Onyx embolization of skull base paragangliomas: a single-center experience

Background Skull base paragangliomas are highly vascular tumors that are often embolized before surgical resection; however, the safety and efficacy of preoperative embolization using an ethylene vinyl alcohol copolymer (Onyx; Medtronic, Dublin, Republic of Ireland) in these tumors is unknown. This retrospective cohort study evaluated patient outcomes after preoperative embolization of skull base paragangliomas using Onyx. Methods We retrospectively analyzed data from all patients with skull base paragangliomas who underwent preoperative Onyx embolization at our institution (January 01, 2005-December 31, 2017). Patient, tumor, embolization, and outcomes data were extracted by reviewing inpatient and outpatient clinical and imaging records. Results Seven patients were studied (5/7 [71%] female), 6 with glomus jugulares and 1 with a glomus vagale. The median age was 52 years, and the most common presenting symptom was cranial neuropathy (6/7 [86%]). The tumor vascular supply was from the ascending pharyngeal artery in all 7 cases (100%) with additional feeders including the occipital artery in 5 (71%); internal carotid artery in 3 (43%); middle meningeal, vertebral, and internal maxillary artery each in 2 (29%); and posterior auricular artery in 1 (14%). The median postembolization tumor devascularization was 80% (range, 64-95%). The only postembolization complication was a facial palsy in 1 patient. Conclusion Preoperative embolization with Onyx affords excellent devascularization for the majority of skull base paragangliomas, and it may facilitate resection of these hypervascular lesions. The advantages provided by Onyx with respect to penetration of intratumoral vessels must be weighed against the risk of cranial neuropathy.