Implantable prosthetic valve with non-laminar flow

Abstract

A valve prosthesis device is disclosed suitable for implantation in body ducts. The device comprises a support stent, comprised of a deployable construction adapted to be initially crimped in a narrow configuration suitable for catheterization through the body duct to a target location and adapted to be deployed by exerting substantially radial forces from within by means of a deployment device to a deployed state in the target location, and a valve assembly comprising a flexible conduit having an inlet end and an outlet, made of pliant material attached to the support beams providing collapsible slack portions of the conduit at the outlet. The support stent is provided with a plurality of longitudinally rigid support beams of fixed length. When flow is allowed to pass through the valve prosthesis device from the inlet to the outlet, the valve assembly is kept in an open position, whereas a reverse flow is prevented as the collapsible slack portions of the valve assembly collapse inwardly providing blockage to the reverse flow. The device is configured so that retrograde flow will be altered from laminar flow and directed towards the leaflets to effect closing.

Description

FIELD OF THE INVENTION [0001] The present invention relates to implantable prosthetic valves. More particularly, the invention relates to a valve prosthesis for cardiac implantation or for implantation in other body ducts where the prosthesis has improved flow characteristics. BACKGROUND OF THE INVENTION [0002] Several prosthetic valves are known. See, for example, U.S. Pat. No. 5,411,552 (Andersen et al.), entitled VALVE PROSTHESIS FOR IMPLANTATION IN THE BODY AND CATHETER FOR IMPLANTING SUCH VALVE PROSTHESIS, which discloses a valve prosthesis comprising a stent made from an expandable cylinder-shaped thread structure comprising several spaced apices. See, also, U.S. Pat. No. 6,168,614 (Andersen et al.), entitled VALVE PROSTHESIS FOR IMPLANTATION IN THE BODY, U.S. Pat. No. 5,840,081 (Andersen et al.), entitled SYSTEM AND METHOD FOR IMPLANTING CARDIAC VALVES, and PCT Application No. PCT / EP97 / 07337 (Letac, Cribier et al.), published as WO 98 / 29057, entitled VALVE. PROSTHESIS FOR IMP...

AI Technical Summary

Benefits of technology

[0014] wherein when flow is allowed to pass through the valve prosthesis device from the inlet end to the outlet end, the valve assembly is kept in an open position; wherein a reverse flow is prevented as portions of the valve assembly collapse inwardly providing blockage to the reverse flow; and wherein the device is configured so that retrograde flow will be altered from laminar flow and directed towards the leaflets to effect closing.

[0018] wherein when flow is allowed to pass through the valve prosthesis device from the inlet to the outlet, the valve assembly is kept in an open position; wherein a reverse flow is prevented as the collapsible slack portions of the valve assembly collapse inwardly providing blockage to the reverse flow; and wherein the device is configured so that retrograde flow will be altered from laminar flow and directed towards the leaflets to effect closing.

[0038] Furthermore, in accordance with another preferred embodiment of the present invention, the valve assembly leaflets are longer than needed to exactly close the outlet, thus when they are in the collapsed state substantial portions of the leaflets fall on each other creating better sealing.

[0043] Furthermore, in accordance with another preferred embodiment of the present invention, the valve assembly leaflets are provided with radio-opaque material at the outlet, to help tracking the valve device operation in vivo.

[0080] Furthermore, in accordance with another preferred embodiment of the present invention, the pliant material is provided with longitudinal bars attached to the pliant material at positions assigned for attachment to the support frame, in order to prevent localized stress from forming.

[0086] Furthermore, in accordance with another preferred embodiment of the present invention, the device is further provided with spring in order to reduce wear of the pliant material.

Problems solved by technology

However, the flow characteristics are critical to effect the closing of the aortic valve, otherwise regurgitation will ensue.

Laminar flow makes the retrograde flow characteristics of valves mounted in cylindrical stents problematic as the flow along the wall is least, which is central to the closing of a valve.

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