[Congenital arteriovenous malformation of the kidney: report of two cases--detection by digital subtraction angiography with carbon dioxide].

Two cases of arteriovenous malformation of the kidney were reported. The first case was a 19-year-old female, complaining of right flank pain and gross hematuria. Right selective renal arteriography revealed a 2 x 1.5 cm large cisoid type arteriovenous malformation at the most distal region of the lower branch of the renal artery. Transcatheter embolization, using Gelfoam and absolute ethanol, was successfully done, which was confirmed with repeated digital subtraction angiography with carbon dioxide (CO2-DSA). The second patient was a 55-year-old female with past history of right idiopathic renal bleeding, complaining of right flank colicky pain and gross hematuria. Right selective renal arteriography was done without any pathological findings, while CO2-DSA documented an arteriovenous malformation in the hilar region. Transcatheter embolization was not done, because the malformation seemed to be proximally located. Thus CO2-DSA was thought to be a reliable method in the diagnosis of arteriovenous fistula.