A brachial fistula is a surgically created connection between an artery and a vein in the arm. This connection is specifically designed to provide a durable and reliable access point for hemodialysis, a medical treatment for kidney failure. The fistula allows for the necessary blood flow to efficiently filter waste and excess fluids from the body when the kidneys can no longer perform this function.
Understanding Brachial Fistulas
A brachial fistula, also known as an arteriovenous (AV) fistula, is formed by joining an artery, which carries blood away from the heart, and a vein, which carries blood back to the heart. This procedure is performed in the non-dominant arm, often in the elbow area, where the brachial artery is connected to either the cephalic or basilic vein. The cephalic vein runs along the outer edge of the biceps muscle, while the basilic vein is deeper and runs along the inner bicep.
Brachial fistulas are the preferred method for vascular access, offering several advantages over options like grafts or catheters. They have a lower risk of infection and blood clots. Fistulas also have a longer lifespan, providing a sustainable solution for ongoing dialysis. The National Kidney Foundation recommends fistulas as the primary vascular access for long-term hemodialysis due to their superior clinical and economic benefits.
Creation and Maturation Process
The surgical creation of a brachial fistula involves a small incision in the arm, usually near the elbow crease. The surgeon dissects and mobilizes the chosen artery and vein, ensuring they can be connected without tension. The artery and vein are then joined, typically by connecting the end of the vein to the side of the artery. This connection allows high-pressure arterial blood to flow directly into the lower-pressure vein. The procedure is performed under local anesthesia, allowing the patient to return home the same day.
After surgery, the fistula needs time to “mature,” a process where the vein enlarges and strengthens due to increased blood flow and pressure from the artery. This allows the vein to expand, making it large and strong enough to withstand repeated needle insertions during dialysis. Maturation takes about 6 to 12 weeks, though it can take longer. During this period, patients might notice the vein becoming more prominent and may feel a “thrill,” a buzzing sensation, and hear a “bruit,” a whooshing sound.
How a Brachial Fistula Works
Once a brachial fistula has matured, it becomes suitable for hemodialysis sessions. The connection between the artery and vein results in a significant increase in blood flow and pressure within the vein, causing it to dilate and its walls to thicken. This transformation makes the vein robust enough to endure the repeated punctures required for dialysis.
During a dialysis session, two needles are inserted into the matured fistula. One needle, the “arterial” needle, draws blood from the body and directs it to the hemodialysis machine. This machine, sometimes referred to as an “artificial kidney,” filters out waste products, excess water, and salts from the blood. The cleansed blood is then returned to the body through the second needle, the “venous” needle, inserted into the same fistula. The larger diameter of the matured vein allows for a high flow rate, ensuring a sufficient volume of blood can be processed efficiently during each session.
Recognizing Potential Complications
While brachial fistulas are reliable, several complications can arise that require prompt medical attention. One issue is thrombosis, or clotting, which can occur due to vessel narrowing or compression of the fistula. Signs of thrombosis include a loss of the “thrill” or “bruit,” a buzzing sensation or whooshing sound.
Another concern is infection, which may present as localized redness, warmth, or more severe issues like abscesses or bloodstream infections. Patients should monitor for any signs of swelling, pain, or fever around the fistula site. Aneurysm, a ballooning of the vein, can also develop over time due to increased blood flow and pressure. This may present as a noticeable bulge or stretched skin over the fistula.
“Steal syndrome” occurs when the fistula diverts too much blood from the hand, leading to insufficient blood flow to the fingers and hand. Symptoms can include numbness, tingling, pain, coldness, or discoloration of the hand, and in severe cases, skin sores or ulcers. Any sudden or significant change in the fistula’s appearance or sensation, or the onset of these symptoms, warrants immediate medical evaluation.
Living With and Protecting Your Fistula
Living with a brachial fistula requires careful daily attention to ensure its longevity and proper function for hemodialysis. Regularly checking the “thrill” and “bruit” is an important self-monitoring practice. Any changes in these sensations or sounds should be reported to your healthcare team.
Maintaining good hygiene around the fistula site is important to prevent infection. The area should be washed daily with soap and water, and before each dialysis session.
- Avoid scratching the area and refrain from applying lotions, creams, or powders near the site.
- Protect the fistula arm from pressure by avoiding tight clothing, watches, or jewelry that could constrict blood flow.
- Avoid sleeping on the fistula arm, as this can restrict blood flow and potentially cause kinking.
- Blood pressure measurements and blood draws should always be performed on the opposite arm to prevent damage.
- Avoid lifting heavy objects or straining the fistula arm.