DE102005015173A1 - Catheter arrangement to be used for avoidance of embolism, comprising expanding part made of metal foil - Google Patents

Abstract

The unit is assembled of a guiding wire (1) and an expanding filter element (3). The element (3) is made of a nickel-titan alloy and is provided with longitudinal pleats extending when the element (3) has reached its destination. Openings (7) for the passage of blood are created with several thin axial bridges (8) between them. The blood is guided into a filter compartment with a perforated hull (6) in order to remove residues from a stenosis from the blood stream.

Description

The The invention relates to a catheter assembly for embolic protection Angioplasty procedures especially in arteries with those in the preamble of claim 1 specified characteristics. Under catheter arrangement should be any kind of tubular or wirelike medical equipment to be understood over longer Route is insertable into body vessels, such as so-called guide wires or thin catheters.

Out the prior art are by prior public use a Variety of such catheter arrangements known. You have an elongated Catheter body, such as a usual one Guidewire together, which is insertable with its distal end into the vessel to be treated. In the area of the distal end of the catheter body is a filter cartridge arranged between a contracted passive position during the introducing and a vessel to be treated with the lumen during angioplasty substantially filling Active position is expandable.

Of the For example, the filter insert is distal to a stenosis placed in the affected vessel and begins possibly in its active position in the case of stenosis treatment, for example, by setting a stent Deposit particles on. Because such particles cause a considerable Embolism risk.

For the filter insert Various embodiments are known from the prior art. So will a filter cartridge used in which bent around a guide wire Wire struts are arranged, on which umbrella-like a perforated polymer film sitting. The filter pores introduced have a diameter of about 100 microns. Alternatively, they are made entirely of a fine metal wire mesh filter Elements known, the käscherartig at one the filter opening defining wire loop are attached.

The Prior art catheter assemblies have the disadvantage that in addition the actual filter medium - so the perforated polymer film or the wire mesh - still carrying Structures for the Filter medium for expanding the filter insert between the contracted Passivstellung and the active position must be present. It these are the umbrella-like ones Ensuring clamping of the polymer film Wire struts or the "wire crusher" with its opening spread in the vascular lumen Wire loop.

These additional On the one hand, load-bearing structures have a need for space Demand for one as possible small cross section of the arrangement in the contracted passive position runs counter to the filter insert. About that In addition, these wire structures stiffen the catheter assembly. in this respect are the known filter cartridges in terms of for a safe setting in the vessel necessary as possible small cross sections and as possible high flexibility in need of improvement.

One Another problem of the known constructions is that especially in vessel curves no form-fitting Adjustment of the filter insert to the vessel lumen takes place. In that regard, particles can between the filter cartridge and the vessel wall in the distal direction with the blood flow, which increases the risk of embolism mentioned above.

Of the The invention is therefore based on the object, a catheter assembly to improve embolic protection so that compactness, flexibility and embolic protection elevated become.

These Task is indicated by the in the characterizing part of claim 1 Characteristics solved, after which the filter insert of a hose-like, for the active position in a spherical shape expandable metal foil hollow body formed is, which is provided in its wall with filter openings.

By The use of a metal foil as a filter medium can be on a load bearing Structures, such as wire struts or loops, are completely dispensed with. such Namely, metal foils have across from Polymer films and wire meshes have the advantage of greater bending strength and intrinsic stiffness, so that the filter medium as such thin-walled, thereby but self-supporting made of one piece or material can be. Thus, the cross section of the filter insert in the Passive position are kept extremely small, so that tight stenoses easier in a vessel are passable. In accordance with thin-walled design are Metal foils nevertheless sufficiently flexible, so that too strong tortuous vascular systems from the catheter assembly according to the invention can be easily passed.

Finally is by the spherical shape in the expanded active position a optimal adaptation to the vessel wall in particular also in curvature areas guaranteed. Under "spherical" are basic forms, like a balloon, like an olive, conical-cylindrical-conical or mushroom-like, to understand.

According to one preferred embodiment the wall of the filter insert with longitudinal folding grooves for contraction and expansion of the filter cartridge be provided. Through this structuring the metal foil longitudinal The arrangement can be an optimal adaptation to the vessel geometry and for the contraction to the later even closer loading the filter cartridge described in the so-called release catheter respectively.

at an introduction of flow openings on one side, in particular in the proximal part of the filter insert the unfolding of the filter insert is in the expanded active position supported by the blood flow. Furthermore, any aspiration that may have been carried out in the filter insert can be carried out retained Particles are ensured using an aspiration catheter.

A further backup for the proper achievement of the expanded active position in the vessel is through the use of a shape memory metal medical, in particular therefor relevant known nickel-titanium alloys achieved.

Further preferred embodiments the catheter assembly relate to the definition and storage of the filter cartridge on the catheter body. That's how it works be, the catheter body in the area of the filter insert to interrupt, the latter bridging the resulting gap. There thus within the filter insert no more structures can be accommodated, the cross-section of the catheter assembly be further reduced in the field of filter cartridge.

Further Features, details and advantages are the following description removable, in the embodiments the invention with reference to the attached Drawings closer explained become. Show it:

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

2 a longitudinal section of in 1 shown arrangement,

3 a cross section according to the section line III-III after 1 .

4 a schematic longitudinal section through the catheter assembly according to 1 in its folded passive position in a folding sleeve with additional guide catheter,

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

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

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

1 and 2 shows a guide wire as a catheter assembly 1 at its distal end by a given bend 2 can also be controlled by curved vessel profiles and branches. The diameter D of the guide wire is 0.010 "to 0.035", which corresponds to about 0.25 mm to 0.90 mm, depending on the application.

Before the bend 2 is on the guidewire 1 a filter cartridge 3 attached in 1 and 2 is shown in its expanded active position. The filter insert 3 is integrally formed from a hose-like metal-foil hollow body made of a nickel-titanium alloy, which is available on the market under the name "Nitinol" .The metal foil in this case has a thickness of about 1-50 microns the spherical shape of the filter element 3 designed like an olive or balloon.

The expansion from the contracted passive position (see later description of 4 ) in this spherical shape, which is due to the super-elastic behavior of the nickel-titanium metal foil due to their Gedchnchniseigenschaft is achieved by the in 3 represented folding grooves 4 relieved, in the wall 5 of the filter insert 3 in the longitudinal direction of the guide wire 1 run. This can be the filter cartridge 3 inflate bellows-like and adapt well to the vessel wall.

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

How out 2 becomes clear, this is proximal the end 11 of the filter insert 3 by an annular fixation 12 in the form of a soldering or gluing on the guidewire 1 permanently attached. The distal end 13 is around the guidewire 1 gathered around, so that it is not possible to expand. However, the distal end is 13 axially displaceable on the guide wire 1 stored, which is there significantly reduced in diameter d compared to the major diameter D. The resulting reduced rigidity is through the filter cartridge 3 compensated, so that a total over the length uniform bending behavior of the catheter assembly is achieved.

4 shows the guidewire 1 with filter element 3 in its folded, contracted passive position in a folding tube 14 , This is axially displaceable on the guide wire 1 with a proximal guide shaft 15 guided. This is followed by the actual folded cover 16 with a slightly larger diameter. This is at its distal end with a discharge opening 17 provided, from which the guidewire 1 This results in the folded filter insert 3 can happen.

After the guidewire 1 with the help of a guide catheter 18 with in the folding tube 14 folded filter insert 3 is moved to its position, for example distally of an angioplastically treated stenosis is using a puller wire 19 the folding sleeve 14 towards the proximal relative to the guidewire 1 postponed. This will make the filter cartridge 3 through the ejection opening 17 released and can be in the in 1 and 2 shown expanded active position in the lumen of the vessel 10 expand. The expansion movement is on the one hand by the shape memory of the filter cartridge 3 forming metal foil into which the expanded form of the filter cartridge 3 is impressed, and on the other hand by the through the passage opening 7 inflowing blood flow 9 supported.

In 5 is the guidewire 1 with filter element 3 shown in a so-called "monorail arrangement", in which the aspiration or withdrawal catheter 20 with the help of an inlet 21 at the distal end over the guidewire 1 is pushed. The entire arrangement of guidewire 1 and aspiration catheter 20 is in turn in a guide catheter 18 accommodated.

When applying the guidewire with filter cartridge 3 in the usual way with the help of the folding sleeve 14 and then the aspiration catheter 20 over the guide wire 1 in the in 5 shown Absaugstellung be moved. In that regard, particles that are in the filter cartridge 3 over the aspiration catheter 20 be sucked off.

For removal of the filter cartridge 3 this can be done by dragging (arrow 22 ) into the distal end of the aspiration catheter 20 pulled, folding 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.

The in 4 and 5 In addition, the catheter arrangements shown are otherwise indicated by a dot-dash line hydrophilic coating 23 in the area of the folded cover 16 or at the distal end of the aspiration catheter 20 to own. Furthermore, the folding sleeve 14 at the proximal end or the aspiration catheter 20 each at the distal end of a metal ring 24 as an X-ray marker.

At the in 6 the embodiment shown is the filter cartridge 3 with its proximal end 11 and distal end 13 each at the associated ends 27 . 28 of the guidewire 1 attached and the latter within the filter cartridge 3 interrupted. Because the filter cartridge 3 So is empty in the interior, it can be folded more strongly for its passive position and thus has a respect to the embodiment according to 1 even smaller cross section.

At the in 7 shown embodiment of the filter cartridge 3 ' In turn, 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 vice versa to the embodiment according to 1 because the filter openings 6 proximal to the blood flow direction 9 opposite side and the flow openings 7 on the distal, in blood flow direction 9 lying facing side. In that regard, the indicated particles 25 before the filter insert 3 recorded.

8th shows an embodiment of the filter cartridge 3 '' in which the spherical shape is not balloon-shaped but limited to a mushroom-like configuration. This means that only the proximal end 11 of the filter insert 3 '' on the guide wire 1 permanently fixed, the distal end 13 but one the blood flow 9 opposite, large end opening 26 forms.

Claims (10)

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 Ge to be treated vessel ( 10 ) is insertable, and - one in the region of the distal end ( 2 ) of the catheter body ( 1 ) arranged filter insert ( 3 . 3 ' . 3 '' ) between a contracted passive position and a lumen of the vessel ( 10 ) is substantially expandable in the active position, characterized in that - the filter cartridge ( 3 . 3 ' . 3 '' ) is formed from a hose-like, for the active position in a spherical shape expandable metal-foil hollow body in its wall ( 5 ) with filter openings ( 6 ) is provided. 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 facilitated contraction and expansion of the filter cartridge ( 3 . 3 ' . 3 '' ) is provided. 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. Catheter arrangement according to claim 3, characterized in that a plurality of sector-shaped, between thin support bands ( 8th ) read flow openings ( 7 ) in the wall ( 5 ) of the filter insert ( 3 ) are created. 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 cartridge (in 3 . 3 ' . 3 '' ) is imprinted in its active position. Catheter arrangement according to one of the preceding claims, characterized in that the filter insert ( 3 ) with its proximal end ( 11 ) on the catheter body ( 1 ) and with its distal end ( 13 ) on the catheter body ( 1 ) Is mounted axially displaceable. Catheter arrangement according to one of claims 1 to 5, characterized in that the filter insert ( 3 ) with its two ends ( 11 . 13 ) at the associated ends ( 27 . 28 ) in the area of the filter insert ( 3 ) interrupted catheter body ( 1 ) connected is. Catheter arrangement according to one of the preceding claims, characterized in that the filter insert ( 3 . 3 ' . 3 '' ) in Passivstellung of a retractable for release in the active position folding sleeve ( 14 ) is surrounded. Catheter arrangement according to one of the preceding claims, characterized in that the filter insert ( 3 . 3 ' ) has a balloon-like shape in the active position. Catheter arrangement according to one of claims 1 to 8, characterized in that the filter insert ( 3 '' ) has a mushroom-like shape in the active position.