Preoperative Embolization in Carotid Body Tumor Surgery—Benefit or Risk?

Abstract

Carotid body tumors (CBTs) are rare head and neck paragangliomas with an incidence of 0.03% of all tumors. Risk of malignant transformation is 5% to 10%. Preoperative transarterial embolization can facilitate resection of the highly vascularized tumors, yet the benefit of this procedure has not yet been demonstrated clearly. The purpose of this study was to assess the results of preoperative transarterial embolization with focus on patient safety and on selection criteria for individual treatment decisions. All consecutive patients operated on for CBTs from 1988 to 2018 were analyzed. After prospective collection in a dedicated database, data were analyzed retrospectively. Diagnosis was confirmed by ultrasound and magnetic resonance imaging. After approval by the university ethics committee and informed consent, genetic testing for mutations of the gene encoding succinate dehydrogenase was initiated routinely in 2006. Preoperative embolization was performed by experienced interventional radiologists using microcatheter techniques. A total of 80 patients underwent resection of 91 CBTs (57 women, 23 men; age, 24-86 years; mean age, 55.7 ± 16.4 years ). In four patients, a tumor recurrence or lymph node infiltration was diagnosed (malignant CBT). Genetic testing detected succinate dehydrogenase mutations in 47% (28/57 patients). Tumor diameter was 1.1 to 7.2 cm. Fourteen patients with a mean tumor diameter of 4.6 cm (range, 2.0-6.2 cm) underwent preoperative embolization after interdisciplinary discussion. In one patient (75-year-old man), embolization could not be completed because of development of a temporary neurologic deficit during the procedure (ipsilateral transitory ischemic attack). No other adverse effects due to embolization were observed. Surgery was performed 24 to 48 hours after intervention. Intraoperative blood loss and operating times did not differ significantly between patients with or without preoperative embolization. However, the subjective impression of the operating surgeons was that tumor resection was facilitated by embolization. Preoperative embolization in CBTs is a safe and effective preoperative strategy in large carotid paragangliomas, rarely leading to neurologic complications. Criteria for optimized selection of patients to develop individualized preoperative strategies and clear recommendations on candidates for embolization have yet to be identified. Because of the rarity of the tumor, a randomized trial is difficult to organize.