Why do I need a fistula?
When your kidney function is declining to a point where you need treatment to take over the job of your kidneys, your kidney team will talk to you about your options, including haemodialysis.
To have haemodialysis, you need a way of connecting the dialysis machine to your bloodstream. This is called vascular access.
An arteriovenous (AV) fistula, usually just called a fistula, is one type of vascular access. It’s a blood vessel that’s created by joining together an artery and a vein in your arm. The result is a larger, stronger blood vessel, so lots of blood can flow through it smoothly.
When you’re having haemodialysis, the dialysis machine is connected to your bloodstream by tubes attached to needles, which are inserted into your fistula.
There are other types of vascular access, but a fistula is considered the gold standard. There’s evidence that patients who dialyse with a fistula have more effective dialysis, get fewer infections, and stay healthier for longer.
Your kidney team will help you decide which option is best for you.
What does having a fistula created involve?
An AV fistula is usually created in your non-dominant arm, and there are three positions or sites where the join is made. The vessel then develops up your arm. The three sites are:
- in your forearm close to your wrist (radio-cephalic)
- in or close to the bend of your arm in the centre (brachio-cephalic)
- in or close to the bend of your arm closer to your body (radio-basilic)
You need a minor operation to create the fistula. It’s a very safe procedure that can be performed under local, regional or general anaesthetic. If you have a brachio-basilic fistula made you may need additional surgery which requires a general anaesthetic and an overnight stay in hospital.
It involves making a small cut in your skin, deep enough so the vascular surgeon can access the vein and artery. The surgeon then cuts a tiny opening in the vein and one in the artery and reconnects them. This allows arterial blood to flow into the vein. The pressure this adds to the vein allows it to grow and develop so it can be used reliably for dialysis and act differently to all your other superficial veins.
You’ll have a short, thin scar – usually around 4cm to 6m in length – where your skin was opened up.
In the last few years, a new type of fistula has been developed called an endovascular arteriovenous fistula, or EndoAVF for short, which uses radiofrequency energy, rather than open surgery, to join the artery and the vein. EndoAVF is still in the development stage in the UK and is not offered in all units.
With both types of fistula, a clinician will either scan your arm or perform a clinical assessment to make sure it can be used for dialysis. A standard fistula usually takes around two to six weeks (sometimes longer) to be functional.
Official guidance recommends that you have a fistula created up to a year before your kidney team thinks you’ll need to start haemodialysis.
How will my everyday life be affected by a fistula?
Fistulas generally don’t require much in the way of maintenance; you can carry on with normal day-to-day activities.
When you have a tube permanently inserted into a blood vessel like you do with a dialysis line (central venous catheter) the tube must always be kept dry and away from water because of the risk of infection and dislodging the line.
One of the benefits of a fistula is that there is no direct access from the inside of the body to the outside when you are not on dialysis, allowing you to shower, bathe and swim without restriction.
When the needles are removed at the end of each dialysis session, it’s normal for the needling sites to bleed a little. Applying pressure with a piece of gauze or a cotton swab for a few minutes is normally enough to stop the bleeding.
Sometimes, a fistula can bleed spontaneously in between dialysis sessions. This should always be reported to your dialysis team, as it may be a sign that there is a problem with your fistula.
Applying direct pressure, as above, will usually stop the bleeding. In rare cases applying pressure isn’t enough to stop the bleeding, and it can quickly become serious. If this happens, it’s essential that you seek medical help urgently.
Why do fistulas make your arm look different?
A drawback of a fistula is that, over time, the blood vessels in your arm may become enlarged and bumpy because of high volumes of blood passing through, and needles being inserted into your fistula at every dialysis session.
This is completely normal and is a sign that your fistula is working well. But it can be very noticeable, and some people are uncomfortable or self-conscious about how their fistula looks.
If you’re worried about this and it’s affecting your body image, it might be worth talking to a member of your kidney team or a renal counsellor (Kidney Care UK offers a free renal counselling service to kidney patients and their families).
What’s the fistula “buzz”?
When a fistula is functioning well, the high volume of blood travelling quickly through it creates a ‘buzz’ or a ‘thrill’, which you can feel when you touch your arm where the fistula is located. You might find this strange to start with, but you’ll soon get used to it.
When you first start haemodialysis, using the fistula may be uncomfortable or painful. It can take time to adjust to having dialysis needles inserted into the fistula, but most people do so quickly.
If you have any questions or concerns about having a fistula, talk to someone in your kidney team.