Haemodialysis is a long term treatment for chronic kidney failure. It removes waste products and fluid from your blood because your kidneys can no longer do this. To circulate your blood through the dialysis machine, a special site or ‘access’ is needed to allow your blood to be removed, cleaned and returned to you. There are several ways this can be done. They all require a minor surgical procedure.
Access for dialysis can be temporary or permanent. Some people may have a temporary method until a permanent access site is ready for use.
We aim to plan and prepare access before the time for dialysis arrives, so that when it does everything is that much more straight forward. Having access for dialysis does not mean that you will have to start dialysis before it is necessary.
When the decision has been made that you need access for haemodialysis, you will be assessed by a renal surgeon. The surgeon will examine you and decide which is the best type of access for you. Once they have discussed this with you, a date will be arranged for you to have the operation. If you are an outpatient, this will usually be within a month. If you are in hospital requiring access urgently, it will be done as soon as possible.
What is a fistula?
A fistula is the most common type of dialysis access. Creating a fistula involves a small operation on the wrist or arm to join together a vein and an artery. It takes about an hour, It is usually carried out under local anaesthetic and you will spend a day in hospital.
Joining a vein to an artery creates a faster and more turbulent flow of blood through the vein. This makes the vein thicker and it gets bigger. Eventually, it becomes visible under the skin, looking a bit like a large varicose vein. When you touch it you can feel a ‘buzz’. This sensation is very important, because it means that the fistula is working properly. You should check your fistula every day and if it ever stops working, contact the hospital immediately.
How does a fistula work?
When the vein enlarges it is easier to insert dialysis needles into it. This is the best and least troublesome method of access and many people learn to insert the needles themselves. Every time you have dialysis, two needles are inserted into the fistula and lines are attached that carry your blood through the machine and then return it to you. After dialysis the needles are removed leaving only a small puncture mark.
2. PTFE graft
A PTFE graft is a small piece of plastic inserted between an artery and a vein in your arm or thigh. A small proportion of people have to have these if their own veins are absent or not strong enough for a fistula. The graft is placed close to the surface of the skin for easier needling.
what is a permcath?
A permcath is used when, for some reason, a fistula is not possible. It is a permanent device and will hopefully last as long as you need it. It involves inserting and securing a soft plastic tube (catheter) about the thickness of a pencil into a large vein in the base of your neck. About 6 inches of the tube protrudes from your skin and a dressing is placed over the site where it enters your skin. This dressing should be kept clean and dry and extra care is needed when bathing and washing your hair. The tube is easily disguised by clothing.
How does a permcath work?
The end of the catheter is forked. When you need dialysis, the lines to remove and return your blood are attached to the end of the permcath. After each dialysis session, the permcath is flushed with a solution to prevent clotting or blocking of the line. Two small caps are placed on the end of the catheter until the next dialysis session.
4. Temporary access
Some sort of temporary access may be needed if you have to have dialysis sooner than planned or if there is a problem with your permanent access. It is also use for people requiring more urgent dialysis treatment.
Temporary access is usually inserted on the ward or the dialysis unit under a local anaesthetic. Many people have these lines until they have made a final decision about options for long term dialysis treatment or until more permanent access is ready for use. The main complications are problems with infection and blockage.
sub-clavian or jugular lines
These are very similar to the permcath except that they are not designed for long term use and the tube is usually harder. The tube is inserted into a large vein under or above your collarbone and approximately 5 inches are left protruding from your skin. You will have to lie flat whilst the line is being inserted and an x-ray is taken afterwards to check that it is in the right place. A dressing is placed over the area where it enters and this should be kept clean and dry. The dressing is changed each time you have dialysis.
The catheter is forked and the lines to remove and return your blood are attached to the ends when you need dialysis. After each dialysis session, two small caps are placed on the end of the catheter.
This is a temporary line, similar to the sub-clavian, placed into a large blood vessel in your groin. This type of access is not often used because walking and washing can be a bit more difficult, although not impossible. It is covered with a dressing which needs to be kept clean and dry.