What Is an Arteriovenous (AV) Fistula in Dialysis?

An artery and vein in your arm are joined by an arteriovenous (AV) fistula. This gives the needles from a hemodialysis machine a more secure access point.

Your kidneys may be unable to remove toxins from your blood if you have end-stage kidney disease (ESKD), also known as end-stage renal disease. Dialysis is used by more than two-thirds of Americans with ESKD to aid in this filtering process.

Dialysis keeps toxins from building up in your blood and harming other organs, just as your kidneys would normally do. When you urinate, the toxins may then go to your bladder and exit your body. Hemodialysis, which makes use of a hemodialyzer filtration machine, is the most used kind of dialysis.

The primary technique for establishing an arteriovenous (AV) fistula is to provide a blood vascular entry point for hemodialysis. A fistula is the joint between two normally unconnected body components. An artery and vein in your arm are joined by a surgeon to form an AV fistula.

To discover more about AV fistulas and the process involved in their creation, continue reading.

Why do I need an arteriovenous fistula for dialysis?

Your AV fistula is inserted with two needles that are attached to tubes from a hemodialyzer at the start of each dialysis session.

Your blood passes via one of the tubes to the hemodialyzer during dialysis. Through the other tube, your blood is purified and returned to your body.

Your veins pump more blood when you have an AV fistula. Your vein gets bigger and thicker as a result, strengthening it to withstand repeated needle insertions for dialysis treatments.

More blood can be cleaned because of the fistula's wider diameter, which also speeds up blood flow to and from the dialyzer.

Dialysis would not be possible if your vein collapsed due to a lack of an AV fistula.

Types of fistulas for dialysis

Dialysis-related AV fistula types include:

• Radiocephalic (Brescia-Cimino): The most typical kind of fistula connects your wrist's cephalic vein and radial artery.
• Brachiocephalic: This joins your forearm's cephalic vein and brachial artery.
• Transposed brachiobasilic: This connects the basilic vein to the brachial artery in your upper arm.

If a radiocephalic fistula is not an option, doctors may produce a transposed brachiobasilic or brachiocephalic fistula.

What is the procedure for creating an arteriovenous fistula?

To give your vein time to expand, a surgeon often makes an AV fistula at least six weeks before your first dialysis session.

To make you unconscious throughout the procedure, you might be given general anaesthesia or local anaesthesia to numb the area of your arm where the fistula will be made.

Usually, you can return home thereafter.

What are the possible risks and complications of AV fistula surgery?

Because an AV fistula often carries a reduced risk of problems and infections than a graft or catheter, it is the recommended access method for hemodialysis.

However, if your vein is compromised and has scar tissue from frequent needle insertions for blood tests, drugs, or other reasons, an AV fistula might not be achievable.

The following are potential side effects of AV fistula surgery:

• Thrombosis: The most frequent side effect is a blood clot that forms as a result of your vein constricting.
• Infection: According to a 2017 scientific analysis, infections rank as the second most frequent cause of complications.
• Aneurysm: Your artery may expand as a result of several needle insertions.
• Dialysis-associated steal syndrome: This problem results in decreased or reversed blood flow to your hand and affects up to 8% of patients with AV fistulas.
• Failure to mature: Factors like blood clot formation or blood artery narrowing that results in reduced blood flow can render the fistula useless.

WHEN TO CONTACT A DOCTOR

Immediately get in touch with your dialysis facility or a physician if you encounter any of the following symptoms around your fistula:

• redness, swelling, or soreness
• bleeding that continues after your dialysis session for more than 20 minutes
• tingling, numbness, or a chill in your arm

How do I prepare for AV fistula surgery?

Do the following to shield the arm where the fistula will form:

• Don't let that arm be used for injections.
• Avoid having that arm's blood extracted.
• Never take your blood pressure on that arm with a cuff.

What are alternatives to arteriovenous fistulas?

Healthcare providers can use a catheter, which is a tube that is usually placed into a major vein in your neck, or a graft, which is a soft tube, to join your blood vessels instead of making a fistula.

The National Institute of Diabetes and Digestive and Kidney Diseases reports that in 2021, 12.2% of individuals entered through an AV fistula and 85.4% entered through a catheter.

According to a 2018 study, AV fistulas are less likely to become infected and persist longer than catheters or grafts.

FAQs

Why is AV fistula important?

Because the blood may flow out of a fistula more quickly than via a line, you can typically receive better, more effective dialysis, receiving more dialysis in each session. For long-term survival and health, this is crucial.

What is AV fistula for dialysis specialists?

A nephrologist, or kidney doctor, recommends that a vascular surgeon perform the AV fistula surgery for dialysis. When performing dialysis access surgery for the treatment of chronic renal disease, the vascular surgeon must take into account several crucial factors.

How long does AV fistula for dialysis last?

For four DaVita patients, the duration of an AV fistula is 35 years.

How is AV fistula removed?

The operation is often carried out in the operating room by a surgeon. At the suggested location, you receive IV sedation to help you relax coupled with a local anaesthetic (numbing medication). There is not much discomfort involved, and you might even nod off throughout the one to two-hour operation.

Takeaway

An artery and vein in your arm are connected by an AV fistula, which strengthens the entrance point for the needles used in hemodialysis. Generally speaking, it has fewer difficulties than access points made via grafting or catheterization.

An AV fistula requires roughly an hour of surgery, and before beginning dialysis, you have to wait a few weeks for your vein to grow.

If you have damage to the veins in your arm, an AV fistula might not be a possibility for you. The appropriate form of dialysis entry point for you can be discussed with your doctor.