Tunnelled Central Venous Catheter

Tunnelled central venous line

A tunnelled central venous line (or catheter) is a long, hollow tube that is inserted into one of the big central veins (e.g., internal jugular vein). They are commonly known as Hickman lines. One end of the line (the distal end) is normally positioned near to the entrance of the heart and the other end travels underneath the skin and comes out from the chest wall (the exit site). The position of the exit site will vary from person to person but is usually in a comfortable position and is as discreet as possible.

The part of the line that is outside the chest may split into as many as three separate branches (lumens) depending on the treatment you require. Each lumen has a clamp on it and an injection bung (cap) at the end.

How is a tunnelled central line put in?

You will have your central line inserted in the operating theatre. This is usually done under local anaesthetic and sedation and takes about 30 minutes. You should feel relaxed and sleepy throughout the procedure, but you may feel some stinging when the local anaesthetic goes in and some pushing and pulling during the procedure. There may some brief periods of discomfort.

You will have an ultrasound and X-ray whilst you are having the procedure.

What stops the tunnelled central line falling out?

There is a small 'cuff' around the central line which can be felt under the skin about 2 -3 cm above the exit site. The tissue under the skin grows around this cuff over a period of about 3 weeks and holds the line safely in place. Until this has happened you will have a stitch holding the line in place – this will be removed by the nursing staff 3-4 weeks after insertion. All the other stitches are dissolvable ones that are under the surface of the skin.

How is it dressed?

When the line has been put in you will have some glue covering the insertion and exit sites, and a transparent dressing at the exit site. The dressing is water resistant but not waterproof – showering is fine but try not to get it too wet.

The transparent dressing will need changing every week, or sooner if the dressing becomes soiled or starts peeling off. At 7 days an antiseptic chlorhexidine disc will be put around your catheter at the exit site. This needs to be changed every week when you have your dressing changes, and it stays in place for as long as you have the stich attached to your skin. Some patients react to the dressings or the antiseptic disc – please let your nurse know if the wound becomes red, itchy, or sore.

Will it be sore?

For a few days you may have some pain or discomfort where the tube has been tunnelled under the skin. A mild painkiller such as paracetamol will help to ease this. There may be some swelling and bruising around the line and this may take a few weeks to completely settle down.

Care of your central line

A transparent dressing will cover the exit site while the stitch is still in place. The dressing is water resistant but not waterproof – showering is fine but try not to get it too wet.

The dressing and the injection bungs will need changing every week and the line will require flushing every week.

After about 3 to 4 weeks, when the wound has healed, the stitch that holds the line in place can be removed by a nurse. After this time, a dressing will no longer be needed, but the line should remain looped and secured with tape to prevent it pulling. When you shower, you can gently wash around the area with unperfumed soap and gently pat the area dry afterwards. You will not be able to submerge the line or swim. Gentle exercise is fine but avoid vigorous exercise that could damage or dislodge the line.

You should check that the bungs are secure and that the clamps are closed when the line is not in use – you should try to do this daily.

Using the line

The line will normally only be used by trained doctors and nurses but in some circumstances you or a friend/relative can be taught how to use the line and care for it.

It is important that whenever the line is being used it is accessed using an aseptic non-touch technique to reduce the chance of infection. The end of the line must be thoroughly cleaned with a chlorhexidine antiseptic wipe before it is used. It should not be flushed with anything smaller than a 10 ml syringe.

How is the central line removed?

When you no longer need the central line, it will be taken out. This will be done in theatre using local anaesthetic and the operation will take about 10-15 minutes; sedation is not normally necessary. I will make a small incision just above the exit site to free up the cuff that holds the line in place. After this I can pull the line out and close the incision with some dissolvable stitches. The hole where the line comes out of the chest (the exit site) will heal on its own - it does not need stitches. You will need a dressing over the site for about 1 week.