A rare complication of ureteral stenting: Case report of a uretero-arterial fistula and revision of the literature.

INTRODUCTION: Uretero-arterial fistulas are a rare condition. The most frequent clinical sign is hematuria. Since these bleedings occur intermittently, the diagnosis is very difficult. If not discovered, uretero-arterial fistulas involve a very high rate of mortality or even results in loss of kidney function.

CASE REPORT: The clinical case we describe is an unusual one. After a radical hysterectomy and a subsequent radiotherapy, a hydronephrosis caused by ureteral fibrosis occurred on both sides. Therefore, the patient received bilateral ureteral stents. During a change of the ureteral stents 18 months later, a massive bleeding appeared in the right ureter. Initially, a clear evidence of a fistula was not possible - neither through CT scan nor through selective angiography. There were some indicators of a uretero-arterial fistula, so an endoluminal vessel stent was placed. Subsequently the fistula probably led to an erosion of the vessel stent.

DISCUSSION: A fistula between the ureter and the iliac artery (UAF) is a rare complication. The increase in known cases during the last years is linked to the possibility of ureteral stenting since 1978. Until now only 140 cases have been described in literature. The mortality rate through UAF has decreased from 69% in 1980 to 7-23% today. Its development can be traced through the pulsation of the artery and the pressure on the ureter. The most important clinical symptom is bleeding. Diagnosis is generally difficult and represents the real problem. The sensitivity of the standard angiography examination is 23- 41%; it can be improved to 63% using the "provocative" method, which means mobilizing the ureteral stent during examination. The therapy in course of the angiography consists of a simultaneous endovascular stent and/or a co-embolisation.

CONCLUSION: Arterial or uretero-arterial fistulas (UAF) are a rare condition; the diagnosis is very difficult and most of the time the treatment requires a multidisciplinary team.