WO2003039618A2

WO2003039618A2 - Catheter guide for umbilical stump

Info

Publication number: WO2003039618A2
Application number: PCT/GB2002/005089
Authority: WO
Inventors: Stuart Neil Alexander
Original assignee: Grampian University Hospitals Nhs Trust
Priority date: 2001-11-09
Filing date: 2002-11-11
Publication date: 2003-05-15
Also published as: WO2003039618A3; GB0126900D0; AU2002339135A1

Abstract

A catheter guide comprising a body member (1) having a channel therethrough to receive a catheter and a slit (4) extending the length of the channel. The catheter guide can be used to guide the insertion of a catheter into the umbilical cord of a newborn baby and can be removed once the catheter is inserted. Preferably, the guide also includes an inner member (10), with a shoulder (21) extending therefrom. When the inner member (10) is inserted into the body member, the shoulder (21) engages with the slit (4) in the body member, filling the slit to form a continnuous outer surface an the body member.

Description

Medical Device

This invention relates to a medical device; and particularly to apparatus for handling catheters and more particularly an apparatus for inserting a catheter into an umbilical stump of a newly born baby.

Babies requiring ventilation need to have their blood checked on a regular basis, even hourly, to ensure optimum ventilation. Additionally, blood samples can provide other critical information and can therefore assist in the treatment of problems such as anaemia, hypoglycaemia and electrolyte imbalances.

To remove blood in an efficient and painless manner an Umbilical Arterial Catheter (UAC) is normally used. This is inserted into an artery in the umbilical stump so that freshly oxygenated blood can be removed. Once inserted the catheter can remain in place for anything up to seven days to allow blood samples to be removed at regular intervals as required.

The umbilical artery is normally very small and is smaller for babies in most need of this monitoring, such as those born premature. The tissue surrounding the arteries is often undeveloped and so provides little support to the arteries particularly when inserting the catheter. Consequently the artery may be pushed down into the surrounding tissue, pierced or may close when an attempt to insert the catheter is made. Insertion therefore requires great care and skill on the part of the paediatrician. Complications are more common when an inexperienced person attempts to insert the catheter.

According to the present invention there is provided a catheter guide comprising: a body member having a channel therethrough to receive a catheter; and a slot extending the length of the channel.

Preferably the slot and the channel are axial .

Preferably the body member has a funnel portion.

Preferably the guide also includes an inner member. Preferably the inner member includes a shoulder extending therefrom. Preferably the inner member is inserted into the body member allowing the shoulder to engage with the slot on the body member. Most preferably the inner member occludes the opening to the channel, and the shoulder fills the slot to form a continuous (preferably arcuate) surface on the body member. In preferred embodiments, the inner member extends through the channel to protrude from the distal end that is inserted into an artery.

Preferably the distal protruding end of the inner member is shaped (e.g. rounded) to enhance insertion of the guide into the artery.

Preferably the body member has a tubular portion extending from the narrow end parallel to the main axis. Typically, the channel extends through the tubular portion.

Preferably the end of the tubular portion is shaped (e.g. rounded) to enhance insertion of the body member into the artery.

Preferably there is an annular lip extending around the proximal end of the funnel portion of the body member.

Preferably there is a radially-extending rim on the outside of the inner member. Preferably the rim is adapted to abut with the lip on the funnel portion of the body member.

Preferably there is a gripping device on the inner member. Most preferably the gripping device is a handle. Optionally the gripping device may be a ring .

Preferably the body member is a sleeve.

According to a second aspect of the present invention, there is provided a method of inserting a catheter into an artery, comprising the steps of :

inserting a catheter guide into the artery, the catheter guide comprising a body member having a channel therethrough and a slot extending the length of the channel; and

inserting a catheter into the artery through the catheter guide.

Typically, the method also includes the steps of removing the catheter guide from the artery and subsequently removing the catheter guide from around the catheter by passing the catheter through the slot in the catheter guide.

Preferably, an inner member is inserted into the body member of the catheter guide before insertion of the catheter guide into the artery and the inner member is removed after the insertion of the catheter guide. Typically the inner member is removed by pulling on a gripping device of the inner member . An embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which;

Fig. 1 is a perspective view of the body member of a first device;

Fig. 2 is a rear perspective view of the Fig. 1 device with inner member present;

Fig. 3 is a perspective view of the Fig. 1 device during removal of the sleeve;

Fig. 4 is a perspective view of a first embodiment of an inner piece of the Fig. 1 device;

Fig. 5 is a perspective view of a second embodiment of an inner piece of the Fig. 1 device;

Fig. 6 is a perspective sectional view of the Fig. 1 device in use;

Fig. 7 is a side elevation of the body member of the Fig. 1 device;

Fig. 8 is a plan view of the body member of the Fig. 1 device;

Fig. 9 is an end view of the Fig. 1 device; Fig. 10 is a side elevation of the Fig. 4 inner piece;

Fig. 11 is a plan view of the Fig. 4 inner piece;

Fig. 12 is an end view of the Fig. 4 inner piece, viewed from the wide end;

Fig. 13 is an end view of the Fig. 4 inner piece, viewed from the narrow end;

Fig. 14 is a is a side elevation through the Fig. 1 device with the Fig. 4 inner piece present;

Fig. 15 is a plan view of the Fig. 1 device with Fig. 4 inner piece present;

Fig. 16 is a front perspective view of the Fig. 1 device with Fig. 4 inner piece present;

Fig. 17 is a perspective view of the Fig. 1 device in use;

Fig. 18 is a sectional view through the tip of the Fig. 1 device with the Fig. 4 inner piece present; and,

Fig. 19 is a sectional view through the tip of the Fig. 1 device without the Fig. 4 inner piece present. With reference to the figures the device comprises a body member or sleeve 1 and an inner piece 10.

The sleeve 1 shown in Fig. 1 has a funnel portion 2 and a tubular or neck portion 3. There is a slot 4 which extends the length of the sleeve 1. The end 5 is rounded as shown in Figs. 18 and 19 to reduce the risk of damaging the artery. A radially-extending rim 7 is present on the end of the funnel portion 2.

The inner piece 10 can have a pair of spacers 13, 13' connected together to form a longitudinally tapered member as shown in Fig 4. In this embodiment, spacers 13, 13' are planar members. Spacer 13' has a longitudinal slot extending at least part way through the spacer 13' and spacer 13 is secured inside the slot so that the spacers 13, 13' are aligned perpendicular to each other. Spacer 13 is axially symmetric, but spacer 13' has a shoulder 21 on one side, providing a greater radial extent in that direction. The shoulder is typically an extension of the spacer 13' and is preferably of the same dimensions as the slot 4.

Extending from the narrow end of the inner piece 10 and along the axis of the inner piece 10 is a neck 14 with a cruciate cross section. The invention is not limited to this form of inner piece 10.

Fig. 2 shows the inner piece 10 located inside the sleeve 1. The neck 14 and the outer edges 13A, 13B, of the spacer 13 engage the inner surface 6 of the sleeve 1 by frictional contact . The contact should be light and should be designed to be easily broken without the necessity to pull hard or jerk the inner piece when removing.

The shoulder 21 fits into the slot 4 thereby filling the slot 4 and completing the continuous arcuate surface on the edge of the body member 1. The shoulder 21 preferably has an arcuate surface to provide a smooth surface to the outer face of the sleeve 1. Alternatively, the surface of shoulder 21 could be flat.

Thus, when the sleeve 1 is introduced into an artery no, or negligible, damage is caused by the presence of the slot 4, as the shoulder 21 on the inner piece 10 fills the slot 4 to provide a smooth continuous arcuate surface comparable to a pre-formed sleeve that did not have a slot.

The end 12 of the inner piece 10 is typically rounded as shown in Fig. 18 to prevent damage to the artery 26 during entry.

An alternative embodiment of the inner piece is shown in Fig. 5. Here the inner piece 30 has a cone-shaped portion 16 and a neck portion 15. The neck 15 is cylindrical in shape. On the wider end 19 of the funnel portion 16 is a handle 17 which may be used to remove the inner piece 30 from the sleeve 1. Also present on the wider end 19 of the funnel portion 16 is a radially outward-extending rim 18. This rim 18 connects with the rim 7 of the sleeve 1 to provide a light seal between the inner piece 30 and the sleeve 1.

A longitudinal shoulder 11 is provided on the outer face of the inner piece. The shoulder 11 typically has an extent equal to the length of the inner piece 30. The dimensions (i.e. width, depth and length) of the shoulder 11 typically match the dimensions of the slot 4 to provide a smooth, continuous surface to the outer face of the sleeve 1 when the inner piece 30 is located inside the sleeve 1. The outer surface of the shoulder 11 is preferably arcuate, but it may be flat .

Thus, when the sleeve 1 is introduced into an artery no damage is caused by the presence of the slot 4, as the shoulder 11 on the inner piece 30 fills the slot 4 to provide a smooth continuous arcuate surface comparable to a pre-formed sleeve that did not have a slot.

The end 32 of the inner piece 30 is preferably rounded as shown in Fig. 18 to reduce the risk of damage to the artery.

The sleeve 1 and inner piece 10 can be made from plastic, metal or any other suitable material and can be manufactured by cast moulding or any other suitable technique. Metals are preferred for sterilisable embodiments. In use the inner piece 10,30 and the sleeve 1 are assembled and the assembly is placed into the artery 26 of the umbilical stump 27 and held in place by the physician or an assistant. The shoulder 11, 21 of the inner piece 10,30 extending into the slot, fills it and provides a smooth continuous arcuate surface to the outer face of the sleeve 1 and so does not substantially damage the artery 26.

When the sleeve 1 is in place, the inner piece 10,30 is removed by leverage on the handle 17 or simply by grasping or pulling on the inner piece 10,30 itself. This removes the shoulder 11, 21 from the slot so that the sleeve 1 now has a continuous open slot 4 which extends the full length of the sleeve 1.

The catheter 25 is then guided into the artery 26 through the funnel portion 2 of the sleeve 1 and through the neck portion 3 into the artery 26 as shown in Fig. 6. The inner diameter of the neck portion 3 is typically only slightly larger than the outer diameter of the catheter 25, so that when the catheter 25 is inserted through the neck portion 3, the slot 4 in the neck portion is sealed by the catheter 25.

When the catheter 25 is safely in place the sleeve 1 may be removed. To achieve this the sleeve 1 is first slipped out of the artery 26 leaving the catheter 25 in place. The slot 4 is wide enough to allow the catheter 25 to pass through. The sleeve 1 can then be completely removed by sliding away obliquely, allowing the catheter 25 to pass through the slot 4 as shown in Fig. 3. To allow this operation the slot 4 must extend the length of the channel .

An advantage of this apparatus is that the sleeve 1 may be removed more easily. This allows a safer introduction of a catheter into an umbilical stump of an infant.

Modifications, changes, improvements and variations may be made without departing from the scope of the invention.

For example, one of the main purposes of the inner piece 10, 30, is to prevent any fluids from escaping from the artery 26 after the catheter guide has been inserted. The sleeve 1 will not usually be inserted into the artery 26 past the neck portion 3. Thus, a useful feature of any inner piece 10, 30 is a portion that, when inserted into the sleeve 1, seals the part of the slot 4 which extends through the neck portion 3. This will prevent fluids from leaking out of the artery 26 before the catheter is ready to be inserted. When inserted, the outer wall of the catheter itself will seal the slot. Whether or not a part of the inner piece also fills the remainder of the slot 4 is not so important, and nor is the shape (funnel, cylindrical, cross-spacer design, etc) of the rest of the inner piece. It is not necessary for the slot 4 to be physically filled, because the part of the slot 4 in the neck portion 3 could be sealed by another means. For example, the inner piece 10 could have a portion which spans the slot, but does not physically fill it. The neck portion 14 of the inner piece 10 could be a cylinder or tube being a close fit with the bore of the neck portion 3 of the sleeve 1. The slot 4 could alternatively be sealed by a member exterior to the sleeve 1, as opposed to an inner piece 10.

Claims

1. A catheter guide comprising: a body member having a channel therethrough to receive a catheter; and a slot extending the length of the channel .

2. A catheter guide as claimed in claim 1, wherein the slot and the channel are axial .

3. A catheter guide as claimed in claim 1 or claim 2, wherein the body member has a funnel portion.

4. A catheter guide as claimed in claim 3, wherein the body member has a tubular portion extending from the narrow end of the funnel portion.

5. A catheter guide as claimed in any preceding claim, having an inner member.

6. A catheter guide as claimed in claim 5 wherein the inner member is shaped to seal the channel through the body member when the inner member is located in the body member.

7. A catheter guide as claimed in claim 5 or claim 6, wherein the inner member has a shoulder extending radially outward and having substantially the same width and height as the slot so that when the inner member is located in the body member, the shoulder fills at least a part of the slot to provide a continuous surface to the outer face of the catheter guide .

8. A catheter guide as claimed in claim 7, wherein the shoulder fills the part of the slot through the tubular portion.

9. A catheter guide as claimed in any one of claims 5 to 8 , wherein the inner member has a neck portion corresponding to the tubular portion of the body member and the neck portion forms a close fit with the tubular portion.

10. A catheter guide as claimed in any one of claims 5 to 9 wherein the continuous surface is arcuate.

11. A catheter guide as claimed in any one of claims 5 to 10, wherein the inner member has a gripping device to facilitate removal of the inner member from the body member.

12. A catheter guide as claimed in any of claims 5 to 11, wherein when located inside the body member, at least a part of the inner member contacts the inner surface of the body member to engage the body member by frictional contact.

13. A catheter guide as claimed in any of claims 5 to 12 when dependent on claim 3, wherein the funnel portion has an annular lip, the inner member has a rim and the rim of the inner member is adapted to abut with the lip on the funnel portion.

14. A catheter guide as claimed in any preceding claim, wherein the end of the catheter guide is rounded to facilitate insertion of the body member into an artery.

15. A method of inserting a catheter into an artery, comprising the steps of:

inserting a catheter into the artery through the catheter guide.

16. A method as claimed in claim 15, further including the step of removing the catheter guide from the artery.

17. A method as claimed in claim 16, further including the step of removing the catheter guide from around the catheter by passing the catheter through the slot in the catheter guide.

18. A method as claimed in any one of claims 15 to 17, further comprising the steps of inserting an inner member into the body member of the catheter guide before insertion of the catheter guide into the artery and removing the inner member after the insertion of the catheter guide.

19. A method as claimed in claim 18, whereby the inner member is removed by pulling on a gripping device of the inner member.