RU2405500C2 - Heart valve prosthesis - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: claimed invention relates to field of medicine, in particular to cardiovascular surgery, and is intended for replacement of affected natural heart valves in course of performing cardiovascular operations. Prosthesis includes ring-shaped body at least two cusps, installed in body with possibility of rotation and formation of main zone of clearing section in centre of body opening, and limiters of cusp stroke, made in form of projections, located on butt surface of body, facing reverse blood flow. On part of cusp lateral surface made is through slot at least part of whose lateral surface is made salient. On each lateral wall of projections of stroke limiters there is concave surface, facing direct blood flow, made with possibility of interaction with salient parts of slot of corresponding cusp when it turns from closed position into open and back.

EFFECT: reduction of energy loss due to reduction of body thickness and improvement of washing prosthesis elements due to simplification of construction with cusp turn limiters.

9 cl, 9 dwg

Description

Technical field

The present invention relates to medicine, in particular to cardiovascular surgery, and is intended to replace the affected natural heart valves during cardiac surgery.

State of the art

The design of the body valve prosthesis includes a ring-shaped body. As a rule, two or three valves are installed in the body with the possibility of repetition between the open position for passing a direct (upward) blood flow and the closed position for blocking the channel and restricting the reverse (downward) blood flow. In addition, the prosthetic valve of the heart contains a connecting mechanism for connecting the valve body to the surrounding tissues of the heart in the form of a cuff, which is sewn to the tissues of the heart and covers the side surface of the valve prosthesis. An important problem is the problem of high hemodynamic resistance introduced by the heart valve prosthesis installed in the heart, and the associated problem of energy loss on the valve during its operation. The resistance is determined by the thickness of the casing and the flaps, as well as by the surface of the travel and rotation limiters of the flaps, partially overlapping the valve bore.

The prior art designs of heart valves, in which the stopper movement of the valves have a minimum area (see, for example, published application US No. 2007193632). However, in the prosthesis disclosed here, the valves rotate on an axis fixed in the body and intersecting the passage section in the center, therefore, the valves themselves create resistance to blood flow due to the overlapping center of the passage section in the open position of the valve.

Known designs of prosthetic heart valves (see US patent 4274437, RF patent 2066984) with the provision of the main zone of the bore in the center. With this arrangement, it is obvious that the central part of the flow through the valve remains weakly perturbed, and the distortions introduced by the wings are minimal. However, these valves are not used in surgical practice due to the low reliability and high likelihood of sash loss.

Thus, the need for a new design of the prosthetic valve of the heart is obvious, the reliability of which would be combined with the undistorted hemodynamics of the blood flow and improved flushing of the elements of the prosthetic valve with jets of forward and reverse blood flows.

The closest analogue to the present invention is an artificial heart valve, disclosed in international publication WO 2007/075121 of July 25, 2007, containing an annular body and at least two flaps installed in the body with the possibility of forming a zone of the passage section of the valve in the center. The valve has stoppers for turning the valves in the form of two pairs of protrusions located on its end surface facing the downward flow of blood. The stops are equipped with stops. However, this heart valve prosthesis also introduces significant distortions into the blood stream and, having a complex design, is poorly washed by the blood stream, which leads to the formation of stagnant zones and the occurrence of complications associated with this. The housing has a substantial thickness, creating resistance to flow and causing energy loss.

SUMMARY OF THE INVENTION

The present invention is directed to solving the problem of creating an artificial heart valve that eliminates the disadvantages of the known analogues, having a simple design, providing improved flushing of prosthetic elements with jets of forward and reverse blood flows, and having low energy loss during operation.

The technical result achieved by using the present invention is to reduce energy loss by reducing the thickness of the body and to improve the flushing of prosthetic elements due to the simplification of the design of the rotation limiters of the flaps.

The technical result is achieved due to the fact that in the prosthesis of the heart valve, which includes an annular body, at least two sashes installed in the body with the possibility of rotation and the formation of the main zone of the passage section in the center of the opening of the body, and the stoppers of the wings made in the form of protrusions located on the end surface of the body facing the return blood flow, a through recess is made on a part of the side surface, at least a part of the side surface of which is convex, and on Each lateral side of the protrusion of the travel limiters has a concave surface facing the direct blood flow, which is configured to interact with the convex parts of the recess of the corresponding leaf when it is rotated from the closed position to the open and back.

The technical result is enhanced due to the fact that at least part of the surface of both protrusions of the travel stops facing the direct blood flow is a part of the cylindrical surface, the axis of which coincides with the axis of rotation of the valves.

In addition, the opposite side surfaces of the through recess have convex parts configured to interact with recesses made on the opposite side surfaces of the protrusions of the travel limiters.

The end surface of the body facing the return flow of blood includes inclined parts made at an angle to the axis of the opening of the body, located on both sides of each protrusion of the travel stops and having the ability to interact with the surfaces of the flaps facing the direct flow of blood in their open position.

The recesses are made in the form of a part of a concave spherical surface, and the parts of the side surfaces of the recesses interacting with it are made in the form of a part of a convex spherical surface.

The inner surface of the hole of the annular body is made in the form of a lateral surface of a circular cylinder and is limited by two flat ends facing the forward and reverse blood flows.

An annular groove is made on the outer surface of the housing for attaching the sewing cuff.

The body and wings are made of pyrolytic carbon.

List of drawings

The invention will be better understood from the description below with reference to the position of the drawings, where

Figures 1 and 2 show a prosthesis of a bicuspid heart valve with closed flaps, respectively, a front view and a top view,

figure 3 and 4 shows the prosthesis of a bicuspid valve of the heart with open sashes, respectively, front view and top view,

figure 5 and 6 shows a variant of the prosthesis of the tricuspid valve of the heart with closed valves, respectively, front view and top view,

7 and 8 are a variant of the prosthesis of the tricuspid valve of the heart with open wings, respectively, front view and top view,

and in Fig.9 a section along II in Fig.8, showing the conjugation of the cutout of the sash and the protrusion of the housing.

Information confirming the possibility of carrying out the invention

The heart valve prosthesis comprises an annular body 1 made of pyrocarbon and having two (Figs. 1-4) or three (Figs. 5-8) flaps 2, also made of pyrocarbon and with the possibility of rotation and the formation of the main passage area (openings) 3, mounted centrally in the housing 1. The annular housing 1 is bounded by two upper 7 and lower 20 ends (the direction is determined in accordance with the direct flow of blood through the valve).

The stoppers of the leaf 2 are made in the form of protrusions 5 located on the end surface 7 of the housing 1 facing the return flow of blood 8. A through recess 10 is made on the side surface of the leaf 2, at least a portion of the side surface of which is convex 15. On each the lateral side of the protrusion 5 of the travel stop 4 has a concave surface 14 facing the direct blood flow 19, configured to interact with the convex parts 15 of the recess 10 of the corresponding leaf 2 when it is rotated from the closed position open and back. At least a portion of the surface of both protrusions 5 of the travel stop 4, facing the direct blood flow 19, is a portion of a cylindrical surface whose axis coincides with the axis of rotation of the leaflets 17. The opposite side surfaces of the through recess 10 have convex portions 15 adapted to interact with recesses 12 made on opposite lateral surfaces of the protrusions 5 of the stroke limiters 4. The end surface 7 of the housing 1 facing the return flow of blood 8 includes inclined parts 21, made which are located at an angle to the axis of the hole 3 of the housing 1, located on both sides of each protrusion 5 of the stroke limiters 4 and having the ability to interact with the surfaces of the valves 2 facing the direct blood flow 19 in their open position. The recesses 12 are made as part of a concave spherical surface 14, and the interacting parts of the side surfaces of the recesses 10 are made as part of a convex spherical surface 15. The inner surface 18 of the hole 3 of the annular body 1 is made in the form of a side surface of a circular cylinder and is limited by two flat ends 20 and 7, facing forward 19 and reverse 8 blood flows. On the outer surface of the housing 1, an annular groove 24 is made for attaching a sewing cuff (not shown). The housing 1 and the sash 2 are made of pyrolytic carbon.

The valve operates as follows. Under the action of the resulting direct pressure drop of the sash 2, interacting with the convex surfaces 15 of the recesses 10 with the corresponding recesses 12 of the protrusions 5, they rotate relative to the axis of rotation 17 of the sash 2 from the closed position to the surface of the sash 2 open to contact, facing the ascending 19 (direct) blood flow, with the inclined part 21 of the end surface 7 of the housing 1. In this case, the blood flows in the forward direction, the central part of the opening 3 of the housing 1 of the prosthesis freely passes without distortion a stream that completely washes Surfaces of the stops 4 turns of the leaves 2.

Reducing the wall thickness of the housing 1 and the location of the flaps 2 outside the zone of the passage opening 3 can reduce the energy loss on the prosthesis to a minimum.

The convex parts 15 of the recesses 10 of the flaps 2 are placed in the recesses 12 of the protrusions 5, which reliably holds them when turning and in the open position. When the direct flow stops and when the pressure drop across the prosthesis of the sash 2 appears, interacting with the convex surfaces 15 of the recesses 10 with the corresponding recesses 12 of the protrusions 5, they begin to turn and return to their original position until the contact surfaces 11 touch each other, interacting with the surface of the sash facing to the ascending (direct) blood flow, with the end face 7 of the housing 1 and the protrusions 6 of the travel limiter, blocking the passage opening of the prosthesis. In the closed position of the prosthesis, the passage of a limited reverse blood flow through the gaps between the recesses 10 of the valves 2 and the protrusions 5 of the housing 1 provides additional washing of their interacting surfaces.

The work of the tricuspid prosthesis (Fig.5-8) is similar to the work of the bicuspid. The flaps 2 at the beginning of the opening cycle and at the end of the closure cycle of the prosthesis are additionally held by the interaction of the supporting surfaces 25 of the side surface 9 of the flaps 2 with the guide surfaces 26 of the sides of the protrusions 6, which increases the reliability of the functioning of the prosthesis.

The design of an artificial heart valve has the following advantages:

1. improved flushing of prosthetic elements with jets of forward and reverse blood flows,

2. high efficiency of the valve cross-section is ensured, there is practically no resistance to flow in the open position of the valves

3. the formation of stagnant zones due to washing the areas of the flow restrictors and stops with direct and reverse blood flow is excluded

4. significantly reduced thrombosis factor,

5. reduced wall thickness of the housing,

6. minimized energy loss during the operation of the prosthesis,

7. high reliability and durability of the prosthesis is ensured,

8. Ensured good compatibility with natural fabrics.

Claims (9)

1. The prosthesis of the heart valve, comprising an annular body, at least two leaves, installed in the body with the possibility of rotation and the formation of the main zone of the passage section in the center of the opening of the case, and the course stop valves made in the form of protrusions located on the end surface of the case, facing the reverse blood flow, characterized in that a through-hole is made on a portion of the lateral surface of the leaflet, at least a portion of the lateral surface of which is convex, and on each side the stupa of the course limiters has a concave surface facing the direct flow of blood, made with the possibility of interaction with the convex parts of the recess of the corresponding leaf when it is rotated from the closed position to the open and back. 2. The prosthesis according to claim 1, characterized in that at least a portion of the surface of both protrusions of the travel stops facing the direct blood flow is a portion of the cylindrical surface, the axis of which coincides with the axis of rotation of the valves. 3. The prosthesis according to claim 1, characterized in that the opposite side surfaces of the through recess have convex parts configured to interact with recesses made on opposite side surfaces of the protrusions of the travel stops. 4. The prosthesis according to claim 1, characterized in that the end surface of the body facing the return flow of blood includes inclined parts made at an angle to the axis of the opening of the body, located on both sides of each protrusion of the travel stops and having the ability to interact with the surfaces of the valves facing the direct flow of blood in their open position. 5. The prosthesis according to claim 3, characterized in that the recesses are made as part of a concave spherical surface, and the parts of the side surfaces of the recesses interacting with it are made as part of a convex spherical surface. 6. The prosthesis according to claim 1, characterized in that the inner surface of the hole of the annular body is made in the form of a lateral surface of a circular cylinder and is limited by two flat ends facing the forward and reverse blood flows. 7. The prosthesis according to any one of claims 1 to 6, characterized in that an annular groove is made on the outer surface of the body for attaching the sewing cuff. 8. The prosthesis according to any one of claims 1 to 6, characterized in that the body and flaps are made of pyrolytic carbon. 9. The prosthesis according to claim 7, characterized in that the body and sashes are made of pyrolytic carbon.

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