GB2245177A

GB2245177A - Arterial device

Info

Publication number: GB2245177A
Application number: GB9113552A
Authority: GB
Inventors: Man Fai Shiu
Original assignee: Individual
Current assignee: Individual
Priority date: 1990-06-22
Filing date: 1991-06-24
Publication date: 1992-01-02
Anticipated expiration: 2011-06-24
Also published as: GB2245177B; GB9113552D0

Abstract

An arterial device for introduction into an arterial puncture to reduce bleeding comprises a flexible tapering cannula 11 having external graduations and an optional protective sleeve 17. The cannula 11 has a central lumen 14 through which a guide wire may extend to facilitate insertion. Gradual withdrawal of the cannula 11 enables the arterial wall to relax gradually to close or reduce the original punctures 16, minimising haemorrhage. <IMAGE>

Description

ARTERIAL DEVICE This invention relates to an arterial device primarily for use in intensive therapy and interventional cardiology but which may have other medical or surgical application.

To gain access to an artery, the arterial wall must be penetrated. The opening in the arterial wall may initially be quite large, to enable the passage of for example a guiding catheter for transluminal coronary angioplasty or an intraaortic balloon pump.

When the procedure requiring access to the artery has been completed, and the large diameter device can be removed, extensive bleeding has been found to occur at the puncture in the artery wall, particularly where, following cannulation with a large diameter device, a thin line needs to be left in place for hours or even days for further access in case of emergencies.

Removal of a large sized cannula therefore currently requires prolonged pressure with associated discomfort and often significant haemorrhage into the surrounding soft tissue. The degree of bruising and trauma is partly related to the size and partly to the duration for which the cannula has been left in situ.

It is an object of the present invention to provide an arterial device for use at the site of an arterial puncture which overcomes or mitigates these problems.

According to the invention there is provided an arterial device comprising a cannula having a proximal access end and a distal insertion tip, the external transverse size of the cannula decreasing continuously from the access end to the tip.

Graduated scale means may be provided on the cannula. The cannula may be of circular cross-section.

The external transverse size of the cannula may vary from 1.3mm to 5mm (4 French to 15 French), and in a preferred form may vary from 1.3mm to 3mm (4 French to 9 French).

The cannula may have a constant cross-section internal lumen.

The internal lumen may have a small transverse size sufficient to allow the passage of a wire, for example 0.97mm (0.038in).

The proximal access end may have a cap fitting, or alternatively may have a tap.

The arterial device may include a variable length protective sleeve surrounding the cannula towards the proximal access end and the protective sleeve may include anchorage means and/or skin entry means.

The protective sleeve may have clamping valve means at each end thereof, adapted to clamp it in a sealing manner to the external surface of the cannula.

An embodiment of the invention will now be described in more detail by way of example only with reference to the accompanying drawings in which Figure 1 is a side elevational view of an arterial device embodying the invention, Figure 2 is a cross-sectional view of the device, Figure 3 shows the device in use, Figure 4 is a sectional view of a sleeve for use with the device.

Referring to the drawings, an arterial device generally indicated at 10 comprises a tapering flexible cannula 11.

This may be made of any suitable material such as polyurethane, which is smooth, flexible and has minimal thrombogenic properties. The cannula has a proximal access end generally indicated at 12 and a distal insertion tip generally indicated at 13. Between the tip 13 and the access end 12, the cannula continuously and gradually increases in external diameter. Reference to Figure 2 will show that an internal lumen 14 of substantially constant cross-section is provided.The cross-section of the internal lumen is very small, typically sufficient to allow the easy passage of a wire of the standard guide wire diameter 0.97mm (0.028in) The outer diameter of the cannula 11 tapers over substantially the whole length between a diameter of about 1.3mm (4 French) and a diameter of about 5mm (15 French), the length of the cannula being in the range 250-450mm and typically 350mm. The cannula is shown as having a circular cross-section but might have a non-circular, for example elliptical, cross-section in some circumstances.

A plurality of graduated markings 15 are visible externally of the cannula. These markings may give a direct reading of diameter or may indicate the length along the cannula from the distal insertion tip 13 to the proximal access end 12, or recommended timings for withdrat#l of the cannula.

Referring to Figure 3 of the drawings, an arterial device embodying the invention is shown in use. An artery 23 has a puncture 16 which has been used for a medical procedure. The cannula 11 of the arterial device 10 of the present invention is inserted into the arterial puncture by a distance sufficient to match the external diameter of the cannula 11 to the arterial puncture made by the initial arterial device.

Insertion is usually facilitated by the presence of a guide wire in the artery 23, around which the cannula is slid.

Before insertion of the cannula 11 into the arterial puncture 16, a transparent concertina plastics sleeve 17, illustrated in Figure 4, may optionally be loaded over the cannula so as to surround it as shown in Figure 3.

The cannula 11 is inserted into the artery 23 so that the arterial puncture 16 is effectively stoppered by insertion of the cannula. The sleeve 17 is slid to a position in which a terminal collar 18 having a short flexible sleeve 19 can be inserted in the skin wound 20 and lightly sutured in place to the skin using the wings 21. Alternatively, it may be taped in place. The other end of the sleeve 17 has a further collar 22 which takes up a position closer to the proximal access end 12 of the cannula 11. The collars 18, 22 are fitted with clamping valves which, once the device 10 is in position, can be tightened to hold the sleeve 17 to the cannula 11 in airtight sealed manner. The clamping valves can be seen in Figure 4.

It will be appreciated that an access wire will normally be in position within the lumen 14, having been used to facilitate insertion of the cannula 11 and being left in position in the artery for a required period to permit further access in the case of emergencies. The wire has been omitted from the drawings for clarity.

The arterial device 10 is used to permit controlled closure of the arterial puncture by being withdrawn at a gradual rate, which can be judged from the markings 15 at the skin wound 20.

These may indicate diameter, length measured from the insertion tip or suggested withdrawal timings.

The arterial wall is enabled to relax onto the external surface of the cannula 11 at a particular point along its length and gradual withdrawal of the tapering cannula permits its eventual removal without the need for considerable pressure to be exerted at the site of the arterial puncture to prevent haemorrhage. If excessive bleeding occurs during controlled withdrawal, it may be stopped by slight advance of the cannula further into the artery. The presence of the sleeve 17 retains the sterility of the withdrawn and reinserted portion of the cannula in the case of such reinsertion.

The rate of withdrawal can be varied depending on the initial size of the arterial puncture 16 and the patient's characteristics and is also dictated by the clinical need for maintaining arterial access, in some circumstances. Where further access to the artery will or may be needed, the insertion tip can be left in position to avoid the need for a further incision. However, the guide wire can usually be removed.

At a specified time decided by the clinician, the arterial device 10 can be completely removed. At this stage only the thin tip portion 13 of the device remains in the artery and complete removal will be accompanied by only minor bleeding, which can readily be controlled by appropriate hand pressure or by a pressure bandage.

The proximal access end 12 of the cannula is provided with a closable one-way or multi-way tap or with a standard Luer lock end cap or other appropriate fitment. A tap may be useful if a saline infusion may be needssd. The transparent variable length sleeve 17 may be omitted, although it provides a useful means of maintaining the sterility of the external surface should it become necessary to reinsert the arterial device as described.

Claims

1. An arterial device comprising a cannula having a proximal access end and a distal insertion tip, the external transverse size of the cannula decreasing continuously from the access end to the tip.

2. An arterial device according to claim 1 wherein graduated scale means are provided on the cannula.

3. An arterial device according to claim 1 or claim 2 wherein the cannula is of circular cross-section.

4. An arterial device according to any preceding claim wherein the external transverse size of the cannula is in the range 1.3mm to 5mm (4 French to 15 French).

5. An arterial device according to claim 4 wherein the external transverse size of the cannula is in a range from 1.3mm to 3mm (4 French to 9 French).

6. An arterial device according to any preceding claim in which the cannula has a cross-section internal lumen.

7. An arterial device according to claim 6 wherein the internal lumen has a transverse size sufficient to allow the passage of a wire.

8. An arterial device according to claim 7 wherein the internal lumen has a transverse size of 0.97mm (0.038in)#

9. An arterial device according to any preceding claim wherein the proximal access end has a cap fitting.

10. An arterial device according to any one of claims 1-8 wherein the proximal access end has a tap.

11. An arterial device according to any preceding claim and further including a variable length protective sleeve surrounding the cannula towards the proximal access end.

12. An arterial device according to claim 11 wherein the protective sleeve includes anchorage means.

13. An arterial device according to claim 11 or claim 12 wherein the protective sleeve includes skin entry means.

14. An arterial device according to any one of claims 11-13 wherein the protective sleeve has clamping valve means at each end thereof, adapted to clamp it in a sealing manner to the external surface of the cannula.

15. An arterial device substantially as hereinbefore described with reference to and as illustrated in the accompanying drawings.