Cranial Nerve Injury following Onyx Embolization of Glomus Jugular Tumors

Background: The surgical management of glomus jugular (GJ) tumors is complicated by their vascular nature as well as the close proximity of the carotid artery, jugular vein, and cranial nerves. In an attempt to reduce intraoperative blood flow to the tumor, many centers advocate for preoperative embolization of feeding vessels. Multiple embolic agents have been used in this setting, and recently, our center has transitioned toward the use of Onyx. Herein, we discuss our experience with preoperative Onyx embolization for glomus jugular tumors, particularly with regard to postembolization cranial nerve function.

Patients and Methods: Patients undergoing preoperative tumor embolization for glomus jugular tumors at a single center were identified. Those who underwent preoperative embolization with Onyx were included. Patients were excluded if their preembolization examination demonstrated paralysis of their lower cranial nerves (IX–XII), facial nerve, and cochleovestibular nerve or, if a postembolization physical examination was not available for review.

Results: A total of seven patients (100% females) meeting criterion were evaluated. The average patient age at the time of embolization was 41.2 years (median, 41.3; range, 21.8–62.8 years). One patient was noted to be diabetic, and an additional patient was a smoker. In two cases (28.6%), prior surgical resection had been attempted at an average of 194.8 months before Onyx embolization. Following embolization, one patient experienced complete facial nerve paralysis. No other new cranial neuropathies were clinically noted in any patient. In the one patient with new-onset facial paralysis, surgical resection was performed on the following day, and it was noted that the tumor encased the vertical segment of the intratemporal facial nerve. At 1 month of follow-up after complete tumor resection and facial nerve decompression, facial function is improving.

Conclusion: Preoperative glomus jugular embolization reduces tumor blood flow, which can be useful during surgical resection. Because of the risk of cranial neuropathy after embolization, a detailed neurologic examination should be considered in the immediate postembolization period. In our experience thus far, one cranial neuropathy has occurred with Onyx use, but the degree of injury has not proven to be absolute.