[Duplex ultrasound studies of the deep femoral artery]

In case of occlusion of the superficial femoral artery (SFA), the deep femoral artery (DFA) supplies the entire lower extremity. Not infrequently, the SFA occlusion is associated with stenosis of the origin of the DFA. The angiographic study of the origin of DFA is often unsatisfactory. The purpose of the present study was to develop objective criteria for the diagnosis of the DFA origin stenosis by duplex scanning. In 60 patients, we examined 75 femoral bifurcations by duplex scanning and compared them with the independently performed angiography. Group 1 (n = 20 DFA origins) consisted of 10 normal individuals. Group 2 (n = 30 DFA origins) consisted of 25 patients with angiographically proven SFA occlusion and normal DFA. Group 3 (n = 25 DFA origins) consisted of 25 patients with angiographically proven SFA occlusion and DFA orifice stenosis. We measured the maximal systolic and mean flow velocity in the orifice of the DFA at rest and during the maximal hyperemia following 3 min of ischemia of the lower leg. At rest, the maximal flow velocity in groups 1-3 was 60 +/- 15, 142 +/- 44, and 255 +/- 60 cm/s (p less than 0.01) and the mean flow velocity was 8 +/- 6, 32 +/- 9, and 96 +/- 42 cm/s (p less than 0.01). During hyperemia, the maximal and mean flow velocity for groups 1-3 was 59 +/- 15, 155 +/- 42, and 286 +/- 82 cm/s (p less than 0.01) and 8 +/- 5, 55 +/- 19, and 144 +/- 51 cm/s (p less than 0.01), respectively. An origin stenosis of the DFA is highly probable when at rest the mean and maximal velocity in the proximal DFA exceed 50 cm/s and 180 cm/s, respectively. These results show that duplex scanning is able to detect safely DFA origin stenosis. The increase in postischemic DFA flow velocity when SFA occlusion is present, helps to evaluate total flow resistance of the deep-outflow channels (run-off) thereby being useful in planning appropriate therapy.