Congenital renal arteriovenous malformation: angiography in its diagnosis.

Two patients with renal arteriovenous malformations are presented along with the distinct changes shown by urography, arteriography, and pharmacoangiography. The relevant roentgen signs in such patients include multiple small cobblestone-like identations caused by well-formed vascular channels projecting into the collecting structures, no angiographic or urographic evidence of a mass displacing the intrarenal vessels or collecting structures, normal sized arteries and veins leading to and from the malformation, and a decrease in size of the malformation after intra-arterial infusion of epinephrine. These patients may have flank pain or hematuria later in life or may remain asymptomatic. A complete urographic and angiographic examination will help to determine the appropriate therapy. Corrective surgery is usually reserved for symptomatic patients and, when indicated, require only surgical ligation of the vessels feeding and draining the malformation.