Vasodilator response in the lower extremity induced by contrast medium. II. Humans.

A new functional test is presented whereby the severity of peripheral obstructive disease can be evaluated during routine angiography utilizing the vasodilator effect of standard contrast medium. The hyperemic response following a sequence of 1 or 2 ml contrast injections into the iliac or femoral arteries is recorded by video dilution technique. The method allows quantitative measure of the functional state of the lower extremity. The vasodilator response in 10 normal human subjects and 23 patients with arterial obstructive disease in compared. Increasing depression of peak flow correlates with increasing symptomatology and a delay in the time to peak flow is seen with small vessel (outflow) disease. The functional severity of outflow disease (trifurcation and superficial femoral artery) as compared with inflow obstruction (iliac arteries) seen at angiography is documented by the test. A new staging of peripheral obstructive disease is proposed based on the results.