Balloon-assisted Onyx embolization of cerebral single-channel pial arteriovenous fistulas: Technical note

Object. Pial arteriovenous fistulas (AVFs) of the brain are rare vascular malformations associated with significant risks of hemorrhage and neurological deficit. Depending on their location and high-flow dynamics, these lesions can present treatment challenges for both endovascular and open cerebrovascular surgeons. The authors describe a novel endovascular treatment strategy that was used successfully to treat 2 pediatric patients with a pial AVF, and they discuss the technical nuances specific to their treatment strategy. Methods. A single-channel high-flow pial AVF was diagnosed in 2 male patients (6 and 17 years of age). Both patients were treated with endovascular flow arrest using a highly conformable balloon followed by Onyx infusion for definitive closure of the fistula. Results. Neither patient suffered a complication as a result of the procedure. At the 6-month follow-up in both cases, the simple discontinuation of blood flow had resulted in durable obliteration of the fistula and stable or improved neurological function. Conclusions. Onyx can be delivered successfully into high-flow lesions after flow arrest to allow a minimally invasive and durable treatment for pial AVFs.