An uncommon cause of gross hematuria: two cases of ureteroarterial fistula.

Ureteroarterial fistula (UAF) is a rare but potentially fatal cause of hematuria seen in patients with prolonged ureteral stenting in the setting of surgery or abdominal radiation. It presents as episodic, transfusion-dependent hematuria with formation of clots. There is no current consensus for the optimal way to diagnose or treat UAF. We report two cases of UAF that required repeated studies and provocative testing to confirm the diagnosis. Both were successfully managed by endovascular stenting. Clinicians must recognize the diagnostic difficulties involved and maintain a high index of suspicion for UAF in stented patients with intermittent, severe hematuria.