Carotid paragangliomas. Alternatives for presurgical endovascular management

Abstract

Carotid paragangliomas (CP) are rare tumors, representing 0.6% of the head and neck tumors. These tumors have their origin in the carotid body located in the adventitia of the vascular wall of the carotid bifurcation. Among their principal characteristics are hypervascularity, primarily dependent on branches of the external carotid artery, the proximity and possible involvement of the cranial nerves IX, X, XI, XII, and extension to the base of the skull. Complete surgical resection is the first line of management; however, this procedure can be a surgical challenge due to the potential risk of bleeding, intraoperative neurovascular injuries, and prolonged surgical time. Tumor embolization, carotid stenting, and tumor embolization with carotid stenting have been developed as alternative presurgical endovascular techniques that decrease tumor vascularity and/or provide structural vascular support, reducing bleeding and facilitating tumor dissection. Two cases of carotid tumors of the same classification, Shamblin II, are presented, one treated by preoperative embolization and the other managed with a carotid stent; the indications, advantages, and possible complications of each one are discussed. Two cases of Shamblin II carotid tumors are presented, one treated preoperatively with a carotid stent and the other with preoperative embolization. A literature review was carried out, with a search in PubMed that includes case reports, case series, review articles, meta-analyses on CP, presurgical tumor embolization, presurgical carotid stent placement, and surgical treatment of carotid body tumor. Hypervascularity and adhesion to the carotid wall are the leading causes of difficulties in surgical resection of CP. Optimal tumor embolization and/or preoperative carotid stent placement reduce intraoperative bleeding and provide vascular structural support, reducing intraoperative and postoperative complications.