A tunnelled central venous catheter (or central line) is a long, hollow tube that is inserted into one of the central veins. One end of the catheter (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. Tunnelled central lines are designed to stay in for months or even years. They are commonly known as Hickman lines (in a similar way that vacuum cleaners are commonly called Hoovers).
You can go home with the central line in and this makes it possible for you to have your treatment without having to have needles frequently put into your veins.
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.
First, I will examine your veins with an ultrasound machine to decide on the best vein (I usually use the axillary vein which sits just underneath the collar bone). Then I will clean your chest and neck with antiseptic solution, and numb the skin with local anaesthetic. After this I will put a needle and a wire into the vein whilst watching with the ultrasound machine. You will then have an X-ray to make sure it is all in the correct position; this is done whilst you are in theatre. Then I will make a small cut in the skin near your collarbone and thread the tube into the vein (this is called the insertion site). The tube is then tunnelled under the skin to reach the exit site. The exit site is the place where the end of the tube comes out of your body, the end of the tube may split into as many as three separate branches (lumens) depending on the treatment you require.
The position of the exit site will vary from person to person but I will try to ensure that it is in a comfortable position and is as discreet as possible.
When the tube has been put in you will have dressings covering the insertion and exit sites. 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.
What stops the 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. All the other stitches are dissolvable ones under the surface of the skin.
Care of your central line
When the central line is not being used there is a small risk that it may become blocked; to prevent this from happening a small amount of fluid is 'flushed' into the line using a syringe. This is usually done once a week and you may be able to do this yourself; otherwise we will arrange for a nurse to do it.
The insertion site will have a dressing on it for the first week, and the exit site for the first three weeks. These dressings will need changing at least weekly. After this you will only need to put a dressing over the exit site when you shower, although some people prefer to keep a dressing on at all times.
You will not be able to bath or swim when you have the central line in, but you will be able to shower. No air must be allowed to get into your central line. If your line has clamps then they should always be closed when the line is not in use. The line must not be left unclamped when the caps at the end are not in place.
How is the central line removed?
When you no longer need the central line it will be taken out. I will do this for you 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 up 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.