A fistula in hemodialysis connects which structures?

• A. An artery to a vein
• B. A vein to an artery
• C. A capillary to a valve
• D. A lymphatic to artery

Answer: (A)

Arteriovenous fistula means connecting an artery directly to a vein. By placing an artery in direct communication with a vein, arterial pressure drives blood straight into the venous system. This high-pressure, high-flow exposure causes the vein to enlarge and strengthen over time (arterialization), creating a durable, low-resistance access site that can be repeatedly cannulated for dialysis. This configuration is chosen because it provides the flow and durability needed for efficient dialysis with fewer complications than other access types. Other hypothetical connections, such as a connection involving capillaries, valves, or lymphatics, would not provide the necessary high-flow, high-pressure pathway for dialysis access.