Dialysis AVF Access
People who develop advanced-stage kidney disease often need dialysis, in which a machine performs a basic function of the kidney: cleansing blood of impurities. Before a patient begins dialysis treatments, a minor surgical procedure called arteriovenous (AV) fistula might be recommended. Such a fistula – when an artery and vein are directly connected – also is an abnormality that in other circumstances might require surgical correction. But for someone has failing kidneys, surgically creating such a passageway can make the dialysis process easier.
In dialysis, all of a patient’s blood is withdrawn from an artery or vein, filtered and returned to a vein. Creating an AV fistula allows arterial pressure to enlarge the vein, over time, better enabling it to receive the volume of blood coming back into the body. Well in advance of the potential surgery, the physician will measure blood pressure and check for circulatory abnormalities, particularly areas of reduced blood flow and especially near the potential location of the arteriovenous (AV) fistula. You may be asked to take any of these diagnostic tests:
- Venogram: Specialized X-ray that provides images of the veins
- Duplex ultrasound: Generates images that identify characteristics of blood flow and blood vessels
- Pulse volume recording: Helps understand the amount of blood flowing through the arteries
During the procedure, you will be placed under anesthesia, though the outpatient surgery does not require overnight hospital stay. The purpose of the surgery is to connect a large vein in the arm or leg to a nearby artery. The procedure diverts a portion – some, not all – of the venous blood through the artery.
The vascular surgeon typically uses one of two surgical techniques:
- The basic procedure joins an artery to a vein, usually in the arm, though sometimes the fistula may be placed in the leg.
- For some patients with advanced vascular disease or who are very weak, or if the vein is blocked, the vascular surgeon might use an artificial graft to create the fistula.
Your vascular surgeon will recommend the procedure based on your health.
Patients can expect to stay in the hospital for one to two hours after the procedure. Pain medication likely will be administered at the hospital and may be prescribed for the first few days of recovery.
After the fistula is created, the new connection begins to strengthen. After just a few weeks, the fistula between the vein and the artery is strong enough to accept a dialysis needle. (The graft procedure will take longer to heal.) After several months, the fistula is more mature and stronger, and the vein may appear more prominently in the arm or leg.
Potential risks of arteriovenous (AV) fistula creation include:
- Clotting of the vessels involved
- Narrowing of the vessels in the fistula
- Aneurysm (weakening of the blood vessel)
A further complication to watch for is something that is called “stealing.” This can happen if too much blood is diverted away from the circulation of the hand, causing loss of feeling.