Arterial Venous Fistulas in Dialysis: A Lifeline for Patients with Kidney Disease

Andrew Kowalski, MD, FASN

For individuals with chronic kidney disease (CKD), dialysis is often a necessary treatment to filter waste products and excess fluid from the blood. Hemodialysis, one of the primary methods of dialysis, requires a reliable way to access the bloodstream repeatedly. One of the most effective ways to achieve this is through the creation of an arterial venous fistula (AVF).

In this post, we’ll explore what AVFs are, why they’re important for dialysis, and what patients can expect when they undergo the procedure.

What is an Arterial Venous Fistula?

An arterial venous fistula is a surgically created connection between an artery and a vein. Normally, arteries carry oxygen-rich blood from the heart to tissues throughout the body, and veins carry oxygen-depleted blood back to the heart. In an AVF, a surgeon connects an artery directly to a nearby vein, usually in the arm, which allows the vein to carry blood under higher pressure. This connection causes the vein to enlarge and thicken over time, making it easier to insert dialysis needles repeatedly.

Why are AVFs Important in Dialysis?

Hemodialysis requires access to the bloodstream because the dialysis machine needs to remove blood from the body, filter it, and then return it to the patient. There are three main types of vascular access used for hemodialysis:

1. Arterial venous fistula (AVF) – a surgically created connection between an artery and vein.

2. Arterial venous graft (AVG) – a synthetic tube connecting an artery and vein.

3. Central venous catheter (CVC) – a catheter placed in a large vein, typically in the chest.

Among these, the AVF is considered the gold standard because it is the most durable and offers the best long-term outcomes. AVFs are associated with lower infection rates, better blood flow, and fewer complications compared to AVGs and CVCs. AVFs can last many years, while AVGs and CVCs are more prone to clotting, infection, and other complications.

How is an AVF Created?

The creation of an AVF is a minor surgical procedure performed by a vascular surgeon, typically on an outpatient basis. The surgeon will make a small incision, usually in the arm, and connect a nearby artery and vein, allowing blood to flow directly between the two vessels.

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Over the course of several weeks to months, the vein begins to enlarge and strengthen, becoming more suitable for the repeated needle insertions required for hemodialysis. This process is known as “maturation,” and it’s essential for the AVF to fully develop before it can be used for dialysis.

Advantages of AVF

• Lower risk of infection: AVFs use the body’s own tissue, making them less prone to infection compared to synthetic grafts or catheters.

• Durability: Once matured, an AVF can last for many years, providing a reliable and long-term access point for dialysis.

• Better blood flow: AVFs allow for higher blood flow during dialysis sessions, making the process more efficient.

• Fewer interventions: Compared to grafts and catheters, AVFs require fewer repairs or replacements over time.

Potential Complications

While AVFs are generally safe and effective, they aren’t without risks. Some potential complications include:

• Non-maturation: In some cases, the fistula may fail to mature properly, making it unsuitable for dialysis. This might require further procedures or an alternative access method.

• Stenosis: Narrowing of the vein at the connection point, which can reduce blood flow and require intervention such as a balloon angioplasty (balloon stretching, very similar to what happens in the heart when a patient has a heart atack).

oung J N, Reyes C A, Erinle A O (May 05, 2022) An Arterial Anastomosis Stenosis Used in Lieu of Banding to Prevent Dialysis Access Steal Syndrome. Cureus 14(5): e24757. doi:10.7759/cureus.24757

• Infection: Although less common than with other types of access, infections can still occur.

• Aneurysm: Over time, the vein may become weakened and bulge, creating an aneurysm that may need treatment.

Living with an AVF

For patients with an AVF, it’s important to take steps to protect the fistula and ensure it remains healthy:

• Exercise: Regularly exercising the arm with the fistula can help the vein mature and grow stronger. Many doctors recommend squeezing a rubber ball to improve circulation in the arm. I have also encountered many patients that tell me that they are not allowed to use the arm with the fistula, that is complete nonscence. Exercise will actually help the blood flow and maintain the fistula.

• Avoid pressure: Patients should avoid wearing tight clothing or jewelry on the arm with the fistula and should avoid using the arm for heavy lifting that will lead to compression of the fistula. Prolonged compression with slow or stop blood flow and increase the chance of the the fistula clotting, requiring a procedure to clear the clot and to get the fistula working agian.

• Routine checks: Patients can check the fistula daily by feeling for a “thrill,” a buzzing sensation indicating good blood flow. If this sensation weakens or disappears, it may be a sign of a problem.

• Hygiene: Good hygiene is crucial to avoid infections, especially before dialysis sessions. Cleaning the area thoroughly and following the dialysis center’s instructions can reduce the risk of complications.

Conclusion

Arterial venous fistulas are a crucial lifeline for patients undergoing hemodialysis. While the procedure requires time to heal and mature, the benefits of an AVF far outweigh other access options in terms of durability, safety, and long-term success. Patients who receive an AVF can enjoy more efficient dialysis treatments, fewer complications, and better overall outcomes.

As with any medical procedure, it’s important for patients to be fully informed and work closely with their healthcare providers to ensure the best possible care. If you or a loved one is considering dialysis, discussing AVF options with your healthcare team can provide invaluable insight into the best course of action for managing chronic kidney disease.