Patent Description:
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 <NUM>, 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, numerous surgical techniques may be used to repair a diseased or damaged heart valve. For example, these surgical techniques may include annuloplasty (contracting the valve annulus), quadrangular resection (narrowing the valve leaflets), commissurotomy (cutting the valve commissures to separate the valve leaflets), or decalcification of valve and annulus tissue. Alternatively, the diseased heart valve may be replaced by a prosthetic valve. Where replacement of a heart valve is indicated, the dysfunctional valve is typically removed and replaced with either a mechanical or tissue valve.

In the past, one common procedure has been an open-heart type procedure. However, open-heart valve repair or replacement surgery is a long and tedious procedure and involves a gross thoracotomy, usually in the form of a median sternotomy. In this procedure, a saw or other cutting instrument is used to cut the sternum longitudinally and the two opposing halves of the anterior or ventral portion of the rib cage are spread apart. A large opening into the thoracic cavity is thus created, through which the surgeon may directly visualize and operate upon the heart and other thoracic contents. Replacement heart valves typically include a sewing ring and are sutured into the annulus, resulting in a time intensive surgical procedure. The patient is typically placed on cardiopulmonary bypass for the duration of the surgery.

Minimally invasive valve replacement procedures have emerged as an alternative to open-chest surgery. A minimally invasive medical procedure is one that is carried out by entering the body through the skin or through a body cavity or anatomical opening, but with the smallest damage possible to these structures. Two types of minimally invasive valve procedures that have emerged are percutaneous valve procedures and trans-apical valve procedures. Percutaneous valve procedures pertain to making small incisions in the skin to allow direct access to peripheral vessels or body channels to insert catheters. Trans-apical valve procedures pertain to making a small incision in or near the apex of a heart to allow valve access. The distinction between percutaneous valve procedures and minimally invasive procedures is also highlighted in a recent position statement, <NPL>).

As valves are implanted less and less invasively, the opportunity for suturing the valves around the annulus is reduced. However, a smaller number of sutures may increase the chance of paravalvular leakage (PVL), i.e. leakage around the valve. A smaller number of sutures may also increase the opportunities for migration and valve stability when placed in-vivo.

Tehrani discloses a superior and inferior o-ring for valve implantation in <CIT>. Such o-rings cover the entire length of the valve and can therefore not easily be placed within the aortic sinus region. The o-rings presented by Tehrani would also block coronary outflow and adversely affect valve dynamics. The non-circular nature of the o-rings also reduces the radial force needed to adequately conform to irregularities within the implantation site, and is thus not optimal for preventing PVL and migration. The large size of the o-rings disclosed by Tehrani is also not practical as they cannot easily be collapsed down, something that is necessary for minimally invasive valve implantation.

Document <CIT> relates to a cardiac-valve prosthesis, which can be used, for example, as valve for percutaneous implantation, comprises an armature for anchorage of the valve prosthesis in the implantation site.

Surgical heart valves include a sewing cuff for direct attachment to the native annulus where the surgeon relies on visual identification to correctly place the inflow ring in the annulus. Minimally invasive heart valves, however, lack any defined feature that interfaces directly with the annulus, instead relying on radial force to hold the valve in position in an attempt to prevent paravalvular leakage. Other conventional designs rely on a "feeler" to locate the native leaflets and when located deploy the valve below the feeler in an attempt to properly seat the valve in the annulus thereby preventing paravalvular leakage. Yet other conventional heart valves rely on a flange construction in which the flange uses double fabric rings to sandwich the device in the native annulus to prevent paravalvular leakage. However, the double fabric rings require additional surgical time in order for the surgeon to verify that the two rings are placed on opposite sides of the annulus.

In addition, while new less invasive valves produce beneficial results for many patients, these valves may not work as well for other patients who have calcified or irregular annuluses because a tight seal may not be formed between the replacement valve and the implantation site. Therefore, what is needed are methods, systems, and devices for reducing paravalvular leakage around heart valves while preventing valve migration and allowing valve collapsibility.

The invention is directed to solving, or at least reducing, some or all of the aforementioned problems.

The invention provides an anchoring structure as defined in claim <NUM> which may be used in systems for reducing paravalvular leakage around heart valves. The methods also disclosed herein are not claimed. As replacement valve procedures become less and less invasive, the opportunity for suturing the valves around the annulus is reduced. However, minimizing the number of sutures used to secure the replacement valve may increase the chance of paravalvular leakage (PVL), as well as the opportunities for valve migration and valve stability when placed in-vivo.

Leakage associated with a heart valve can be either paravalvular (around the valve) or central (through the valve). Examples of various heart valves include aortic valves, mitral valves, pulmonary valves, and tricuspid valves. Central leakage may be reduced by heart valve design. Paravalvular leakage, on the other hand, may be reduced by creating a seal between the replacement heart valve and the implant site to prevent blood from flowing around the replacement heart valve. It is important that the seal between the replacement heart valve and the implant site does not adversely affect the surrounding tissue. Furthermore, it is important that the seal does not affect the flow dynamics around the replacement heart valve. In the case of the aortic valve, it is also important that the seal does not obstruct coronary flow.

Accordingly, it is one object of the disclosure to provide methods and devices for preventing paravalvular leakage around a replacement valve, such as a heart valve, while also preventing migration. It should be noted that while reference is made herein to aortic valves, the current invention is not limited to the aortic valve. While replacement valves are typically implanted in native heart valve positions, the replacement valve systems and sealing devices discussed herein may be used to seal any type of in-vivo valve without departing from the intended scope of the invention. Moreover, while the present heart valve with tubular anchoring structure may be used with minimally invasive procedures such as percutaneous, trans-femoral and trans-apical procedures, it is not limited to such procedures and may also be used with surgical, or so called "open-chest," procedures.

In one embodiment a tubular anchoring structure with a concave landing zone is provided. The anchoring structure includes a body having a proximal or inlet end and a distal or outlet end. The inlet frame has a sinusoidal-shaped single or double rail construction and is commonly referred to as the inlet rim. The outlet frame has a sinusoidal-shaped single or double rail construction. The body of the anchoring structure may be formed of a variety of shapes such as diamond-shaped or hexagonal-shaped patterns. The sinusoidal-shaped single or double rail construction of the inlet rim is C-shaped in cross section and forms the concave landing zone of the invention.

In another embodiment a valve assembly that reduces paravalvular leakage is provided. The valve assembly includes a bioprosthetic tissue heart valve attached to an anchoring structure. The anchoring structure includes a body having a proximal or inlet end and a distal or outlet end. The inlet frame has a sinusoidal-shaped single or double rail construction and is commonly referred to as the inlet rim. The outlet frame has a sinusoidal-shaped single, double or triple rail construction and is commonly referred to as the outlet rim. The sinusoidal-shaped construction of the inlet rim is C-shaped in cross section and forms the concave landing zone of the invention. The C-shape in cross section construction provides a bioprosthetic valve that is self-seating and that requires minimal adjustment.

In another embodiment there is provided a valve prosthesis 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 collapsible leaflets may comprise polyurethane or tissue.

In yet another embodiment the leaflets are attached to the main body at the support beams.

In yet another embodiment the heart valve is movable between a closed position in which the outflow edges of adjacent leaflets engage each other, and an open position in which the outflow edges of adjacent leaflets are separated from each other except along the side edges, the sewn portions of the side edges of the leaflets biasing the leaflets toward a partially closed position.

In another embodiment the C-shape in cross section construction forms a landing zone that allows the native annulus to rest in the valley of the inflow region, with the flared rails lying proximally and distally of the annulus.

In yet another embodiment the concave landing zone of the bioprosthetic heart valve assembly provides an effective seal between the bioprosthetic replacement heart valve and the implant site to prevent paravalvular leakage. According to the invention, the inflow rim comprises a three rail construction having outwardly flared distal and/or proximal portions.

In a further embodiment the construction of the triple rail may include a proximal portion that is longer than the distal portion, for example, to match the flaring of the aortic valve sinuses.

In another embodiment the cross-sectional area of the inflow rim includes direct correspondence of the concave portion of the frame to the native annulus. The frame of the inflow rim engages the native annulus, with the flared inflow rails lying above and below the annulus. The radial force exerted by the self-expanding frame holds the valve in position.

In yet another embodiment there is provided a valve prosthesis device suitable for implantation in body ducts, the device comprising a generally cylindrical anchoring structure having deployable construction adapted to be initially crimped in a narrow configuration suitable for surgical, trans-apical, trans-femoral placement, or other catheterization through a body duct, to a target location and adapted to be seated in the target location by the self-expansion of radially compressed forces, the cylindrical anchoring structure provided with a plurality of longitudinally rigid or semi-rigid support beams of fixed length; a valve assembly comprising a flexible conduit having an inlet and an outlet, made of a pliant material having commissural tab portions coupled to the support beams.

The disclosure provides a method of preventing paravalvular leakage. Using the single, double and/or triple rail flared designs described herein, paravalvular leakage may be reduced by ensuring the inflow rim is substantially pushed against the aorta, hence forming a tight seal. In one method of implantation, a self-expanding replacement valve may be deployed into position with a delivery member, thereby pushing the inflow rim against the aorta to create a seal around the valve. In other words, a self-expandable inflow rim comprising the replacement heart valve provides the radial force necessary to position the bioprosthetic heart valve in the annulus.

It should be noted that for the purposes of this invention, the phrase "generally sinusoidal" is intended to include waves characterized by sine and cosine functions as well as waves which are not rigorously characterized by those functions, but nevertheless resemble such waves. In a more general way, such waves include those which are characterized as having one or more peaks and troughs. As an example, a wave whose peaks and troughs are U-shaped or bulbous is intended to be included. Also intended to be included, without limiting the definition, are waves which are more triangular in shape such as a saw-tooth wave or waves whose peaks and troughs are rectangular.

Although many of the above embodiments are described in reference to the aortic valve in the heart, the claimed invention may also be utilized for procedures related to other valves including, but not limited to, the mitral valve, tricuspid valve, and the pulmonary valve.

The above aspects, features and advantages of the invention will become apparent to those skilled in the art from the following description taken together with the accompanying figures.

While this invention may be embodied in many different forms, there are described in detail herein various embodiments of the invention. This description is an exemplification of the principles of the invention and is not intended to limit the invention to the particular embodiments illustrated.

For the sake of consistency, the terms "peak" and "trough" are defined with respect to the proximal and distal ends of the anchoring structure in accordance with the invention. As seen in the Figures, each of the tubular anchoring structures has an inflow end, referred to herein as an inflow rim, and an outflow end, referred to herein as an outflow rim. With respect to the inflow and outflow rims "peaks" are concave relative to the proximal end of the anchoring structure and convex relative to the distal end of the anchoring structure. Troughs, on the other hand, are convex relative to the proximal end of the anchoring structure and concave relative to the distal end of the anchoring structure.

Turning now to the FIGS. , the invention relates to methods, systems, and devices for reducing paravalvular leakage in heart valves. <FIG> generally illustrate one exemplary embodiment of a heart valve <NUM>. As illustrated in <FIG>, valve <NUM> includes a distal outflow end <NUM>, a plurality of leaflets <NUM>, and a proximal inflow end <NUM>. A typical valve functions similar to a collapsible tube in that it opens widely during systole or in response to muscular contraction to enable unobstructed forward flow across the valvular orifice, as illustrated in <FIG>. In contrast, as forward flow decelerates at the end of systole or contraction, the walls of the tube are forced centrally between the sites of attachment to the vessel wall and the valve closes completely as illustrated in <FIG>.

<FIG> illustrate the anatomy of a typical aortic valve. In particular, <FIG> shows a top view of a closed valve with three valve sinuses, <FIG> shows a perspective sectional view of the closed valve, and <FIG> shows a view from outside the vessel wall.

One important consideration in the design of valve replacement systems and devices is the architecture of the valve sinus. Valve sinuses <NUM> are dilations of the vessel wall that surround the natural valve leaflets. Typically in the aortic valve, each natural valve leaflet has a separate sinus bulge <NUM> or cavity that allows for maximal opening of the leaflet at peak flow without permitting contact between the leaflet and the vessel wall. As illustrated in <FIG>, the extent of the sinus <NUM> is generally defined by the commissures <NUM>, vessel wall <NUM>, inflow end <NUM>, and outflow end <NUM>. The proximal intersection between the sinus cavities defines the commissures <NUM>.

<FIG> also show the narrowing diameter of the sinuses at both inflow end <NUM> and outflow end <NUM>, thus forming the annulus and sinotubular junction, respectively, of the sinus region. Thus, the valve sinuses form a natural compartment to support the operation of the valve by preventing contact between the leaflets and the vessel wall, which, in turn, may lead to adherence of the leaflets and/or result in detrimental wear and tear of the leaflets. The valve sinuses are also designed to share the stress conditions imposed on the valve leaflets during closure when fluid pressure on the closed leaflets is greatest. The valve sinuses further create favorable fluid dynamics through currents that soften an otherwise abrupt closure of the leaflets under conditions of high backflow pressure. Lastly, the sinuses ensure constant flow to any vessels located within the sinus cavities.

<FIG> is a schematic representation of the geometry and relative dimensions of the valve sinus region. As shown in <FIG>, the valve sinus region is characterized by certain relative dimensions which remain substantially constant regardless of the actual size of the sinuses. Generally, the diameter of the sinus is at its largest at the center of the sinus cavities <NUM>, while there is pronounced narrowing of the sinus region at both the inflow annulus <NUM> near the inflow end <NUM> and the outflow sinotubular junction <NUM> near the outflow end <NUM>. Furthermore, the height of the sinus <NUM> (i.e. the distance between inflow annulus <NUM> and outflow annulus <NUM>) remains substantially proportional to its overall dimensions. It is thus apparent that the sinus region forms an anatomical compartment with certain constant features that are uniquely adapted to house a valve. The systems and devices of the invention are designed to utilize these anatomical features of the native sinus region for optimal replacement valve function and positioning.

<FIG> is a perspective view of replacement valve <NUM>, which represents one exemplary embodiment of a typical, tri-leaflet replacement valve useable with the valve replacement system in accordance with the invention. One of ordinary skill in the art will appreciate that the replacement valve may also be of two leaflet construction. Replacement valve <NUM> includes valve body <NUM> having proximal inflow end <NUM> and a distal outflow end <NUM>. Valve body <NUM> includes a plurality of valve tissue leaflets <NUM> joined by seams <NUM> sewn, stitched or otherwise coupled, wherein each seam <NUM> is formed by a junction of two leaflets <NUM>. A commissural tab <NUM> co-extensively formed from the valve material extends from each seam <NUM> at the distal end of valve body <NUM>. Inflow end <NUM> of valve body <NUM> includes a peripheral edge that may be scalloped or straight. In addition, inflow end <NUM> of valve body <NUM> may optionally comprise reinforcement structure <NUM> that may be coupled, stitched, adhesively or chemically joined or otherwise attached thereto. The valve replacement system in accordance with the invention may also comprise a reinforcement structure coupled to the bioprosthetic tissue valve and positioned about the inflow end of the tubular anchoring structure as hereinafter will be described. The reinforcement structure may comprise cloth or any porous material that promotes tissue ingrowth. This reinforcement structure 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.

The valve replacement systems and devices of the invention are not limited, however, to the specific valve illustrated in <FIG>. For example, although the proximal inflow end <NUM> of valve body <NUM> is shown in <FIG> with a scalloped peripheral edge, other shapes and configurations are contemplated and within the intended scope of the invention. Valve leaflets <NUM> may be constructed of any suitable material, including but not limited to expanded polytetrafluoroethylene (ePTFE), equine pericardium, bovine pericardium, or native porcine valve leaflets similar to currently available bioprosthetic aortic valves. Other materials may prove suitable as will be appreciated by one skilled in the art.

<FIG> is a perspective view of an exemplary embodiment of a tubular anchoring structure <NUM> in accordance with the invention cut along line A-A and laid flat and showing a concave landing zone <NUM>. <FIG> represents one exemplary embodiment of a typical anchoring or support structure <NUM> useable with valve replacement system <NUM> in accordance with the invention. In general, tubular anchoring structure <NUM> is designed as a collapsible and expandable anchoring structure adapted to support valve <NUM> distally along commissural tab region <NUM> and proximally along the proximal inflow end <NUM>. As shown in <FIG>, valve <NUM> has been detached from tubular anchoring structure <NUM> so as to focus on the structure and features of the tubular anchoring structure.

Anchoring structure <NUM> has a generally tubular or cylindrical configuration within which replacement valve <NUM> may be secured, and includes inflow rim <NUM>, support posts <NUM> and outflow rim <NUM>. Replacement valve <NUM> may be secured at the proximal inflow end <NUM> by attachment to inflow rim <NUM> of tubular anchoring structure <NUM> and at the distal outflow end <NUM> via commissural tabs <NUM> that are threaded through axially extending slots <NUM>, which are formed in support posts <NUM> that extend longitudinally from inflow rim <NUM> to outflow rim <NUM> of tubular anchoring structure <NUM>. Thus, distal ends <NUM> of support posts <NUM> contact outflow rim <NUM> of tubular anchoring structure <NUM>, whereas proximal ends <NUM> of support posts <NUM> contact inflow rim <NUM> of tubular anchoring structure <NUM>. Support posts <NUM> may be rigid, substantially rigid or may also include a degree of inward deflection.

As shown in <FIG> outflow rim <NUM> of support structure <NUM> is depicted as comprising a single wire ring or rail that extends between support posts <NUM> generally at or above the axially extending slots <NUM> that reside therein. The outflow rim <NUM> is configured in an undulating or sinusoidal wave pattern forming peaks <NUM> and troughs <NUM>. However, the number of rails comprising the outflow rim <NUM> can comprise numerous other configurations which are contemplated by the invention and may be utilized such as single, double and triple configurations of varying patterns. Inflow rim <NUM> is depicted as comprising a double wire ring or rail that includes a distal inflow wire ring <NUM> and a proximal inflow wire ring <NUM>. Distal inflow wire ring <NUM> and proximal inflow wire ring <NUM> are configured in an undulating or sinusoidal wave pattern forming peaks <NUM> and troughs <NUM>. As can be seen, the double wire rail is configured so that a peak <NUM> of proximal inflow wire ring <NUM> couples to a trough <NUM> of distal inflow wire ring <NUM> thus forming a diamond pattern although any number of desired shapes may be achieved such as pentagonal, hexagonal, rectangular, etc., all of which are within the scope of the invention.

The inflow rim <NUM> optionally includes finger-like elements <NUM> positioned between distal and proximal inflow wire rings <NUM>, <NUM> extend in an axial direction therefrom. Finger-like elements <NUM> are designed to lend additional support to fabric that may cover inflow rim <NUM> to anchor the fabric and permit tissue ingrowth.

In an exemplary embodiment of a tubular anchoring structure <NUM> illustrated in <FIG>, outflow rim <NUM> is formed with a single ring, while inflow rim <NUM> is formed with a double ring that extends between support posts <NUM>. However, the number of rings may vary, and numerous other configurations are contemplated. For example, <FIG> illustrates a triple ring construction for the inflow rim according to an embodiment of the invention, while <FIG> illustrates a single ring construction for the inflow rim.

Both inflow rim <NUM> and outflow rim <NUM> of tubular anchoring structure <NUM> may be formed with an undulating or sinusoidal wave-like configurations. In various embodiments of tubular anchoring structures, inflow rim <NUM> may have a shorter or longer wavelength (i.e., circumferential dimension from peak to peak) and/or a lesser or greater wave height (i.e., axial dimension from peak to peak) than outflow rim <NUM>. The wavelengths and wave heights of inflow rim <NUM> and outflow rim <NUM> may be selected to ensure uniform compression and expansion of tubular anchoring structure <NUM> without substantial distortion. The wavelength of inflow rim <NUM> may be further selected to support the geometry of the inflow end of the valve attached thereto, such as the scalloped inflow end <NUM> of replacement valve <NUM> shown in <FIG>. Notably, as shown in <FIG>, the undulating or sinusoidal wave pattern that forms inflow rim <NUM> of tubular anchoring structure <NUM> may be configured such that proximal ends <NUM> of vertical support posts <NUM> are connected to troughs <NUM> of distal inflow ring <NUM>. This arrangement allows the distal inflow wire ring and proximal inflow wire ring to move together when the valve is in its radially compressed state prior to delivery thus preventing possible damage to the bioprosthetic heart valve. Similarly, the undulating or sinusoidal wave-like pattern that forms outflow rim <NUM> of support structure <NUM> may be configured such that distal ends <NUM> of support posts <NUM> are connected at a peak <NUM> of outflow rim <NUM>.

As shown in <FIG>, an embodiment of the invention of an inflow rim <NUM> is shown. Inflow rim <NUM> comprises a three rail construction including a distal inflow ring <NUM>, a proximal inflow ring <NUM> and a central inflow ring <NUM>. In this three-rail construction for inflow rim <NUM>, peaks <NUM> of proximal inflow ring <NUM> may be joined to the troughs <NUM> of central inflow ring <NUM>. Peaks <NUM> of central inflow ring <NUM> may be joined to the troughs <NUM> of distal inflow ring <NUM>. This arrangement allows the distal inflow wire ring and proximal inflow wire ring to move together when the valve is in its radially compressed state prior to delivery thus preventing possible damage to the bioprosthetic heart valve.

<FIG> and <FIG> further show that the distal ends <NUM> of support posts <NUM> are configured generally in the shape of a paddle with axial slot <NUM> extending internally within blade <NUM> of the paddle. Blade <NUM> of the paddle is oriented toward outflow rim <NUM> of tubular anchoring structure <NUM> and connects to outflow rim <NUM> at a trough of the undulating sinusoidal wave-like pattern of outflow rim <NUM>. An important function of support posts <NUM> is the stabilization of prosthetic valve <NUM> in general, and in particular the prevention of any longitudinal extension at points of valve attachment to preclude valve stretching or distortion upon compression of replacement valve system <NUM>. Blades <NUM> of the paddle-shaped support posts <NUM> are also designed to accommodate commissural tabs <NUM> of valve <NUM>.

The number of support posts <NUM> generally ranges from two to four, depending on the number of commissural posts present in the valve sinus. Thus, in one embodiment of the invention, tubular anchoring structure <NUM> comprises three support posts for a tri-leaflet replacement valve <NUM> with a sinus that features three natural commissural posts. Support posts <NUM> of tubular anchoring structure <NUM> may be structured to generally coincide with the natural commissural posts of the valve sinus.

Tubular anchoring structure <NUM> may be formed from any suitable material including, but not limited to, stainless steel or nitinol. The particular material selected for tubular anchoring structure <NUM> may be determined based upon whether the support structure is self-expanding or non-self-expanding. For example, preferable materials for self-expanding support structures may include shape memory materials, such as Nitinol.

Turning now to <FIG> and <FIG> a cross-sectional view of the inflow rim <NUM> is depicted which illustrates the concave landing zone <NUM> in accordance with the invention. As can be seen, peaks <NUM> of the distal inflow ring <NUM> and troughs <NUM> of the proximal inflow ring <NUM> flare outwardly so that inflow rim <NUM> forms a C-shape in cross section upon deployment. This cross-sectional area <NUM> of the inflow rim <NUM>, or in other words the concave portion of the frame, directly corresponds to the native annulus. The frame of the inflow rim engages the native annulus, with the flared rails <NUM>, <NUM> lying above and below the annulus. Upon deployment, the radial force exerted by the self-expanding frame holds the valve in position.

The concave landing zone <NUM> of the invention substantially prevents paravalvular leakage. Using the double, triple and single rail flared designs as best seen in <FIG>, <FIG>, <FIG> paravalvular leakage may be reduced by ensuring the inflow rim <NUM>, <NUM> is substantially secured proximally and distally of the annulus, hence forming a tight seal. Concave landing zone <NUM> also allows the surgeon to easily place the bioprosthetic heart valve in the annulus thus minimizing patient time spent in surgery.

<FIG> is an illustration of a heart <NUM> with right and left atriums <NUM>, <NUM>, right and left ventricles <NUM>, <NUM>, aorta <NUM> and aortic heart valve <NUM>. The bundle of His <NUM>, also known as the AV bundle or atrioventricular bundle comprises a collection of heart muscle cells specialized for electrical conduction that transmits the electrical impulses from the AV node <NUM> (located between the atria and the ventricles) to the point of the apex of the fascicular branches. The fascicular branches then lead to the Purkinje fibers which innervate the ventricles, causing the cardiac muscle of the ventricles to contract at a paced interval. If the bundle of His is blocked, a serious condition called "third degree heart block," namely the dissociation between the activity of the atria and that of the ventricles, occurs. A third degree block most likely requires an artificial pacemaker. Consequently, a great number of heart valve replacement surgeries result in secondary operations to implant a pacemaker because the stented portion of the heart valve impinges on the bundle of His.

Thus, those of ordinary skill in the art will appreciate that there are many different configurations that may be employed for the distal and proximal inflow rings <NUM>, <NUM>. For example, each of distal and proximal inflow rims <NUM>, <NUM> may be substantially of the same vertical height. If each of distal and proximal inflow rings <NUM>, <NUM> are substantially the same vertical height, the proximal ring may be flared slightly less outwardly to avoid compromising or impinging on the bundle of His while the distal ring <NUM> may be flared slightly more outwardly to ensure solid engagement with the distal side of the aortic annulus. Alternatively, the proximal inflow ring <NUM> may be constructed to be shorter than the distal inflow ring or may be flared slightly more outwardly so that upon placement, the proximal inflow ring does not contact and does not impinge on the bundle of His. Alternatively, either of the distal or proximal inflow rings <NUM>, <NUM> may be constructed to be shorter than the other depending on the anatomy of the particular patient and valve replacement involved. Those of ordinary skill in the art will appreciate, however, that both the distal inflow ring <NUM> and the proximal inflow ring <NUM> may be comprised of any number of varying vertical heights and degrees of flare without deviating from the spirit of the invention.

As shown in <FIG>, the heart valve replacement system <NUM> including the exemplary tubular anchoring structure <NUM> of <FIG> and/or 6A has expanded within the sinus cavities of aorta A, thereby forcing inflow rim <NUM> against inflow annulus <NUM> of aorta A to form a tight seal between replacement valve <NUM> and aorta A. More specifically, upon deployment inflow rim <NUM> assumes a substantially C-shaped in cross section concave landing zone <NUM> as can be seen in <FIG>, <FIG> and <FIG>. Distal inflow ring <NUM> abuts the distal side of the annulus while proximal inflow ring <NUM> abuts the proximal side of the native annulus.

The concave landing zone <NUM> prevents and/or minimizes paravalvular leakage and migration of replacement valve <NUM> from the implantation site. Thus, with inflow ring <NUM> in contact with inflow annulus <NUM>, the concave landing zone <NUM> acts as a gasket to seal the junction between replacement valve system <NUM> and aorta A. Optionally, inflow ring <NUM> is covered with fabric to stimulate tissue ingrowth over time and secure the replacement heart valve in position. The fabric may comprise any suitable material including, but not limited to, woven polyester, polyester velour, polyethylene terepthalate, polytetrafluoroethylene (PTFE), or other biocompatible material. The valve assembly may be compressed in ice, loaded into a delivery system, and deployed into the aortic valve position. The self-expanding characteristic of the anchoring structure provides the radial strength required to hold the valve in position after implant.

Turning now to <FIG>, yet another alternative embodiment of an anchoring structure with a concave landing zone in accordance with the principle of the invention is shown. A valve <NUM> supported by a generally cylindrical or tubular anchoring structure <NUM> having a concave landing zone <NUM> is shown. Valve <NUM> includes optional reinforcement structure <NUM>. In this embodiment, anchoring structure <NUM> utilizes a diamond and hexagon shaped structure that facilitates collapsibility and dynamic compliance. Those skilled in the art however will appreciate that there are numerous designs for the anchoring structure that can be utilized. As can be seen from <FIG>, inflow rim <NUM> includes a single wire ring that is structured to flare out from the vertical support posts to anchor it firmly against the aortic inflow valve sinus as hereinbefore disclosed. Outflow ring <NUM>, which is depicted as having a two-rail construction, may optionally also be flared-out to anchor it against the aortic outflow annuli of the valve sinuses. The outflow ring <NUM> of the anchoring structure <NUM> is adapted to support the commissural tab regions <NUM> of the valve <NUM> while the inflow ring <NUM>, depicted as having a single rail construction, allows the anchoring structure <NUM> to be securely positioned in a sinus cavity of the vascular passageway. Commissural tabs <NUM> may be stitched directly to the outflow rim or optionally may be stitched to support posts <NUM>. The single ring of the flared inflow ring <NUM> of the anchoring structure <NUM> may comprise an undulating or zigzag pattern to which the valve's optional fabric ring or sewing cuff <NUM> can be sewn. The inflow ring <NUM> of the anchoring structure may be connected to the outflow ring <NUM> by vertical support posts <NUM> that are positioned to coincide with the commissural posts of the native sinus region. However, it should be understood that the number of vertical support posts may be adapted to the number of native commissural posts present in the particular sinus region.

Those of ordinary skill in the art will appreciate that there are many different configurations that can be employed for the configuration of inflow rim <NUM> or outflow rim <NUM>. For example, each of the peaks and troughs may be substantially of the same vertical height. Alternatively, either of the peaks or troughs may be constructed to be shorter than the other depending on the anatomy of the particular patient and valve replacement involved. Those of ordinary skill in the art will appreciate, however, that both the single ring construction may be comprised of any number of vertical heights without deviating from the spirit of the invention.

Referring to <FIG> a perspective view of prosthetic heart valve <NUM> is shown mounted in a tubular anchoring structure with concave landing zone (not shown). Valve <NUM> is an exemplary embodiment of a typical, tri-leaflet replacement valve useable with the tubular anchoring structure <NUM> with concave landing zone <NUM> in accordance with the invention. One of ordinary skill in the art will appreciate that the replacement valve may also be of two leaflet construction. Replacement valve <NUM> includes valve body <NUM> having proximal inflow end <NUM> and a distal outflow end <NUM>. Valve body <NUM> includes a plurality of valve tissue leaflets <NUM>. A commissural tab <NUM> co-extensively formed from the valve material extends from each seam <NUM> at the distal end of valve body <NUM>. As shown in <FIG> inflow end <NUM> of valve body <NUM> optionally includes reinforcement structure <NUM> that may be coupled, stitched, adhesively or chemically joined or otherwise attached thereto. The valve replacement system <NUM> in accordance may also comprise a reinforcement structure coupled to the bioprosthetic tissue valve and positioned about the inflow end of the tubular anchoring structure. The reinforcement structure may comprise cloth or any porous material that promotes tissue ingrowth. This reinforcement structure 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. Single outflow rail <NUM> of tubular anchoring structure <NUM> is operably coupled to paddle-shaped blade <NUM>. In use, the commissural tabs <NUM> of the valve <NUM> are aligned with axially extending slots <NUM> formed in support posts <NUM>. The overall size of the slots <NUM> correspond in size with tabs <NUM>. In addition, tabs <NUM> may be optionally covered with a cloth covering <NUM>.

As noted above, valve leaflets <NUM> may be constructed of any suitable material, including but not limited to expanded polytetrafluoroethylene (ePTFE), equine pericardium, bovine pericardium, or native porcine valve leaflets similar to currently available bioprosthetic aortic valves. Other materials may prove suitable as will be appreciated by one skilled in the art.

It should be noted that the novel anchoring structure device and bioprosthetic valve system in accordance with the invention is designed to be fitted in the annulus without sutures of any kind. However, those of ordinary skill in the art will also appreciate that sutures may or may not be used to secure the bioprosthetic valve system in place in the annulus.

During manufacture, the anchoring structure is cut from a smaller tube and expanded and heat set to the final desired size. Depending on the design, the tips of the single inflow ring and the tips distal inflow ring and the proximal inflow ring in the double and triple constructions may be flared outwardly to form the C-shaped in cross section concave region extending from the cylindrical body of the anchoring structure frame. Additional fingers, such as those shown in <FIG>, may be used in any of the constructions and may be flared outwardly to assist in engaging the annulus and support the fabric covering.

Claim 1:
An anchoring structure (<NUM>) adapted to be anchored within a vessel of a body, said anchoring structure comprising:
a generally cylindrical tubular body having an inflow end (<NUM>) and an outflow end (<NUM>);
wherein the inflow end comprises an inflow rim (<NUM>), characterized in that the inflow rim comprises a three rail construction having outwardly flared distal and/or proximal portions.