WO2011117665A1

WO2011117665A1 - Automated ancillary device for inserting and fixing an annular body by means of clips

Info

Publication number: WO2011117665A1
Application number: PCT/IB2010/001196
Authority: WO
Inventors: Sidney Chocron
Original assignee: Universite De Franche-Comte
Priority date: 2010-03-22
Filing date: 2010-03-22
Publication date: 2011-09-29
Also published as: WO2011117725A1

Abstract

Automated ancillary device (1) for inserting and fixing by means of clips (6) an annular body, namely a prosthetic heart valve (42), on a substantially annular resilient volume, including an opening, including, coaxially fitted about a longitudinal axis, means for receiving and supporting said annular body designed capable of receiving the latter coaxially to its axis of rotation. It includes means for longitudinally pushing about said longitudinal axis, clip- supporting means designed capable of bearing clips made out of shape-memory material, of nitinol or the like, said clips including two legs connected by a heel, and designed so that at least one of said legs passes through both a thickness of a material belonging to said annular body and a thickness of a material belonging to said substantially annular resilient volume, under the action of said longitudinal pushing means.

Description

AUTOMATED ANCILLARY DEVICE FOR INSERTING AND FIXING AN ANNULAR BODY BY MEANS OF CLIPS

The invention relates to an automated ancillary device for inserting and fixing, by means of clips, an annular body, namely a prosthetic heart valve .

The present invention is related to the field of the surgery tools.

The invention relates more particularly to an automated ancillary device for inserting and fixing a prosthetic heart valve . A prosthetic heart valve is a prosthesis with a circular or annular shape, which is implanted instead of a patient's heart valve , in particular an aortic valve or a mitral valve .

The surgical operation during which the practitioner resects, i.e. cuts and removes the patient's native valve or valves so that only the patient's ring remains, i.e. an annular surface belonging to the heart, to which the prosthetic valve will be fixed, then implants and fixes a prosthetic heart valve, is long and delicate. Indeed, in order to carry out a replacement of a natural valve by a prosthetic valve it is necessary to bring about an extra-corporal circulation biassing the patient's blood, and to exclude the heart from the circulation. During this phase of exclusion, the heart is suffering. It is interesting to reduce to a minimum the duration of this extra-corporal circulation and exclusion of the heart, which are not good for the patient. Indeed, an extended duration causes complications.

The invention thus proposes to put at the disposal of the heart-surgery practitioners an ancillary device, which permits them to considerably reduce the duration of the operation, so as to reduce the risk of complications .

In a known way, a prosthetic heart valve is fixed by suture . The suture of the prosthetic valve is performed by means of separated suture stitches between the prosthetic valve and the ring, essentially according to two usual methods, i.e. the insertion at simple separate points, and the insertion at separate points in the form of a U on a felt.

These operations are time-consuming for a type of surgery in which time is important. Indeed, while carrying out these gestures, the heart is stopped, and blood circulation as well as its oxygenation depend on the extra-corporal circulation.

Alternatives to the traditional techniques of stitching the prosthetic valve have already been provided, in order to cope with the above-mentioned drawbacks .

Thus, the technique consisting in using a "stent" incorporating a prosthetic valve is known, which is inserted either folded through the femoral artery and moved upwards to the heart, to be unfolded there, or unfolded through the ascending aorta, which is opened once the heart has been excluded from the circulation . The drawback is that the durability of these new prosthetic valves is not known .

From US 6 413 274 is also known a device for placing, at the level of the patient's ring, a crown of clips implanted in radial directions with respect to the axis of the patient' s ring to which are connected the ends of the wires inserted in the prosthetic valve . This method allows a reduction of the operational time , the practitioner must however still carry out all the finishing of the suture work, in particular tying. In addition, the clips are implanted at the periphery of the patient's ring, and a risk of tear of the tissues cannot be excluded .

US2001/0031972 , in turn, describes an apparatus for placing a prosthetic valve through fastening with clips, which is designed so as to unfold the clips radially with respect to the axis of the patient's ring. These clips include, each, two tapping ends . The first one is straight and is designed capable of perforating a collar the prosthetic valve includes, after radial extension of a clip holder . The other tapping end is bent and is designed capable of separating the tissues during the radial extension of the clip holder, then of perforating same during its deformation towards a closing position enclosing the tissues in the vicinity of said collar, under the action of the translation of a tube inserted into the tissues. It is obvious that the use of such a device damages the tissues during the insertion of the tube in order to close the bent end, and that the straight end is inserted at a very short distance from the surface of the patient's ring. Thus, in these two areas there exists a risk of tear, which should absolutely be avoided. This solution does not guarantee a complete closing of the clip around the prosthesis and the patient's ring, at the level of the tissues there is a fragile area in the vicinity of the two tips of the clip when the latter is bent. The problem is that, as a matter of fact, this zone in which the clip is not fully closed is also the most strained by the blood pressure. In short, the method using the device according to this document US2001/0031972 Al does not permit to transfix the patient's ring, but only to perform a simple hooking, with a high risk of damaging the tissues .

The purpose of the present invention is to permit to reduce the operational time while coping with the various above- mentioned drawbacks , and while permitting the placing of an already existing and evaluated prosthetic heart valve, irrespective of its type, biological or mechanical type, and irrespective of its origin, i.e. its manufacturer.

The automated ancillary device for inserting and fixing by means of clips an annular body, namely a prosthetic heart valve, on a substantially annular resilient volume, including an opening, according to the invention, includes, coaxially fitted about a longitudinal axis, means for receiving and supporting said annular body designed capable of receiving the latter coaxially to its axis of rotation, and is essentially characterized in that it includes means for longitudinally pushing about said longitudinal axis, clip-supporting means designed capable of bearing clips made out of shape-memory material , of nitinol or the like , said clips including two legs connected by a heel, and designed so that at least one of said legs passes through both a thickness of a material belonging to said annular body and a thickness of a material belonging to said substantially annular resilient volume, under the action of said longitudinal pushing means .

According to an additional feature of the ancillary device according to the invention, the longitudinal pushing means include pushing means performing a percussion under the action of springy restoring means formed by at least one spring or the like.

According to another additional feature of the ancillary device according to the invention, the clip-supporting means are substantially annular and include means for the passing through of fluids.

According to another additional feature of the ancillary device according to the invention, the clip-supporting means include recesses designed capable of receiving said clips in a pre-stressed position, in which both legs of each clip are parallel, or substantially parallel, to said longitudinal direction of insertion .

According to a first embodiment, each recess is oriented according to a plane radial to the main axis of the ancillary device .

According to an additional feature of the first embodiment of the ancillary device according to the invention, the clip- supporting means are shaped so that each of its recesses can hold one clip the leg of which arranged on the internal side is longer than that arranged on the external side .

According to a second embodiment, each recess is oriented according to a plane tangent to the clip-supporting means.

The invention relates to a surgical device including such an ancillary device and a set of such clips, characterized in that each clip has, at a first temperature lower than that of an animal body, a U- or V-shape and, at a second temperature corresponding to that of the animal body on which said clip is aimed at being implanted, a gamma-shape.

The advantages and features of the ancillary device according to the invention will appear more clearly from the following description, which refers to the attached drawings that represents a non-restrictive embodiment of same.

In the attached drawing :

- figure 1 represents a schematic and perspective view of an ancillary device according to the invention.

figures 2a and 2b represent schematic and cross- sectional views according to a median longitudinal plane of the same ancillary device, in two different positions of use.

- figure 3 represents a schematic perspective and exploded view of part of the same ancillary device .

- figures 4a and 4b represent schematic perspective and partially exploded views of the same ancillary device in different phases of use.

- figures 5 and 6 each represent a schematic, partial and perspective view of a prosthetic heart valve placed by means of the ancillary device according to the invention .

The invention relates to an automated ancillary device 1 for inserting and fixing an annular body 2, namely, in a preferred application, a prosthetic heart valve, on a substantially annular resilient volume 3 and including an opening. In fact, in natural state, this resilient volume, when it is formed by the patient's ring, generally has a triangular cross-section with rounded angles. This volume 3, after a preparation by the surgeon to remove very hard areas, is shaped and a cylindrical tool, called phantom, is passed through it, which permits to define the diameter of the prosthesis, the latter being generally circular.

When referring to figures 1 and 2a, one can see an ancillary device 1 according to the invention. It mainly includes a cylindrical hand grip 10 axially extended by a tube 11 provided at its free end with clip-supporting means 4 that is in the form of a cup 40, which will be described below. On the tube 11 can slide an ejector body 5 including, on the one hand, on the side of the cup 40, a cup 50 dimensioned so as to cover the cup 40 and, on the other hand, on the side of the hand grip 10, an annular element 51 forming a stop for a spring 12 inserted onto the tube 11, the hand grip 10 forming the other stop, and incorporating means for blocking the ejector body 5 in stand-by position when the spring 12 is compressed.

The cup 40 includes a tubular peripheral wall 41 provided at its free end with an annular element 42 defining a bearing surface 43. In the tubular wall 41 are provided for, distributed over the periphery, recesses 44 extending in the annular element 42, each aimed at containing and holding a clip 6, comprising two legs 60 and 61 connected by a heel 62, the legs 60 and 61 being oriented parallel to the main axis of the ancillary device 1.

It should be noted that, in the embodiment shown, the recesses 44 are designed so that each clip 6 is in a plane radial to the cup 40, knowing that it is perfectly possible, according to another embodiment, not shown, to contemplate recesses 44 that are arranged in a different way, for example so that the clips 6 are in tangent planes .

It should be noted that, when the clips 6 are arranged in radial planes, the legs 60 and 61 are, preferably and advantageously, not of a same length, thus the leg 60, arranged on the internal side of the cup 40, is longer than the leg 61 arranged on the external side .

To this end, the recesses 44 are configured in the tubular peripheral wall 41 so as to be capable of holding such clips 6, thus, in the embodiment shown, the annular element 42 in which the recesses 44 extend has a sufficient height to permit to contain the ends of the legs 61 and to compensate for the difference in length of the latter.

It should also be noted that the clips 6 are made out of shape-memory material , of nitinol or the like , and are designed so as to have, at a first temperature lower than that of an animal body, a shape permitting that the legs pass through an element, for example by being parallel or substantially parallel, and, at a second temperature corresponding to that of the animal body on which the clips 6 are aimed at being implanted, a shape in which the legs are folded, in order to impede their extraction, for example gamma-shaped.

The cup 50 of the ejector body 5 includes a tubular wall 52 having an inner diameter larger than the outer diameter of the tubular wall 41 of the cup 40, and its free outermost end is provided with teeth 53, in the number equal to the recesses 44 and distributed in a similar angular way, each aimed at cooperating with a recess 44 and at entering into contact with the heel 62 of the clip 6 contained in this recess 44.

When referring to figures 2a and 2b, one can see the two extreme positions of use of the ancillary device 1, in the first one, the ejector body 5 is in stand-by position, the spring 12 is compressed, the clips 6, only one of which is shown, are in the recesses 44. In the second one, under the action of the release of the spring 12, the ejector body 5 is pushed back, and the teeth 53 eject the clips 6 from the cup 4, which pass through the bearing surface 43.

One can also see in these figures that the ancillary device 1 comprises blocking and releasing means permitting maintaining and releasing the ejector body 5.

Thus, the annular element 51 of the ejector body 5 includes radial bores 54 each containing a pin 55 restored towards the axis of the ancillary device 1 , through springy restoring means such as a spring 56. On the other hand, the tube 11 is drilled with holes 13, into each of which can insert a pin 55 when the holes 13 are in front of the bores 54, i.e. when the ejector body 5 is in a stand-by position, the spring 12 being compressed.

Thus, the release of the ejector body 5 requires the withdrawal of the pins 55 into their bore 54 , which is achieved through control means comprising a piston 14, axially movable in the tube 11, and the conical surface 15 of which can, depending on the positioning of the piston 14 in the tube 11, push the pins 55 into their bore 54 , the pins advantageously having a conical free end. The piston 14 is integral with the end of a rod 16 movable through axially sliding in the hand grip 10, and provided at its other end with a button 17 pushed away from the hand grip 10 by a spring 18.

In stand-by position, the button 17 is separated from the hand grip 10, and when the button is pressed 17, the piston 14 slides in the tube 11, its conical surface 15 pushes the pins 55 outwardly, which releases the ejector body 5, which under the action of the spring 12 moves towards the cup 40 and releases the clips 6.

Advantageously, the ancillary device 1 is provided with a safety system permitting, when it is in stand-by position, to avoid an unexpected triggering. In figure 1, one can see that this safety system consists, non-restrictively, of a spacer 19 intercalated between the button 17 and the hand grip 10.

When referring now to figure 3, one can see the end of the ancillary device 1, i.e. the ejector body 5 and the clip- supporting means 4 , which the annular body 2 to be fixed is in progress of being secured to.

The annular body 2 consists , in this case , of a prosthetic heart valve that includes a peripheral ring 20 made out of « Dacron », aimed at being crossed by the clips 6.

When the annular body 2 is fitted, the clip-supporting means 4, the peripheral ring 20 enters into contact with the bearing surface 43, and the longer ends of the legs 60, which in stand-by position protrude beyond the bearing surface 43 penetrate into the latter.

It should be noted that, preferably, the portion of the legs 60 that protrudes beyond the bearing surface 43 has a length smaller than the thickness of the peripheral ring 20, so as not to protrude out of it when the annular body is secured to the ancillary device 1.

Furthermore , it should also be noted that the diameter of the peripheral ring 20 varies between that of the circle containing the legs 60 and that of the circle containing the legs 61, so that the latter are not aimed at passing through the peripheral ring 20, but only at pricking and drilling the resilient body so as to protrude out of same, formed by the patient's ring in heart surgery.

When the clips are positioned in tangent mode, the two legs having the same length are both aimed at passing through the Dacron of the prosthetic valve .

When referring now to figures 4a and 4b, one can see that, in practice, the user, after having determined the proper size, thanks to a phantom, lowers the ancillary device 1 provided with the prosthetic heart valve 2 into the aorta 30, and positions the peripheral ring 20 of the prosthetic heart valve 2 against the patient's ring 31, which is facilitated in that the ends of the legs 60 do not pass through the peripheral ring 20, then, when pressing the button 17, the clips 6 are released, the legs 60 pass through the peripheral ring 20 and the patient's ring 31, while the legs 61 pass through the patient's ring 31.

The following operation consists in injecting through the aorta or through the ancillary device 1 , which can to this end be provided with means permitting a flow, a serum, or the like, at a temperature preferably higher than 30°C and close to the normal temperature of the animal body involved.

Under the action of the raising of this temperature, the clips 6 then close inwardly and adopt a gamma-shape, each forming a loop that ties the prosthetic heart valve 2 to the patient's ring 31, as can be seen in figures 5 and 6. The user can then remove the ancillary device 1 from the aorta 30.

The shape-memory clips can never reach their closed resting position, because of the hardness of the tissues. Therefore, a dynamic tension remains at the level of the clips, which exerts an elastic restoring of the prosthetic valve onto the patient's ring. This elastic restoring permits that both structures - prosthetic valve and patient' s ring - remain integral with each other despite the pressure changes exerted during the heat cycle .

Claims

1) Automated ancillary device for inserting and fixing by means of clips an annular body, namely a prosthetic heart valve, on a substantially annular resilient volume, including an opening, including, coaxially fitted about a longitudinal axis, means for receiving and supporting said annular body designed capable of receiving the latter coaxially to its axis of rotation, wherein it includes means for longitudinally pushing about said longitudinal axis, clip-supporting means designed capable of bearing clips made out of shape-memory material, of nitinol or the like, said clips including two legs connected by a heel, and designed so that at least one of said legs passes through both a thickness of a material belonging to said annular body and a thickness of a material belonging to said substantially annular resilient volume , under the action of said longitudinal pushing means .

2) Ancillary device according to claim 1, wherein the longitudinal pushing means include pushing means exerting a percussion under the action of springy restoring means formed by at least one spring or the like.

3) Ancillary device according to claim 1 or claim 2, wherein the clip-supporting means are substantially annular and include means for the passing through of fluids .

4) Ancillary device according to any of the preceding claims, wherein the clip-supporting means include recesses designed capable of receiving said clips in a pre-stressed position in which the two legs of each clip are parallel , or substantially parallel, to said longitudinal direction of insertion .

5) Ancillary device according to claim 4, wherein each recess is oriented according to a plane radial to the main axis of the ancillary device . 6) Ancillary device according to claim 5, wherein the clip-supporting means are shaped so that each of its recesses can hold one clip the leg of which arranged on the internal side is longer than that arranged on the external side .

7) Ancillary device according to claim 4, wherein each recess is oriented according to a plane tangent to the clip- supporting means .

8) Surgical device including an ancillary device according to any of the preceding claims as well as a set of clips made out of shape-memory material, wherein each of said clips has, at a first temperature lower than that of an animal body, a U- or V-shape and, at a second temperature corresponding to that of the animal body on which said clip is aimed at being implanted, a gamma-shape.