Patient undergoes a fistulogram that confirms the diagnosis of steal syndrome. Lets review the images below.
When the cephalic venous outflow is blocked manually (see forceps) causing the flow through the fistula to stop, the flow into the radial artery towards the hand is visible.
When the forceps are removed and the venous outflow is no longer obstructed, flow is seen from the brachial artery exclusively through the anastomosis into the cephalic vein. No flow is seen into the radial artery (see first picture for comparison where the outflow is manually obstructed).
When the brachial artery is cannulated and contrast injected, no flow is seen going into the radial artery because all the flow is shunted through the fistula.
