Assembly for replacing the tricuspid atrioventricular valve
An assembly for the tricuspid orifice of a human heart, comprises an external frame connected to an internal stent carrying a tricuspid valve bioprosthesis and a sealing skirt. The external frame is configured to hold its position in the native tricuspid annulus. The internal stent is connected to the external frame by one or more fixing strands. The sealing skirt covers the interstitial space existing between the external frame and the internal stent. Developments are described which comprise in particular the use of a deformable region of the frame, various alternative embodiments of the sealing skirt, the use of a frame composed of multiple sub-sections, the use of fixing strands between the stent and the frame and of fixing elements for fixing the assembly to the native tissue, the use of sensors and/or actuators, and also the use of a stent in the inferior vena cava. Method aspects are described.
1. An assembly for the tricuspid orifice of the right side of a human heart, comprising:
an external frame connected to
an internal stent carrying
a tricuspid valve bioprosthesis and
a sealing skirt,
wherein
the external frame comprising a plurality of sub-sections that are independent of one another, the external frame being configured to hold its position in the native tricuspid annulus, the external frame having a ventricular end, an opposing atrial end and a middle portion, the external frame defining an interstitial space between the external frame and the internal stent, the external frame having an outward convex zone between the ventricular end and the middle portion, the middle portion being a concave zone and having a diameter smaller than a diameter of the atrial end;
each of the independent sub-sections of the external frame is connected to the internal stent by one or more fixing strands connecting the external frame to the internal stent; and
the sealing skirt covers the interstitial space existing between the external frame and the internal stent; and
wherein the sealing skirt is configured to obstruct the contact space between the external frame and the site of the native tissue in the region of the native tricuspid annulus; and
wherein the tricuspid valve bioprosthesis is operable to block flow in a direction from the ventricular end of the external frame to the atrial end of the external frame.
2. The assembly as claimed in claim 1 , wherein the external frame has a deformable region configured to hold the assembly in position inside the native tricuspid annulus.
3. The assembly as claimed in claim 1 , wherein the external frame has, upstream from the region of the native annulus, a shape configured to reinforce the hold of the assembly in the native tricuspid annulus.
4. The assembly as claimed in claim 1 , wherein the external frame has, downstream from the region of the native annulus, a shape configured to reinforce the hold of the assembly in the native tricuspid annulus.
5. The assembly as claimed in claim 1 , wherein the each of the one or more strands is made of nitinol.
6. The assembly as claimed in claim 1 , further comprising at least one fixing element for fixing to the native tissue.
7. The assembly as claimed in claim 1 , the sealing skirt being composed of several sub-sections, of several layers of materials, or of several sub-sections and several layers of materials.
8. The assembly as claimed in claim 1 , wherein at least one of the frame, the stent, a fixing strand, or a fixing element is composed of a heat-sensitive material, a shape-memory material, or a shape-memory material that is heat-sensitive.
9. The assembly as claimed in claim 1 , further comprising at least one sensor, a radiopaque marker, or both the at least one sensor and the radiopaque marker.
10. The assembly as claimed in claim 1 , further comprising an actuator suitable for modifying the structure of the assembly, for adjusting the positioning of a part of the assembly with respect to the native annulus, or both for modifying the structure of the assembly and adjusting the positioning of a part of the assembly with respect to the native annulus.
11. The assembly as claimed in claim 1 , said assembly being connected to a stent suitable for positioning in the inferior vena cava, said stent being connected to the frame of the assembly by a strand made of nitinol.
12. The assembly as claimed in claim 1 , said assembly being folded up in a packaged state in a catheter for introduction by a percutaneous route.
13. The assembly as claimed in claim 1 , wherein the one or more strands are connected to the atrial end of the external frame.
14. The assembly as claimed in claim 1 , wherein the external frame extends outwardly with respect to the tricuspid valve bioprosthesis from the middle portion to the atrial end.
15. The assembly as claimed in claim 1 , wherein each of the plurality of sub-subsections comprises a loop, the loops not being interconnected with each other.
16. The assembly as claimed in claim 1 , wherein the one or more fixing strands connect the external frame to an atrial end, representing an atrial portion, of the internal stent.
17. The assembly as claimed in claim 1 , wherein the one or more fixing strands connect the external frame to the internal stent in the region of the annulus.
18. A method for replacing the tricuspid valve, comprising the steps of positioning the assembly as claimed in claim 1 in a folded state in a catheter, and introducing and deploying said assembly by a percutaneous route.