FIG. 4 shows the valve structure, stent, or frame seen from the top (i.e. at the outflow side).
FIG. 5 shows the frame with a cloth cover around the inflow edge.
FIG. 6 shows the frame with a cloth cover around the inflow edge.
FIG. 7 shows the frame with cloth cover around the inflow edge.
FIG. 8 shows the frame with cloth cover around the inflow edge.
FIG. 9 shows the frame with cloth cover around the inflow edge. The valve is also attached in this figure. The tabs of the valve are aligned with the eyelets of the frame.
FIG. 10 shows the frame with cloth cover around the inflow edge. The valve is also attached in this figure. The tabs of the valve are aligned with the eyelets of the frame.
FIG. 11 shows the frame with cloth cover around the inflow edge. The valve is also attached in this figure. The tabs of the valve are aligned with the eyelets of the frame.
FIG. 12 shows the frame with cloth cover around the inflow edge. The valve is also attached in this figure. The tabs of the valve are aligned with the eyelets of the frame.
FIG. 13 shows the frame with cloth cover around the inflow edge. The valve is also attached in this figure. The tabs of the valve are aligned with the eyelets of the frame. Cloth has been added and keeps the valve tabs attached to the frame eyelets.
FIG. 14 shows the frame with cloth cover around the inflow edge. The valve is also attached in this figure. The tabs of the valve are aligned with the eyelets of the frame. Cloth has been added and keeps the valve tabs attached to the frame eyelets.
FIG. 15 shows the frame with cloth cover around the inflow edge. The valve is also attached in this figure. The tabs of the valve are aligned with the eyelets of the frame. Cloth has been added and keeps the valve tabs attached to the frame eyelets.
FIG. 16 shows the frame with cloth cover around the inflow edge. The valve is also attached in this figure. The tabs of the valve are aligned with the eyelets of the frame. Cloth has been added and keeps the valve tabs attached to the frame eyelets.
FIG. 17 shows one of the leaflets described in U.S. application Ser. Nos. 09/772,526, 09/853,463, 09/924,970, 10/121,208, 10/122,035, 10/153,286, 10/153,290 and shows how this is aligned with the frame and frame eyelets. The cloth cuff around the inflow edge has been removed for clarity.
FIG. 18 shows the outflow side of a prototype valve prosthesis.
FIG. 19 shows the inflow side of a prototype valve prosthesis.
FIG. 20 shows a side view of a prototype valve prosthesis.
FIG. 21 shows the stent of the valve assembly crimped down to 7.5 mm
FIG. 22 shows the assembly of the valve tab to frame eyelet
FIG. 23 shows final cloth covering of tab/eyelet assembly.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

A main aspect of the present invention is the introduction of several novel designs for an implantable prosthesis valve. Another aspect of the present invention is the disclosure of several manufacture methods for the manufacturing of implantable prosthesis valves in accordance with the present invention. A further aspect of the present invention is the provision of novel deployment and positioning techniques suitable for the valve of the present invention.
Basically the implantable prosthetic valve of the present invention comprises a leafed-valve assembly, preferably tricuspid but not limited to tricuspid valves only, consisting of a conduit having an inlet end and an outlet, made of pliant material arranged so as to present collapsible walls at the outlet. The valve assembly is mounted on a support structure such as a stent adapted to be positioned at a target location within the body duct and deploy the valve assembly by the use of deploying means, such as a balloon catheter or similar devices. In embodiments suitable for safe and convenient percutaneous positioning and deployment the annular frame is able to be posed in two positions, a crimped position where the conduit passage cross-section presented is small so as to permit advancing the device towards its target location, and a deployed position where the frame is radial extended by forces exerted from within (by deploying means) so as to provide support against the body duct wall, secure the valve in position and open itself so as to allow flow through the conduit.
The valve assembly can be made from biological matter, such as a natural tissue, pericardial tissue or other biological tissue. Alternatively, the valve assembly may be made form biocompatible polymers or similar materials. Homograph biological valves need occasional replacement (usually within 5 to 14 years) and this is a consideration the surgeon must take into account, when selecting the proper valve implant according to the patient type. Metal mechanical valves, which have better durability qualities, carry the associated risk of long-term anticoagulation treatment.
The frame can be made from shape memory alloys such as nickel titanium (nickel titanium shape memory alloys, or NiTi, as marketed, for example, under the brand name Nitinol), or other biocompatible metals. The percutaneously implantable embodiment of the implantable valve of the present invention has to be suitable for crimping into a narrow configuration for positioning and expandable to a wider, deployed configuration so as to anchor in position in the desired target location.
The support stent is preferably annular, but may be provided in other shapes too, depending on the cross-section shape of the desired target location passage.
Manufacturing of the implantable prosthetic valve of the present invention can be done in various methods, for example, by dipping, injection, electrospinning, rotation, ironing, or pressing.
The attachment of the valve assembly to the support stent can be accomplished in several ways, such as by sewing it to several anchoring points on the support stent, or riveting it, pinning it, or adhering it, to provide a valve assembly that is cast or molded over the support stent, or use any other suitable way of attachment.
To prevent leakage from the inlet it is optionally possible to roll up some slack wall of the inlet over the edge of the frame so as to present rolled-up sleeve-like portion at the inlet.
Furthermore, floating supports may be added to enhance the stability of the device and prevent it from turning inside out.
An important aspect of certain embodiments of the present invention is the provision of rigid support beams incorporated with the support stent that retains its longitudinal dimension while the entire support stent may be longitudinally or laterally extended.
The aforementioned embodiments as well as other embodiments, manufacturing methods, different designs and different types of devices are discussed and explained below with reference to the accompanying drawings. Note that the drawings are only given for the purpose of understanding the present invention and presenting some preferred embodiments of the present invention, but this does in no way limit the scope of the present invention as defined in the appended claims.
Reference is now made to FIG. 1, which illustrates a valve support structure or frame shown in a deployed position. The frame has an inlet 9 and an outlet side 10. The frame is arranged in a net-like frame designed to be crimped evenly so as to present a narrow configuration and be radially deployable so as to extend to occupy the passage at the target location for implantation in a body duct. Support beams 3 are provided on annular support stent 2 to provide rigidity and anchorage to the valve. Support beams 3 may be provided with bores to provide attachment for a valve. In the current Figure, the support beams are solid as to provide extra rigidity to the stent. The support beams 3 transition into oval eyelets 1 at the outflow edge.
FIGS. 2-4 show the same frame seen in FIG. 1 from different perspectives.
Note that the entire valve structure is adapted to be radially crimped and radially expanded, and this lends to provide ease of navigation through narrow passages in the vasculature during positioning of the device and adequate deployment on the final location. This is made possible by the provision of a collapsible support stent structure. However, the support beams always maintain the same length. Because the support beams maintain the same length, the distance between the inflow edge and the tab attachments of the valve are maintained during crimping and expansion. This allows the valve to function properly. In prior art implantable valve devices the entire support structure changes its dimensions from its initial first crimped position and final deployed position, and this means that in the attachment of the valve assembly to the support structure one must take into consideration these dimension changes and leave slack material so that upon deployment of the device the valve assembly does not tear or deform. In the valve device of the present invention there is no relative movement between the valve assembly and the support beams (along the longitudinal central axis of the device). As a result, the valve device of the present invention acquires greater durability and is capable of withstanding the harsh conditions prevailing within the heart. The novel design of the valve device of the present invention leads to longitudinal strength and rigidity whereas its collapsible support structure results in radial flexibility.
FIG. 5 shows the cloth cuff (4 and 5) at the inflow edge of the stent. The cloth cuff may consist of a thin cloth cuff 5 and a thicker cloth cuff 4 and thus create a lip 11 at the intersection between these two cuffs. This “lip” or “step” may help position and secure the valve prosthesis at the correct position. It may, for example, help hold the valve prosthesis at the inflow annulus when placed in the aortic position.
FIGS. 6-8 show the same frame and tissue cuffs seen in FIG. 5 from different perspectives.
FIG. 9 shows one of the valves 6 disclosed in U.S. patent application Ser. Nos. 09/772,526, 09/853,463, 09/924,970, 10/121,208, 10/122,035, 10/153,286, 10/153,290. The tabs 7 of the valve are aligned with the eyelets 1 of the support beams. The overall size of the eyelets 1 match the size of the tabs 7. The valve 6 is attached at the inflow side of the frame 9 and is sutured to the cloth cuff 5 and 4.
FIGS. 10-12 show the same valve assembly seen in FIG. 9 from different perspectives.
FIG. 13 shows the complete valve assembly. In this Figure, the tabs 7 and the eyelets 1 have been covered with cloth 8. Covering the tabs 7 with a cloth cuff may induce tissue ingrowth. The cloth may initially clot when it is exposed to blood. The cloth may further induce endothelial and fibroblast, and hence tissue ingrowth. Inducing tissue ingrowth will reduce the loads imposed on the stent. Covering the tabs 7 and the eyelets 1 with cloth 8 in this manner will also help distribute the load seen by the commissural posts across the entire tab, hence reducing wear and tear on the commissural posts of the valve.
FIGS. 14-16 show the same valve assembly seen in FIG. 13 from different perspectives.
FIG. 17 shows one of the leaflets 12 described in U.S. application Ser. Nos. 09/772,526, 09/853,463, 09/924,970, 10/121,208, 10/122,035, 10/153,286, 10/153,290 and shows how this is aligned with the frame 15 and frame eyelets 13. The cloth cuff around the inflow edge has been removed for clarity. Another embodiment that is evident in FIG. 17 is how the scalloped edge of the leaflet 14 is positioned relative to the inlet of the stent 15.
FIGS. 18-20 show pictures of a prototype valve that has been assembled.
FIG. 21 shows a picture of a stent crimped to 7.5 mm.
FIG. 22 shows the assembly of the valve tab to frame eyelet.
FIG. 23 shows the final cloth covering of tab/eyelet assembly.
A typical size of an aortic prosthesis valve is from about 19 to about 31 mm in diameter. A maximal size of a catheter inserted into the femoral artery should be no more than 8 mm in diameter. The present invention introduces a device, which has the ability to change its diameter from about 4 mm to about 33 mm. Artificial valves are not new; however, artificial valves in accordance with the present invention posses the ability to change shape and size for the purpose of delivery and as such are novel. These newly designed valves require new manufacturing methods and technical inventions and improvements, some of which were described herein.
As described before, one embodiment of the present invention is to make it impossible for the stent to be crimped down below the size of the femoral artery or vein. In other words, one may create mechanical stops or add tissue or cloth in a manner as to prevent the stent from being capable of being crimped further down than beyond the size of the femoral artery or vein. In this manner, the stent is made such that it intentionally cannot be used through a femoral vein or femoral artery access. Creating such size constraints on the valve assembly may make it possible to create a sturdier device for prolonging the longevity of the valve assembly. Such a device could be implanted through the apex of the heart, as described in details in a U.S. patent application submitted Apr. 23, 2004 entitled “Method and System for Cardiac Valve Delivery”. An early version of this document is submitted at the same time as the current provisional. No application number exists at this point. The application is appended to this provisional patent application, and is hereby included in this application in its entirety.
As mentioned earlier, the material of which the valve is made from can be either biological or artificial. In any case new technologies are needed to create such a valve.
To attach the valve to the body, the blood vessels determine the size during delivery, and the requirements for it to work efficiently, there is a need to mount it on a collapsible construction which can be crimped to a small size, be expanded to a larger size, and be strong enough to act as a support for the valve function. This construction, which is in somewhat similar to a large “stent”, can be made of different materials such as Nitinol, biocompatible stainless steel, polymeric material or a combination of all. Special requirement for the stent are a subject of some of the embodiments discussed herein.
The mounting of the valve onto a collapsible stent is a new field of problems. New solutions to this problem are described herein.
Another major aspect of the design of the valve of the present invention is the attachment to the body.
Yet another major aspect of the valve apparatus is the attachment of the valve to the frame.
In the traditional procedure the valve is sutured in place by a complicated suturing procedure. In the case of the percutaneous procedure there is no direct access to the implantation site therefore different attachment techniques are needed.
Another new problem that is dealt herein is the delivery procedure, which is new and unique. Positioning of the device in the body in an accurate location and orientation requires special marking and measuring methods of the device and surgical site as was disclosed herein.
Artificial polymer valves require special treatment and special conditions when kept on a shelf, as well as a special sterilization procedure. One of the consequences of the shelf treatment is the need to crimp the valve during the implantation procedure. A series of devices and inventions to allow the crimping procedure are disclosed herein.
It should be clear that the description of the embodiments and attached Figures set forth in this specification serves only for a better understanding of the invention, without limiting its scope as covered by the following claims.

Claims

1. A prosthetic valve assembly comprising:

(a) a valve having an inlet end and an outlet made of pliant material arranged so as to present collapsible walls at the outlet; and

(b) a support structure adapted to be positioned at a target location within the body duct and deploy the valve assembly by the use of deploying means.