FR2748197A1 - Surgical implant positioning device - Google Patents

Abstract

The device has a tubular catheter (4,6) to be introduced into the anatomical conduit. A rod (1) has a first exterior maximum diameter which is less than that of the catheter to allow it to be introduced for the displacement of the prosthesis and its ejection from the catheter by axial sliding relative to the catheter. The rod has at least one interior passage (1d) of a greater diameter of the guide wire (2) and it has a first maximum diameter section and a second section of smaller diameter.

Description

 The present invention aims to improve the implantation of medical prostheses intended to be introduced into an anatomical conduit.

 Within this general framework, the invention relates in particular to a device for implanting a tubular prosthesis and a method for introducing a wire guide into a tubular rod equipping the device.

 The term prosthesis should be understood, in a vascular application, any implantable device promoting blood circulation, such as "stents" (see in particular FR-A-2 714 816 and FR-A-2 693 366) or "dressed" prostheses intended to double or strengthen the wall of a vessel by channeling the blood (see EP-A-0 423 916 and EP-A-0 177 330 in particular).

It is already known, to implant a tubular prosthesis in a conduit of a living human or animal body, to use a device comprising:
- a tubular sheath adapted to be introduced into said conduit and having an internal diameter,
a rod having a first maximum external diameter less than the internal diameter of the sheath (to be introduced therein substantially coaxially), this rod being intended for the displacement of the prosthesis and for its expulsion out of the sheath by relative axial sliding between it and the sheath, and
- a wire guide.

Such a device is notably described in the PCT application
WO / 95 401 695.

 However, the rod and the wire guide, by their constitution, are not usually intended to be used concomitantly, so that it is not possible to take advantage of the guiding qualities of the wire guide when using the rod , that is to say concretely when one acts on the prosthesis inside the sheath for its "release".

To remedy this problem, the invention proposes a device which is characterized, with respect to the aforementioned basic structure of WO / 95 401 695, in that the rod comprises:
- at least one axial inner conduit with a diameter greater than the outer diameter of the wire guide, so that the latter can slide therein,
a first part having said maximum outside diameter, and
- A second part having a second outside diameter smaller than said maximum outside diameter and intended to be disposed inside the prosthesis, in its internal passage.

 To facilitate the introduction of the wire guide into the rod conduit, said rod may have a determined length adapted so that its second part protrudes a few millimeters from the distal end of the sheath.

In addition to the device, the invention also describes below various methods, some of them innovative, for implanting prostheses having an internal passage, as well as a method for introducing a wire guide (or small diameter cable) into a rod. '' an intraluminal device as presented above, where:
- a free end of the rod is brought as close as possible to the distal end of the sheath which surrounds the prosthesis,
- And the wire guide is passed through the internal conduit of the rod through the central passage of the prosthesis.

The following description is made with reference to the accompanying drawings in which:
- Figures 1 to 7 show the different elements constituting the implantation device according to the invention:
* Figure 1 shows a wire guide,
* Figure 2 shows a sheath on a smaller scale
external installation around a dilator and
wire guide,
FIG. 3 represents an enlarged view and partially in section of the device as it occurs in the body,
FIG. 4 illustrates, in a further enlarged view in section, the prior art of the implantation device as illustrated in FIGS. 5, 6 and 7,
* Figures 5, 6 and 7 show, on the same scale as Figure 4, three alternative embodiments of the implantation device illustrated in Figure 3, Figure 7 corresponding to an enlargement of the reference VII of this Figure 3 (without the outer sheath),
- Figure 8 shows in section the implantation of a prosthesis
branched in a branching area of a vessel,
- Figure 9 shows in section the implanted prosthesis, in view
enlarged,
- Figure 10 shows in section the installation of a first prosthesis
elongation in a first branch of a prosthesis
bifurcated aortic,
- Figure 11 shows in section the installation of a second prosthesis
elongation in a second branch, and
- Figures 12 and 13 show two successive stages
to pass the thread guide from the first to the
second branch and to install a second extension.

 Figures 1, 2 and 3 show an implantation device according to the invention, comprising a wire guide 2 (flexible metal wire of about 1 mm in diameter for example) with curved distal end, a dilator 8, a sheath external introduction 6, an intermediate catheter 4 and at least one internal rod 1 "for operating the prosthesis inside the catheter and / or the sheath 6.

 FIG. 2 represents this tubular sheath 6 placed around the dilator 8 and the wire guide 2.

 Figure 3 shows the arrangement of some of the elements constituting the implantation device, when it is in the patient's body. The assembly forming the guide rod 1 "is inserted into the intermediate catheter 4 which contains a radially" tightened "prosthesis 11, the catheter itself being slid into the sheath 6.

 Figures 5, 6 and 7 show in more detail three variants (respectively 1, 1 'and 1 ") of the assembly forming the guide rod (which will be referred to hereinafter as" rod ") while the FIG. 4 represents a rod 10 as disclosed in the prior art This rod 10 is solid, of constant diameter and ends inside the catheter 4.

 In FIG. 5, the "rod" 1 has a single tubular part of constant diameter but with an inner axial conduit and of diameter greater than the outer diameter of the wire guide 2, in order to be able to introduce it.

 In Figures 6 and 7, the "rod" 1 ', 1 "also tubular has a first part a, 1" a and a second part 1'b, 1 "b, respectively.

 The first part has it, the "plays the role of pusher or" retaining element "behind the prosthesis and has an outside diameter substantially smaller than the inside diameter of the catheter 4 in which this part is inserted (in the image from the distal end of the tube 1 in FIG. 5).

The second part 1'b, 1 "b in FIGS. 6 and 7 constitutes in particular a guide tube for the wire guide 2. This guide tube has an outside diameter smaller than that of the part la, a, so that it can pass through prosthesis 11, which for this internally has an axial passage îîa (identified in Figures 4 and 5).

 In the state where the prosthesis is loaded into the catheter and in its version of FIGS. 6 and 7, the hollow rod has a length adapted so that the distal end 1'c, 1 "c of its part of smaller diameter is approximately at the level of the free distal end 4a of the catheter 4 or, as here, comes out a few millimeters from the catheter, after having passed through the prosthesis, so that it then has an axial length L greater than or equal to that of the prosthesis (figure 7) .The introduction of the wire guide 2 into the stem is then easier.

 In FIG. 5, the distal end 1c of the rod is distant from the distal end 4a of the catheter 4. The introduction of the non-curved end of the wire guide is more delicate, since after having approached the rod just behind the prosthesis, as close as possible to the end 4a, it is then necessary to pass the wire guide through the interior passage 11a of the prosthesis before it can be introduced into the interior passage ld.

 In Figure 6, the "rod" is made in one piece. It has an external shoulder e at the junction between its parts a and 1'b. This shoulder is intended to serve as a rear support for the prosthesis, with a view to its release.

 In FIG. 7, the parts 1 "a and l" b are separate, the part l "b being introduced inside the part l" a. Preferably, the total length (along the general axis 3) of the tube 1 "b will be greater than that of the outer tube 1" a, thus facilitating the maneuvers.

 Whatever the version, the rod is made of a flexible biocompatible material, in order to offer only a low flexural strength.

 FIGS. 8 to 13 show diagrammatically the implantation by percutaneous route (and preferably, more precisely here, by femoral route) of an apparatus 20 intended to promote blood circulation in an implantation area 18 presenting a deformation, in order to constitute there a substitute and / or a reinforcement of the existing vascular branching. This assembly 20 includes a bifurcated prosthesis 22 and possibly two elongation prostheses 24 and 26. It is shown entirely implanted in FIG. 13 and is detailed in PCT application WO / 95 401695.

 The prosthesis 22 is here intended to double internally and locally essentially the wall of the conduit 32, around the bifurcation 38. In particular, this prosthesis 22 is intended for the treatment of an aortic aneurysm formed towards the confluence 38 of the iliac arteries 34, 36 and aorta 32.

 The prosthesis, which may be of the self-expanding type (or even inflatable by a balloon), comprises a "ducting" tubular sleeve 12 and a support structure, or frame, 13. The sleeve 12 comprises a main tubular section 42 connected to a first and second tubular branches, 44 and 46 respectively.

 The frame 13 essentially comprises spring means 52, 54, 56 connected by curved longitudinal metal strips 57, means 58 for fixing the prosthesis to the vessel (such as hooks carried by the distal spring means 52) and a spacer of branches, 60, in "V".

The spring means 52, 54, 56, located respectively towards the free end of the section 42 and towards each free end of the two branches 44, 46, are provided for folding or deploying the prosthesis with a view to its implantation. I1 here are "stents" in the present case as metallic son in zig-zags closed on themselves to form a tubular structure which can be radially stressed under stress to occupy a reduced diameter allowing percutaneous implantation of the prosthesis (see Figure 3). Other forms of usable stents are described in particular in WO / 95 26695, WO / 94 17754,
WO / 95 21592, US-A-5 330 500, WO / 95 08966, US-A-5 282 824,
WO / 89 08433 ...

 The lamellae 57 prevent longitudinal compaction of the prosthesis, in particular at the time of its implantation.

 The extension prostheses 24, 26 each comprise (like the prosthesis 22) a tubular fabric sleeve 14, a support structure with springs 64a, 64b and with connecting strips 65. They are essentially distinguished from the branched prosthesis 22 only in that that the sleeves 14, which are not branched, consist of a single tube of fabric (Dacron (B), for example). And the longitudinal connecting strips are straight and parallel.

 To set up the bio-compatible assembly 20, we will first implant the bifurcated prosthesis 22 and for this place it in its "tightened" state inside the catheter 4 (Figures 3 to 6).

 In the case of a femoral approach, after having practiced a percutaneous approach 31, the wire guide 2, then the dilator 8 surrounded by the sheath 6 are slid into the patient's body up to one of the areas iliac, then advanced into aorta 32, preferably beyond the "distal" end 18a of the aneurysm.

 Then, the dilator is removed by sliding it along the wire guide 2 which, with the sheath, is left in place in the body as far as the aforementioned vessels (Figure 8). The diameter of the sheath is quite clearly smaller than that of the vessel (s) in question.

 Then, the wire guide 2 (which emerges from the body) is inserted into the recess ld of the rod (this is the one, 1 ", in FIG. 7 which was used).

 Before that, however, the prosthesis was preloaded in the distal end part 4b of the catheter, around the terminal portion of the second tube 1 "b which opens out from the first tube l" a. While preventing any axial translation of the concentric tubes l "a, 1" b, and while the prosthesis itself is practically locked in translation "back" by pressing against the distal end l "e of the outer tube l" a ( see FIG. 7), the end of the central guide tube 1 "b and the distal end of the catheter are placed substantially at the same level. It is then easy to introduce the straight proximal end of the wire guide into the axial duct id of the tube central guide 1 "b, until it comes out at the opposite end.

 Guided by tubes 1 "a and 1" b, the catheter 4 is then advanced along the sheath to the vascular location of implantation, by sliding along the wire guide 2.

 The prosthesis can thus be surrounded, during its introduction, by two "envelopes" (sheath 6 and catheter 4), the sheath 6 as well as the catheter, the "rod" and the wire guide being at least as long as the anatomical path crossed by the prosthesis during its implantation. There is therefore no risk of the prosthesis injuring the patient during his journey.

 At the implantation zone 18, the prosthesis is expelled from the catheter 4 by relative axial sliding of the catheter, the sheath and the rod whose end l "e of the first tube l" a always serves as a support back to the prosthesis. The prosthesis "self-expands" then radially, until it is stowed by its distal hooks against an unenforced portion of the vessel 32 (FIG. 8). A progressive retraction of the introducer 4, 6 then allows the expansion of the branches 24 and 26 which, thanks to the stiffener 60, come to lie respectively substantially in the axis of the vessels 34 and 36. It will however be noted that the branches 24 and 26 are short and here do not enter the iliac arteries.

 The prosthesis 22 then being fully deployed (FIG. 9), the catheter 4 and the guide tubes 1 "are then withdrawn through the sheath 6, by sliding them along the wire guide 2. The sheath is left in place.

 A second catheter 41 is then presented, containing the elongation prosthesis 24 and a second "rod" 12. The proximal end of the same wire guide 2 is introduced outside the patient's body into the recess of this second rod. The catheter and the rod are introduced (always by the same route firstly 31, and therefore through the vessel 34, if it is the branch 44 which one wishes to lengthen), as far as the free end part of the corresponding branch of the prosthesis 22, by sliding along the wire guide 2 (Figure 10).

 It will have been noted that the same wire guide 2 is therefore used for the introduction of the bifurcated prosthesis 22 and the elongation prosthesis 24.

 With the same precautions as for the bifurcated prosthesis, the elongation prosthesis 24 is then expelled into the conduit 34 so that it comes locally to engage in the free end of the branch 44, its natural radial expansion plating it substantially against the wall of the vessel 34 (Figure 10).

 As illustrated in FIG. 11, the prosthesis 24 is fixed to the prosthesis 22 by fitting the tubular spring 64a into that, 54, of the bifurcated prosthesis 22. There is a partial overlapping or overlapping of the prostheses. The elements 12, 41 and 6 are then removed. The prostheses 22, 24 are held in place, preferably the same as the wire guide 2, if it is then desired to implant the second elongation prosthesis 26, as illustrated in FIGS. 12 and 13.

We will first have to pass the same wire guide 2 from the right iliac artery 34 into the left iliac artery 36 (têCeS pnmitiuas),
To do this, a second wire guide 82 with a hooked distal end, 82a, is introduced (by a second first route 31 'made through the skin) into the iliac artery 36 up to the vascular branching zone. 38. The yarn guide 2 is then crocheted using the yarn guide 82 (FIG. 12). Then pulled from outside the patient's body on the proximal end 82b of the wire guide 82 to gradually bring the wire guide 2 into the iliac artery 36 until the proximal end 2b of the guide -wire 2 comes out with the wire guide 82 by the first path 31 '. Only the wire guide 2 is then left in the vessels, its distal end being able to be held to facilitate its passage from one artery to the other.

 The release of the elongation prosthesis 26 in the branch 46 is then carried out in the same manner as the release of the elongation prosthesis 24. A second sheath 61, a third catheter 42 and a third rod 112 are introduced for this by the second path first 31 ′ and the vessel 36, along the wire guide 2 (FIG. 13), as previously using an introducer.

 Of course, the invention is in no way limited to the embodiments described above. Thus, one could plan not to use an intermediate catheter: instead of advancing the intermediate catheter, stem and prosthesis assembly along the axis of the sheath and the wire guide to the implantation area, one could then directly insert the prosthesis into the sheath. Note however that the implantation of tubular "stents" and "dressed" prostheses (stents provided with a tubular sleeve 12 or 14 for blood channeling) practically requires preloading of the prostheses in the extreme distal part of the sheath or catheter. of implantation used, which poses particular problems.

 We could also plan not to use a sheath.

The intermediate catheter, stem and prosthesis assembly would then advance along the axis of the wire guide directly inside the anatomical canal.

 In other words, what has been referred to above as "implantation sheath" and "catheter" having similar shapes and functions, these two parts could be combined into one.

 To drop the elongation prosthesis 26 into the prosthesis branch 46, the first wire guide 2 could also be removed and another introduced through the iliac artery 36.

 The tubular prostheses to be implanted could moreover be other than those described above. It could, for example, be a "stent" made up like an elongation prosthesis above, without coating sleeve, or even have a structure in lattice or in wire (s) in zig- zag wound in helix.

Claims (7)

Claims  1. Device for implanting, in an anatomical conduit, a prosthesis (11, 20) having an interior passage, said device comprising:  - a tubular catheter (4, 6) adapted to be introduced into said conduit and having an internal diameter,  - at least one rod (1) having a first maximum outside diameter less than the inside diameter of the catheter to be introduced therein, with a view to displacement of the prosthesis (11) and its expulsion from the catheter (4, 6) by relative axial sliding between the rod and the catheter (4, 6), and  - a wire guide (2) having an outside diameter, characterized in that said rod (1) comprises:  - at least one inner conduit (nest) with a diameter greater than the outer diameter of the wire guide (2), so that the latter can slide therein,  a first part (a, 1 "a) having said maximum outside diameter, and  - a second part (1 'b, 1 "b) having a second outer diameter less than said maximum outer diameter.  2. Device according to claim 1, characterized in that the rod is made in one piece, the junction between the first and second parts materializing by a shoulder (e) adapted for support of the prosthesis.  3. Device according to claim 1, characterized in that the first and second part of the rod (1 ") are distinct and hollow, and the second part (1" b) has an outside diameter smaller than the inside diameter of the first part (1 "a), to slide there.  4. Device according to claim 3, characterized in that the length of the second part (1 "b) of the rod is greater than that of the first part (l" a).  5. Device according to one of claims 1 to 4, characterized in that:  the catheter has an extreme distal part (4b) where the second part of the rod (1) is arranged and,  - This second part (1 'b, 1 "b) of rod has a determined length adapted to come out of a few millimeters out of the distal end of the catheter (4, 6), in a step of introduction of the wire guide to the inside the rod.  6. Device for implanting a prosthesis in a blood vessel, said device comprising:  - a tubular catheter (4, 6) adapted to be introduced into said conduit and having an internal diameter,  - Said prosthesis (11), which reserves at least one internal passage (IIa) and is adapted to have a first tight diameter allowing its introduction into the catheter and a second enlarged diameter, to ensure proper blood circulation in said vessel, outside the catheter,  - at least one rod (1 ′, 1 ″) having a first maximum external diameter less than the internal diameter of the catheter to be inserted therein, with a view to displacement of the prosthesis and its expulsion from the catheter (4, 6), by sliding relative axial between the rod and the catheter, and  - a wire guide (2) having an outside diameter1  characterized in that said rod comprises:  - at least one inner conduit (nest) with a diameter greater than the outer diameter of the wire guide (2) so that the latter can slide therein,  a first part (a, l "a) having said maximum outside diameter, and  - A second part (1'b, 1 "b) having a second outside diameter smaller than said maximum outside diameter and intended to be disposed, at least locally, inside the prosthesis, through its internal passage (lia).  7. Device according to claim 6, characterized in that, in a state where the prosthesis is disposed in the catheter, around the second part (1'b, l "b) of the rod, this second part extends, inside the passage (11a) of said prosthesis, beyond the first part (a, l "a) of the rod with a length greater than or equal to the length of the prosthesis.