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In dialysis, all of a patient’s blood is withdrawn from an artery or vein, filtered and returned to a vein.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.
ConsiderationsYou may be asked to not eat or drink (fast) for part of the day before having the arteriovenous (AV) fistula procedure. Also, some medications, such as blood thinners, can influence the outcome of the surgery. Let your doctor know about all the medications and supplements you are taking.
After the procedure, you will be asked to keep the surgery site (arm or leg) elevated. You may be prescribed pain medication, if needed. Avoid heavy lifting soon after surgery. After the surgical site has healed, your doctor may also recommend special exercises to strengthen the fistula.
If a graft has been inserted, extra care must be taken to prevent infection. A graft might also require more recovery time, sometimes as long as four to six weeks, before it can be used as a source of dialysis access. While the graft heals, a catheter will be used for dialysis access.
The doctor will check for infection and provide directions about caring for the AV fistula. You may experience some temporary numbness in the limb with the fistula. If the numbness persists, talk to your doctor immediately. You may also be asked to check for a vibration that can be felt through the fistula. This will indicate that the fistula is available and functioning.
EffectivenessOnce healed, the AV fistula will allow for dialysis access for several years. If a graft has been inserted, it might have less longevity; a graft typically lasts about two years.
The long-term effects of the surgery can also be helped by daily routines in order to maximize the benefits of dialysis. Self-care might be combined with other treatment therapies. The goal of self-care methods is to help prevent further complications of kidney disease.
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.
Temporary numbness soon after the procedure is normal, but tell your doctor if the numbness persists.
UrgencyThe procedure is not usually urgent.
The successful creation of the arteriovenous (AV) fistula will help dialysis. The fistula provides more convenient access and reduces the risks of infection and discomfort when compared with a catheter. Until the fistula is complete, a catheter may be used to gain blood-vessel access.