A new non-invasive technique for assessment of superficial femoral artery obstruction

Abstract

A transcutaneous technique is described utilizing two ultrasonic Doppler-shift flow-velocity meters simultaneously at sites down the arterial system of the leg in patients with superficial femoral disease. The change in shape of the blood-velocity/time wave-form over the cardiac cycle and the pulse propagation time between the two sites are measured. The transit time and change in pulse shape are used to assess limb viability. This method is compared with two other non-invasive techniques: whole-limb flow measured by a strain-gauge plethysmograph and with the systolic pressure difference between the arm and the calf. It is shown that as the pulse propagation time and the degree of damping of the blood-velocity/time wave-form increase, then limb perfusion decreases, and a nomogram is presented relating these parameters.