BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention is directed to systems for implanting expandable prosthetic heart valves and, in particular, a prosthetic heart valve and a shaped expansion member for deploying the heart valve.

2. Description of the Prior Art

Minimally-invasive heart valve replacement has become very common in recent times. Such minimally-invasive heart valve replacement typically involve a self-expandable or a balloon-expandable stent integrated with a bioprosthetic valve having flexible leaflets, with the stent-valve device deployed across the native diseased valve to permanently hold the valve open, thereby alleviating a need to excise the native valve. These devices are designed for percutaneous delivery in a cardiac catheterization laboratory under local anesthesia using fluoroscopic guidance, thereby avoiding general anesthesia and open-heart surgery.

These expandable heart valves use either balloon- or self-expanding stents as anchors. The uniformity of contact between the expandable valve and surrounding annulus, with or without leaflets, should be such that no paravalvular leakage (PVL) occurs, and therefore proper expansion is very important. Perhaps more problematic is the quality of coaptation of the leaflets once the valve is expanded into place. Coaptation refers to the degree that the individual flexible leaflets come together in the valve orifice to occlude the back flow. If the leaflets do not quite meet, which could happen if the flexible valve is not expanded properly, regurgitation may occur. These and other issues make proper implant of the valve extremely critical. However, unlike open-heart surgery, the implant site is not directly accessible or visible and the valve must be implanted remotely at the end of a catheter or cannula under indirect visualization (e.g., fluoroscopic imaging).

Balloon-expandable heart valves typically require expansion with a cylindrical balloon of clear nylon. The inflation fluid consists of saline mixed with a more viscous contrast media. The inherent viscosity of the mixture increases the inflation/deflation time, which is undesirable because the balloon occludes the target annulus when in use, and more and more procedures are being done off-pump, or on a beating heart.

In addition, PVL remains as one of the major issues post transcatheter valve implant. Various designs have been developed but have proven to be unable to eliminate PVL.

Thus, there is a need for implantation systems and techniques that reduce the time for and increase the chances of a successful implant, while minimizing or eliminating PVL.

SUMMARY OF THE DISCLOSURE

The present invention provides a system and method for deploying balloon-expandable prosthetic heart valves so that they assume their desired operational shape. The system includes a prosthetic heart valve and an expansion member that accommodates non-uniform expansion resistance in the heart valve to expand to its desired tubular or other shape.

The prosthetic heart valve assembly according to the present invention provides an outflow (aortic) end of the stent-frame that is slightly larger than that of the inflow (ventricular) end. This design can maximize the valve geographic effective orifice area (EOA) and reduce the stagnant blood near the cupid area during the diastolic cardiac phase when the valve is closed. This design can also reduce the risk of patient prosthetic mismatch due to the increase in EOA and can also reduce the valve related thrombosis.

To accomplish the objectives of the present invention, there is provided a system that has a heart valve assembly that includes a stent-frame having an anchoring section and an outflow section, with the anchoring section having a distal annulus section and a support section that is positioned between the distal annulus section and the outflow section. The distal annulus section is defined by a single distal row of cells that has a distal-most annular ring of alternating peaks and valleys, with the distal row of cells having a concave inflection. A leaflet assembly is stitched to the anchoring section. The system also includes a balloon on which the heart valve assembly is crimped, the balloon having a proximal section and a distal section, and a central valve contact portion positioned between the proximal and distal sections. The contact portion has an outflow portion, a neck portion, and a central portion between the outflow portion and the neck portion, and the neck portion has an inflection zone that corresponds in size and shape with the concave inflection of the distal annulus section. The outflow portion of the balloon receives the outflow section of the stent-frame, the central portion of the contact portion of the balloon receives the support section of the stent-frame, and the neck portion receives the annulus section of the stent-frame.

The expansion member according to the present invention provides a mechanism to restore the stent-frame into its initial-designed operating shape by a unique balloon design. Specifically, the stent-frame is pre-set in a desirable geometry as mentioned above while the balloon is also pre-set in a shape that is matched with the stent-frame. Therefore, during the deployment of the heart valve assembly, the stent-frame can be restored in its preset shape when fully expanded.

The present invention provides a method for deploying the heart valve assembly using the expansion member or balloon of the present invention. The heart valve assembly is mounted on to the balloon in a manner where the outflow portion of the balloon receives the outflow section of the stent-frame, the central portion of the contact portion of the balloon receives the support section of the stent-frame, and the neck portion receives the annulus section of the stent-frame. The combined balloon and the mounted heart valve assembly are then delivered to the aortic annulus, and the balloon is expanded to cause the aortic annulus to be received inside the concave inflection.

