Balloon-assisted coil embolization for high-flow renal arteriovenous fistula with inferior vena cava dilatation: A report of two cases.

Renal arteriovenous fistulae are rare vascular anomalies that can lead to hypertension, high-output heart failure, or renal dysfunction when associated with a large left-to-right shunt. Renal arteriovenous fistulae with dilatation of the inferior vena cava are particularly uncommon, and the optimal endovascular strategy remains controversial. This report describes the cases of 2 asymptomatic patients with incidentally detected right renal arteriovenous fistulae and dilatation of the inferior vena cava who were treated with balloon-assisted transarterial coil embolization of the shunt while preserving the normal renal arterial branches. In 1 patient, migration of a coil into the right atrium occurred after deflation of the balloon, but was successfully managed with endovascular retrieval and additional coil packing under renewed flow control. Four months after treatment, both patients showed durable angiographic occlusion of the fistula, a reduction in the diameter of the inferior vena cava, and preserved global renal function, although a limited perfusion defect was observed in the lower pole of the kidney in 1 patient. Balloon-assisted coil embolization may represent a valuable treatment option for high-flow renal arteriovenous fistulae with inferior vena cava dilatation when performed with meticulous flow control and careful coil selection.