Kohei Kanaya1, Tetsuyoshi Horiuchi2. 1. Department of Neurosurgery, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano, 390-8621, Japan. kanaya@shinshu-u.ac.jp. 2. Department of Neurosurgery, Shinshu University School of Medicine, 3-1-1 Asahi, Matsumoto, Nagano, 390-8621, Japan.
Abstract
PURPOSE: Delayed facial palsy (DFP) is a rare postoperative complication after vestibular schwannoma (VS) surgery. The exact mechanism of DFP remains uncertain and the risk factors for DFP are still controversial. The authors aimed to investigate the characteristics, risk factors, and etiology of DFP after VS resection retrospectively. METHODS: Ninety-one consecutive surgeries with VS were analyzed. Patients with neurofibromatosis 2 in eight surgeries and postoperative facial palsy House-Brackmann (HB) grade more than 3 in two surgeries were excluded. Eighty-one surgeries were included in this research. Facial nerve function was evaluated using the HB grade. Delayed facial palsy was defined as deterioration in the facial function of at least 1 HB grade more than 1 day after undergoing VS resection. The characteristics of patients with VS and risk factors for DFP were analyzed. RESULTS: All surgeries were performed via a retrosigmoid approach. DFP was observed in nine patients. There were no statistically significant differences between the DFP group and non-DFP group in terms of the following characteristics: sex, age, side, size, Koos grading system, postoperative facial palsy, or extent of resection. Postoperative hematoma in the cerebellopontine angle (CPA) cistern was significantly higher in the DFP group than in the non-DFP group (p = 0.0023), and was significantly associated with DFP after VS surgery (odds ratio 18.40, p < 0.001). DFP improved in seven patients, but two patients did not improve. CONCLUSION: DFP occurred in 11.1% of patients after VS surgery. This study revealed that postoperative hematoma in the CPA cistern was significantly associated with DFP after VS surgery.
PURPOSE: Delayed facial palsy (DFP) is a rare postoperative complication after vestibular schwannoma (VS) surgery. The exact mechanism of DFP remains uncertain and the risk factors for DFP are still controversial. The authors aimed to investigate the characteristics, risk factors, and etiology of DFP after VS resection retrospectively. METHODS: Ninety-one consecutive surgeries with VS were analyzed. Patients with neurofibromatosis 2 in eight surgeries and postoperative facial palsy House-Brackmann (HB) grade more than 3 in two surgeries were excluded. Eighty-one surgeries were included in this research. Facial nerve function was evaluated using the HB grade. Delayed facial palsy was defined as deterioration in the facial function of at least 1 HB grade more than 1 day after undergoing VS resection. The characteristics of patients with VS and risk factors for DFP were analyzed. RESULTS: All surgeries were performed via a retrosigmoid approach. DFP was observed in nine patients. There were no statistically significant differences between the DFP group and non-DFP group in terms of the following characteristics: sex, age, side, size, Koos grading system, postoperative facial palsy, or extent of resection. Postoperative hematoma in the cerebellopontine angle (CPA) cistern was significantly higher in the DFP group than in the non-DFP group (p = 0.0023), and was significantly associated with DFP after VS surgery (odds ratio 18.40, p < 0.001). DFP improved in seven patients, but two patients did not improve. CONCLUSION: DFP occurred in 11.1% of patients after VS surgery. This study revealed that postoperative hematoma in the CPA cistern was significantly associated with DFP after VS surgery.