Interpretation of duplex ultrasound dialysis access testing.

Conditions producing dialysis access dysfunction include failure of access maturation, cannulation injury to the conduit wall, thrombosis, low-volume flow, and aneurysmal degeneration. Duplex ultrasound is an accurate diagnostic technique to assess dialysis access anatomy and function, including the obligatory criteria for maturation, eg, volume flow >800 mL/min, conduit depth 0.6 cm from skin surface, and adequate (>5 mm) conduit diameter for cannulation. Measurement of access volume flow from the brachial artery or access conduit is prognostic for effective dialysis and conduit patency; including the determination of whether access maturation has occurred or when to intervene for a duplex-identified access stenosis. The application of duplex surveillance after autogenous vein or prosthetic bridge dialysis access construction has the potential to improve patency and function in the patient whose life is dependent on effective hemodialysis.