PROSTHETIC AORTIC ROOT REPLACEMENT GRAFT

Abstract

A prosthetic aortic root replacement graft for preserving the native aortic valve that includes a biocompatible flexible material having a) a tubular superior segment (3), with an upper free edge (2) for anastomosis of the prosthesis to the aortic arch, and a lower edge (4); b) a hollow medial segment (5) with an upper edge (6) that is connected to the lower edge (4) of the superior segment (3) and a lower edge (8); and c) optionally a tubular inferior segment (10).

The medial segment (5) includes three triangular-like tongues (7) tapering towards the upper edge (6) and three bulges (12). The bulges (12) and the tongues (7) are in an alternating arrangement.

Claims

1. A prosthetic aortic root replacement graft for preserving a native aortic valve, said prosthetic aortic root replacement graft comprising a biocompatible flexible material including a) a tubular superior segment having an upper free edge for anastomosis of the prosthesis to an aortic arch, and a lower edge; b) a hollow medial segment having an upper edge that is connected to the lower edge of the superior segment, and a lower edge; and c) optionally a tubular inferior segment; wherein the medial segment comprises three tongues tapering towards the upper edge and three bulges, wherein the bulges and the tongues are in an alternating arrangement.

2. The aortic root prosthesis graft according to claim 1, wherein the tubular inferior segment is present, and wherein the tubular inferior segment is provided with a free lower edge for fixation at an aortic root base upper surface, and an upper edge that is connected to the lower edge of the medial segment.

3. The aortic root prosthesis graft according to claim 2, wherein a middle axis of the superior, medial and inferior segments define a longitudinal axis of the prosthesis.

4. The aortic root prosthesis graft according to claim 1, wherein the three tongues extend from the lower edge of the medial segment towards the upper edge of the medial segment in a vertical direction.

5. The aortic root prosthesis graft according to claim 1, wherein a middle axis of the superior and medial segments define a longitudinal axis of the prosthesis, and wherein the three tongues run essentially parallel to the longitudinal axis.

6. The aortic root prosthesis graft according to claim 1, wherein the three tongues reach the upper edge of the medial segment.

7. The aortic root prosthesis graft according to claim 1, wherein the tongues are reinforced by wire-like elements, which are positioned in an interior of the tongues.

8. The aortic root prosthesis graft according to claim 7, wherein the wire-like elements have a semilunar shape.

9. The aortic root prosthesis graft according to claim 1, wherein the three tongues are stiffer as compared to the three bulges.

10. The aortic root prosthesis graft according to claim 1, wherein the three tongues are configured for fixation to intervalvular triangles of the native aortic root.

11. The aortic root prosthesis graft according to claim 1, wherein a middle axis of the superior and medial segments define a longitudinal axis of the prosthesis, and wherein the superior and inferior segments are elastically expandable in a direction of the longitudinal axis.

12. The aortic root prosthesis graft according to claim 1, wherein a middle axis of the superior and inferior segments define a longitudinal axis of the prosthesis, and wherein the three bulges of the medial segment are elastically expandable transversally to the longitudinal axis.

13. The aortic root prosthesis graft according to claim 1, wherein the biocompatible flexible material has a textile structure.

14. The aortic root prosthesis graft according to claim 13, wherein the textile structure comprises a polyester material.

15. The aortic root prosthesis graft according to claim 13, wherein the textile structure is impregnated with an absorbable protein.

16. The aortic root prosthesis graft according to claim 1, wherein the biocompatible flexible material comprises a GORETEX material.

17. The aortic root prosthesis graft according to claim 1, wherein the graft exhibits three symmetric planes having a middle axis in common.

18. The aortic root prosthesis graft according to claim 1, wherein the medial segment has a tubular structure.

19. A method for curing a patient afflicted with Marfan and Loeys-Dietz syndrome comprising, connecting an aortic root prosthesis graft according to claim 1 to an aortic arch of the patient.

20. A method for preserving a native aortic valve comprising: a) dissecting an aortic root and ascending aorta free from surrounding tissue; b) separating the an aortic root base from the surrounding tissue at a level of the aortic root; c) following the dissection of the aortic root from the surrounding tissue, opening the ascending aorta in circular manner about 1.5 cm above a sinotubular junction; d) performing an excision of three sinuses; e) leaving approximately 5 mm of tissue wall at a level of intervalvular triangles and at a nadire of each sinus, superior to a point of valve attachment; f) suspending an opening of both coronary vessels; g) separating the aortic root base from surrounding tissue in order to provide adaptation for an inferior segment of a prosthetic aortic root replacement graft according to claim 2; h) placing pledget-mounted sutures from an inside of the aortic root base toward the outside of the aortic root base; i) placing sutures between nadirs of the left coronary sinus and nadirs of the non-coronary sinus in a straight line, just superior to a left atrium and mitral valve transition; j) placing stitches from a middle of the non-coronary sinus to the nadir of the right coronary sinus, the stitches being placed in a semilunar fashion in a form following attachment of leaflets at the non-coronary and the right coronary sinus; k) placing stitches from the nadir of the right coronary sinus to the nadir of the left coronary is in a straight line, corresponding to a border of the aortic root base; l) positioning staying sutures in each of three commissures, and pulling up the staying sutures in a vertical straight direction such that the intervalvular triangles are positioned in a natural vertical direction; m) while holding the three commissures in the vertical position, estimating the diameter of the sinotubular junction using a circular graft sizer; n) pulling the three commissures and the intervalvular triangles through the hollow inner space of the graft; o) tying down the sutures such that the inferior part is pulled down to the level of the aortic root; p) Asuturing the intervalvular triangles with a running suture to the tongues of the middle segment from a deepest point of the middle segment up to the superior edge of each tongue in semilunar fashion; q) suturing each of the three commissures with one single pledged suture to the superior edge of the tongue; r) re-implanting both coronary artery ostia to the bulges of the medial segment; and s) suturing the superior segment at its free edge to the ascending aorta or to the aortic arch.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0079] Several embodiments of the invention will be described in the following by way of example and with reference to the accompanying drawings in which:

[0080] FIG. 1 illustrates a schematic perspective view of an embodiment of the device according to the invention;

[0081] FIG. 2 shows an exploded view of the embodiment of FIG. 1.

[0082] FIG. 3 illustrates the dimensional relationship of the various parts of the embodiment of FIG. 1.

[0083] FIG. 4 shows a portion of the medial segment of an alternative embodiment of the invention.

[0084] FIG. 5 indicates the location of various cross sections A-A, B-B, C-C, D-D, E-E and F-F through the embodiment of FIG. 1 and represented in detail in section sectional views according to FIGS. 6-11, respectively.

[0085] FIG. 6-11 show detailed sectional views at the cross sections A-A, B-B, C-C, D-D, E-E and F-F, respectively.

[0086] FIG. 12 shows a sizer to be used in the method for preserving the native aortic valve from profile.

[0087] FIG. 13 shows a superior view of the sizer according to FIG. 12, with the dimensions R.sub.0, R.sub.1 and R.sub.2.

[0088] FIG. 14 shows the process of measurement of the prosthesis with the aid of the sizer according to FIGS. 12/13.

DETAILED DESCRIPTION OF THE INVENTION

[0089] The following example clarifies the invention further in more detail.

[0090] The aortic root prosthesis according to the invention has three segments: [0091] (i) a tubular superior segment 3 which has the shape of a straight cylinder-like part; [0092] (ii) a medial segment 5, with three bulges 12 simulating the natural morphology of three sinuses of Valsalva andstaggerdly arranged between the bulges 12tongues 7 having an approximate triangular shape and serving for fixation of the natural intervalvular triangles and the commissures; and [0093] (iii) an inferior segment 10 having the shape of a straight cylinder and serving for fixation of the prosthesis at the aortic root base. All three segments 3, 5, 10 of the prosthesis are arranged along a common longitudinal axis 1, and are made of woven polyester graft. The woven structure of the superior segment 3, of the inferior segment 10 and of the three tongues 7 of the medial segment are in horizontal direction that is perpendicular on the axe of the prosthesis. The prosthesis is preferably made of polyester, such as sold under the trademark DACRON and includes a plurality of integrally formed as Z-folds extending around in circumferential fashion around the tube. This with exception of the three sinuses, where the folds in graft are in vertical direction. This horizontal arrangement at tubular segment 3 allows vertical expansion that is expansion along the long axis of the prosthesis. Vertical arrangement of the folds such at the three sinuses of the prosthesis, in contras aloud horizontal expansion. So, tube part, the sinus part and intervalvular triangles are formed from double waved polyester material that is known under trademark DACRON and Hemishield. Whereas in case of sinus the fold in Dacron graft represents vertical direction. To add is that the three triangles like shapes 12 are made of as well of the same polyester material (DACRON) implementing the wire reinforcement 5. Alternatively, the triangular posts 12 may be made of double polyester layer with wire enforcement in between two layers. This allows a vertical expansion of each of these structural elements 3, 10 and 7. Whereas in the woven structure of the three bulges 12 of the medial segment 5 are in vertical direction that is parallel to the axis and as such allows expansion in horizontal direction.

[0094] As shown in FIG. 1 the superior segment 3 is a straight tubular/cylinder like structure, with an upper edge 2 serving for suture to the aortic arch. The lower edge 4 and upper edge 2 have a circle like structure and are of the same diameter. The lower edge 4 is mounted (connected to) by the manufacturer to the superior segment, or superior border 3 of the medial segment 5 of the prosthesis 5, 7. With another words, the inferior edge 4 is transient to the superior edges of the triangular posts 5 and to the superior edges of the bulgings 7. This attachment is performed during production process by manufacturer.

[0095] The transition between the medial segment 5 of the prosthesis and the straight tubular part of the superior segment 3 is smooth and aligned at the lower edge 4 of the superior segment 3.

[0096] The medial segment 5 of the prosthesis has two different kinds of components.

[0097] The first kind of components comprises three outwardly flaired bulges 12. These outwardly flaired bulges 12after the implantationsimulate or mimic the anatomy of the natural sinuses of Valsalva, and bulge outward in order to provide horizontal flexibility after implantation. This function is provided by horizontally directed Z folds of the material. The three bulges 12 have the same dimensions. The lower edge 8 of the three bulges 12 is in smooth transition to inferior segment 10.

[0098] The three bulges 12 serve also for re-implantation of the coronary vessels.

[0099] The second kind of components of the medial segment 5 comprises three straight, in vertical direction oriented, triangular like tongues 7. As shown in FIG. 2 the central axis 14 of the tongues 7 are parallel to the middle axis 1 of the prosthesis.

[0100] These three tongues 7 are not flaired and do not follow the bulging shape of the three bulges 12. They are rather straight and show vertical expansion similar to the superior segment 3. Therefore the tongues 7 are extending in the same imaginary cylindrical surface as the surface of the superior segment 3.

[0101] The transition between the bulges 12 and the tongues 7 is smooth, and aligned.

[0102] The lower edge 8 of the three bulges 12 is in smooth transition to the inferior part of the triangles 7.

[0103] The tongues 7 serve, after implantation of the prosthesis, as suture platform for the native intervalvular triangles and the three commissures. In this form the natural vertical, almost straight alignment of the natural intervalvular triangles and of three commissures (and with this the attachment of the aortic valve) is assured. The superior edge 13 of the tongues 7 reaches up to the lower edge 4 of the superior segment 3. The three tongues 7 have an internal stiffening system, in order to provide straight alignment during the whole cardiac cycle.

[0104] The third part of the prosthesis comprises an inferior segment 10 having the shape of a straight cylinder with its upper edge 11 in smooth transition to the lower edge 8 of the medial segment 5. Its lower edge 9 is circular with the same radius as the upper edge 11. The inferior segment 10 serves for fixation at the aortic root base.

[0105] In FIG. 2 all structural elements of the prosthesis are represented as separate elements.

Superior Segment 3

[0106] It has the form of a straight cylinder with an upper edge 2 and lower edge 4. Both edges 2, 4 are parallel. The expansion direction of this straight part is in vertical direction corresponding to the middle axis 1.

Medial Segment 5

[0107] The lower edge 4 of the superior segment 3 is smoothly transient to the upper edge 6 of the medial segment 5 with the three bulges 12 and with superior edges 13 of the three tongues 7.

[0108] The bulges 12 have its upper edges 6 which are circular and have the same radius as the lower edge 4 of the superior segment 3. The three bulges 12 are of the same dimensions. One bulge 12 is destined for the left coronary sinus, one for the non-coronary sinus and one for the right coronary sinus. The space between each bulge 12 corresponds to the dimensions of the three tongues 7 and fits the shape of each tongue 7; the transition between the bulges 12 and the tongues 7 is being smooth. The inferior or the deepest part of the bulges 12 corresponds to the deepest point of each natural sinus and is transient to the lower edge 8 of the tongues 7. The three bulges 12 are expandable in horizontal direction (radially with respect to the middle axis 1).

[0109] The three tongues 7 of the medial segment 5 of the prosthesis have a triangular shape that fits exactly in between the bulges 12. The three tongues 7 are of the same shape, and correspond to the natural intervalvular triangles. One tongue 7 is destined for the anterior one for the left and one for the right. These tongues 7 serve for suturing the natural intervalvular triangles, in order to provide natural almost vertical position of the leaflets attachment. The superior edge 13 of the tongues 7 is for the fixation/suture of the three commissures. And the body of the tongues 7 is for suturing the intervalvular triangle to the prosthesis.

[0110] The lower edge 8 of the medial segment 5 is circular and has the same shape and radius as the upper edge 11 of the inferior segment 10.

[0111] The inferior segment 10 of the prosthesis according to the invention has the shape of a straight circular cylinder and is of the same structure as the superior segment 3. It is expandable in vertical direction and serves for suture of the prosthesis at the aortic root base. Its upper edge 11 is continuous with the lower edge 8 the medial segment 5. Its lower edge 9 and upper edge 11 are parallel and, have the same radius as the superior segment 3.

[0112] The dimensional relations of the prosthesis according to FIG. 1 are shown in FIG. 3 and can be summarized as follows: [0113] a) R.sub.0 is the radius the hollow cylinder which forms the superior segment 3 and the inferior segment 10; [0114] b) R.sub.1 is the radius of the tubular sinus part (bulges 12) of the prosthesis in the middle of the middle segment 5. This is the distance between the middle axis of the prosthesis and the maximal bulging of the medial segment 5; [0115] c) The relation between R.sub.0 and R.sub.1 is preferably as follows: R.sub.1=R.sub.0+(0.2R.sub.0); [0116] d) h.sub.1 is the height of the inferior segment 10 and is preferably maximal 1 cm; and [0117] e) h.sub.2 is the height of the medial segment 5, its relation to R.sub.0 is preferably as follows: h.sub.2=4R.sub.0.

[0118] The tongues 7 of the medial segment 5 of a another embodiment of the prosthesis is shown in FIG. 4

[0119] The tongues 7 which have a triangular shape are reinforced by wire-like elements 15 being positioned in the interior of the tongues 7. The wire-like elements 15 have a semilunar shape, similar to the basic structure of the tongue 7, which is again the same as the structure of the natural aortic valve attachment. The wire-like elements 15 run from each individual superior edge 7 of the tongue 7 in vertical direction downstream toward the base of the individual tongue 7. Reaching the base of the individual tongue 7 it turns from vertical direction toward the horizontal direction toward the opposite tongue 7.

[0120] It then reaches the deepest point of the neighbor tongue 7. Here it curves again toward the superior edge 13. At the top of each tongue 7 the tips of the wire-like elements 15 are shaped in a simple curve. This may also be realized by means of separate U shaped wires 16 connecting two upstreaming wire-like elements 15.

[0121] The frame supporting the three tongues 7 may be fabricated by three individual semilunar wire-like elements 15. The cross-section thickness may be different; however it is purposeful to be constant for all three wire-like elements 15

[0122] The tissue of the triangular part comprises the reinforcement frame in itself. The wires 16 are incorporated into the tissue. Alternatively the three tongues 7 may be manufacture as double layer tissue structure, but preferably the wires 16 are integrated into the tissue.

[0123] However, it is desirable to have enough tissue material for suturing/fixing the native intervalvular triangles with surgical suture

[0124] In order to better understand the construction of the prosthesis according to FIG. 1 a number of cross-sections are indicated in FIG. 5 and shown in detail in FIGS. 6-11.

[0125] Level A represents a cross section of the superior segment 3, where R.sub.0 is the radius of the straight cylinder representing the superior segment 3 and is shown in FIG. 6.

[0126] Level B is at the lower edge 4 of the superior segment 3 which coincides with the upper edge 6 of medial segment 5 as shown in FIG. 7. x, y and z mark the distances between the superior edges 13 of the tongues 7. The distances x, y and z have preferably the same length. The almost upper parts of bulges 12 have here the same radius as the intervalvular tongues 7, namely R.sub.0.

[0127] Level C is at the middle of the three bulges 12 (where the prosthesis has is major radial dimension) and is shown in FIG. 8. Here R.sub.0 corresponds to the diameter of the superior segment 3 (being a straight cylinder) and R.sub.1 is the diameter measured from the middle axis 1 of the prosthesis till the maximal convexity of the prosthesis. The bulges 12 at this location have preferably a radius of R.sub.1=R.sub.0+(0.2R.sub.0).

[0128] Level D is at the inferior part of the medial segment 5 and is shown in FIG. 9. Here the bulges 12 and the intervalvular tongues 7 are seen. At this level the circumference of the graft is equally built up from the triangular spots 7 and from bulgings 12. Consequently each individual triangular as well each individual bulging represents of the whole circumference.

[0129] Level E shown in FIG. 10 is at the upper edge 11 of the inferior segment 10 having the form of a straight cylinder where the radius is R.sub.0.

[0130] Level F shown in FIG. 11 is at the lower edge 9 of the inferior segment 10 having the shape of a straight cylinder.

[0131] In FIGS. 12 and 13 a sizer 17 for performing the method for preserving the native aortic valve is represented. The cylinder structure 18 is not a hollow part. Its radius corresponds to the radius of the superior segment 3 and the inferior segment 10 of the prosthesis according to the invention. It is a cylinder-like structure with a height fixed at 2 cm. The hand holder 19 is fixed to the cylinder structure 17 with an intermediate segment 20.

[0132] FIG. 14 is showing the process of measurement with the sizer 17. After Valsava sinuses were excised, all three intervalvular triangles 22 are pulled in straight vertical direction, by using the stay sutures 21, positioned just above of the three commissures. Following that, the sizer 17 is placed over the three commissures, and the radius at the sinotubular junction is evaluated. The sizer 17 is positioned in horizontal direction just at the level of the three commissures. After the corresponding radius has been defined with the sizer 17, a prosthetic aortic root replacement graft according to the invention with the same diameters for the inferior segment 10 and the superior segment 3 is chosen and implanted. The position of the staying sutures 21 is to be noted as marked in FIG. 14.

[0133] Although the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art. Accordingly, it is intended to embrace all such alternatives, modifications and variations that fall within the scope of the appended claims.

[0134] It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the invention, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination or as suitable in any other described embodiment of the invention. Certain features described in the context of various embodiments are not to be considered essential features of those embodiments, unless the embodiment is inoperative without those elements.