WO2006105856A1

WO2006105856A1 - Catheter arrangement for embolism protection in angioplasty

Info

Publication number: WO2006105856A1
Application number: PCT/EP2006/002442
Authority: WO
Inventors: André Burch; Stéphane Delaloye
Original assignee: Biotronik Vi Patent Ag
Priority date: 2005-04-02
Filing date: 2006-03-17
Publication date: 2006-10-12
Also published as: DE102005015173A1

Abstract

A catheter arrangement for embolism protection in angioplasty comprises an elongate catheter body (1) and a filter insert (3) disposed in the area of the distal end. The filter insert can be expanded between a contracted passive position and an active position in which it substantially fills the lumen of the vessel (10). The filter insert (3) consists of a tubular metal film hollow body which can be expanded to a convex shape and the wall (5) of which is provided with filter openings (6).

Description

Catheter assembly for embolic protection in angioplasty

The invention relates to a catheter assembly for Embolieschutz in angioplasty procedures, especially in arteries with the features specified in the preamble of claim 1. The term "catheter assembly" is intended to mean any type of tubular or wire-like medical equipment that can be introduced over long distances into body vessels, such as, for example, so-called guide wires or thin catheters.

From the prior art, a variety of such catheter arrangements are known by public prior uses. They have an elongate catheter body, such as a common guide wire, in common, which is insertable with its distal end into the vessel to be treated. In the region of the distal end of the catheter body, a filter insert is arranged, which is expandable between a contracted passive position during insertion and a lumen of an angioplasty vessel to be treated substantially filling active position.

For example, the filter insert is placed distally with respect to a stenosis into the affected vessel and in its active position it captures the deposition particles which may be discharged during the stenosis treatment, for example by setting a stent. Namely, such particles cause a considerable risk of embolism.

For the filter element, various embodiments are known from the prior art. Thus, a filter cartridge is used in which

_A ; _A 'r ~. ^{i #} . L ". .. similar to a screen a perforated polymer film sits. The filter pores introduced therein have a diameter of about 100 μm. Alternatively, filter inserts which are purely made of a fine metal wire mesh are known, which are fastened like a rake to a wire loop defining the filter opening.

The previously known catheter arrangements have the disadvantage that in addition to the actual filter medium - so the perforated polymer film or the wire mesh - still supporting structures for the filter medium for expanding the filter insert between the contracted passive position and the active position must be present. These are the wire struts guaranteeing the umbrella-like clamping of the polymer film or the wire loop holding the "wire scrubber" with its opening spread in the vessel lumen.

On the one hand, these additional supporting structures have a space requirement, which runs counter to the requirement for the smallest possible cross section of the arrangement in the contracted passive position of the filter insert. In addition, these wire structures stiffen the catheter assembly. In that regard, the known filter cartridges are in need of improvement in terms of the lowest possible cross-sections necessary for a secure setting in the vessel and the highest possible flexibility.

Another problem of the known constructions is that, in particular in vessel curves, there is no form-fitting adaptation of the filter insert to the vessel lumen. In that regard, particles between the filter cartridge and the vessel wall can depart in the distal direction with the blood flow, which increases the risk of embolization mentioned above.

The invention is therefore an object of the invention to improve a catheter assembly for Embolieschutz so that compactness, flexibility and Embolieschutz be increased. This object is achieved by the features specified in the characterizing part of claim 1, according to which the filter insert is formed from a hose-like, for the active position in a spherical shape expandable metal foil hollow body, which is provided in its wall with Filteröff- openings.

By using a metal foil as a filter medium can be completely dispensed with supporting structures, such as wire struts or loops. In contrast to polymer films and wire meshes, such metal foils have the advantage of greater flexural strengths and intrinsic stiffnesses, so that the filter medium as such can be produced from a single piece or material in a thinner-walled manner, but in a self-supporting manner. Thus, the cross section of the filter insert in the passive position can be kept extremely small, so that narrow stenoses in a vessel are easier passable. With correspondingly thin-walled design, the metal foils are still sufficiently flexible, so that even highly tortuous vascular systems can be easily passed by the catheter assembly according to the invention.

Finally, the convex shape in the expanded active position ensures optimal adaptation to the vessel wall, in particular also in regions of curvature. Under "crowned" are basic shapes, such as balloon-like, an olive-shaped, conical-cylindrical-conical or mushroom-like to understand.

According to a preferred embodiment, the wall of the filter cartridge can be provided with longitudinal folding grooves for the contraction and expansion of the filter cartridge. As a result of this structuring of the metal foil in the longitudinal direction of the arrangement, optimal adaptation to the vessel geometry and for the contraction to the loading of the filter insert, which will be described in more detail later, can take place in the so-called release catheter. When introducing flow openings on one side, in particular in the proximal part of the filter insert, the unfolding of the filter insert into the expanded active position is assisted by the blood flow. Furthermore, any aspiration of the particles retained in the filter insert can be ensured by means of an aspiration catheter.

Another safeguard for the perfect achievement of the expanded active position in the vessel is achieved by the use of a medical shape memory metal, in particular for this purpose known nickel-titanium alloys.

Further preferred embodiments of the catheter arrangement relate to the fixing and mounting of the filter cartridge on the catheter body. Thus, it may be provided to interrupt the catheter body in the region of the filter insert, the latter bridging the resulting gap. Since no further structures can be accommodated within the filter insert, the cross section of the catheter arrangement in the region of the filter insert can be further reduced.

Further features, details and advantages of the following description can be removed, will be explained in more detail in the embodiments of the invention with reference to the accompanying drawings. Show it:

1 is a schematic side view of the distal end of a guide wire with filter cartridge,

2 shows a longitudinal section of the arrangement shown in Fig. 1,

3 shows a cross section along the section line III-III of Fig. 1, 4 shows a schematic longitudinal section through the catheter arrangement according to FIG. 1 in its folded passive position in a folding sleeve with additional guide catheter, FIG.

5 shows a schematic longitudinal section of the catheter arrangement according to FIG. 1 in an alternative application with aspiration catheter and guide catheter, FIG.

Fig. 6 is a longitudinal section of a guide wire with filter insert in a second embodiment, as well

7 and 8 are schematic side views of filter cartridges in a third and fourth embodiment.

Fig. 1 and 2 shows a catheter assembly as a guide wire 1, which is controllable at its distal end by a predetermined bend 2 by curved vessel profiles and branches. Depending on the application, the diameter D of the guide wire is 0.010 "to 0.035", which corresponds to approximately 0.25 mm to 0.90 mm.

Before the bend 2 a filter insert 3 is mounted on the guide wire 1, which is shown in Fig. 1 and 2 in its expanded active position. The filter insert 3 is formed in one piece from a hose-like metal-foil hollow body made of a nickel-titanium alloy, which is available on the market under the designation "Nitinol." The metal foil has a thickness of approximately 1-50 The convex shape of the filter element 3 is recognizable as an olive-like or balloon-like design.

The expansion from the contracted passive position (see later description of Fig. 4) in this spherical shape, which is due to the super-elastic behavior of the nickel-titanium metal foil due to their memory property is achieved by the folding grooves 4 shown in Fig. 3 - wire 1 run. Thus, the filter element 3 can inflate bellows-like and adapt well to the vessel wall.

The filter medium used in Fig. 1 and 2 in the left of the equatorial plane E lying distal region of the wall 5 attached filter openings 6, which have a width of about 60 - 120 microns. In the proximal region of the filter element 3 sector-shaped passage openings 7 are mounted, which can stand between them thin straps 8 in the wall 5 of the filter element 3. As indicated by the arrows 9 in Fig. 1, the blood flow through the passage openings 7 in the filter cartridge 3 can enter freely and the blood on the filter openings 6 of any residues from a stenosis freed further flow in the vessel. The latter is indicated by dashed lines in Fig. 1 and provided with the reference numeral 10.

As is clear from Fig. 2, the proximal end 11 of the filter cartridge 3 is permanently secured by an annular fixation 12 in the form of a soldering or gluing on the guide wire 1. The distal end 13 is gathered around the guide wire 1 so that expansion is not possible there. However, the distal end 13 is axially displaceably mounted on the guide wire 1, which is significantly reduced there in diameter d relative to the main diameter D. The thus reduced rigidity is compensated by the filter element 3, so that overall a uniform over the length bending behavior of the catheter assembly is achieved.

4 shows the guide wire 1 with filter insert 3 in its folded, contracted passive position in a folding sleeve 14. This is axially displaceably guided on the guide wire 1 with a proximal guide shaft 15. This is followed by the actual folded envelope 16 with a slightly larger diameter. This is provided at its distal end with an ejection opening 17, from which the guide wire 1 runs out and which can pass through the folded filter cartridge 3. After the guidewire 1 has been moved by means of a guide catheter 18 with folded in the folding sleeve 14 filter cartridge 3 to its position, for example distally of an angioplastically treated stenosis, using a puller wire 19, the folding sleeve 14 is displaced in the proximal direction relative to the guide wire 1. As a result, the filter cartridge 3 is released through the discharge opening 17 and can expand into the expanded active position shown in FIGS. 1 and 2 into the lumen of the vessel 10. The expansion movement is supported on the one hand by the shape memory of the metal foil forming the filter element 3 into which the expanded form of the filter insert 3 is embossed, and on the other hand by the blood flow 9 flowing through the passage opening 7.

5, the guide wire 1 with filter insert 3 is shown in a so-called "monorail arrangement", in which the aspiration catheter 20 is pushed over the guide wire 1 at the distal end with the aid of an inlet 21. The entire arrangement Guidewire 1 and aspiration catheter 20 are again housed in a guide catheter 18.

In the application of the guide wire with filter element 3 can be introduced in the usual way using the folding sleeve 14 and then the aspiration catheter 20 are moved over the guide wire 1 into the suction position shown in Fig. 5. In that regard, particles that have accumulated in the filter cartridge 3, are sucked through the aspiration catheter 20.

To remove the filter cartridge 3, this can be pulled by pulling (arrow 22) into the distal end of the aspiration catheter 20, whereby it folds into the passive position. If no aspiration of the particles with the aspiration catheter has taken place beforehand, these are trapped in the filter insert during retraction and can thus be wholly or partly drawn into the aspiration catheter. Incidentally, the catheter arrangements shown in FIGS. 4 and 5 have a hydrophilic coating 23 indicated by the dot-dash line in the area of the folded sheath 16 or at the distal end of the aspiration catheter 20. Furthermore, the folding sleeve 14 at the proximal end and the aspiration catheter 20 at the distal end each have a metal ring 24 as an X-ray mark.

In the embodiment shown in FIG. 6, the filter insert 3 is fastened with its proximal end 11 and distal end 13 to the associated ends 27, 28 of the guide wire 1, respectively, and the latter is interrupted within the filter insert 3. Because the filter element 3 is thus empty in the interior, it can be more folded together for its passive position and thus has a relation to the embodiment of FIG. 1 even smaller cross-section.

In the embodiment of the filter element 3 'shown in FIG. 7, again a balloon-like or olive-shaped shape of the filter insert made in one piece from a nitinol metal foil can be seen. In this embodiment, however, the arrangement of the filter 6 and passage openings 7 is the reverse of the embodiment of FIG. 1, since the filter openings 6 are proximal on the blood flow direction 9 opposite side and the flow openings 7 on the distal, in blood flow direction 9 facing side , In that regard, the indicated particles 25 are held in front of the filter element 3.

8 shows an embodiment of the filter cartridge 3 "in which the spherical shape is not balloon-shaped but limited to a mushroom-like configuration, meaning that only the proximal end 11 of the filter cartridge 3" is permanently fixed to the guide wire 1, the distal end 13, however, a blood flow 9 facing away from, large end opening 26 forms.

Claims

claims

A catheter assembly for embolic protection in the angioplasty of vessels, in particular of arteries with - an elongated catheter body (1), with its distal

End (2) into the vessel to be treated (10) is insertable, and in the region of the distal end (2) of the catheter body (1) arranged filter insert (3, 3 ', 3 "), which between a contracted passive position and the Lumen of the vessel (10) substantially filling active position is expandable, characterized in that the filter insert (3, 3 ', 3 ") of a hose-like, expandable for the active position in a spherical shape metal foil hollow body is formed in its wall (5) is provided with filter openings (6).

2. Catheter arrangement according to claim 1, characterized in that the wall (5) of the filter insert (3, 3 ', 3 ") with longitudinal folding grooves (4) for the facilitated contraction and expansion of the filter insert (3, 3', 3" ) is provided.

3. Catheter arrangement according to claim 1 or 2, characterized in that the wall (5) of the filter insert (3, 3 ') on one side of its equatorial plane (E) with the filter openings (6) and on the opposite side of the equatorial plane (E) with flow openings (7) is provided.

4. Catheter arrangement according to claim 3, characterized in that a plurality of sector-shaped, between them thin straps (8) let flow openings (7) in the wall (5) of the

Filter insert (3) are created.

5. Catheter arrangement according to one of the preceding claims, characterized in that the metal foil of the filter insert (3, 3 ', 3 ") consists of a medical shape memory metal, in particular a nickel-titanium alloy, in which the expanded form of the filter insert (3, 3 ', 3 ^Λλ ) is impressed in its active position.

6. Catheter arrangement according to one of the preceding claims, characterized in that the filter insert (3) with its proximal end (11) fixed on the catheter body (1) and with its distal end (13) on the catheter body (1) axially displaceable is stored.

7. Catheter arrangement according to one of claims 1 to 5, character- ized in that the filter insert (3) with its two ends

(11, 13) at the associated ends (27, 28) of the interrupted in the region of the filter insert (3) catheter body (1) is connected.

8. Catheter arrangement according to one of the preceding claims, characterized in that the filter insert (3, 3 ', 3 ") is surrounded in passive position by a retractable to release in the active position folding sleeve (14).

9. Catheter arrangement according to one of the preceding claims, characterized in _/ that the filter insert (3, 3 ') in the active position has a balloon-like shape.

10. Catheter arrangement according to one of claims 1 to 8, characterized in that the filter insert (3 ") in the active position has a mushroom-like shape.