Treatment of solitary arteriovenous fistulas. Four patients with a solitary arteriovenous fistula were treated by transvascular balloon embolization technique, which resulted in complete fistula closure in three patients and partial closure in one. There were two vertebral arteriovenous fistulas, one peroneal arteriovenous fistula, and one radial arteriovenous fistula. The first two fistulas were spontaneous, the other two were traumatic. The only partial occlusion of the peroneal fistula was, in our opinion, due to a technical failure, the balloon was inflated slightly proximal to the fistular orificium instead of in the orificium itself. There were no complications, and there was no morbidity. In our opinion transvascular balloon embolization technique is the treatment of choice for solitary arteriovenous fistulas. 