WO2001030275A1

WO2001030275A1 - Heart valve stent, in particular mitral heart valve stent

Info

Publication number: WO2001030275A1
Application number: PCT/PL2000/000078
Authority: WO
Inventors: Zbigniew Religa; Marek KRZYŚKÓW; Bogdan Stolarzewicz; Jolanta WSZOŁEK
Original assignee: Fundacja Rozwoju Kardiochirurgii
Priority date: 1999-10-29
Filing date: 2000-10-27
Publication date: 2001-05-03
Also published as: AU1064901A; PL190345B1; PL336364A1

Abstract

The invention relates to a heart valve stent, in particular mitral heart valve stent, which is applicable during preparation of implantable biological heart valve. The stent consists of an implantable ring (1), which has arms (2) formed by rods (3), said rods (3) separated by slots (4). Outside end portions of rods (3), advantageously formed of oval plates (5), create an outline (6) of the arm (2). A generating line of a three-dimensional figure defined by arms (2) is convergent in opposite direction to ring (1), whereas central axes (0) of rods (3) can be a line segment or a curved line with convexity directed out of central axis (01) of the stent.

Description

HEART VAL Ε STENT, IN PARTICULAR MITRAL HEART VALVE STENT

Field of the Invention

The present invention relates to a heart valve stent, in particular a mitral heart valve stent, which can be used during preparation of an implantable biological mitral heart valve for surgical treatment in human heart disorders.

Background Art

Polish patent PL 176273 Bl discloses a flexible stent for a biological mitral valve implant, having a supporting element with a flange, both covered with coating material. Said supporting element forms a Cassini's oval shape in cross section. Cylindrical surface of the supporting element has a flange in its atrial cordis part, and also has two twin arms with wavy formed edges, in particular sinusoidal, in its heart ventricular part. Arched openings between the arms have their bottoms in the short axis of the stent, whereas radius of the openings differ from each other. Furthermore the arms of the stent are advantageously convergent in the heart ventricle direction. The convergent angle is not bigger than 7°. Further the flange of the stent has trapezium - like shape in cross section, whereas the longer base of the trapezium is adjacent to the cylindrical supporting element along its circumference. In different embodiment of the invention the arms have their top radius not longer than 1/8 of the length of the stent' s long axis.

Mitral heart valve provided from a donor is sewn into the ring of a stent, whereas its tendinous chords, which had been previously cut from muscles, are individually one by one attached to the arms of the stent. The operation of fastening the chords to the arms of the stent absorbs plenty of time, and the final result depends mainly on manual skills of the person who prepares the heart valve. There is no possibility to sew a complete heart valve unit with portion of muscles into the stent.

The present invention is directed to creating a heart valve stent, in particular mitral heart valve stent, which would allow to sew complete heart valve unit with muscles in order to simplify the preparation of the implant.

Object of the Invention

According to the invention, single arm of the stent consists of a number of rods, said rods are separated by slots and are located along the length of the arm. The outside end portions of the rods form the outline of the arm.

Preferably each of the rods has a plate at its end, which simplifies attaching the muscles.

Most preferably the plate has an oval shape. This allows an easy covering with coating material and also prevents the coating material from tearing due to lack of sharp edges.

In simpler embodiment of the stent, a central axis of each rod lays in a plane which goes through the central axis of the stent.

In the simplest embodiment of the invention the central axis of each rod is a straight line.

Because of anatomical reasons it is preferred that the central axis of each rod has an curvilinear shape, with convexity directed outside to the central axis of the stent.

In accordance with a different embodiment of the invention single arm of the stent consists of a number of rods, said rods having central axes mutual convergent.

It is preferred that the central axes of said rods are mutual convergent in the direction of the ring.

In simpler embodiment of such stent the central axes of said rods and central axis of the ring create an element of a cone.

It is most preferably when the central axes of said rods as well as the circumference of the ring create a barrel - shaped element, with its convexity directed outside the central axis of the stent.

It is also preferably that said rods of an arm are set on a single shaft protruding from said ring.

The main advantage of the invention relates to the possibility of using a complete mitral heart valve unit with pieces of muscles. Due to the above during preparation of the heart valve its individual geometry is maintained. Additionally the arms formed of rods make the stent flexible, which allows the tendinous chords to work properly and prevents them from tearing. It is also possible to bend the rods in order to adapt the stent to individual shape and size of a mitral heart valve. Apart from that, the stent with arms formed of rods has better blood flow characteristic in comparison to a stent with solid arms. After flowing through the ring blood run between the rods, which makes preferred blood distribution in the vicinity of mitral heart valve.

The invention together with additional features may be best understood by reference to the following description taken in connection with the accompanying illustrative drawings.

Description of the Drawings

Fig. 1 is a view of a stent with arms formed of parallel rods. Fig. 2 shows a developed view of a part of a stent with an arm consisted of three parallel rods. Fig. 3 is a developed view of a part of a stent with an arm consisted of three convergent rods. Fig. 4 is a developed view of a piece of a stent with an arm consisted of three convergent rods protruding from a single shaft. Fig. 5 shows a piece of a stent in longitudinal section through a curvilinear rod. Finally fig. 6 is a view in longitudinal section of a straight lined rod.

Detailed Description of the Invention

The mitral heart valve stent is formed as an oval ring 1 with two arms 2. Each of the two arms 2 is created by three rods 3 located along the length of the arms 2, said rods separated by slots 4. There are oval plates 5 at the ends of rods 3. Outside end portion of plates 5 form the outline 6 of an arm 2.

Rods 3 of the arms 2 create a generator of a spatial figure, and said generator is convergent in opposite direction to said ring 1.

In the simplest embodiment of the invention ( fig. 1 and fig. 2 ) central axes 0 of the rods 3 are located inside the plane going through the central axei 0ι of the stent ( fig. 5 ). They also may be formed as straight lines ( fig.6 ).

In different embodiment of the invention said rods 3 have central axes 0 which are mutual convergent in direction of ring 1 (fig.3), whereas in particular embodiment rods 3 of each arm 2 are set on a shaft 7 which protrudes from ring 1. Said ring 1 as well as rods 5 are covered with coating material 8.

The foregoing detailed description has been provided for better understanding of the invention only, and for those skilled in the art it is obvious that various modifications and alternations may be made to the preferred embodiment without departing from the intended spirit and scope of the invention, and it is intended that such modifications and alternations are included within the scope of the following claims.

Claims

1. Heart valve stent, in particular mitral heart valve stent, having a ring with arms, said arms defining a generator of a three - dimensional figure convergent in opposite direction to said ring, said stent covered with coating material, characterised in that a single arm (2) of the stent consists of a number of rods (3) separated by slots (4), said rods (3) located along the length of the arm (2), whereas the outside end portions of rods (3) create an outline (6) of the arm (2).

2. Heart valve stent according to claim 1, characterised in that each of rods (3) has an outer end formed as a plate (5).

3. Heart valve stent according to claim 2, characterised in that plate (5) is of an oval shape.

4. Heart valve stent according to claim 1 or 2 or 3, characterised in that central axis (0) of each rod (3) is situated within a plane ninning through a central axis (0ι) of the stent.

5. Heart valve stent according to claim 4, characterised in that central axis (0) of each rod (3) is a line segment.

6. Heart valve stent according to claim 4, characterised in that central axis (0) of each rod (3) has a curved shape, with convexity directed to opposite direction of central axis (0ι) of the stent.

7. Heart valve stent according to claim 1 or 2 or 3, characterised in that central axes (0) of rods (3) are mutual convergent.

8. Heart valve stent according to claim 7, characterised in that central axes (0) of rods (3) are convergent towards said ring Q).

9. Heart valve stent according to claim 8, characterised in that central axes (0) of rods (3) and circumference of ring (1) determinate a cone generator.

10. Heart valve stent according to claim 8, characterised in that central axes (0) of rods (3) and circumference of ring (1) determinate a barrel - like generator with convexity directed outside of longitudinal axis (0j).

11. Heart valve stent according to claim 9 or 10, characterised in that rods (3) are set on a shaft (7), which protrudes from ring (I).