Pial arteriovenous fistulas: two pediatric cases and a literature review

Pial arteriovenous fistulas (AVFs) of the brain are rare vascular malformations associated with significant risk of hemorrhage and neurological deficits. Depending on their location and high-flow dynamics, these lesions can present treatment challenges for both endovascular and open cerebrovascular surgeons. We present a novel approach to treat intracranial high-flow pial AVFs. A single-channel high-flow pial AVF was diagnosed in two children aged 4 and 12 years, respectively. The patients were treated with coil and/or embolization with balloon-assisted liquid emboli to ensure fistula closure. The pial AVFs were transarterially embolized via feeding arteries. Immediate and complete angiographic obliteration was achieved without procedural complications. At the 5-month follow-up, the simple discontinuation of blood flow resulted in a sustained obliteration of the fistula and the headaches disappeared. In conclusion, arterial feeder embolization represents a potentially effective novel treatment for the rare occurrence of high-flow pial AVFs. The liquid embolism agent was successfully delivered into high-flow lesions after flow arrest using coils and/or a balloon combination, to enable minimally invasive and durable treatment of pial AVFs.