AV Fistula surgery illustration
The radiocephalic arteriovenous fistula (RC-AVF) is a shortcut between vena basilica and radial artery at the wrist. It is the recommended first choice for hemodialysis access. Possible underlying causes for failure are stenosis and thrombosis especially in diabetics and those with low blod flow such as due to narrow vessels, arteriosclerosis and high age. Reported potency of fistulae after 2 years is about 90%.
Normal blood flow in the brachial artery is 85 to 110 milliliters per minute (mL/min). After the creation of a fistula, the blood flow increases to 400-500 mL/min immediately, and 700-1,000 mL/min within 1 month. A bracheocephalic fistula above the elbow has a greater flow rate than a radiocephalic fistula at the wrist. Both the artery and the vein dilate and elongate in response to the greater blood flow and shear stress, but the vein dilates more and becomes "arterialized". In one study, the cephalic vein increased from 2.3 mm to 6.3 mm diameter after 2 months. When the vein is large enough to allow cannulation, the fistula is defined as "mature.