[Congenital renal arteriovenous fistula complicated with multiple renal arteries malformation: case analysis]

Congenital renal arteriovenous fistula complicated with multiple renal arteries malformation is rare and hard to diagnose at early stage. Blood loss and complications after embolization are both severe. Some cases can be diagnosed by ultrasound, enhanced CT scan or digital subtraction angiography (DSA). Cystoscopy and ureteroscopy can identify the location of bleeding, exclude tumors, and discharge ureteral obstruction. A case of congenital renal arteriovenous fistula complicated with multiple renal arteries malformation was reported to investigate the pathogenesis, clinical characteristics, diagnosis and treatment of congenital renal arteriovenous fistula with multiple renal arteries malformation. A 36-year-old female patient with congenital renal arteriovenous fistula with multiple renal arteries malformation was hospitalized in the Department of Urology of Peking University People's Hospital. Five days before admission, the patient experienced whole course painless gross hematuria for 5 days with many blood clots. The patient's blood pressure was 90/70 mmHg, and hemoglobin was 60 g/L. The urinary CT scan showed a right hydronephrosis associated with dilatation of the upper ureter which was obstructed by space occupying lesion of the lower ureter. Many clots in the bladder could also be found in the CT scan. Cystoscopy showed many blood clots in the bladder and confirmed that the bleeding was fromthe right ureteral orifice. Ureteroscopy confirmed that the bleeding was from the right renal pelvis and many blood clots in the right ureter, and found no tumor in the right ureter and renal pelvis. We cleared the blood clots in the right ureter and inserted a ureteral stent.We thought that renal vascular malformation of the right kidney might lead to the hematuria from right renal pelvis. DSA showed a double renal arteries malformation in the right kidney. The diagnosis of "renal arteriovenous fistula" was considered with renal arteriovenous fistula in the right kidney. Selective arteriography revealed the presence of tortuous, coiled, dilated, and multichannelled vessels in the middle of the right kidney. With stainless steel coils, we embolized the vessels which supplied the fistula. Four days after the procedure, gross hematuria disappeared. Five days after the procedure, the patient's anemia improvedand the patient was discharged in good condition. Four months after the procedure, gross hematuria did not recur. The Doppler showed that the right kidney was normal and the renal dynamic showed that the right kidney function was normal. So DSA is the golden standard for diagnosis of congenital renal arteriovenous fistula complicated with multiple renal arteries malformation. Confirming the number of renal arteries by abdominal aorta angiography is necessary to avoid missed diagnosis. Renal arterial embolization is safe and effective.