Αρτηριοφλεβική επικοινωνία – fistula

Information for patients from the Kent Kidney Care Dialysis Access Team
This leaflet will explain what an arteriovenous fistula is, how is created and how it is used.

What is an arteriovenous fistula?

An artery and a vein are joined under the skin by surgery to create a stronger vein
An arteriovenous fistula can also be known as an AV fistula or fistula or AVF for short.

Why am I having a fistula created?
You are having a fistula created to make your vein stronger to allow adequate access to your blood for haemodialysis; this is the best access for long term haemodialysis. Compared to central venous catheters (lines), fistulas have reduced risks of infection and complications.

How is a fistula created?

a fistula is created in a surgical procedure performed by a vascular surgeon in an operating theatre. By joining a vein and an artery together the new connection (fistula) will become a strong vein with a longer flow of blood.
The pressure of blood is greater inside an artery than inside a vein. Therefore when the surgeon creates the fistula between the artery and the vein some of the arterial pressure is transferred into the vein causes it to enlarge, making it suitable for insertion of haemodialysis needles.

How is a fistula used for dialysis?
The fistula is used for haemodilysis by placing two needles at different places along the fistulas. The needles have special tubing attachments, the blood will flow through the first needle out of the body, through the dialysis machine to clean the blood and back through the second needle into the body.

How will I be assessed to plan a fistula?

You will be given a clinic appointment to see a vascular surgeon and access nurse in renal outpatients at Kent and Canterbury Hospital (K&C). Usually, you will have an ultrasound scan of both arms before you see the surgeon. Once the surgeon has identified which arm is best to have the graft we advise that you do not have any procedures on that arm.
Do not use your arm for blood pressure, injections or infusions. In future this arm will be used for dialysis only.
A date for the surgery will be agreed with you.

Will the operation hurt?

The majority of fistula procedures are done under local anaesthetic which means you will be awake. You may experience some discomfort for a few days afterwards, you will be advised regarding pain relief.
Your surgeon will advise and explain if a general anaesthetic is required for surgery

How long will I stay in hospital?

Please refer to your surgery appointment letter.
The majority of fistulas are completed as a day case. Allow four to five hours for the whole visit. If you are well enough, you will be able to go home several hours after surgery. If you have had a general anaesthetic you may have to stay overnight.

What will happen when I arrive at hospital?

On admission you will report to either Marlowe Ward and be seen by the access nurse and surgeon who will fully explain your procedure and ask you to sign a consent form. This is the time to ask any final questions.
Before having your operation you will need to put on a theatre gown for the duration of the procedure; you may want to bring a dressing gown with you.
Your appointment letter will tell you if you need to fast before your operation and if you can take your normal medication. This letter will also tell you if you need to bring an overnight bag in case you have to stay.
You may want to bring something to read and a snack for after the surgery.

What will happen after the operation?

Before you go home the access nurse or renal nurse will see you. You will be advised and given a leaflet on the care of your fistula and shown how to check it is working. A follow-up appointment will be given to you. Please ask if you have any questions.
We advise that you do not drive for at least three days after our surgery.

What possible complications may occur?

Infection is not common in a fistula. If you develop pain, redness or the skin around your fistula becomes hot please tell a nurse or doctor. You may require an antibiotic if an infection is present.
Thrombosis (a blood clot) is a common cause of fistula failure.
Arterial steal syndrome is caused by the fistula diverting too much blood into the vein. The hand then does not receive adequate blood supply. The signs and symptoms of steal syndrome are coldness in the hand/fingers. In mild cases this will be monitored, in more severe cases your fistula may need to be refashioned surgically.

If you have any concerns please call your dialysis unit if you are on dialysis or contact the Renal Access Nurses.

When is a fistula ready to use?

How quickly a fistula develops varies, depending on how good the vessels were before the surgery and the general health of the patient.
We will provide a soft ball for you to squeeze which will help improve the blood flow through the fistula.
A fistula is ready or mature, when the vein has grown large enough and strong enough to support the required dialysis needles. This usually takes around six weeks but can take less or longer in some individuals. Your dialysis nurse will check your fistula and will know when it is mature.

How long will my fistula last?

There is no definite answer to this question. A small number of fistulae never work and you may return from theatre with a failed fistula. Fistulae can also fail at any stage even after years of use if you become ill or suffer an episode of low blood pressure. Other reasons for failure can be direct trauma(hit or knock) to your fistula, infection or if something alters how your blood clots.
However, the majority of fistulae work immediately following surgery. You should remember that a successful fistula is less likely to form clots or become infected than other types of access. Also, fistulae tend to last years longer than any other kind of access.