[A case of renal arteriovenous fistula complicated with pyelonephritis].

We report a case of renal arteriovenous fistula, which was found during treatment for pyelonephritis. A 61-year-old woman was referred to our hospital because of lumbar backache and infectious fever. The computed tomographic scan showed right hydronephrosis and perinephritis. We treated her conservatively for pyelonephritis, but 5 days later, the contrast-enhanced computed tomographic scan showed retroperitoneal hemorrhage. Renal angiography demonstrated an arteriovenous fistula in the central portion of the right kidney. Superselective transcatheter arterial embolization of the AVF was performed. Hemostasis was possible by embolization. She has not had any recurrence of renal arteriovenous fistula. To our knowledge, this is the 5th report of a rupture in the retroperitoneum of an arteriovenous fistula, and renal arteriovenous fistula with the pyelonephritis is very rare.