An arteriovenous fistula, often called an AV fistula, is a direct surgical connection established between an artery and a vein. This procedure typically occurs in the arm, though it can occasionally be created in the leg. The creation of this connection reroutes blood flow, allowing arterial pressure to directly enter the vein. This process results in a larger, more robust blood vessel pathway.
Purpose in Medical Treatment
The primary medical application for an arteriovenous fistula is to facilitate hemodialysis for individuals with kidney failure. When kidneys are unable to adequately filter waste products from the blood, dialysis becomes a necessary treatment. Hemodialysis requires frequent access to a patient’s bloodstream to efficiently remove these waste products. The fistula provides a reliable and long-lasting access point for this repeated blood filtration.
The surgical connection causes the vein to enlarge and its walls to thicken over time, a process known as maturation. This makes the vein more resilient and accessible for the needles used during dialysis sessions. The increased blood flow through the fistula allows for a higher volume of blood to be processed, which improves the efficiency of waste removal during each treatment.
An AV fistula is generally considered the most suitable type of long-term vascular access for hemodialysis due to its durability and lower risk of complications.
Surgical Creation Process
Creating an arteriovenous fistula involves a surgical procedure, typically performed on an outpatient basis. The operation usually takes place under local anesthesia, meaning the patient remains awake but the surgical area is numb. The surgeon makes an incision, commonly in the forearm, to locate a suitable artery and a vein. These vessels are then surgically joined together, forming the fistula. Following the procedure, the newly created fistula requires a period of maturation, ranging from several weeks to several months, to become wide and sturdy enough for repeated hemodialysis treatments.
Care and Monitoring
Proper care and regular monitoring are important for maintaining an arteriovenous fistula and ensuring its longevity. Patients should perform daily checks to confirm the fistula is functioning correctly. This includes gently feeling for a vibration, known as a “thrill,” and listening with a stethoscope for a distinct whooshing sound, called a “bruit,” both indicating proper blood flow.
Maintaining good hygiene around the fistula site is important to prevent infection, including regular washing of the arm with soap and water before dialysis. Patients should avoid activities that put undue pressure on the fistula arm, such as wearing tight clothing or jewelry. Blood pressure measurements should always be taken on the arm without the fistula to prevent damage or clotting.
Avoiding heavy lifting or carrying heavy objects with the fistula arm is also recommended. Protecting the arm from injury, such as bumps or cuts, is equally important. Any changes in the thrill or bruit, or signs of redness, swelling, warmth, or pain around the fistula site, should be reported to a healthcare provider promptly.