Fig 1.

Doppler ultrasound examination. After snuffbox fistula (SBAVF), the blood in the middle one-third of the forearm flows into the deep vein system, and in the area of the antecubital fossa (AF), it returns through the proximal perforating vein (PPV) back to the superficial system (ie, cephalic vein [CV] on the arm. A, Doppler ultrasound longitudinal view through the CV. B, Ultrasound transverse view through the radial artery (RA) and radial vein (RV). C, Doppler ultrasound transverse view through the RA and RV. D, Doppler ultrasound transverse view through CV in the arm. BA, Brachial artery; DPV, distal perforating vein.