Spontaneous thrombosis of an iatrogenic arteriovenous fistula of the kidney

A 44-year-old woman underwent radial nephrotomy for a symptomatic stone in a caliceal diverticulum. Five days after an uneventful postoperative course of 1 week, she presented with gross hematuria. Routine ultrasound demonstrated a hypoechoic lesion in the kidney; color-coded sonography revealed an arteriovenous fistula. The hematuria ended before the scheduled angiography to embolize the fistula was performed. Repeated color-coded sonography revealed spontaneous thrombosis of the lesion. The follow-up examination 6 months later confirmed these findings. As traumatic arteriovenous fistulas have a good chance of spontaneous closure, invasive treatment should be postponed for as long as possible.