EP0975283A1

EP0975283A1 - Heart valve prosthesis

Info

Publication number: EP0975283A1
Application number: EP97929106A
Authority: EP
Inventors: Karl-Heinz Otto; Gerd Pfister
Original assignee: Tricumed Medizintechnik GmbH
Current assignee: Tricumed Medizintechnik GmbH
Priority date: 1996-07-11
Filing date: 1997-06-10
Publication date: 2000-02-02
Also published as: WO1998002115A1; DE19627859C1; US6179869B1

Abstract

The invention concerns a prosthesis for replacing heart valves comprising a valve ring (10) with a radius (R) in which at least two essentially flat pivoted flaps (12, 14, 16) are rotatably mounted on an axis (18) in the ring plane such that the axes (18), when projecting on the ring plane, are at a distance of 0.5 R to 0.9 R from the centre of the ring plane, and the edges of the inner sections lie flush with the edges of the corresponding sections of the other pivoted flaps (12, 14, 16) and the pivoted flaps (12, 14, 16), when open, in the area (20) facing the direction of flow are provided with a bevel (24) which runs in the direction of flow from the outside inwards, forming an acute breakaway edge (22).

Description

Heart valve prosthesis

The invention relates to a heart valve prosthesis used to replace natural heart valves with the features of the preamble of claim 1.

In - post-published - DE 195 32 973 Cl a heart valve with the features of the preamble of claim 1 is proposed, in which the surface of the wing flaps facing outward in the open state is continuously curved and the axes are offset to the outside relative to the body of the wing flaps are. EP 0 283 413 AI shows a similarly designed flap, in which the area pointing in the direction of flow forms a bevel running from the outside inwards. The axis of the wing flaps runs through their body.

The design shown in DE 195 32 973 has the advantage that the flow resistance is low, but the inadequate closing behavior is disadvantageous.

The invention is based on the object of developing the previously known heart valve in such a way that it exhibits good closing behavior with low flow resistance.

According to the invention, this object is achieved by the features of claim 1, claim 2 specifies a preferred embodiment of the invention.

The invention is explained below with reference to a drawing. It shows:

1 is a plan view of the prosthetic heart valve with closed valves, 2 is a plan view of the prosthetic heart valve when open,

Fig. 3 is a section along the line III-III of Figure 1, and

Fig. 4 shows a section through the heart valve in the state shown in Figure 2 along the line IV-IV.

The prosthesis for replacing the heart valves shown in a top view in FIG. 1 is provided with a valve ring 10, the radius of which is indicated by R. In the flap ring 10, three wing flaps 12, 14, 16 are each mounted about a pivot axis 18 running in the ring plane. The distance between the pivot axis and the center of the ring plane has a distance of 0.5 R to 0.9 R when projected onto the ring plane. In the closed state, the wing flaps 12, 14, 16 are flush with the ring boundary with their bent part. In doing so, they abut flush against the wing flaps 12, 14, 16 adjacent to them at their straight boundaries and form a tripod with them.

The flap ring 10, which receives the axis 18 of the wings and is attached to the valve seam for sewing into the aorta, can be circular or can also have a shape corresponding to the anatomy, approximating a triangle. The illustration in FIG. 2, in which the flaps are open, shows that there is a large central flow which is limited by convex edges of the wing flaps. The large cross section of the space delimited by the inner surfaces of the wing flaps 12, 14, 16 allows a high flow rate of the main flow. The flow gradients in the main flow HS and the three secondary flows NS1, NS2, NS3 outside the wing flaps 12, 14, 16 are minimized.

The flap ring 10 is curved in the ring plane in such a way that it largely corresponds to the anatomy of the installation environment. In the area of the mounting of the axles 18, the flap ring 10 is pulled up in order to give the bearings 18 the necessary stability and to form a stop for the wing flaps 12, 14, 16 in their open state.

The wing flaps 12, 14, 16 are essentially stretched, but the section of the flap pointing in the systole (i.e. with the wing flap open) against the direction of flow relative to the section pointing in the direction of flow, forming an obtuse angle as seen from the axis of symmetry of the prosthesis is slightly bent outwards. At the end of the systole, this configuration causes the early occurrence of a rotation acting in the direction of a closing.

In order to reduce turbulence increasing the flow resistance in the systole (ie when the flap is open), the wing flaps are rounded in their area 26 pointing against the flow direction and in their area 20 pointing in the flow direction with a bevel. supply 24 provided, which forms a sharp tear-off edge 22 on which the flow separates without the formation of considerable turbulence.

In order to ensure a good closing behavior of the flaps, the bevel 24 runs in the direction of flow from the outside to the inside, so that in the axial projection a surface is formed, which is flowed against by the blood flowing back in the diastole and thereby an inward, the closing exerts an introductory moment on the valve. The axes 18 are offset in relation to the body of the wing flaps 12, 14, 16 (seen from the axis of symmetry of the flap), which increases this effect.

The bevels 24 of the surfaces of the wing flaps (12, 14, 16) which point outward in the open state, extend from 0.2 to 0.5 R. from the center of the ring plane in the closed state of the flap.

Claims

EXPECTATIONS

1. prosthesis for replacement of the heart valves, with a valve ring (10), the radius of which is R, in which three wing valves (12, 14, 16) are rotatably mounted about an axis (18) lying in the ring plane, whereby

the axes (18) in the projection onto the ring plane are at a distance of 0.5 R to 0.9 R from the center of the ring plane,

the axes (18), viewed in the direction of flow, are arranged offset to the outside relative to the body of the wing flaps (12, 14, 16), and

in the closed state, the edges of the sections pointing inwards lie flush against the edges of the corresponding sections of the other wing flaps (12, 14, 16),

characterized in that

the surfaces of the wing flaps (12, 14, 16) which face inwards in the open state are essentially stretched, and the surfaces of the wing flaps (12, 14, 16) which point outwards in the open state are provided in their area pointing in the direction of flow with a bevel (24) which runs from the outside inwards and which, when the flap is closed, extends from the center of the ring plane 0.2 to 0.5 R.

2. Prosthesis according to claim 1, characterized in that the wing flaps (12, 14, 16) are rounded in their open state against the flow direction region (26).