Hemodynamics of the hypogastric arterial circulation.

This study was designed to assess the major sources of collateral supply to the hypogastric arterial bed (HGA). Peak systolic HGA and radial arterial pressure were obtained before and after clamping a patent HGA and after additional clamping of the contralateral HGA, the contralateral external iliac artery (EIA), or the ipsilateral EIA both selectively and in combinations. These procedures were performed in 10 patients with aortoiliac (AI) aneurysms or occlusive disease. In seven patients with aneurysms, clamping the contralateral HGA decreased the HGA stump pressure index from 0.57 to 0.49 (p less than 0.05), and clamping only the ipsilateral EIA decreased the stump pressure index to 0.38 (p less than 0.001). In three patients with occlusive disease, clamping the contralateral HGA did not decrease the stump pressure index, clamping both the contralateral HGA and EIA decreased the index from 0.61 to 0.57 (p greater than 0.05), and clamping only the ipsilateral EIA decreased the pressure index to 0.40 (p less than 0.01). These data suggest that branches of the ipsilateral EIA femoral arterial system provide a more significant collateral pathway than the contralateral HGA. These results suggest that it is important to relieve occlusive disease in the ipsilateral EIA femoral arterial system if a patent HGA is ligated or bypassed during AI reconstructions. Conversely, it is especially important to preserve forward perfusion in a patent HGA in a patient with compromised ipsilateral EIA femoral runoff.