JP2013039428A - Prosthetic mitral heart valve having contoured sewing ring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a prosthetic mitral heart valve having contoured sewing ring.SOLUTION: The prosthetic mitral heart valve includes a contoured sewing ring that better matches the mitral heart valve. The sewing ring includes an inflow end and an outflow end, the outflow end has at least one raised portion. There may be two raised portions located approximately 120° apart from each other and designed to register with two anterior trigones of the prosthetic mitral valve. The raised portions may gently curve upward to a height of about 2 mm above the adjacent portions of the outflow end of the sewing ring. The sewing ring may also be constructed so as to be more flexible around a posterior aspect than around an anterior aspect to accommodate calcified tissue more commonly found around the posterior annulus. The contoured sewing ring can be combined with various types of heart valve including bioprosthetic and mechanical valves.

Description

  The present invention relates generally to implantable prosthetic heart valves for mitral annulus, and more specifically to a sewing ring molded to such prosthetic heart valves.

  Two main types of heart valve replacement or prosthesis are known. One is a mechanical-type heart valve that provides unidirectional blood flow by using a ball and cage arrangement or a rotating mechanical closure supported by a substructure, such as Stobie et al. In U.S. Patent Nos. 5,099,049 and 2,047,989 to Brendzel et al., The disclosures of which are expressly incorporated herein by reference. The other is a tissue type or “bioprosthetic” valve with a flexible leaf supported by the substructure, protruding into the flow stream and functioning like that of the original human heart valve, and their natural By simulating a simple bending motion, they are joined to each other to ensure one-way blood flow. One example of a flexible leaf-like valve is disclosed in US Pat. No. 6,057,059 to Huynh et al., The disclosure of which is expressly incorporated herein by reference.

  In tissue-type valves, the entire xenograft valve (eg, pig) or multiple xenograft leaflets (eg, bovine pericardium) usually provide a fluid occlusion surface. Synthetic leaflets have been proposed, so the term “soft leaflet” refers to both natural and artificial “tissue type” valves. Two or more flexible leaf-like valves are mounted within the surrounding support structure, which usually includes posts or commissures that project in the outflow direction to provide natural fibrous commissures in the natural ring. mimic. The valve components are typically assembled using one or more biocompatible fabric (eg, Dacron) covers, and a fabric-covered sewing ring is provided at the inflow end of the peripheral support structure Is done.

  In most bioprosthetic type valves, the metal or polymer structure provides base support for the flexible leaf that protrudes therefrom. One such support is an elastic “support frame”, sometimes referred to as a “wire form” or “stent”, having multiple (usually three) large radius cusps. And support the cuspid region of the flexible leaflet (ie, either the overall xenograft valve or three separate leaflets). The ends of each pair of adjacent cusps form an upright commissure that tapers off by asymptotically gathering, each of the ends extending in a direction opposite the arcuate cusp, Has a smaller radius. The support frame is a generally conical tube with commissural tips at the small diameter ends. This provides a wavy reference shape where the fixed edges of each lobe join (via components such as fabrics and sutures) like a natural fibrous structure in the aortic ring. Another “support frame” structure presents a tube-like shape like a sheet, but nevertheless defines commissures and cusps at its outflow end, as shown, for example, in US Pat. Are expressly incorporated herein by reference.

  The most common locations where a prosthetic heart valve is implanted are the aortic and mitral valves associated with the left ventricle, producing higher pressures in the two ventricles. The anatomical structure of the aortic valve and the mitral valve is quite different, the former being a three-lobe structure and the latter having two different lobes. The aortic ring defines a wavy fibrous structure around a substantially circular ring and supports the natural leaf-like apex and commissural up-and-down shape. On the other hand, the mitral annulus has a somewhat fibrous and linear anterior surface across the heart diaphragm from the aortic valve, but the posterior surface defining the majority of the annulus is relatively It is not fibrous and more muscular. Also, the back surface is almost elliptical, so that the mitral annulus is represented by a deformed “D” shape. Furthermore, the mitral annulus does not present an up-and-down wavy shape like the aortic ring at its periphery and is generally flat, but its anterior surface is lower at the position of the fiber triangle and higher between It is shaped like a saddle. The present invention is directed to a prosthetic heart valve and is particularly suitable for implantation in a mitral annulus.

  The left ventricle LV and its associated valve are illustrated in FIG. 1 in a vertical cross-sectional view along the anterior-posterior plane. The mitral valve MV controls the flow between the left atrium LA and the left ventricle LV, and the aortic valve AV functions between the left ventricle LV and the ascending aorta AA. Both the mitral valve and the aortic valve include a leaflet that extends into the blood flow path and is supported around its periphery by a respective ring. For discussion purposes, a normal healthy heart mitral annulus is generally defined perpendicular to the average blood flow direction 20 (see FIG. 1) through the mitral valve MV. Present in the mitral annulus MAP. A normal mitral valve annulus can be three-dimensional, but the mitral valve face MAP is used as a reference plane that extends toward the front and rear sides of the ring. The papillary muscle is not shown, but binds to the lower part of the inner wall of the left ventricle LV, and the chords extend between and link the anterior and posterior foliate papillary muscles and free edges.

FIG. 2 illustrates the mitral valve from the left atrium exposed during surgery, and FIG. 2A schematically identifies the commonly identified features in plan view. Sectional area of the mitral valve annulus of an average human is 5~11cm ^2. The anterior surface of the mitral annulus forms part of the “cardiac skeleton” and includes the anterolateral ALT and posterior medial PMT fiber triangles. The mitral valve annulus MV is a bicuspid valve with a posterior leaflet (separated into _three cusps P ₁ , P ₂ and P ₃ ) that cooperates or joins with the anterior leaflet A. Triangle anterolateral ALT and rear inner PMT is shown at the branching point of the respective front side of the first and third leaflets P ₁ and P ₃ of the leaflet A and back side of the leaflet. These branch points are also known as commissures between the foliations.

  Referring to FIG. 2A, as described above, the mitral annulus has a deformed “D” shape with a straight portion, ie, an anterior surface, which is an anterior ALT and an posterior medial It extends between the triangles of the PMT. The longest dimension of the mitral annulus defines the major axis 22 and the shortest dimension defines the minor axis 24. The short axis 24 generally bisects the front leaf A. The mitral annulus is not circular, but its center 26 can be defined at the intersection of the major axis 22 and the minor axis 24. Radial lines are shown outwardly from this imaginary center 26 through the anterior ALT and posterior medial PMT triangles, indicating the separation points φ forming the corners therebetween. The separation point φ forming this corner varies from patient to patient, but is generally one third of the circumference around the mitral annulus, or 120 degrees.

  A variety of prosthetic heart valves have been proposed in the art, but none has taken into account the inherent characteristics of generally different annulus. In particular, few attempts have been made in these proposals to better adapt the prosthetic valve to the mitral annulus.

US Pat. No. 6,143,025 US Pat. No. 6,719,790 US Pat. No. 6,585,766 US Pat. No. 5,984,973

  According to one aspect of the present invention, a sewing ring for a prosthetic heart valve includes a ring-like member through which a suture is arranged, arranged about an axis defining an inflow-outflow direction. The annular member has a substantially flat inflow end and outflow end, the outflow end including at least a portion that projects axially relative to an adjacent portion of the outflow end. The axially raised portion can gently rise upward to a height of about 50% of the largest axial dimension of the ring-shaped member. In one embodiment, the largest axial dimension of the ring-shaped member is about 4 mm. Preferably there are two axially raised portions on the outflow end, separated by about 120 degrees.

  The ring-shaped member is located around a shorter distance between the raised portions at an intermediate point between the raised portions in the axial direction and may be less flexible than a position directly opposite the intermediate point. The ring-shaped member may be made from a molded polymer having a plurality of radial walls, the plurality of radial walls defining a space between the radial walls and spaced apart on the outflow end 2. There are two axial ridges. In one embodiment, the radial wall is located at a midpoint between the axial ridges, around a shorter distance between the ridges, and at a location directly opposite the midpoint. Thicker than the wall. In another embodiment, the space is located at a midpoint between the axially raised portions, around the shorter distance between the raised portions, than the space at a location directly opposite the midpoint. Is also small. Alternatively, the ring-shaped member is made from a wound fabric and there are two axially raised portions spaced apart on the outflow end, the fabric between the axially raised portions At the midpoint, it is located around a shorter distance between the raised portions and is more tightly wound than the fabric in a position directly opposite the midpoint.

  Another aspect of the present invention provides a sewing ring for a prosthetic heart valve, the sewing ring comprising an annular member threading a suture arranged about an axis defining an inflow-outflow direction; The annular member has a changeable compliance around its circumference. The annular member can be made from a molded polymer having a plurality of radial walls, the plurality of radial walls defining a space between the radial walls. In one embodiment, the radial wall around one side is thicker than the radial wall around the other side, and in an alternative embodiment, the space around one side is the one around the other side. Smaller than space. Alternatively, the ring-shaped member can be made from a polymer fabric, such as a non-woven felt or rolled fabric. In the latter configuration, the fabric is wound more tightly on one side than on the other side.

  In a particularly preferred embodiment, the sewing ring forms a component of the mitral heart valve for implantation in a mitral valve annulus having two triangles spaced about the anterior and posterior sides. . The ring-shaped member then has a front side and a back side, and the ring-shaped member is more compliant at its front side than its back side. The ring-shaped member may define an inflow end and an outflow end by being arranged about an axis, the outflow end including two portions that define an anterior side that is axially raised relative to an adjacent portion. The two axially raised portions of the outflow end are separated by about 120 degrees and spaced apart.

  According to a further aspect, a prosthetic mitral heart valve for implantation in a mitral annulus is provided. The mitral annulus includes two anterior triangles spaced about 120 degrees apart. The heart valve includes a support frame defining an orifice about an axis along the inflow-outflow direction and a plurality of unidirectional valves at the orifice by being mounted for movement on the support frame And a leaf-like portion. A sewing ring is connected to and placed around the support frame to couple the heart valve to the mitral annulus. The sewing ring has an inflow end and an outflow end, and the outflow end is axially associated with the remainder of the outflow end that is spaced to fit the two forward triangles during implantation. Including the raised part.

  In a prosthetic mitral heart valve, the support frame has a wavy shape and includes three axially arranged commissures extending in the outflow direction alternating with three cusps extending in the inflow direction. In this case, two of the commissures are located adjacent to the two axially raised portions of the sewing ring, and a heart valve is attached around the wavy shape of the support frame 3 Includes two flexible foliations. Alternatively, the support frame has a generally annular profile and the heart valve includes two rigid lobes attached for pivotal movement within the support frame. In one embodiment, the axially raised portion gently curves upward from an adjacent portion at the outflow end to a height of about 50% of the largest axial dimension of the sewing ring. Further, the ring-shaped member that passes the suture may have variable compliance around its circumference.

  The present invention also provides a method of implanting a prosthetic mitral heart valve in a mitral annulus, the annulus comprising an anterior triangle with two spaces. The method provides a prosthetic mitral heart valve having an outwardly directed sewing ring, and coupling the heart valve to a mitral annulus, the sewing ring having an inflow end and an outflow end. The outflow end includes an axially raised portion associated with the remaining portion of the outflow end spaced to fit two forward triangles, and two axial directions Implanting a prosthetic mitral heart valve in the mitral annulus such that the raised portion is located adjacent to the two anterior triangles of the annulus.

  Preferably, the sewing ring includes an annular member for threading the suture, and the step of implanting includes sewing the sewing ring to the mitral annulus. For example, a sewing ring can be a ring-shaped member that passes a suture surrounded by a fabric cover. The prosthetic mitral heart valve may have three axially arranged commissures that extend into the ventricle in the outflow direction when the valve is implanted, the first two commissures being in two axial directions Located around the heart valve at the same position as the raised portion, the third commissure is equidistant from the first two commissures. In this case, the method tilts the prosthetic mitral heart valve to an angle relative to the annulus surface such that the third commissure is angled away from the adjacent ventricle, reducing the likelihood of contact therebetween. Including that.

  In another embodiment, the sewing ring is less flexible at the raised portion in the axial direction than at a position directly opposite from the raised portion in the axial direction. The method may be performed on a mitral annulus having a more calcified portion than the rest of the annulus. In such pathologies, the method includes prosthetic mitral on the mitral annulus such that a relatively more compliant portion of the annular member is located adjacent to a portion of the more calcified mitral annulus. Including transplanting a heart valve.

  Another inventive method of the present invention provides a prosthetic heart valve on a patient's heart annulus by first providing a prosthetic heart valve having an outwardly oriented sewing ring to couple the heart valve to the annulus. Including transplantation. The sewing ring has a ring-shaped member for passing a suture disposed around an axis that defines an inflow-outflow direction, and has a variable compliance at its circumference. The method includes implanting a prosthetic heart valve in the annulus such that a portion of the annular member that is relatively more compliant than the diametrically opposed portion is positioned in place around the annulus. For example, the annulus may have a more calcifying surface than the rest of the annulus, and the implantation step may include a relatively more compliant portion of the annular member adjacent to the more calcifying annulus surface. Including positioning. More specifically, the method may be practiced with a mitral annulus having an anterior surface and a posterior surface, the annulus being coupled to the anterior surface of the mitral annulus, and the mitral valve A relatively more compliant portion of the ring-shaped member is located on the rear side of the ring-shaped member.

A further understanding of the nature and advantages of the present invention will become apparent in the following description and claims, particularly when considered in conjunction with the accompanying drawings, wherein like parts are designated with like reference numerals.
For example, the present invention provides the following items.
(Item 1)
A sewing ring for a prosthetic heart valve,
Comprising an annular member threaded through a suture arranged about an axis defining an inflow-outflow direction;
The sewing ring, wherein the annular member has a substantially flat inflow end and outflow end, the outflow end including at least a portion raised axially relative to an adjacent portion of the outflow end.
(Item 2)
The sewing ring according to item 1, wherein the axially raised portion is gently curved upward from the adjacent portion of the outflow end to a height of about 50% of the largest axial dimension of the annular member.
(Item 3)
The sewing ring according to item 2, wherein the largest axial dimension of the ring-shaped member is about 4 mm.
(Item 4)
The sewing ring of item 1, wherein two axially raised portions separated by about 120 degrees are present on the outflow end.
(Item 5)
The ring-shaped member is located at a midpoint between the raised portions in the axial direction around a shorter distance between the raised portions and is less flexible than a position directly opposite the midpoint. The sewing ring as described in.
(Item 6)
The annular member includes a molded polymer having a plurality of radial walls, the plurality of radial walls defining a space between the radial walls;
There are two axial ridges spaced apart on the outflow end,
The radial wall is at a midpoint between the axially raised portions located around a shorter distance between the raised portions than the radial wall at a location directly opposite the midpoint. The sewing ring according to item 1, which is also thick.
(Item 7)
The annular member includes a molded polymer having a plurality of radial walls, the plurality of radial walls defining a space between the radial walls;
There are two axial ridges spaced apart on the outflow end,
The space is smaller at the midpoint between the axially raised portions located around a shorter distance between the raised portions than at the location directly opposite the midpoint; The sewing ring according to 1.
(Item 8)
The annular member includes a wound fabric;
There are two axial ridges spaced apart on the outflow end,
The fabric is wound at a midpoint between the axially raised portions around a shorter distance between the raised portions and is more tightly wound than the fabric at a location directly opposite the midpoint The sewing ring according to item 1, wherein
(Item 9)
A sewing ring for a prosthetic heart valve,
Comprising an annular member threaded through a suture arranged about an axis defining an inflow-outflow direction;
The sewing ring, wherein the ring-shaped member has a changeable compliance around its circumference.
(Item 10)
The annular member includes a molded polymer having a plurality of radial walls, the plurality of radial walls defining a space between the radial walls;
10. A sewing ring according to item 9, wherein the radial wall around one side is thicker than the radial wall around another side.
(Item 11)
The annular member includes a molded polymer having a plurality of radial walls, the plurality of radial walls defining a space between the radial walls;
10. A sewing ring according to item 9, wherein the space around one side is smaller than the space around another side.
(Item 12)
10. The sewing ring according to item 9, wherein the ring-shaped member includes a polymer fabric.
(Item 13)
The sewing ring according to item 12, wherein the ring-shaped member includes a wound fabric, and the fabric is wound more firmly on one side than on the other side.
(Item 14)
The sewing ring forms a component of a mitral heart valve for implantation in a mitral valve annulus having two triangles spaced about anterior and posterior sides;
The ring-shaped member has a front side and a rear side,
The sewing ring according to item 9, wherein the ring-shaped member is more compliant at the front side than at the rear side.
(Item 15)
The ring-shaped member defines an inflow end and an outflow end by being arranged about an axis, the outflow end including two portions, generally defining the front side, raised axially relative to adjacent portions. Item 15. The sewing ring according to Item 14.
(Item 16)
16. The sewing ring of item 15, wherein the two axially raised portions of the outflow end are spaced apart at about 120 degrees.
(Item 17)
A prosthetic mitral heart valve for implantation in a mitral valve annulus, the annulus comprising two anterior triangles spaced about 120 degrees apart, the heart valve comprising:
A support frame defining an orifice about an axis along the inflow-outflow direction;
A plurality of leaves that are attached for movement on the support frame to provide a one-way valve at the orifice;
A sewing ring connected to the support frame and disposed about and coupling the heart valve to the mitral annulus, the sewing ring having an inflow end and an outflow end, the outflow end being an implant A sewing ring that includes an axially raised portion that is sometimes associated with the remainder of the outflow end that is spaced to match the two forward triangles;
A prosthetic mitral heart valve.
(Item 18)
The support frame has a wavy shape and includes three axially arranged commissures extending in the outflow direction alternating with three cusps extending in the inflow direction;
Two of the commissures are located adjacent to the two axially raised portions of the sewing ring, and the heart valve is attached to three flexible arms mounted around the wavy shape of the support frame. 18. A heart valve according to item 17, comprising a leaf.
(Item 19)
18. A heart valve according to item 17, wherein the support frame has a generally annular profile, and the heart valve includes two rigid lobes mounted for pivotal movement within the support frame.
(Item 20)
18. A heart valve according to item 17, wherein the axially raised portion gently bends upward from the adjacent portion of the outflow end to a height of about 50% of the largest axial dimension of the sewing ring.
(Item 21)
18. A heart valve according to item 17, wherein the annular member for passing the suture has a variable compliance around its circumference.
(Item 22)
The sewing ring is less flexible at an intermediate point between the axially raised portions located around a shorter distance between the raised portions than an intermediate point diametrically opposite the intermediate point; Item 22. The heart valve according to Item 21.
(Item 23)
The sewing ring includes a ring-shaped member for passing a suture surrounded by a fabric cover;
The annular member has a plurality of radial walls, the plurality of radial walls defining a space between the radial walls;
The radial wall at a midpoint between the axially raised portions located around a shorter distance between the raised portions at a location directly opposite the midpoint 23. The heart valve of item 22, wherein the heart valve is thicker.
(Item 24)
The sewing ring includes a ring-shaped member for passing a suture surrounded by a fabric cover;
The annular member has a plurality of walls, the plurality of radial walls defining a space between the radial walls;
The space is smaller at the midpoint between the axially raised portions located around a shorter distance between the raised portions than at the location directly opposite the midpoint; 23. The heart valve according to 22.

FIG. 1 is a diagram of the heart illustrating the left ventricle LV and its associated valves, viewed as a partial vertical section along the anterior and posterior planes. FIG. 2 is a view from above of the aortic and mitral annulus, enlarged with the associated atrium removed. FIG. 2A is a schematic diagram of the mitral annulus seen corresponding to FIG. 2, showing the most prominent anatomical features and terminology. FIG. 3A is a partial vertical section along the anteroposterior plane illustrating a conventional arrangement of a prior art prosthetic heart valve in a mitral annulus. FIG. 3B is a partial vertical section along the anteroposterior plane illustrating the placement of the prosthetic heart valve of the present invention in the mitral annulus, showing a slightly tilted implantation position. FIG. 4 is a perspective view of an exemplary wavy heart valve support frame. FIG. 5 is a perspective view of three flexible lobes assembled using the support frame of FIG. 4 and used in an exemplary heart valve of the present invention. FIG. 6 is a perspective view of an assembled flexible leaflet mitral heart valve of the present invention having a shaped sewing ring. FIG. 7A is a perspective view of the outflow end for an exemplary ring-shaped member of the sewing ring of the present invention. FIG. 7B is a perspective view of the outflow end for an exemplary ring member of the sewing ring of the present invention. FIG. 8 is a front view of one side of the ring-shaped member of the sewing ring. FIG. 9 is a plan view of the inflow end of the ring-shaped member. FIG. 10 is a plan view of the outflow end of the ring-shaped member, showing a plurality of radial walls that define various sized spaces therebetween. FIG. 10A is an enlarged view of a portion of the outflow end of the ring-shaped member showing details of different sized spaces. FIG. 11 is a front view of another side of the ring-shaped member. FIG. 11A is a cross-sectional view of the radius taken through another side of the ring-shaped member. FIG. 12 is a front view of a further front side of the ring-shaped member. FIG. 12A is a cross-sectional view of the radius taken through the further side of the ring-shaped member. FIG. 12B is an enlarged view of a cross section of the radius through the ring-shaped member. FIG. 13 is a perspective view of an assembled rigid leaflet mitral heart valve of the present invention having a shaped sewing ring. 13A is a cross-sectional view of the radius through the shaped sewing ring of FIG. 13 taken along line 13A-13A showing the different compliance portions. 13B is a radial cross section through the shaped sewing ring of FIG. 13, taken along line 13B-13B, showing the different compliance portions.

  The present invention provides an improved prosthetic heart valve for the mitral annulus. The prosthetic heart valve disclosed herein has a shaped suture ring or sewing ring, sometimes known as a sewing cuff, which is better adapted to the structure of the mitral annulus and Position the valve at an angle with respect to the surface. The sewing ring has at least one axially raised portion at its outflow end that fits snugly with the anterior side of the mitral annulus. In the illustrated embodiment, there are two such axially raised portions, each corresponding to one of the fiber triangles of the mitral annulus, while the back side of the outflow end is Usually flat. However, it should be understood that the back side of the outflow end can also be shaped or have a shape other than the face of the annulus.

  The sewing rings disclosed herein are useful with any kind of bioprosthetic or mechanical prosthetic heart valve, flexible leaf or rigid leaf. The first exemplary embodiment is a flexible leaf-like valve, and a rigid leaf-like valve is illustrated in FIG. It should be appreciated by those skilled in the art that the particular advantages embodied by the shaped sewing ring are applicable to all prosthetic mitral heart valves, regardless of the occluder structure. For example, although a separate flexible leaflet is illustrated, the present invention can also be used with general xenograft (eg, porcine) valves. Furthermore, while the term “sewing ring” is used throughout this application, it should be understood that connection structures other than sutures can be used to implant the heart valve of the present invention. For example, staples, glues, hooks, barbs, etc. are also contemplated for coupling a sewing ring to a mitral annulus.

  As an introductory knot, various angle values are provided to space the raised portions and other structures in the axial direction of the illustrated sewing ring. These angle values depend to some extent on the surrounding mitral structure and to some extent on the occluder structure. For example, an entire pig valve often has three lobes but has commissures that are not equidistantly spaced around the valve. The general distribution of commissures is not 120 degrees / 120 degrees / 120 degrees, but rather has an interval of 115 degrees / 120 degrees / 125 degrees. Thus, for example, a slight offset distribution of pig valve commissures may require placement of offsets corresponding to the commissures of the support structure and the axially raised portions of the sewing ring. Further, the original triangle of the mitral annulus can be spaced less than 120 degrees or more. Thus, in this context, the term “about 120 degrees” should be understood to encompass a range of angle values of about 20 degrees on each side, or between 100 degrees and 140 degrees.

Prior to a detailed description of the structure of an exemplary prosthetic heart valve, one of the main advantages of the present invention will be described with reference to FIGS. 3A and 3B. FIG. 3A shows a prosthetic heart valve 30 having an annular, flat sewing ring 32 implanted in the position of the mitral annulus. The flat nature of the sewing ring 32 and particularly its outflow end 34 allows the valve 30 to be positioned so that the sewing ring is parallel to the mitral annulus plane (MAP) described above. A blood flow arrow 36 in the outflow direction typically extends to the left ventricle LV, perpendicular to the MAP. The prosthetic heart valve 30 shown has a plurality of outflow commissures 38 that support the flexible lobes 40 between the valves. By convention, two of the outflow commissures 38 are placed adjacent to the anterior triangle (not shown) of the mitral annulus, while the third (shown on the right) commissure is on the back side. Yes, extending to the left of the left ventricle LV, close to its inner wall. Gap G ₁ between this third commissure 38 and the left ventricle LV is shown.

  FIG. 3B shows the prosthetic heart valve 50 of the present invention implanted in the position of the mitral annulus. The sewing ring 52 has a molded outflow end 54 that includes a portion 56 that projects axially in the outflow direction relative to the adjacent portion of the outflow end, and is positioned on the front side of the sewing ring. The presence of the protruding portion 56 raises that side of the valve 50 and positions the valve so that the sewing ring 52 is deflected by an angle δ relative to the face MAP of the mitral annulus. The angle δ is desirably about 3 to 15 degrees, and more preferably about 7 degrees. A blood flow arrow 58 in the outflow direction extends into the left ventricle LV at an angle that is not at all perpendicular to the MAP.

Like the valve 30 described above, the prosthetic heart valve in FIG. 3B has a plurality of outflow commissures 62 that support the flexible lobes 64 between the valves. Two of the outflow commissures 62 are positioned adjacent to the anterior triangle (not shown) of the mitral annulus, while the third (shown on the right) commissure is on the back side, It extends to the left of the left ventricle LV and close to its inner wall. Gap G ₂ between the third commissure 62 and the inner wall of the left ventricle LV is shown. Gap _{G 2} is, because of the inclination angle δ of the valve 50 is greater than the gap _{G 1} shown in FIG. 3A. This increased spacing between the commissures 62 closest to the inner wall of the left ventricle LV helps prevent contact therebetween, thereby reducing the possibility of undesirable trauma or wear to the left ventricle.

  Referring now to FIGS. 4-7, the basic structure of an exemplary prosthetic mitral heart valve 50 of the present invention will be described. FIG. 4 illustrates a heart valve support frame 70 that supports the leaflets 64 described above and defines the commissure 62 of the valve seen in FIG. 3B. Support frame 70 includes outflow end commissures 72a, 72b, and 72c that alternate with inflow end cusps 74a, 74b, and 74c. The ends of each pair of adjacent cusps 74 form upstanding commissures 72 that end by tapering asymptotically, each of the ends extending in a direction opposite the arcuate cusp. Have a relatively smaller radius. When viewed from above, the shape of the periphery of the support frame 70 is substantially tubular, and the three commissures 72 are spaced equidistantly and have an angular distance of about 120 degrees. It is divided by. Desirably, the commissures 72 are bent slightly radially inward from the adjacent cusps 74 so that the support frame 70 defines a generally conical shape.

  The prosthetic valve 50 is a trilobal valve having three flexible leaf-like portions 64a, 64b and 64c (FIG. 5). Three lobes are preferred, mimicking a real aortic valve, but the principles of the present invention can be applied to prosthetic valve structures having two or more flexible lobes. Each of the leaflets 64 includes an arcuate lower apex edge 66 that ends in an upstanding commissure region 67, together defining a “peripheral edge” of each leaflet. Each leaf 64 includes a joint or free edge 68 that faces the apex edge 66. In the assembled valve 50, the apex edge 66 and commissural region 67 are fixed around the periphery of the valve, allowing the free edge 68 to meet or "join" in the middle.

  In the exemplary structure of the heart valve 50, the peripheral edges (66, 67) of the leaflets 64 are coupled to the support frame 70, thus defining the shape of the flow orifice and the three-dimensional support structure for the leaflets. To do. The three lobes 64a, 64b and 64c are arranged as shown in FIG. 5, and the support frame 70 is lowered to the top of the assembly so that the juxtaposed peripheral edges of each of the two lobes are The axial space defined in the commissure 72 of the support frame 70. Although not shown, the fabric covers the support frame 70 and provides a bonded structure to which the lobes 74 are connected, usually using sutures. As mentioned above, other valve structures may not use the support frame 70 but may still be combined with the shaped sewing ring 52.

  An assembled prosthetic mitral heart valve 50 is shown in FIG. The side closer to the valve 50 is the front side, and the opposite side is the rear side. The aforementioned commissures 62a, 62b and 62c project “upward” toward the outflow end of the valve 50 in the orientation shown. The terms “upward” and “axial bulge” are used herein in connection with the orientation of the valve 50 as seen in FIG. 6, with the outflow end facing upward. Of course, the valve 50 can be reversed to reverse this direction as previously seen in FIGS. 3A and 3B.

  The sewing ring 52 surrounds the apex 74 covered with the fabric of the support frame 70 and is coupled to the apex using a suture thread or other means. As stated, the outflow end 54 of the sewing ring 52 includes at least one portion 56 that projects axially in the outflow direction relative to the adjacent portion of the outflow end of the sewing ring. In the illustrated embodiment, there are two such axially raised portions 56 spaced approximately 120 degrees and radially outward from two of the commissures 62a and 62b. A radial line 80 drawn across the outflow end 54 means the top of both of these axial ridges 56a and 56b and may be included as a position marker outside the sewing ring 52.

  The preferred structure of the sewing ring 52 includes a ring-shaped member 90 that is covered with a fabric and that passes the suture seen in FIGS. 7A and 7B. Annular member 90 has a shaped outflow end 94 that includes a substantially planar inflow end 92 and two axially raised portions 96a and 96b. Preferably, the ring-shaped member 90 is made of a biocompatible polymer, such as silicon resin, through which the suture passes, and has a plurality of walls defining spaces or cells therebetween. As seen in FIG. 7A, the space is open to the outflow end 94, and FIG. 7B illustrates a substantially continuous, closed inflow end 92.

FIGS. 8-12 depict exemplary structural details of a ring-shaped member 90 for threading sutures. FIG. 8 shows the raised portions 96a and 96b associated with the annular member 90 and the remainder of the outflow end 94 in the front view. The overall axial dimension of the ring-shaped member 90 is shown on the left as H. The reference height h ₁ for most of the ring-shaped member is about _one-half of the overall ring-shaped member height H, as are the additional heights h _{2 of} the axially raised portions 96a and 96b. It is. In other words, the axially raised portions 96a and 96b bulge upward from the adjacent portion of the outflow end 94 to a height of about 50% of the largest axial dimension of the annular member 90. According to one embodiment, the raised portions 96a and 96b in the axial direction, raised from the adjacent portions of the outflow end 94 to the height h ₂ of about 2 mm, the overall height H of the annular member 90 is about 4mm .

  In the preferred embodiment, the axially raised portions 96a and 96b are gently curved toward their tops upward from adjacent portions of the outflow end and are substantially symmetrical about the midpoint of the circumference. As described above, the raised portions 96a and 96b of the annular member 90 are provided on the front side of the member. The rear side 97 of the outflow end 94 is substantially planar and parallel to the inflow end 92 as seen in FIG. FIG. 11 illustrates the symmetry between two raised portions 96a and 96b centered on the trough 98. FIG. FIG. 12 shows raised portions 96a and 96b that curve and descend away from each other toward a substantially planar back side 97. FIG. As defined herein, the raised portions 96a and 96b are raised relative to the “adjacent portion” and are usually defined in one direction by a rear side 97 that is planar and the other by a front trough 98. Defined in direction.

  Referring now to the plan view of the outflow end 94 in FIG. 10, the short radial line is the apex 100 at the midpoint of the circumference of the raised portions 96a and 96b along the inner shelf 102 (described in more detail below). Indicates. An overall symmetry plane 104 that bisects the two tops 100 and passes through the center thereof is illustrated through the ring-shaped member 90. This plan view illustrates the symmetrical circumferential distribution of the top 100 with respect to the surface 104. Preferably, the apex 100 is located about 60 degrees from the plane of symmetry, or about 120 degrees from each other, and is measured by the shortest distance around the ring-shaped member 90.

  The ring-shaped member 90 seen in FIGS. 10-12 is provided with a plurality of walls defining a space or cell therebetween. As best seen in FIG. 12B, a relatively thick continuous inner wall 100 extends 360 degrees around the ring-shaped member 90 and bends radially outward and outward from the inner wall 110. The same is true for the continuous conical wall 112. As seen from the bottom in FIG. 9 and the cross section in FIG. 11, the bottom surface 114 of the inner wall 110 and the conical wall 112 together define a continuous or non-hollow wall of the ring-shaped member 90 facing the inflow direction. FIG. 12B is a radial cross-section through one of the raised portions 96a, illustrating the outer partial tubular wall portion 116 projecting upward from the outermost rim of the conical wall 112. FIG. To do. An inner partial tubular wall portion 118 projects upwardly from the inner wall 110 in the region of the raised portion 96. A plurality of radial walls 120 connect the inner wall 110, the conical wall 112, and the outer wall portion 116, and define a plurality of cells or spaces 122 open to the outflow end 94 therebetween. The combined shape of the upwardly projecting wall portions 116, 118 and the radial wall 120 therebetween defines the raised portions 96 a and 96 b of the ring-shaped member 90.

  As can be seen in FIG. 10, the radial walls 120 and the spaces 122 between the walls are distributed around the entire circumference of the ring-shaped member 90. As can also be seen in FIG. 7A, the space 122 is open to the outflow end 94 of the ring-shaped member 90. Eventually, the sewing ring 52 is wrapped by the fabric as seen in FIG. 6, so that the space 122 is not visible in the finished valve. The space 122 provides a “waffle” structure to the ring-shaped member 90, making it very compliant. Desirably, the annular member 90 is made from a suitable biocompatible polymer, such as silicon resin or polyurethane, and the space 122 facilitates the formation of the walls 110-120 and allows easy removal of the molded part. .

  10 and 10A also illustrate a preferred structure for changing the compliance of the annular member 90 around the circumference. As described above, the tops 100 of the projecting portions 96a and 96b are spaced about 120 degrees apart. Within this arc, the walls 120 are separated by a smaller distance than at positions facing away from this arc, resulting in a smaller space 122 and a more rigid ring 90. More preferably, the angle θ is shown bisected by the symmetry plane 104, thereby being centrally disposed between the tops 100. The line forming the angle θ extends through the radial wall 120 that defines the change between the differently sized spaces 122. In one embodiment, the angle θ = 90 degrees, where θ is desirably in the range of 80 degrees to 120 degrees.

The enlarged FIG. 10A best illustrates the change between the differently sized spaces 122. The radial wall 120 ′ separates the first space 122a from the second space 122b. The first space 122a extends to an angle α, and the second space 122b extends to an angle β, where β> α. This angular relationship results in the dimensions of the arcs of S ₁ and S ₂ respectively, and the dimensions of the arcs of S ₁ and S ₂ are the reference radii through the respective radial midpoints of the spaces 122a and 122b And shows a size depending on the size of the ring-shaped member 90. It should be understood that heart valves are manufactured in various sizes, typically between 21-35 mm in outer diameter, so that the sewing ring 52 and ring member 90 are provided in various sizes. . It is understood that the ring-shaped member 90 is more compliant when the space 122b is larger, assuming other conditions are the same.

  The following table provides exemplary dimensions of an annular member 90 dimensioned for a 27 mm prosthetic valve, each space 122 being referred to as a “cell”. In this embodiment, the cell walls 120 all have equal thickness.

上述のように、図１０の頂部１００によって輪郭を描かれた隆起部分９６の間の弧は、部材９０の角度のある部分に対するものであり、該部分は、僧帽弁輪の前側の面において配置されるように意図される。空間１２２ａは、概して、頂部１００の間（または、少なくとも角度θ内）においてより小さく、部材９０および裁縫リング５２の前側は、従って後ろ側９７よりもコンプライアンスを有さない。よりコンプライアンスを有し、比較的に堅くはない後ろ側９７は、裁縫リング５２が僧帽弁輪の後ろ側の面のしばしば石灰化する組織により容易に順応し得るので望ましい。しかし、好ましい実施形態において、裁縫リングは、隆起部分９６の間のより短い距離に位置している、軸方向への該隆起部分の間の中間の点において、中間点と正反対に向かい合う位置におけるよりも柔軟ではない。

As described above, the arc between the raised portions 96 outlined by the top 100 of FIG. 10 is relative to the angled portion of the member 90, which portion is in the front face of the mitral annulus. Intended to be placed. The space 122a is generally smaller between the tops 100 (or at least within the angle θ), and the front side of the member 90 and the sewing ring 52 is therefore less compliant than the back side 97. A more compliant and less rigid posterior side 97 is desirable because the sewing ring 52 can be more easily adapted to the often calcifying tissue of the posterior surface of the mitral annulus. However, in a preferred embodiment, the sewing ring is located at a shorter distance between the raised portions 96, at a point midway between the raised portions in the axial direction than at a position directly opposite the midpoint. Also not flexible.

  Designing the annulus 90 to be more compliant on the posterior side 97 is just one possible configuration motivated by a specific understanding of the tissue characteristics around the mitral annulus, in this case Those skilled in the art will appreciate that the back side is the more calcified side. Of course, the compliance characteristics of the ring around the circumference can be customized in other ways, so that the ring is more compliant, for example around the front side. In general, the present invention contemplates a sewing ring 52 having variable compliance around the circumference. For example, one arrangement to contemplate is having alternating large and small cells, where the areas where high and low compliance alternate are smaller and more, either on one side or the other Contrast with those separated on one side.

Still referring to FIG. 10A, the compliance of the sewing ring 52, or more specifically the ring-shaped member 90, can be varied differently, other than changing the space between the walls 120 on its circumference. For example, the walls 120 themselves can be provided with different thicknesses, for example by making the angles λ and μ in the above table unequal. It is shown on the left of the transition wall 120 ', in a more compliance less (rigid) parts, the radial walls 120 may have a thickness t _1, whereas in the right transition of wall, radial walls 120 Can have a thickness t ₂ , where t ₂ <t ₁ (λ> μ with respect to angle). By making the radial wall 120 thinner around the back side 97 of the ring member 90, the wall is also more compliant in that region. Further, changing the thickness of the radial wall 120 may result in a greater difference in flexibility by being combined with changing the size of the space 122. Furthermore, a clear transition in the wall 120 'between areas of unequal flexibility can be replaced with a more gradual transition.

  It should also be understood that the structure of the sewing ring can be different from that shown in FIGS. Making a sewing ring using a “waffle” of silicon resin made in the illustrated mold has certain distinct advantages, but has an axial ridge in front of the outflow end of the sewing ring. The general advantage of providing and varying flexibility can be achieved using a variety of structures. For example, other polymers (eg, polyurethane) can be used to form the waffle structure, or the specific arrangement and spacing of the walls can be modified. Certain biocompatible fabrics such as non-woven and uncompressed polyester or polyethylene terephthalate can also be used to form the sewing ring. Indeed, one particularly useful way of forming a sewing ring is to wind or fold such a fabric to the required contour and then heat set the fabric to the desired shape. Such rolls or folded fabrics or fabrics can be manufactured with different compliances around the circumference of the sewing ring. For example, the front side can be made stiffer than the back side 97 by winding such fabric tighter on the front side of the sewing ring. Thus, it is to be understood that the invention is not limited to molded “waffle-like” polymer inner members for sewing rings unless specifically claimed.

  Details of other particular structures of the exemplary annular member 90 that facilitate assembly of other portions of the flexible lobular heart valve are shown in perspective views of FIGS. 7A and 7B, and in detail of FIGS. Shown in the figure. More specifically, FIG. 7A best illustrates the inner shelf 102 that is supported on the three cusps 74a, 74b and 74c (FIG. 4) of the support frame 70 in the assembled valve 50. It has been. The inner shelf 102 is also in the cross-sectional views in FIGS. 11, 12A and 12B from the horizontal platform 132 at the midpoint of the rear side 97 to the small horizontal flange 134 and from there upward to the top 100 at the raised portions 96a and 96b. It can be seen in the transition of. The shelf 102 falls to another small horizontal flange 136 in the middle between the front midpoint and the top 100. As seen in FIG. 11A, shelf 102 is substantially horizontal at its lower end and transitions to have a slightly inward and downward angle as it rises upward in the axial direction, enlarging FIG. 12B. As seen in the figure, the highest point is reached at the top 100.

  Making the assembly of the valve 50 includes covering the support frame 70 shown in FIG. 4 with a fabric having an essentially outwardly extending flange. Annular member 90 is also covered with fabric, and the peripheral edge of leaf 64 is sandwiched between support frame 70 and annular member 90 and secured to the fabric cover. As mentioned, the apex 74 of the support frame 70 closely conforms to the contour of the inner shelf 102 and the assembly is made to be relatively dimensionally stable when the various elements are stitched together. That is, the support frame 70 is prevented by the inner shelf 102 from moving in the inflow direction via the ring-shaped member 90. A more complete discussion of these fabrication techniques is provided in US Pat. No. 11 / 039,522 entitled US Pat. No. 6,585,766 to Huynh et al. The disclosure is expressly incorporated herein by reference.

  The profile of the raised portions 96a and 96b is also important to increase contact between the sewing ring 52 and the surrounding mitral annulus, and is inclined to release the entire valve from the left ventricular wall. It is important to provide the advantage of raising the front side upwards. As best seen in the front views of FIGS. 11 and 12, each of the raised portions 96a and 96b defines a smooth curvature with no sharply exposed corners. FIG. 11 illustrates the symmetry between the two raised portions 96 a and 96 b, where the front side of the outflow end 94 gradually decreases in height from the raised portion to the trough 98. The trough 98 has approximately the same height as the opposite side of the outflow end 94 of the annular member 90 as seen on the left side of FIG. Thus, the circumferential arc in which the axial dimension of the ring-shaped member 90 changes from the highest point of the raised portions 96a and 96b to the lowest point of the trough 98 is about 60 degrees. On the other hand, referring to FIG. 12, the transition between the highest points of the raised portions 96a and 96b and the substantially flat rear side 97 is not modest but still smooth. The circumferential arc distance between the raised portions 96a and 96b and the flat rear side 97 of the outflow end 94 is about 20 degrees.

  Referring now to FIG. 13, an alternative prosthetic heart valve 150 of the present invention includes a mechanical valve member 152 coupled with a molded sewing ring 154 of the present invention. The valve member 152 includes rigid leaves 156a and 156b that are coupled for pivotal movement within the surrounding support frame 158. Sewing ring 154 couples around the periphery of support frame 158. In this figure, the inflow end of the valve member 152 is on the top and the outflow end is on the bottom. Two raised portions 160a and 160b are provided in the sewing ring 154, like the flexible leaf embodiment described above. The raised portions 160a and 160b coincide with the original triangle (usually about 120 degrees) by being spaced apart on the circumference, preferably on the front side of the sewing ring 154. It should be noted that the mechanical valve member 152 is normally rotatable within the surrounding support frame 158 and therefore the orientation shown with respect to the shaped sewing ring 154 should not be considered limiting. That's what it means. The sewing ring 154 has an outer surface 162 of the fabric that can cover a ring-shaped member such as an internal waffle, as described above, or simply on the outer layer of the wound or folded fabric structure. Can be.

  13A and 13B are radial cross-sections through the shaped sewing ring 154 of FIG. 13, taken along respective lines 13A-13A and 13B-13B showing the different compliance portions. In this embodiment, the sewing ring 154 is made of a wound fabric structure, and different compliance is obtained by winding the fabric more securely on one side 170 than on another side 172. Desirably, the side 170 that is more tightly wound, i.e., less compliant, is on the front side of the mitral valve 150, and the more gently wound, i.e., more compliant side 172, is the back side. It is. In another commercial construction, a non-woven polymer fabric or polyester felt (such as a pillow stuffing) is used. In the latter construction, the polyester felt can be packed more tightly around one side of the sewing ring 154 compared to the other side.

  It will also be appreciated by those skilled in the art that various modifications can be made to the examples and embodiments of the invention described in this provisional application without departing from the intended scope of the invention. The specific embodiments of the present invention described herein are therefore to be understood as examples of the broad inventive concepts described in this application.

Claims (22)

  A sewing ring for a prosthetic heart valve,
  Comprising an annular member threaded through a suture arranged about an axis defining an inflow-outflow direction;
  The sewing ring, wherein the ring-shaped member has a compliance that can be changed around its circumference so that at least one side of the ring-shaped member has a smaller compliance at a position facing the opposite side of the ring-shaped member.   The annular member includes a molded polymer having a plurality of radial walls, the plurality of radial walls defining a space between the radial walls;
  The sewing ring according to claim 1, wherein the radial wall around the one side is thicker than the radial wall on the opposite side.   The annular member includes a molded polymer having a plurality of radial walls, the plurality of radial walls defining a space between the radial walls;
  The sewing ring according to claim 1, wherein the space around the one side is smaller than the space on the opposite side.   The sewing ring according to claim 1, wherein the ring-shaped member includes a polymer fabric.   The sewing ring according to claim 4, wherein the ring-shaped member includes a wound fabric, and the fabric is wound more firmly on the one side than on the opposite side.   The sewing ring forms a component of a mitral heart valve for implantation in a mitral annulus having two triangles spaced about an anterior and posterior sides;
  The ring-shaped member has a front side opposite to the rear side,
  The sewing ring according to claim 1, wherein the ring-shaped member is more compliant on the rear side than on the front side.   The ring-shaped member defines an inflow end and an outflow end by being arranged about an axis, the outflow end including two portions that define a generally front side raised in an axial direction relative to an adjacent portion. The sewing ring according to claim 6.   The sewing ring according to claim 7, wherein the two axially raised portions of the outflow end are spaced apart by about 120 degrees.   The sewing ring according to claim 7, wherein the axially raised portion is gently curved upward from the adjacent portion of the outflow end to a height of about 50% of the largest axial dimension of the annular member. .   The sewing ring according to claim 9, wherein the largest axial dimension of the ring-shaped member is about 4 mm.   A prosthetic mitral heart valve for implantation in a mitral annulus, the annulus comprising two anterior triangles spaced apart by about 120 degrees, wherein the heart valve comprises:
  A support frame defining an orifice about an axis along the inflow-outflow direction;
  A plurality of leaves that are attached for movement on the support frame to provide a one-way valve at the orifice;
  A sewing ring through which a suture is passed, connected to the support frame and disposed about the heart valve to couple the heart valve to the mitral annulus, wherein the sewing ring has a compliance at least on one side smaller than another position. A sewing ring, arranged around to have a changeable compliance around its circumference, as
  It has a heart valve.   The sewing ring includes an annular member, the annular member includes a molded polymer having a plurality of radial walls, the plurality of radial walls defining a space between the radial walls;
  The heart valve according to claim 11, wherein the radial wall around the side with the smaller compliance is thicker than the radial wall in another location.   The sewing ring includes an annular member, the annular member includes a molded polymer having a plurality of radial walls, the plurality of radial walls defining a space between the radial walls;
  The heart valve according to claim 11, wherein the space around the side with smaller compliance is smaller than the space at another location.   The heart valve according to claim 11, wherein the sewing ring includes a ring-shaped member, and the ring-shaped member includes a polymer fabric.   15. The heart valve of claim 14, wherein the annular member includes a wound fabric, the fabric being wound more tightly around another side having less compliance than another location.   The heart valve according to claim 11, wherein the sewing ring includes a ring-shaped member, and the ring-shaped member has a front side opposite to a rear side, and the front side has a smaller compliance than the rear side.   17. A heart valve according to claim 16, wherein the annular member defines an inflow end and an outflow end, the outflow end including two portions that define a generally anterior side that is axially raised relative to an adjacent portion.   18. A heart valve according to claim 17, wherein the two axially raised portions of the outflow end are separated and spaced apart by about 120 degrees to match the two anterior triangles during implantation.   The heart valve of claim 17, wherein the axially raised portion is gently curved upward from the adjacent portion of the outflow end to a height of about 50% of the largest axial dimension of the annular member. .   20. A heart valve according to claim 19, wherein the largest axial dimension of the annular member is about 4 mm.   The support frame has a wavy shape and includes three axially arranged commissures extending in the outflow direction alternating with three cusps extending in the inflow direction;
  The heart valve according to claim 11, wherein the heart valve includes three flexible lobes mounted around the wavy shape of the support frame.   The heart valve of claim 11, wherein the support frame has a generally annular configuration, and the heart valve includes two rigid lobes mounted for pivotal movement within the support frame.

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