Assessing the safety and efficacy of EVOH Pre-Embolization in head and neck paraganglioma tumors: A comprehensive analysis of current literature

Background: Head and Neck Paragangliomas are characterized by having a rich blood supply. Presurgical embolization with Onyx as a neoadjuvant treatment is not a consensus regarding its efficacy and safety. Our study aimed to answer this matter through a single-arm meta-analysis. Methods: We systematically reviewed 4 databases. Sixteen studies were described and suitable papers were selected for meta-analysis of estimated intraoperative blood loss (EBL), percentage of tumor devascularization, and complications associated with embolization. Results: The study identified 198 patients with 203 tumors, aged between 8 and 70 years. Commonly reported symptoms included neck mass perception and cranial nerve impairment. Carotid Body Tumors were most prevalent (127, 62.5 %), followed by jugular (48, 23.6 %), or vagal (29, 14.2 %) tumors. Eight studies reported estimated intraoperative blood loss (EBL) averaging 261.89 ml (95 %CI: 128.96 to 394.81 ml). In an analysis of 9 studies, 99 % (95 %CI: 96 to 100 %) achieved 70 % or more devascularization, and 79 % (95 %CI: 58 to 100 %) achieved 90 % or more devascularization. Complications from endovascular procedures were observed in 3 % (95 %CI: 0 to 8 %) of 96 patients across 10 studies, including 4 facial nerve deficits. Eighteen postoperative neurological deficits were reported across 15 articles. Conclusion: Despite acknowledged limitations, with refined indications, EVOH, especially Onyx embolization may significantly bolster patient safety, decreasing EBL and easing surgical resection. Further research with larger studies will refine criteria, optimize techniques, and improve patient care and treatment outcomes in the management of head and neck paragangliomas.