FR2772257A1 - Surgical apparatus for repairing diseased blood vessel, used to treat aneurysms - Google Patents

Abstract

The assembly includes a reinforcing element to surround the outer wall of the duct and fixings for attaching the reinforcing element to the implant through the duct wall. The apparatus consists of an implant (100) designed to be introduced into the duct being treated, a reinforcing element (140) to go round outside of the duct opposite the proximal end (100a) of the implant, and fixings for attaching the reinforcing element to the implant through the duct wall. It also incorporates an instrument (320) for delivering the reinforcing element and the fixings, preferably from outside the duct. The reinforcing element has a core, e.g. of metal wires or plastic filaments, to make it mechanically resistant to crushing and form an outer support for fixings such as staples delivered through an endoscopic stapler. The reinforcing element also has a protective cushion, at least one its inner surface.

Description

 The invention relates to a medical assembly improving the conditions for placing and holding an implant in an anatomical conduit, in particular if it is a vascular implant, or stent, for aneurysm adapted to be placed at least in part by the percutaneous endoluminal route.

 In the field, different types of implants and different fitting techniques are known.

 Thus, in patent US-A-5,527,355, there is taught an apparatus and a method for treating aneurysms by applying a band around the outer surface of the vessel, at the locations where the spring means of holding the implant against the vessel (stents).

 Nevertheless, a certain number of problems remain linked to the conditions of placing the strip around the duct in question, of fixing the implant to the wall of this duct, as well as to the possible conditions of effective sealing to be obtained vis- screw of the fluid which can circulate there, in particular in the event of treatment of aneurysms.

 Note that in US-A-5,527,355, the system for attaching this band around the duct can pose a problem, in particular if it is the aorta, since it can be particularly delicate to try to go around it entirely.

Under these conditions, an important characteristic of the invention provides that the medical unit includes
an implant (or endoprosthesis) which can be inserted into the duct to be treated, which has an upstream zone with respect to the direction of the fluid flowing therein, the implant, which has a general axis, having substantially along this axis two free ends, respectively proximal and distal,
- at least one external lining of the wall of the conduit, to be placed (at least) substantially opposite the proximal end of the implant,
means for fixing the lining to the implant, through the wall of the conduit, to apply internally at least the proximal end of the implant against the wall of the conduit in its upstream area,
- And means for placing said lining and fixing means, to arrange the lining around the duct and fix it to the implant.

 At least in the case of a vascular affection (in particular aneurysm) and to favor a minimally invasive intervention, the endoluminal implant will advantageously include a structure adapted to occupy a first radially tightened state, for its introduction into the vessel, or a second radially deployed state in which the structure will have the general shape of a single or bifurcated tube.

 The lining may be presented as a point (or local) pad placed at the location of the considered fixing means, or as a strip at the periphery of the duct.

 Advantageously, the means of attachment between the pain and the implant will consist of clamping means for internally pressing the implant against the wall of the conduit in question, in a manner substantially impermeable to the fluid flowing therein, at least at the upstream end. of the implant, which is preferably provided with a stent.

 To ensure sufficiently uniform contact between the lining and the conduit, while ensuring "soft" contact, this lining may have a frame covered (at least on one inner side) by a buffer pad.

 To promote its holding at the time of fixing and over time, the lining may be mechanically resistant in the direction of its thickness, so that it constitutes a forestay for said fixing means.

 Given that the anatomical conduits do not all have the same section and that the same conduit can also have different sections for different people, an additional consideration of the invention provides that if it is a strip , the lining can be split to be adapted to the external section of the duct.

 Another characteristic of the invention is concerned with defining the means of fixing, or even tight tightening, between the lining and the implant.

 In a first variant, these means may include suturing means (thread and needle in particular) adapted to be put in place, maneuvered and then removed preferably by the endoscopic route, and in particular by laparoscopy.

 According to another embodiment, these fixing means could be presented for example as staples, or any equivalent means, then offering as advantage a variable length to a certain extent, to be clean if necessary to tighten the wall of the conduit between the external lining. (even inside) and the implant located in the duct.

 As regards the lining itself, an additional characteristic of the invention provides that it is suitable for being traversed by, or that it has structurally, openings for the passage through it of the fixing means.

An even more detailed description of the invention will now be provided with reference to the accompanying drawings in which
FIG. 1 shows the implant in place in the aneurysm with the lining strip ready to surround it,
FIG. 2 shows in perspective and in enlarged view a possible embodiment of the strip,
FIG. 3 is an alternative embodiment of the strip according to the same view as FIG. 2,
FIG. 4 shows another variant of the strip seen from above,
- Figure 5 shows a staple with suture,
- Figure 6 shows schematically the placement of the implant and the lining,
- Figure 7 shows the clip in place through the conduit,
- And Figure 8 shows an alternative embodiment of the lining, like a local pad.

 In what follows, we only consider the case of an implant consisting of a stent intended to treat an aortic aneurysm, even if other vessels, or even other types of condition, can benefit from the improvements made. by the invention.

 Thus, FIG. 1 shows an aorta V suffering from an aneurysm 110. The aneurysm is delimited by an upper collar (or upstream) 112 and a lower collar (or downstream) 114. The reference 10 indicates the direction of circulation of the blood .

 A stent 100, of axis 100c, is implanted at least at the location of the aneurysm.

The implant 100 may in particular be presented as described in patent US-A-4,533,665, or
FR-A-2 732 404.

 The implant is pressed, towards its proximal end 100a, against the wall P of the vessel V, by means of at least one radially deployable enlarger, usually called "stent", 105.

 In addition to stent 105 (which in this case comprises three stages of zigzag metallic wires wound on themselves on each stage), implant 100 includes a flexible, synthetic, biocompatible sheath, 108, for example made of Dacron (registered trademark ), allowing blood to be channeled through it, once the prosthesis is implanted. The stent is sutured to the sheath in 161.

 The (each) stent 105 is in this case radially "self-expanding" (as in FR-A-2 732 404), although it may, as a variant, be constituted by an openwork metal tube, radially deployable beyond its elastic limit under the effect of an internal force of radial expansion, such as a balloon, as in US-A-4,533,665.

 Given that in this case, the plating of the implant against the upper collar 112 is effected by means of the first stage 105a of stent, this stage may have a radial force (or a resistance to radial compression) greater than what the other stages and / or the rest of the implant have. This mechanical effect is obtained for example by increasing the number of zigzags at this first stage and / or by decreasing the axial length 1 of this stage compared to the other stages of the stent. Another solution would be to add an added reinforcement means, such as for example a split ring (not shown).

 Around the duct V, and more particularly around the upper collar 112, there appears a piece 140 of lining the duct.

 It is a part which will serve to secure the implant to the vessel at the location (or in the vicinity) of the collar 112 (at least), preferably in a blood-tight manner. In this case, this part is presented as an elongated strip.

 Once in place, the strip 140 will locally double the wall of the vessel to favor the establishment of means for fixing this strip to the implant 100, therefore through the wall of the conduit V, in order to apply this internally. implant against wall P.

 Different embodiments of the strip 140 can be imagined.

 If the strip is sufficiently resistant to crushing, in the direction of its thickness (marked e in FIG. 2), the strip will then advantageously constitute an external forestay for the fixing means, the implant 100 being able, for its part, constitute the internal forestay, this for example by means of the stent 105, or even a band of a local pad or of a complementary split ring marked 150 in FIG. 1 and fixed and attached (e) toward the proximal end of the implant to support it.

 In FIG. 2, the lining is presented as a strap containing one or more wires (303) of metal or plastic (in this case, two parallel wires) embedded in a shock absorbing pad 305 (for example, made of felt), the everything can be covered with a thin 307 envelope, for example in Dacron (registered trademark).

 In FIG. 3, the strip 140 comprises a relatively rigid mesh 309, embedded in a protective layer 312 to absorb contact with the vessel.

Optionally, layer 312 could only be provided on the inner side where the strip comes into contact with the vessel, the forestay frame 309 then being on the surface.

 In another variant not shown, one could imagine making the strip like a felt pad reinforced by an interlacing of metallic or plastic filaments.

 Concerning these fixing means, it will be noted that the solution of FIG. 3, or that of reinforced felt, are in particular suitable for a connection by suture (surgical threads) between the strip and the implant 100, while the solution of the FIG. 2 can in particular be provided if the fixing means is of the "clip" type, as illustrated in particular in FIGS. 5, 7 and 8.

 If the fixing means risk exerting an excessive penetration force on the strip and / or on the sleeve 108 of the prosthesis, then one and / or the other of these two parts may have open passages such as the through cuts, for example in a cross or in a portion of a circle, as shown in 319 in FIG. 2. Note that the size of the meshes 309a of the trellis 309 of FIG. 3 can make it possible to obtain the same effect.

 In FIG. 4, a curved suture needle 321 has been shown diagrammatically linked to its suture thread 323 to bind the prosthesis and the strip 140 of lining together, through the wall of the vessel. The wire 323 is terminated by a knot 325 allowing the wire to hold in place after being laid.

 In FIG. 5, a surgical fastening clip 361 in a "U" has been shown diagrammatically.

 In FIG. 6, there is shown schematically the technique for implanting the stent 100, by percutaneous endoluminal route (in particular, the so-called "SELDINGER" technique), as well as the positioning of the band 140, by laparoscopic route. .

 More specifically, after having practiced a VA access route through the patient's skin, and having introduced a widening catheter (not shown) on the wire guide 210, the external sheath 230 enclosing a second sheath 240 near the distal end from which the implant 100 has been preloaded beforehand is introduced after removal of the enlarger.

 When it reaches zone 110 of the aneurysm, the implant is correctly positioned, radiographically.

 The two sheaths 230, 240 are then successively withdrawn, the internal catheter 250 serving, if necessary, as rear support for the implant, so that it does not move back when the sheaths are withdrawn.

 The implant 100 then deploys radially by itself if it is self-expanding or under the effect of an internal inflation means, if such a means has been provided, or by any other equivalent means.

 Once the implant in the situation in FIG. 1, a sheath 310 containing the lining 140 is engaged laparoscopically (endoscopy), and this substantially at the level of the upstream collar 112 of the aneurysm, transverse to the axis of the vessel and therefore of the implant, via the percutaneous access route VB practiced here in the abdominal area.

 Once the distal end 311 of the sheath 310 is substantially opposite the end 100a of the implant, the sheath is removed, with the use again of a rear support catheter 320 on which will be able to bear the strip 140 which, for its introduction, could have been previously laid flat in the sheath, at the end of the "pusher" 320.

 If the lining 140 is a strip having a capacity to close more or less on itself in a ring, as shown in FIG. 1, a progressive release will allow it to naturally surround the collar 112. Otherwise, and in particular if the reinforcement of the lining is not elastically deformable, the introduction (always laparoscopically, preferably) of one or more clamps must allow the practitioner to conform the strip 140 to the local external shape of the zone 112, a like a split ring. The deformability of the strip which may have a length of between 2 and 6 cm approximately and a thickness of between 0.5 mm and a few millimeters, facilitates its conformation.

 If, for fixing this lining, suturing means are used (see FIG. 4), then the forceps can be used to maneuver the needle 321 (previously also introduced laparoscopically inside a catheter or 'an introducer sheath), until the practitioner has been able to pass the wire 323 several times through the strip 140, the zone 112 of the vessel and the zone 100a of the implant, going around a part at the less from the ship. Preferably, the wire will be passed behind the stent 105a and / or through the forestay ring of the implant possibly provided (reference 150 in Figure 1), which could be located on the outer periphery of the implant as in Figure 7 and can be constituted as the lining 140. One could also provide in its place only a simple "shock absorbing" pad, for example made of biocompatible felt fixed to one endoprosthesis.

 Advantageously, the suture will be tight, so as to apply the portion 100a of the implant closely against the interior surface of the collar 112, thus ensuring a seal against the blood.

 It will preferably be the same if the fixing is effected by means of staples such as 361, as shown in FIG. 7, the bending zone 363 of the free ends of this staple ensuring effective retention.

 After verifying that all the implantation instruments and means have been removed, the first tracks are closed.

 As a conduit other than a vascular one on which one could intervene in the context of the invention, mention may be made of the gallbladder (see in this regard WO-A-97/09008, for dimensions, materials, etc., cf. in particular pages 8 to 11).

 Note also that, as an alternative, the endoprosthesis 100 could be presented as a bifurcated tube, as in US-A-5,527,355.

 Other types of endoluminal implants may also be suitable.

 In FIG. 8, the external duct lining has been marked 140a. It is a round piece but it can have any other desired shape (in particular rectangular). Its structure can be made of felt, silicone or, more generally, of the same nature as the strip 140 already described.

 The diameter (or width) dl of this shoe is greater by a few millimeters or centimeters than the width d2 of the clip 361, so as to then replace the strip 140, in this case with a more localized outer covering. of conduit V.

Claims (10)

 1.- Medical unit for the treatment of an affection of an anatomical conduit (V) including  an implant (100) which can be inserted into the duct to be treated, which has an upstream zone (112) relative to the direction of circulation of a fluid flowing therein, the implant having a general axis (100c) and having substantially along this axis two free ends, respectively proximal and distal (100a, 100b),  - at least one lining (140) for externally lining at least part of the wall of the duct, substantially facing the proximal end of the implant,  - means for fixing (321, 323, 361) of the lining to the implant, through the wall of the conduit, for applying the implant internally against the wall of said conduit, at least towards its proximal end (100a),  - And means (310, 320) for positioning the lining and fixing means, for placing the lining around said conduit and fixing it to the implant.  2.- Medical assembly for the treatment of an affection of an anatomical conduit (V) consisting of a vessel comprising  an implant (100) which can be inserted into the vessel to be treated, which has an upstream zone (112) relative to the direction of circulation of the blood, the implant which has a general axis (100c) and has substantially two free ends along this axis , respectively proximal and distal (100a, 100b), comprising a structure adapted to occupy a first radially constricted state, for its introduction into the conduit, or a second radially deployed state in which the structure has a general shape of single or bifurcated tube intended to be placed substantially in abutment, at least towards its proximal end, against the wall of the vessel, near its upstream zone,  - at least one lining (140) for externally lining the wall of the vessel, substantially facing the proximal end of the implant,  - means for fixing (321, 323, 361) of the lining to the implant, through the wall of the vessel, for applying the implant internally against the wall of said vessel,  - And means (310, 320) for positioning the lining and fixing means, for placing the lining around said conduit and fixing it to the implant.  3.- assembly according to claim 1 or claim 2, characterized in that the lining (140) has a frame (303, 309) to be mechanically resistant to crushing in the direction of its thickness (e) to constitute a forestay outside the conduit for said fixing means passing through the wall of this conduit (V).  4.- assembly according to one of claims 1 to 3, characterized in that the lining has a protective pad (305, 312), at least on one inner side intended to be placed against the conduit (V).  5. An assembly according to claim 3 or claim 4, characterized in that the frame of the strip (140) is non-elastically deformable to be conformed to the external shape of the conduit (V), like a split ring, substantially.  6.- An assembly according to any one of claims 2 to 5, characterized in that the frame of the lining (140) has structurally, or is adapted to be traversed by, openings (319) for passage through them fixing means (361).  7.- An assembly according to any one of the preceding claims, characterized in that the fixing means (323, 361) are arranged through an area of the implant (100) provided with a stent (105).  8.- assembly according to any one of the preceding claims, characterized in that the lining (140) is breakable to be adapted to the outer section of the conduit (V).  9.- An assembly according to any one of the preceding claims, characterized in that the fixing means has an adaptable length to be able to tighten the wall of the conduit (V) between the outer lining (140) and the inner implant ( 100), so as to create a seal vis-à-vis the fluid circulating in the conduit, between the implant and the wall of said conduit.  10. - assembly according to any one of the preceding claims, characterized in that the lining (140a) is in the form of a shock-absorbing pad located essentially at the location of the fixing means, to form a screen outside, and possibly a the interior of the conduit between these fixing means and said conduit (V).