Preoperative embolization of the head and neck: indications, patient selection, goals, and precautions.

Preoperative embolization was performed in 39 patients with 44 paragangliomas of the head and neck. Because of their complex vascular supply and their relation to vital structures such as the internal carotid artery and the lower cranial nerves, paragangliomas of the temporal bone represent challenging lesions to both the neuroradiologist and the otoneurosurgeon. Detailed classification by high-resolution CT and recognition of the multi- or monocompartmental vascular composition and of dangerous situations by selective angiography are essential prerequisites for safe and effective devascularization of paragangliomas of the temporal bone. Major complications that may occur if embolic material reaches intraaxial vessels through anastomoses between external carotid artery branches and the internal carotid and/or the vertebral artery can be avoided with the use of specific precautionary techniques. Palsies of the facial and lower cranial nerves can also be avoided if reabsorbable material is used for embolization of vessels supplying cranial nerves in asymptomatic patients. In selected cases with significant supply from the internal carotid artery, special interventional techniques, including embolization of the pericarotid tumor portion through the caroticotympanic artery and pre- or peroperative balloon occlusion of the petrous internal carotid artery, allow radical removal of extensive paragangliomas of the temporal bone. Techniques and selection of materials for embolization of carotid body, vagal body, and other paragangliomas of the head and neck mainly depend on the vascular composition of the tumor and on the specific vascular territory in which the tumor is located. In this series, preoperative embolization significantly improved surgical conditions of paragangliomas of any location in the head and neck and proved to represent an essential prerequisite for successful surgery of extensive paragangliomas of the temporal bone.