Risk Factors of Postoperative Facial Palsy for Benign Parotid Tumors: Outcome of 1,018 Patients

Objective The aim of this study was to evaluate the rate of postoperative facial palsy in benign parotid tumors, as well as its risk factors, pathology, and clinical results. Study design Retrospective analysis. Methods We performed a retrospective analysis of data from patients whose initial operation for a benign parotid tumor had been performed in our department between 1999 and 2020. Results We included 1,018 patients in this study. The most common tumor observed was pleomorphic adenoma (614 patients), followed by Warthin tumor (234 patients). Fine-needle aspiration cytology and frozen section biopsy were used to identify the tumor histopathology. The overall rate of postoperative facial nerve palsy was 19.5%; the rate was significantly higher in patients with large-diameter tumors or deep lobe tumors. Postoperative facial palsy improved within 24 months of surgery in all cases. There were no cases with permanent facial palsy. Conclusions Postoperative facial nerve palsy developed regularly after surgery to remove benign parotid tumors despite preservation of the nerve. Palsy rate was high in patients with large tumors or deep lobe tumors. Despite the high risk of facial palsy in these patients and the benign nature of the tumor, we recommend surgery rather than follow-up observation, as the risk of postoperative facial palsy may increase as the tumor grows. It is important to provide an accurate explanation on the risks of postoperative complications to all patients to obtain appropriate informed consent for surgery. Level of evidence 4 Laryngoscope, 131:E2857-E2864, 2021.