Arteriovenous fistula

n arteriovenous (AV) fistula is an irregular connection between an artery and a vein. Usually, blood flows from the arteries to tiny blood vessels (capillaries), and then on to the veins. Nutrients and oxygen in the blood travel from the capillaries to tissues in the body. With an arteriovenous fistula, blood flows directly from an artery into a vein, avoiding some capillaries. When this happens, tissues below the avoided capillaries receive less blood.

Symptoms

Small arteriovenous fistulas in the legs, arms, lungs, kidneys or brain often won’t have any signs or symptoms. Small arteriovenous fistulas usually don’t need treatment other than monitoring by a health care provider. Large arteriovenous fistulas may cause signs and symptoms.

Arteriovenous fistula signs and symptoms may include:

• Purplish, bulging veins seen through the skin, similar to varicose veins
• Swelling in the arms or legs
• Decreased blood pressure
• Fatigue
• Heart failure
• A significant arteriovenous fistula in the lungs (pulmonary arteriovenous fistula) is a serious condition and can cause:
• Pale gray or blue lips or fingernails due to lack of blood flow (cyanosis)
• Fingertips to spread out and become rounder than normal (clubbing)
• Coughing up blood
• An arteriovenous fistula in the digestive tract can cause gastrointestinal (GI) bleeding.

Causes

Arteriovenous fistulas may be present at birth (congenital) or they may occur later in life (acquired). Causes of arteriovenous fistulas include:

• Injuries that pierce the skin. An arteriovenous fistula may result from a gunshot or stab wound that occurs on a part of the body where a vein and artery are side by side.
• Congenital arteriovenous fistulas. In some babies, the arteries and veins don’t develop properly in the womb. It’s unclear exactly why this happens.
• Genetic conditions. Arteriovenous fistulas in the lungs (pulmonary arteriovenous fistulas) can be caused by a genetic disease that causes irregular blood vessels throughout the body, but especially in the lungs. One such disease is Osler-Weber-Rendu disease, also known as hereditary hemorrhagic telangiectasia.
• Dialysis-related surgery. People who have late-stage kidney failure may have a surgery to create an arteriovenous fistula in the forearm to make it easier to perform dialysis.

Who Needs Arteriovenous Fistula

Arteriovenous Fistula is primarily indicated for patients with end-stage renal disease (ESRD) who require long-term hemodialysis treatment. It is preferred over other dialysis access methods, such as central venous catheters and synthetic grafts, due to its lower risk of infection, longer lifespan, and better blood flow rates during dialysis.

When to See a Specialist

Patients with end-stage renal disease (ESRD) who are preparing for or currently undergoing hemodialysis treatment should see a vascular specialist or a vascular surgeon to evaluate their suitability for an Arteriovenous Fistula. The specialist will assess the patient’s vascular health, blood flow, and vein condition to determine the most appropriate access method for hemodialysis.

Procedure

• Pre-operative Assessment: The patient undergoes a thorough medical evaluation, including blood tests, imaging studies, and vascular mapping, to assess the suitability of the vessels for creating an AVF.
• Anesthesia: The procedure is typically performed under local anesthesia, with sedation or general anesthesia, depending on the patient’s health and preference.
• Surgical Incision: The surgeon makes an incision near the selected artery and vein in the arm.
• Connection Creation: The artery and vein are carefully dissected, and a connection is created between them to form the fistula.
• Blood Flow Evaluation: The surgeon ensures that the blood flow through the AVF is sufficient and free from any obstructions.
• Closure: The incision is closed and sutured, and the patient’s arm is bandaged.

Road to Recovery
Recovery after the creation of an Arteriovenous Fistula is usually straightforward. The patient is encouraged to keep the fistula area clean and dry and avoid putting unnecessary pressure on the arm. The fistula typically takes a few weeks to mature and develop adequate blood flow for dialysis use.

Risk Management

Arteriovenous Fistula creation is a relatively safe procedure, but like any surgical intervention, it carries some risks, including infection, bleeding, blood clots, and fistula failure. However, the benefits of a well-functioning AVF, such as better dialysis outcomes and reduced risk of complications, often outweigh the risks.

Benefits of Arteriovenous Fistula

• Improved Hemodialysis Access: The AVF provides a reliable and long-lasting access point for hemodialysis, minimizing the need for frequent needle insertions and reducing the risk of infection.
• Increased Blood Flow Rates: Compared to other dialysis access methods, AVF allows for higher blood flow rates during hemodialysis, leading to more effective waste removal and better dialysis outcomes.
• Lower Risk of Complications: AVF has a lower risk of complications, such as infections and blood clots, compared to central venous catheters and synthetic grafts.

Frequently Asked Questions

1. Can anyone with end-stage renal disease get an Arteriovenous Fistula?

Not all patients with end-stage renal disease are suitable candidates for an AVF. The suitability of an AVF depends on the patient’s vascular health and the condition of their blood vessels. Your vascular specialist will assess your eligibility for the procedure.

2. How long does it take for an AVF to mature?

It typically takes a few weeks to a few months for an AVF to mature and develop adequate blood flow for dialysis use.

3. Is AVF creation a permanent solution?

Once an AVF is created, it is considered a permanent dialysis access method, and it can be used for hemodialysis for many years if properly maintained.

4. How do I care for my AVF after the procedure?

Your healthcare team will provide instructions on caring for your AVF after the procedure, including how to keep the area clean and avoid activities that could damage the fistula.

5. Can an AVF be used for other medical procedures?

In some cases, an AVF can be used for certain medical procedures, such as blood draws or contrast dye injections, if the vein is large enough and has adequate blood flow. However, it is essential to consult with your healthcare team before using the AVF for any other purpose.