Tubular support for setting, by percutaneous route, a substitution cusp

CA 02425342 2003-04-04 WO 02/36048 PCT / FRO1 / 03258 1 TUBULAR SUPPORT FOR IMPLEMENTATION, BY PERCUTANEOUS ROUTE, OF A REPLACEMENT HEART VALVE The present invention relates to a tubular support for positioning, percutaneously , a replacement heart valve.

It also relates to an instrument for positioning this support.

The classic technique for replacing a heart valve is to operate with an open heart.

This technique requires a general anesthesia, a wide approach, and a heart failure involving putting the patient under cardiopulmonary bypass.

It is therefore particularly cumbersome to implement and induces significant operating risks for the patient.

To remedy this drawback, it has been envisaged to operate the ablation of a deficient heart valve percutaneously, with a peripheral vascular approach.

Patent application No. FR 99 14462 illustrates a technique and a device which can be used for this purpose.

With regard to the installation of a replacement heart valve, it has been envisaged to fix this valve on a support having a structure of wire or network of wires, commonly called a "stent".

This support can be contracted radially in order to be able to be introduced into the patient's body percutaneously, by means of a catheter, and can be deployed radially once positioned at the site to be fitted with the valve to thus ensure the assembly of this valve.

US Pat. No. 5,411,552 illustrates one such technique.

The “stent” systems envisaged to date for the placement of a heart valve induce more or less significant uncertainties as regards their maintenance in position in the sites to be treated.

In particular, the shape of the known stents does not appear to be adapted to that of these sites, in which the cardiac wall widens on either side of the cardiac ring.

In addition, the cardiac annulus remaining after removal of the native valve may interfere with the placement of these stents.

These known systems also induce, in certain cases, sealing problems of the replacement valve.

Indeed, said remaining cardiac ring may have a more or less irregular and more or less calcified surface, which not only reduces the quality of the support of the stent against this ring but also may be the source of leaks between the valve and this ring.

CA 02425342 2003-04-04 WO 02/36048 PCT / FRO1 / 03258 2 Certain existing equipment also has drawbacks with regard to their actual installation.

In particular, these materials can hardly be moved after deployment of the support even if their position is not optimal.

The present invention aims to remedy these significant drawbacks.

Its main objective is to provide a support (“stent”) providing a better certainty of retention in position after implantation.

Another objective of the invention is to provide a support making it possible to eliminate the discomfort caused, when the replacement valve is put in place, by the native valve leaflets which are readily calcified, thickened and indurated, or the remains of the Valve leaflets after valve resection.

Yet another objective of the invention is to provide a support allowing perfect sealing of the replacement valve, even in the event of a remaining heart ring which has a more or less irregular and / or more or less calcified surface.

The invention also aims to provide a support whose position can be adapted and / or corrected if necessary at the time of implantation.

The support concerned comprises, in a manner known per se, a wire structure or a network of wires capable of being contracted radially to allow the introduction of the support-valve assembly into the patient's body, by means of a catheter. , and to be deployed to allow the support of this structure against the wall of the site to be fitted with the valve.

According to the invention, this structure comprises - an axial valve support portion, having a wire structure or wire network suitable for receiving the replacement valve mounted on it, and suitable for resting against the cardiac ring remaining after removal of the deficient native valve;

- at least one axial wedging portion, having a wire structure or wire network distinct from the structure of said axial valve support portion, and at least part of which, in the deployed state, has a diameter greater than diameter in the deployed state of said CA 02425342 2003-04-04 WO 02/36048 PCT / FRO1 / 03258 3 axial valve support portion, such that this axial wedging portion is suitable for resting against the wall bordering said ring cardiac subsisting; and - at least one connecting wire of said portions, this or these wires being punctually connected to these portions, so as not to obstruct the deployment of said axial portions according to their respective diameters.

. The invention thus provides a support in at least two axial portions individualized with respect to each other as regards their structure, which are connected in a localized manner by at least one wire; this or these threads do not constitute an obstacle to a different deployment of the axial portion comprising the valve and of the axial wedging portion or portions.

The presence of a wire structure or a network of wires at the level of the axial valve support portion allows a perfect assembly of this valve to this structure, and the shape as well as the diameter of this axial portion can be adapted to a support in the best conditions against the remaining cardiac ring.

In particular, this axial valve support portion may have a radial expansion force such that it pushes back ("impacts") the readily calcified valve leaflets, or the remains of the valve leaflets after valve resection on or in the sub- tissues. adjacent, so that these elements do not interfere with the placement of the replacement valve.

This structure also makes it possible to support any means for anchoring the support and / or any means for sealing the space existing between the remaining cardiac ring and the replacement valve, as indicated 1 below.

The shape and / or the diameter of each axial wedging portion can be adapted to a bearing under the best conditions against the cardiac wall located near the remaining cardiac ring.

In particular, this axial wedging portion may have a tubular shape of constant diameter greater than that of the axial valve support portion, or a frustoconical shape whose diameter increases as it moves away from the axial valve support portion.

Preferably, the tubular support has an axial valve support portion in at least two parts, at least one of which is adapted to support the valve and at least another of which is adapted to push back the native valve leaflets or the remains of the CA leaflets. 02425342 2003-04-04 WO 02/36048 PCT / FRO1 / 03258 4 native valves after valve resection, in or on the adjacent tissue in order to make this zone suitable for receiving the tubular support.

This axial valve support portion eliminates the discomfort caused by these cardiac valve or annular elements when the replacement valve is put in place.

The radial force of this axial valve support portion in fact ensures, by impacting all or part of the valve tissue in or in the vicinity of the wall, a more regular surface and more suitable for receiving the valve support axis.

It also ensures better attachment to the wall while reducing the risk of para-prosthetic leakage.

The axial valve support portion may in particular comprise a portion of wide-wave corrugated wire, to support the valve, and a portion of reduced-wave corrugated wire, adjacent to said wide-wave portion, having a relatively large radial force to allow to push said valve tissue against or into the wall of the duct.

Preferably, the support according to the invention has two axial wedging portions, one being connected to an axial end of said valve support portion and the other to the other axial end of this same valve support portion. .

These two axial wedging portions thus allow wedging of the support on either side of the remaining cardiac ring, and consequently allow perfect wedging of the support in two opposite directions relative to the treated site.

If necessary, for example in the case where the duct comprising the valve presents an aneurysm, the support according to the invention comprises - an axial holding portion, suitable for resting in the deployed state against the wall of the duct, and - connecting rods as mentioned above, connecting said axial valve support portion and said axial holding portion, these wires having a length such that the axial holding portion is located after implantation at a distance from the axial valve support portion.

This distance allows said axial retaining portion to bear against an area of ​​the wall of the duct not affected by any disease that may exist in the vicinity of the valve, in particular an aneurysm.

The length of the connecting threads can also be CA 02425342 2003-04-04 WO 02/36048 PCT / FRO1 / 03258 calculated in order to prevent the axial holding portion from coming into contact with the ostia of the coronary arteries.

The aforementioned axial portions (of valve support, wedging, holding) may have a corrugated, zig-zag wire structure or, preferably, a mesh structure having a diamond shape, the meshes being juxtaposed in the sense of the circumference of these portions.

This latter structure allows an adapted radial force, making it possible to ensure a perfect bearing of said portions against the wall which receives them.

The support according to the invention can be made of a plastically deformable metal. The instrument for placing the support then comprises a balloon having an axial portion of a predetermined diameter, adapted to carry out the deployment of said axial valve support portion, and at least one axial portion shaped to present, to the swollen state, a section greater than that of the duct to be treated, so as to achieve the deployment of the axial wedging portion placed on it until this axial wedging portion meets the wall against which it must bear.

The support according to the invention can also be made of a shape memory material, such as a nickel-titanium alloy of the type called "NITINOL", which can be contracted radially at a temperature different from that of the patient's body and regaining a original form when its temperature approaches or reaches that of the patient's body.

According to another possibility, the support is made of a material with shape memory but capable of plastic deformation, or comprises parts of a material with shape memory and parts of a material capable of plastic deformation, and is shaped in such a way that it can be brought, by shape memory or by plastic deformation, from a state of contraction to a state of stable intermediate deployment between the state of contraction and the state of total deployment, then, by plastic deformation or by shape memory respectively, from said intermediate deployment state to said fully deployed state; in said intermediate deployment state, the support has dimensions such that it remains mobile with respect to the site to be treated.

CA 02425342 2003-04-04 WO 02/36048 PCT / FRO1 / 03258 6 The support is thus brought to the level of the site to be treated and then is deployed in said intermediate state; its position can then optionally be adapted and / or corrected then the support is brought into its fully deployed state.

The aforementioned shape memory material but capable of plastic deformation may in particular be a nickel-titanium alloy of the type known as “martensitic NITINOL”, capable of being plastically deformed by means of a balloon.

Advantageously, the support according to the invention comprises anchoring means suitable for inserting into the wall of the site to be treated, shaped so as to be movable between an inactive position, in which they do not prevent the introduction of the support in the patient's body, and an active position, in which they fit into the wall of the site to be treated.

Perfect immobilization of the support at the site is thus obtained.

In particular, these anchoring means may have the form of needles and may be mounted on the support between positions of radial retraction and positions of radial projection.

Advantageously, the axial valve support portion comprises, at its outer face, a sealing means shaped so as to absorb the surface irregularities which may exist at or near the remaining cardiac ring.

This sealing means may be constituted by a peripheral strip made of a compressible material or by a peripheral strip delimiting a chamber and having a radially expandable structure, this chamber being able to receive an inflation fluid capable of freezing within a determined time after introduction into the chamber. said room.

This sealing means may also comprise a material which can be applied between the remaining cardiac annulus and the axial valve support portion, this material being suitable for setting within a determined period after this application.

In this case, this material can in particular be heat-activatable, for example by means of a laser, through the balloon, or activated by emission of light of a determined frequency, for example by means of an ultra-violet laser, through the balloon.

Said sealing means may also be in the form of an inflatable insert CA 02425342 2003-04-04 WO 02/36048 PCT / FRO1 / 03258 7 having a diabolo cross section in the inflated state, which can be inserted between the remaining heart ring and the axial valve support portion.

Said diabolo shape allows this insert to conform as well as possible to the adjacent irregular structures and to ensure better sealing.

For a better understanding, the invention is described again below with reference to the appended schematic drawing showing, by way of non-limiting examples, several possible embodiments of the tubular support to which it relates.

FIG. 1 is a developed view of the structure of this support, according to a first embodiment;

FIG. 2 is a sectional view of the support in the deployed state, with the heart valve that it comprises;

FIG. 3 is an end view of this support in the deployed state;

FIG. 4 is an end view of this support in the contracted state;

FIG. 5 is a view of a heart in partial section, on which a replacement heart valve has been placed by means of the support according to the invention;

FIG. 6 is a developed view of the structure of the support according to a second embodiment;

FIG. 7 is a developed view of the structure of the support according to a third embodiment;

FIG. 8 is a detail view of part of this structure, on an enlarged scale; FIG. 9 is a view of the support according to FIG. 7, after placement in a body duct having an aneurysm;

. FIG. 10 is a developed view of the structure of the support according to a fourth embodiment;

FIG. 11 is a detail view of an alternative embodiment of an anchoring hook which the support according to the fourth embodiment comprises;

fa figure 12 is a view of the same detail, in section along the line XII-Xll of figure 11;

Figure 13 is a view similar to Figure 11, the structure being in an expanded state;

CA 02425342 2003-04-04 WO 02/36048 PCT / FRO1 / 03258 - Figure 14 is a view similar to Figure 12, the structure being in this same expanded state;

FIG. 15 is a partial view of a structural portion of the support according to a fifth embodiment;

FIG. 16 is an enlarged view of a mounting zone of a prosthetic valve on this portion;

FIG. 17 is a partial view, in longitudinal section, of the support according to the first embodiment and of a calcified heart ring;

Figure 18 is a view similar to Figure 17, according to a variant;

FIG. 19 is a view similar to FIG. 17, according to another variant;

FIGS. 20 and 21 are views similar to FIG. 17, according to yet another variant, in two phases of installation of the support;

Figure 22 is a longitudinal sectional view of a balloon allowing expansion of the structure of the support shown in Figures 7-9;

Figure 23 is a longitudinal sectional view of a balloon according to an alternative embodiment, and Figure 24 is a view similar to Figure 5, showing a heart on which a replacement heart valve has been placed by means of the support according to the invention, according to a sixth embodiment.

For simplicity, the parts or elements of these different embodiments which are identical or similar from one embodiment to another are defined by the same reference numerals. Figures 1 to 4 show a tubular support 1 for positioning, percutaneously, a replacement heart valve 2.

The structure of the support 1 comprises a middle portion 3 comprising the valve 2, two end portions 4 for wedging and wires 5 for connecting these portions 3 and 4.

The middle portion 3 further comprises a peripheral band 6 provided with anchoring needles 7 and a bandage 8 made of compressible material.

CA 02425342 2003-04-04 WO 02/36048 PCT / FRO1 / 03258 9 As appears more particularly in FIG. 1, the portions 3 and 4 are each formed by a corrugated wire, and the wires 5 punctually connect the ends of the corrugations of portion 3 at the end of an adjacent corrugation of portion 4.

The portions 4, seen in development, have lengths greater than the length of the portion 3, so that, when the ends of the wires respectively forming the portions 3 and 4 are connected to constitute the tubular structure of the support 1, the diameter of portion 3 is smaller than the diameter of portions 4.

The diameter of the portion 3 is such that this portion 3 can, as shown in Figure 5, bear against the heart ring 10 remaining after the withdrawal of the deficient native valve, while your portions 4 can bear against your walls. 11 bordering the ring 10.

These respective diameters are preferably such that said support takes are made with a slight radial stress of the ring 10 and of the walls 11.

Portion 3 has, in the deployed state, a constant diameter.

The portions 4 may have a constant diameter or a frustoconical shape the diameter of which increases as it moves away from the portion 3.

The entire structure of the support 1 is made of a shape memory material, such as a nickel-titanium alloy of the type called "NITINOL".

This material allows this structure to be contracted radially, as shown in figure 4, at a temperature different from that of the patient's body and to regain the original shape shown in figures 2 and 3 when its temperature approaches or reaches that of the patient. patient's body. The entire structure of the support 1 can also be made of a material which can be expanded on a balloon, such as, for example, medical stainless steel (316 L steel).

The valve 2 can be of biological or synthetic fabric.

It is connected to portion 3 by sutures or by any other appropriate fixing means. ENe can also be molded on portion 3.

Band 6 is in "NITINOL".

It is connected to the corrugations of portion 3, at mid-height thereof, and comprises the needles 7 at the level of its zones connected to these corrugations.

The needles 7 are formed by strands of metal wire sharpened at their free ends, and project radially outwardly from the strip 6.

CA 02425342 2003-04-04 WO 02/36048 PCT / FRO1 / 03258 The latter can take the wavy shape visible in Figure 4 in the contracted state of the support 1 and the circular shape visible in Figure 3 in the deployed state of this support 1.

In its corrugated form, the strip 6 forms corrugations 6a projecting radially on the outside of the support 1, 5 beyond the needles 7, so that these needles 7, in this retracted position, do not hinder the introduction. of the support 1 in a catheter nor, once the support 1 has been introduced into the heart using this catheter, the deployment of this support 1.

The return of the strip 6 to its circular shape brings the needles 7 into a deployed position, allowing them to fit into the ring 10 in order to complete the anchoring of the support 1.

The bandage 8 is attached to the band 6.

Its compressible material allows it to absorb any surface irregularities that may exist at or near the ring 10 and thus ensure perfect sealing of the valve 2.

FIG. 6 shows a structure of the support 1 comprising a single portion 4, connected to the portion 3 by wires 5.

This portion 4 is formed by two corrugated son 14 interconnected by son 15.

FIG. 7 shows a structure of the support 1 having a portion 3 and a portion 4 connected by connecting wires 5.

These portions 3 and 4 have diamond-shaped mesh structures, these meshes being juxtaposed in the direction of the circumference of these portions and being connected to each other at two of their opposite angles in the direction of the circumference of these portions 3 and 4.

The son 5 are connected to these structures at the junction zone of two consecutive stitches.

These meshes further include anchoring hooks 7 extending through them from one of their angles located in the longitudinal direction of the support 1.

FIG. 8 illustrates, on an enlarged scale, the structure of this portion 4 and of part of the wires 5, such as cut for example by laser from a stainless steel plate, and after bending the sharp ends 7a of the hooks 7.

The latter have, seen in profile, a shape as shown in Figures 12 or 14.

The structure shown in FIG. 7 also comprises an axial holding portion 20, having a structure identical to that of portion 4 but with larger mesh, and three wires 5 of length CA 02425342 2003-04-04 WO 02/36048 PCT / FRO1 / 03258 11 important, connecting this portion 20 to portion 3.

These threads 5 have, on the side of the portion 20, a unitary suture 5a and, on the side of the portion 3, a double structure 5b.

Their number corresponds to the three commissures formed by the three valves of the valve 2, which facilitates the mounting of the valve 2 on the support 1 thus shaped.

The holder according to figure 7 is intended for use, as it appears in figure 9, when the body duct comprising the valve to be replaced, in particular the aorta, has an aneurysm in the vicinity of the valve.

The length of the wires 5 connecting the portions 3 and 20 is provided such that, after implantation, the portion 20 is located in an unexpanded zone of said bodily duct, and this portion 20 is provided so as to bear against the wall of the body. this leads.

FIG. 10 shows a structure similar to FIG. 7 but not expanded, and otherwise that the three wires 5 have a unitary structure but include a corrugated wire 21 providing additional support near the port 3.

This wire 21 is designed to support a valve 2 with three valves.

Figures 11 to 14 show an alternative embodiment of the structure of portions 3, 4 or 20, when this structure is equipped with hooks 7.

In this case, the structure is zig-zag and each hook 7 comprises two branches 7b; each of these branches 7b is connected to the other branch 7b by one end and to a branch of the structure 1 by its other end.

The junction zone of the two branches 7b has a curved hooking lug 7a.

FIG. 15 shows a portion 3 comprising two corrugated wires 25, 26 extending close to each other and a secondary corrugated wire 27.

As shown in Figure 16, the threads 25, 26 can be used to achieve the insertion of a valve 2 of biological material between them and the attachment of this valve 2 to them by means of sutures 27.

Figure 17 shows part of the carrier 1 according to Figures 1 to 5, and how the compressible material constituting the tire 8 can absorb the surface irregularities which may exist at or near the ring 10, which result from calcifications.

FIG. 18 shows a support 1, the strip 6 of which is devoid of compressible bandage.

A material can then be applied, by means of an appropriate cannula (not shown), between the ring 10 and this CA 02425342 2003-04-04 WO 02/36048 PCT / FRO1 / 03258 12 band 6, this material being clean to freeze within a specified time after this application.

FIG. 19 shows a support 1, the strip 6 of which has a broken line section, delimiting, on the radially outer side, a lower shoulder.

In the step formed by this shoulder and the adjacent circumferential wall, is housed a peripheral band 8, inflatable by means of a catheter (not shown).

This strip 8 delimits a chamber and has a radially expandable structure, such that it has in cross section, in the inflated state, two widened ends projecting on either side of the strip 6.

This chamber can receive an inflation fluid suitable for freezing within a determined period of time after introduction into said chamber.

Once this material has set, the inflation catheter is severed.

FIGS. 20 and 21 show a support 1, the band 6 of which receives an inflatable insert 8 having a diabolo cross section in the inflated state, this insert 8 being able to be inflated by means of a catheter 29.

The insert 8 is placed in the deflated state (Figure 20) at the locations where there is a space between the band 6 and the remaining cardiac annulus 10.

Its diabolo shape allows this insert 8 (cf. FIG. 21) to conform as best as possible to the adjacent irregular structures and to ensure better sealing.

Figure 22 shows a balloon 30 for deploying the support 1 according to Figures 7 to 9.

This balloon 30 comprises a cylindrical portion 31 whose diameter in the inflated state allows the expansion of the holding portion 20, a cylindrical portion 32 of smaller diameter, adapted to achieve the expansion of the portion 3, and a frustoconical portion 33, allowing the expansion of portion 4.

As shown in Figure 23, the portion 32 can be limited to what is strictly necessary to deploy the portion 3, which allows the balloon 30 to be made in two parts instead of just one, thus limiting the volume of this balloon. 30.

FIG. 24 shows a support 1, the middle portion 3 of which is in two parts 3a, 3b.

Part 3a is made of corrugated wire with wide waves, to support the valve 2, and part 3b, adjacent to said part 3a and connected to the latter by bridges 35, is made of corrugated wire with reduced waves.

This part 3b, by its structure, has a relatively high radial expansion force CA 02425342 2003-04-04 WO 02/36048 PCT / FRO1 / 03258 13 and is intended to be placed opposite the ring 10 in order to push back native valve leaflets that are readily calcified, thickened and indurated, or the remains of valve leaflets after valve resection against or in the wall of the duct.

This axial portion 3a, 3b thus eliminates the discomfort caused by these leaflets or leaflet residues when the valve 2 is put in place.

It appears from the foregoing that the invention provides a tubular support for the percutaneous placement of a replacement heart valve providing, thanks to its portions 3 and 4, perfect certainty of being held in position after implantation.

This support also allows a perfect sealing of the replacement valve, even in the event of a heart ring having a more or less irregular surface and / or more or less calcified, and its position can be adapted and / or corrected if necessary. time of implantation.

It goes without saying that the invention is not limited to the embodiment described above by way of example but that, on the contrary, it encompasses all the variant embodiments thereof covered by the appended claims.