Effect of radiographic contrast media on renal perfusion - First results.

BACKGROUND Intra-arterial administration of radiographic contrast media (CM) is discussed to impair renal perfusion. The pathogenesis of contrast-induced Nephropathy (CIN) is still not clarified. OBJECTIVE This trial was performed to prove the effects of two CM with different molecular structure on renal perfusion. METHODS A prospective, randomized study on 16 pigs was designed to compare the outcome after application of a low-osmolar iodinated CM (770 mOsm/kg H2O - Group1) and an iso-osmolar iodinated CM (290 mOsm/kg H2o - Group2).Color Coded Doppler Sonography (LOGIQ E9, GE, Milwaukee, USA) was applied for measuring the Renal Resistive Index (RRI) before and after the first, fifth, and tenth bolus of CM. Statistics was performed using analysis of variance for repeated measurements with the Factor "CM". RESULTS All flow spectra were documented free of artifacts and Peak Systolic Velocity (PSV), Enddiastolic Velocity (EDV) and RRI respectively could be calculated. Mean PSV in Group 1 led to a decrease while in Group 2 PSV showed a significant increase after CM (p = 0,042). The course of the mean EDV in both groups deferred accordingly (p = 0,033). Mean RRI over time significantly deferred in both groups (p = 0,001). It showed a biphasic course in Group 2 and a decrease over time in Group 2. CONCLUSION While iso-osmolar CM induced an increase of PSV and EDV together with a decrease of RRI, low-osmolar CM could not show this effect or rather led to the opposite.