RESUMO
RATIONALE AND OBJECTIVES: To investigate the influence of nonionic contrast media on the arterial blood flow velocity (BFV) during iliofemoral arteriography. MATERIALS AND METHODS: Iliofemoral arteriography with three contrast media--iopromide, iopamidol, and iodixanol--was carried out in 55 patients in a prospective manner. Hemodynamic changes were investigated using the change in the maximal systolic BFV in the dorsal artery of the foot and were recorded by simultaneous Doppler sonography. RESULTS: Comparable reductions in BFV were demonstrated for iopromide and iopamidol, but the iso-osmolar iodixanol produced no change in the maximal systolic BFV. The reduction in BFV by iopromide and iopamidol is attributed to a vasoconstrictive effect on the resistance vessels and is explained by a direct depolarization of the vascular smooth muscles with predamaged endothelium; the effect lasts for less than 1 minute. The time from the greatest change in BFV until the baseline value was achieved (recovery time) depended on the degree of vascular damage present. This can be explained by the inadequate compensation in circulatory regulation of patients with peripheral arterial occlusive disease. Iodixanol's lack of influence on BFV may result because its osmolality and chemotoxicity differ from those of iopromide and iopamidol. CONCLUSIONS: The peripheral hypoxemia observed in patients with arteriosclerotic vascular changes can be expected to increase through the vasoconstrictive effect of iopromide and iopamidol, whereas no such blood flow deficit is to be expected with the use of iodixanol. Nevertheless, the reduction in blood flow is of short duration and thus will probably not contribute significantly to this hypoxemia.
