FR2696636A1 - Temporary wire-based blocking system for blood vessel etc. - uses coiled tubular tungsten@ wire to promote localised clotting, with hollow catheter for introduction of wire to required location - Google Patents

Abstract

A flexible tubular wire (3), open at at least one end, is formed in a coil, and may be temporarily straightened for pushing into the tubular body of a positioning catheter (5). The catheter is insertable in a relevant vessel, and the wire may be pushed from its distal end at the required location. The wire comprises a tungsten filament wound helically, treated to form a roughened surface. The wire may be treated thermally to be easily cuttable. An end wire (6) of smaller diameter is attached to one end of the tubular wire to facilitate introduction into the catheter. USE/ADVANTAGE - Temporary blocking system for blood vessel etc. Improved ease of implantation, with surface roughness promoting rapid clotting.

Description

 Vascular occlusion system and method of use

 The invention relates to a vascular occlusion system and its method of use.

 To suppress the blood supply to a tumor or to treat an aneurysm by limiting or suppressing any pressure in the blood, the vessel concerned is occluded or the aneurysm is occluded.

 To effect this occlusion, it is known to use a solidifiable liquid or gel.

 It is also known to position an inflated balloon at the desired location.

 However, for many years, flexible and elastic threads have been used which are wound and / or form loops.

 These threads may even include hairs in order to increase the desired effects of thrombosis.

 To put them in place, a catheter is generally used, a technique recalled in particular in US Pat. No. 4,994,069.

 In this patent, the occlusion wires are tubular but closed at their ends.

 To facilitate implementation, the inventor has devised a set of means hereinafter called the entirely effective occlusion system.

 This occlusion system comprises in known manner at least one flexible tubular occlusion wire forming at rest coils and can be temporarily straightened to be introduced and pushed into a delivery catheter until being expelled therefrom by its distal end to reach the desired location of the vessel to be treated and it is remarkable in that the tubular wire is open at at least one of its ends.

 Advantageously, the tubular occlusion wire is itself formed of a tungsten filament wound helically and whose surface condition is treated to be roughened, while it is heat treated to make it easily breakable. The roughness of the surface in particular facilitates the effects of thrombosis.

 Compared to the prior art, the fact that the tubular occlusion wire is open makes it possible to provide a straightening mandrel in the form of an at least semi-rigid wire with a diameter smaller than that of the tubular occlusion wire and intended to be introduced into the latter to straighten it and introduce it into the catheter.

 Preferably in this case, the system comprises at least one tubular plunger intended to be crossed by the straightening mandrel during the straightening operation in order to then exercise its function as a plunger.

 To finish the occlusion of a vessel or an aneurysm after introduction of one or more occlusion wires, it is useful to be able to remove the last tubular wire after having evaluated the necessary length, in order to cut the good length.

 Until now, a known technique consists in soldering said wire at the end of a pusher and then, in order to definitively put this last wire in place, destroying said weld by a weak direct current.

 This technique is particularly long.

 This is why the inventor has imagined a system which is remarkable in that it comprises at least one hook pusher provided at its end with a curved part forming an elastic hook so that it allows to hang the occluding tubular wire and moving it into the catheter, while its curved end straightens at least partially elastically as soon as said end leaves the distal end of the catheter, thereby releasing the occluding tubular wire when hook pusher is pulled through the proximal end of the catheter.

 Advantageously in this case, the system comprises a tubular introducer intended to store the tubular occlusion wire and / or to facilitate its introduction with its hook pusher into the catheter by the proximal end of the latter.

 The invention also relates to a method of using the system mentioned above.

The method according to the invention is remarkable in that it consists in:
a) straightening a tubular occlusion wire by means of the mandrel
rectifier, which crosses the tubular plunger,
b) introduce the tubular occlusion wire thus straightened into
the catheter by pushing it using the tubular plunger,
c) remove the tubular plunger,
d) push the tubular occlusion wire until ejecting it by
the distal end of the catheter by means of an injection of
liquid and / or a long pusher,
A variant consists in repeating operations a) to d) at least one more time with other tubular occlusion wires and in addition to:
e) introduce by means of the tubular introducer and the
hook pusher tubular occlusion wire and expulsion
partially to assess the necessary length,
f) withdraw completely from the catheter through the proximal end
from it, the tubular occlusion wire by removing the
hook pusher,
g) cut the desired length of the tubular occlusion wire,
h) reintroduce the tubular occlusion wire after setting
length.

The invention will be clearly understood and other particularities will appear on reading the description which follows and which refers to the appended drawings in which:
- Figure 1 shows schematically the establishment of several son
tubular occlusion in an aneurysm,
- Figures 2 to 6 show various phases of the process according to
the invention by means of the system according to the invention,
- Figure 7 shows the introduction of an occlusion wire at
by means of a tubular introducer and a cross plunger
chet,
- Figures 8 to 10 show schematically the expulsion of the occlusal thread
Figure 7.

 Figure 1 shows schematically an aneurysm 1, on a blood vessel 2.

 To treat aneurysm 1, the technique consists in filling it as well as possible by means of a plurality of occlusion wires 3 (FIGS. 2 to 10) forming by interlacing and convolution, a stopper referenced 4 in FIG. 1, said wires being introduced by means of a catheter 5.

 Each occlusion wire 3 according to the invention is a tubular wire 3 open at its ends and itself constituted by a filament wound helically as shown in the drawings.

 The filament used is advantageously made of a non-ferromagnetic material and in particular tungsten heat treated to make it easily breakable and treated at the surface so that it is rough.

 Each occlusion wire constitutes a kind of spring which retains or resumes its helical shape elastically.

 The method of use is illustrated in the drawings.

 As shown in Figure 2, is introduced into the tubular wire 3, a straightening mandrel 6 in the form of a wire of a diameter smaller than that of said wire 3, in order to straighten the latter.

 The straightening mandrel 6 advantageously passes through a tubular pusher 7 (FIG. 2).

 The tubular pusher 7 will thus allow the wire 3 to be pushed after the introduction of the latter into the delivery catheter 5, as illustrated in FIG. 3.

 As shown in Figure 4, the straightening mandrel 6 is then withdrawn (possibly temporarily holding the tubular plunger 7).

 The wire 3 is then ejected from the catheter 5, by the distal end of the latter, for example by injection of a contrast liquid by means of a syringe 8, as illustrated in FIG. 5 and / or also by means of another pusher shown diagrammatically at 9 in FIG. 6.

 In this way, the wires 3 become entangled, resuming their shape as shown in particular in FIG. 1.

 To complete the filling of the aneurysm shown diagrammatically at 1 in FIG. 1, a last wire referenced 3 ′ in FIGS. 7 to 10 is used.

 The wire 3 'is introduced into the catheter 5, by means of a tubular introducer 10 (FIG. 7) and a hook plunger 11 (FIGS. 7 to 10), the tubular introducer 10 being able moreover to serve as a means of storage of said wire 3 '.

 The hook pusher 11 has, at its end, as its name suggests, a curved and elastic part 12 which is engaged with the occlusion wire 3 '.

 It is thus possible to push the wire 3 'to the distal end of the catheter (end visible in Figures 1 and 8 to 10).

 The length required for the latter element is evaluated by radioscopy (thanks to the opacity of the wires to X-rays) and, thanks to the hook plunger 11, it is possible to completely remove said wire 3 ', to cut it to the correct length and to reintroduce it.

 To allow the wire 3 'to escape definitively into the aneurysm, it suffices, as shown in FIGS. 8 to 10, to take out the said wire 3' through the distal end of the catheter so that the curved end 12 of the pusher 11 straightens elastically, as shown in Figure 9.

 Then by removing the hook plunger 11, as shown in Figure 10, the curved end 12 straightens again before being returned to the catheter 5 so that the wire 3 'is completely released.

 Other means and variants can also be imagined.

 For example, FIGS. 8 to 10 show rings such as 13 and 13 ′ on the catheter 5, and 14, 14 ′ on the hook plunger 11.

 The rings 13, 13 'and 14, 14' are, for example, made of gold in order to assess by radioscopy the position of the wire 3 'relative to the end of the catheter 5.

Claims (7)

 1) Vascular occlusion system comprising at least one flexible tubular occlusion wire (3.3 ′) forming coils at rest and which can be temporarily straightened to be introduced and pushed into a catheter (5) for placement up to to be expelled therefrom by its distal end to reach the desired location of the vessel (2) to be treated, characterized in that the tubular wire (3,3 ') is open at at least one of its ends.  2) System according to claim 1, characterized in that the tubular occlusion wire (3.3 ′) is itself formed of a tungsten filament wound helically and whose surface condition is treated to be roughened .  3) System according to one of claims 1 and 2, characterized in that the tubular occlusion wire (3,3 ') is heat treated to make it easily breakable.  4) System according to one of claims 1 and 2, characterized in that it comprises a straightening mandrel (6) in the form of an at least semi-rigid wire with a diameter less than that of the tubular occlusion wire ( 3) and intended to be introduced into the latter to straighten it and introduce it into the catheter (5).  5) System according to claim 4, characterized in that it comprises at least one tubular plunger (7) intended to be crossed by the straightening mandrel (6) during the straightening operation to then exercise its function as a plunger.  6) System according to one of claims 1 to 5, characterized in that it comprises at least one hook pusher (11) provided at its end with a curved part (12) forming an elastic hook so that it allows the tubular occlusion wire (3 ') to be hooked and to move it in the catheter, while its curved end (12) straightens at least partially elastically as soon as said end (12) leaves the 'distal end of the catheter, thus releasing the tubular occlusion wire (3') when the hook pusher (11) is pulled by the proximal end of the catheter.  7) System according to claim 6, characterized in that it comprises a tubular introducer (10) intended to store the tubular occlusion wire (3 ') and / or to facilitate its introduction with its hook pusher (11) into the catheter (5) through the proximal end thereof.