AVFs

AVF stands for arteriovenous fistula, a surgically created connection between an artery and a vein used to provide access for hemodialysis in people with kidney failure. AVFs are one of the preferred forms of vascular access because they generally have longer patency and lower infection and thrombosis rates than arteriovenous grafts or central venous catheters, though they require time to mature before they can be used.

Creation and sites: A vascular surgeon creates the fistula by connecting an artery to a nearby vein, typically in the forearm or upper arm. Common configurations include radiocephalic (wrist), brachiocephalic (elbow), and, when needed, brachiobasilic (upper arm with vein transposition). The goal is to provide a vein that can be repeatedly cannulated for dialysis, with sufficient flow to support treatment.

Maturation and use: After creation, the vein enlarges and thickens in response to arterial blood flow, a process called maturation. Maturation commonly takes several weeks to a few months. Not all fistulas mature adequately for cannulation; some require revision or alternative access methods.

Advantages and limitations: AVFs generally offer longer-term access with fewer interventions than catheters or grafts and have lower infection risk. They may require periodic surveillance and interventions to maintain patency. Limitations include the time required to mature, potential failure to mature, and complications such as stenosis or thrombosis.

Complications and care: Possible problems include venous outflow stenosis, aneurysm formation, infection, steal syndrome (hand ischemia), and, rarely, high-output cardiac stress. Maintenance involves regular access checks for thrill and bruit, avoidance of needle sticks or compression in the fistula area outside dialysis, and timely imaging or procedures if dysfunction is suspected.