Hemodynamic evaluation of the aortoiliac system based on pharmacologic vasodilatation

Selection of the appropriate vascular reconstructive procedure in patients with multisegment disease requires the differentiation of aortoiliac from femoropopliteal occlusive disease and the detection of subcritical stenoses in the aortoiliac segment. Triplane arteriography and common femoral intra-arterial papaverine injection (30 mg) were done in 43 lower extremities in patients who subsequently had arterial bypass. The percent diameter stenosis was measured on the arteriograms and common femoral intra-arterial pressure was continuously monitored before and after papaverine injection. A resting femoral/brachial pressure index (FBI) was obtained and the percent decrease in this index (% delta FBI) was calculated using the maximum decrease in FBI following injection. Regression analysis revealed a significant correlation between % delta FBI and percent aortoiliac stenosis (r = 0.5446, P less than 0.005). In relation to clinical course, receiver-operator characteristic curve analysis revealed a % delta FBI of greater than or equal to 0.15 to be optimal in the detection of hemodynamically significant aortoiliac stenoses. When compared to clinical course, this % delta FBI was 88% sensitive, 100% specific, and 95% accurate. However, when analyzed with arteriography as the standard (50% stenosis), the same % delta FBI was only 70% sensitive, 100% specific, and 86% accurate. All limbs with a % delta FBI of 0.15 or greater improved following aortoiliac revascularization; 21% of these limbs had a normal preoperative resting FBI. No patient with a % delta FBI lower than 0.15 had improvement following aortoiliac revascularization. All limbs that had infrainguinal bypass had normal FBIs and % delta FBIs before bypass. After operation 90% of these limbs improved. Overall, this technique correctly predicted the clinical course in 95% of the limbs tested.