Onyx embolization of an intracranial hemangiopericytoma by direct transcranial puncture

Intracranial hemangiopericytomas are uncommon but highly vascular dural-based tumors which commonly derive arterial blood supply from both intracranial and extracranial circulations. Microsurgical resection of these lesions may result in excessive blood loss without the aid of pre-operative embolization. We describe a case of a large tentorial hemangiopericytoma for which initial resection was aborted due to excessive blood loss. After failed endovascular access, we performed a direct transcranial puncture of the hemangiopericytoma through the craniotomy defect and successfully embolized the tumor with Onyx. Post-embolization gross total resection was achieved with a limited amount of operative blood loss. Direct puncture embolization provides several advantages over traditional endovascular embolization including decreased procedural duration, circumventing challenging arterial anatomy, and a lower risk of stroke in the presence of extracranial-to-intracranial anastomoses. While direct puncture embolization has been described for tumors of the neck and skull base, this is the first reported case of an intracranial hemangiopericytoma successfully devascularized by direct transcranial puncture Onyx embolization.