[Renal arteriovenous fistula induced by blunt renal trauma : a case report]

We report a case of renal arteriovenous fistula (RAVF) following blunt renal trauma. An 84-year-old woman who presented with massive gross hematuria after striking her right flank region on the corner of a table was transferred to neighboring hospital on October 24, 2006. Plain computerized tomography (CT) revealed a small subcapsular hematoma on the right kidney, corresponding to a type I renal injury according to the classification of the Japanese Association for the Surgery of Trauma. However, subsequent enhanced CT demonstrated the migration of injected contrast material from the main trunk of the right renal artery to the inferior vena cava in the early phases. Because these findings suggested the occurrence of RAVF, the patient was referred to our hospital for further evaluation and therapy. Selective right renal arteriography enabled observation of trauma-induced RAVF in the upper pole of the affected kidney. Consecutively, transcatheter arterial embolization was performed with a metal coil, after which the shunt blood flow was successfully stopped. RAVF associated with blunt renal injury is extremely rare : only four cases have been previously reported in the literature.