Severe renal vasoconstriction and anuria after intravenous urography in a patient with renal impairment.

Acute renal failure caused by radiocontrast agents remains a severe problem, particularly in patients with risk factors. There is debate concerning the pathophysiology of contrast media-induced acute renal failure, including, but not limited to, renal ischemia or tubular damage. Vascular ischemia is considered a major contributor because consistent changes in renal hemodynamics have been recorded experimentally. We describe a patient who has a typical course of contrast-associated renal failure manifested by severe renal vasoconstriction and backflow of the contrast agent during renal angiography performed after 6 days of an intravenous urography. Such degree of renal vasoconstriction is noteworthy in that this particular case might serve as a model in delineation of the pathogenetic mechanisms of acute renal failure after contrast media administration.