Which value represents the highest recommended minimum venous diameter for an access graft?

• A. Greater than or equal to 2.5 mm
• B. Greater than or equal to 4 mm
• C. Greater than or equal to 2 mm
• D. Greater than or equal to 6 mm

Answer: (D)

In planning a dialysis access graft, having a vein with a generous diameter is crucial for good graft maturation and reliable cannulation. A larger venous outflow channel allows higher flow through the graft, reduces the risk of stenosis at the anastomosis, and makes cannulation with standard dialysis needles more feasible. Because of these benefits, a venous diameter of 6 mm or larger is recommended as the minimum to maximize success. Smaller diameters, such as 2 mm, 2.5 mm, or 4 mm, may work in select situations but are associated with higher failure rates and complications, so they are not the preferred standard.