[A CASE OF URETEROARTERIAL FISTULA REQUIRING SURGICAL TREATMENT AFTER ENDOVASCULAR STENT PLACEMENT].

A 36-year-old woman was operated on at the age of 29 years for cervical cancer, and bilateral ureteral stents were inserted during radical hysterectomy. Subsequently, total pelvic irradiation and para-aortic lymph node irradiation were administered as postoperative radiation therapy. Four years following the surgery, the patient visited previous hospital for ureteral stent replacement; however, following this visit, there was no further contact with her. Seven years after the surgery, the patient presented with gross hematuria. Removal of right ureteral stent led to the observation of severe bleeding. The patient was, thus, transferred to our hospital because of suspected right ureteroarterial fistula. Angiography and intravascular ultrasonography showed a pseudoaneurysm at the distal end of the right common iliac artery. Thus, an endovascular stent graft was placed in the right common iliac artery, which led to resolution of the gross hematuria. One month after discharge, the patient developed right pyelonephritis and hydronephrosis; thus, she underwent right nephrostomy. Six months after undergoing right nephrostomy, the patient developed a fever of 39°C and started bleeding from the site of the right nephrostomy. A computerized tomography scan revealed a pseudoaneurysm in the right common iliac artery, and the endovascular stent graft was seen sliding into the artery. Thus, endovascular stent graft removal, pseudoaneurysm resection, and femoral-femoral artery bypass surgeries were performed. Thereafter, the patient showed no recurrence of infection or hematuria and no evidence of blood flow disorder to the lower extremities. In recent years, endovascular treatment for ureteroarterial fistulas is considered as the first-line treatment modality. However, in cases with infection, there is a possibility of vascular wall weakening, resulting in the formation of pseudoaneurysms, and sliding of the endovascular stent graft.