GB2432319A

GB2432319A - Probing catheters for intravascular procedures

Info

Publication number: GB2432319A
Application number: GB0523636A
Authority: GB
Inventors: Richard Kilbey
Original assignee: Taunton & Somerset Nhs Trust
Current assignee: Taunton & Somerset Nhs Trust
Priority date: 2005-11-21
Filing date: 2005-11-21
Publication date: 2007-05-23
Also published as: GB0523636D0

Abstract

A catheter for use in an intravascular procedure comprises an elongate lumen portion having first and second end regions, and an elongate control portion which extends from the second end region of the lumen portion, wherein the lumen portion defines a passageway therethrough, the passageway extending from a first aperture, in the first end region of the lumen portion, to a second aperture, in the second end region of the lumen portion, such that the passageway extends only partially along the catheter.

Description

PROBING CATHETERS FOR INTRAVASCULAR PROCEDURES

The present invention relates to probing catheters for intravascular procedures.

BACKGROUND OF THE INVENTION

During some intravascular procedures, such as angioplasty, a guide wire is passed into the target vessel via a guide catheter. The correct positioning of the wire is sometimes difficult, and during the positioning of the wire it may become apparent that an alternative wire (for example a stiffer wire) is required, or that a second wire is required in the same position as the first. Passing a second wire into the vessel increases the difficulty of the procedure and the risk of damaging the vessel.

!JMMARY OF THE INVENTION This catheter facilitates exchange of the first wire, or the addition of a second wire, along the same track as the first.

The essential feature of this catheter is an entry port into the catheter which is accessible for a guide wire within the guide catheter lumen.

According to the present invention, there is provided a catheter for use in an intravascular procedure, the catheter comprising an elongate lumen portion having first and second end regions, and an elongate control portion which extends from the second end region of the lumen portion, wherein the lumen portion defines a passageway therethrough, the passageway extending from a first aperture, in the first end region of the lumen portion, to a second aperture, in the second end region of the lumen portion, such that the passageway extends only partially along the catheter.

In one example, the passageway increases in cross sectional area to the second aperture. Such an enlarged aperture serves to ease location of the guide wire in the aperture during insertion.

In a preferred embodiment, the lumen portion defines a second passageway therethrough, which second passageway extends from a third aperture, in the first end region of the lumen portion, to a fourth aperture, in the second end region of the lumen portion, the second passageway extending only partially along the catheter. The second passageway enables a second guide wire to be introduced independently of the first guide wire. The second passageway may increase in cross sectional area to the fourth aperture, thereby aiding insertion of the second guide wire.

In another preferred embodiment, the passageway is bifurcated in the first end region, the first end region defining respective apertures from which the bifurcations of the passageway extend.

At least one x-ray opaque marker may be provided on at least one of the first and second send regions of the lumen portion. In particular, an x-ray opaque marker may be provided adjacent at least one of the apertures. Such x-ray opaque markers aid identification of the various parts of the catheter during a procedure.

At least a part of the control portion may be solid.

In another emobodiment, a balloon and stent arrangement for use in an angioplasty procedure may be provided, such an arrangement being located outside of the lumen portion of the catheter. In that case, an inflation passageway may be provided for supply of pressurised gas to the balloon and stent arrangement.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a cross-sectional side view of a first embodiment of the present invention; Figure 2 is a simplified cross-sectional view of the embodiment of Figure 1 in use; Figure 3 is a cross-sectional side view of a second embodiment of the present invention; Figure 4 is a cross-sectional end view of the second embodiment of the present invention; Figure 5 is a cross-sectional view of a distal end region of a third embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Figure 1 is a cross-sectional side view of a first catheter embodying the present invention. This catheter 1 comprises an elongate lumen portion 2, and an elongate control portion 3. The lumen portion 2 comprises a body 4 which defines a passageway 5 therethrough from an insertion aperture 6 at a distal end of the lumen portion 2 to an exit aperture 7 at a proximal end of lumen portion 2. The passage way thus extends only partially along the length of the catheter. The control portion 3 does not have a passageway running therethrough, and is provided to enable the catheter to be inserted into a guide catheter during an intravascular procedure. In order to aid location of the distal end region and the insertion aperture, respective x-ray opaque markers 6a and 7a are provided in locations adjacent the appropriate portion of the lumen portion 2.

Use of a probing catheter embodying the present invention will now be described with reference to Figure 2. In common with known techniques, a guide catheter 8 is inserted into a blood vessel 91 of a patient and guided to a target vessel 92. The blood vessel 91 and target vessel 92 are shown in very simplified form in Figure 2 for the sake of clarity. A first guide wire is then fed along the guide catheter in order to reach the target vessel 92. The guide wire extends into the target vessel 92 past the end of the guide catheter 8. Typically, the guide catheter 8 does not enter the target vessel 92.

In an angioplasty procedure, this first guide wire would then be used to guide and position a balloon and stent arrangement for completing the procedure. However, as mentioned above, in some cases, there is a need to replace the first wire, for example with a wire having greater stiffness. Removing and replacing the first guide wire 30 can cause unwanted damage to the target vessel 92, and so the first embodiment of the invention is intended to enable replacement of the first guide wire, with a low risk of damage occurring to the blood vessel 91 and target vessel 92.

Such a catheter 1 is fed onto the first guide wire 30 by feeding the proximal end of the guide wire 30 into the insertion aperture 6 of the catheter 1, and then passing the catheter 1 along the guide wire 30, such that the wire 30 extends along the passageway 5 and out of the exit aperture 7. Since the passageway 5 does not extend the full length of the probing catheter 1, such that the guide wire exits the probing catheter part way along its length, control of both the probing catheter 1 and the first guide wire 30 can be maintained. It is possible for the probing catheter 1 to be controlled using the control portion 3. As will be readily appreciated from Figure 2, the exit aperture 7 is positioned inside the guide catheter, such that the guide wire 30 and the control portion 3 of the probing catheter exit the guide catheter separately from one another. This arrangement enables the guide wire 30 and probing catheter to be controlled independently of one another.

When the probing catheter reaches the region of interest in the target vessel 92, the first guide wire 30 can be removed safely by pulling it back along the passageway 5 of the probing catheter and out of the exit aperture 7.

A second, replacement, guide wire can then be inserted into the exit aperture 7 of the probing catheter 1, and passed along the passageway 5 into the target vessel 92. The probing catheter can then be removed along the guide catheter 8 and the procedure can continue.

A variation of the first embodiment is to provide a passageway 5 that is sufficiently large to accommodate two guide wires at the same time. In such a design, both guide wires enter and leave the single passageway via the same apertures. Such a design would allow the use of two guide wires simultaneously.

A disadvantage of this variation is that the necessarily wide exit aperture might cause trauma to the vessel as it is deployed. To overcome such a disadvantage, a collar of soft material, which virtually closes the redundant space around the first guide wire until the second wire is introduced, can be provided at the insertion aperture 6 at the distal end of the lumen portion 2.

Figure 3 illustrates a second embodiment of the present invention which is intended to aid insertion of a second guide wire in addition to the first guide wire mentioned above.

The guide wires are not shown in Figure 3 for the sake of clarity. The second embodiment 10 has a lumen portion 12 and a control portion 13. The control portion 13 is preferably solid in cross section, as before, and is used to manoeuvre the probing catheter in place.

The lumen portion of the second embodiment has a body 14 through which first and second passageways 15 and 18 are defined. The first passageway 15 extends from an insertion aperture 16 at a distal end region of the lumen portion 12 to an exit aperture 17 at a proximal end region of the lumen portion 12. As in the first embodiment, this means that the first guide wire exits the probing catheter part way along its length, which enables control of the catheter and guide wire to be maintained without the need for use of extremely long guide wires. Extremely long guide wires can be very difficult to use successfully.

In the embodiment shown in Figure 3, a second passageway 18 extends from an insertion aperture 19 in the proximal end region of the lumen portion 12 to an exit aperture 20 in the distal end region of the lumen portion 12. The insertion aperture 19 broadens out from the diameter of the passageway so as to provide a large target aperture through which the second guide wire is inserted. The body 14 of the lumen portion 12 has an enlarged portion 21 which defines the enlarged insertion aperture 19.

Preferably, the overall outer dimension of the probing catheter at the enlarged portion 21 is only marginally less than that of the internal diameter of the guide catheter, in order to maintain contact between the insertion aperture and guide catheter wall. This facilitates insertion of the guide wire tip, which normally slides along the inside wall of the guide catheter as it is advanced. When the enlarged portion 21 is designed to be in contact with the guide catheter wall, it is preferable for the overall cross section of the probing catheter not to be circular in order to allow some free space between the probing catheter and the guide catheter. Such free space allows injection of contrast fluid or medication through the guide catheter at all times.

In common with the first embodiment, x-ray opaque markers 17a, 19a, and 20a can be provided in order to aid identification of the distal and proximal apertures during use of the catheter.

Figure 4 is a cross sectional view through A-A in Figure 3, and illustrates the enlarged insertion aperture 19. Having an enlarged aperture aids insertion of the second guide wire into the probing catheter 10. The cross sectional shape of the catheter as shown in Figure 4 is arbitrary, and therefore can be any suitable shape The exit aperture 20 for the second guide wire may benefit from having a flap cover in order to reduce possible trauma to the vessel during deployment of the catheter.

A cross-sectional view of part of a third embodiment of the present invention is illustrated in Figure 5. This third embodiment differs from the first embodiment by virtue of the provision of a single passageway, which is of large enough diameter to accommodate two guide wires simultaneously, and which defines a pair of exit apertures 31 and 32 which are in communication with the passageway. The third embodiment allows a pair of guide wires to be introduced in to the target vessel through respective apertures. The twin aperture approach serves to prevent the guide wires becoming entangled when leaving the probing catheter.

In a fourth embodiment of the present invention, a catheter as described with reference to one of the first to third embodiments is provided with a balloon and stent arrangement for use in an angioplasty procedure. The fourth embodiment enables a second guide wire to be introduced even after the balloon and stent arrangement has been located in the target vessel. An inflation passageway may then be provided in order to allow supply of high pressure gas used to inflate the balloon, and hence enlarge the stent, in known manner.

Probing catheters embodying the present invention are preferably made from a flexible medical-grade polymer material.

Claims

CLAIMS: 1. A catheter for use in an intravascular procedure, the

catheter comprising an elongate lumen portion having first and second end regions, and an elongate control portion which extends from the second end region of the lumen portion, wherein the lumen portion defines a passageway therethrough, the passageway extending from a first aperture, in the first end region of the lumen portion, to a second aperture, in the second end region of the lumen portion, such that the passageway extends only partially along the catheter.

2. A catheter as claimed in claim 1, wherein the passageway increases in cross sectional area to the second aperture.

3. A catheter as claimed in claim 1 or 2, wherein the lumen portion defines a second passageway therethrough, which second passageway extends from a third aperture, in the first end region of the lumen portion, to a fourth aperture, in the second end region of the lumen portion, the second passageway extending only partially along the catheter.

4. A catheter as claimed in claim 3, wherein the passageway increases in cross sectional area to the fourth aperture.

5. A catheter as claimed in claim I or 2, wherein the passageway is bifurcated in the first end region, the first end region defining respective apertures from which the bifurcations of the passageway extend.

6. A catheter as claimed in any one of the preceding claims, further comprising at least one x-ray opaque marker on at least one of the first and second send regions of the lumen portion.

7. A catheter as claimed in claim 6, wherein an x-ray opaque marker is provided adjacent at least one of the apertures.

8. A catheter as claimed in any one of the preceding claims, wherein the control portion is solid.

9. A catheter as claimed in any one of claims I to 7, wherein at least a part of the control portion is solid.

10. A catheter as claimed in any one of the preceding claims further comprising a balloon and stent arrangement for use in an angioplasty procedure, such an arrangement being located outside of the lumen portion of the catheter.

11. A catheter as claimed in claim 10, wherein an inflation passageway is provided for supply of pressurised gas to the balloon and stent arrangement.

12. A catheter as claimed in any one of the preceding claims, wherein the first aperture is provided with a collar of soft material that partially closes the first aperture.