Study on Risk Factors Affecting Facial Nerve Function After Microsurgical Resection of Acoustic Neuroma

To investigate the risk factors affecting facial nerve function following acoustic neuroma surgery via the retrosigmoid approach.

Clinical data from 47 patients with acoustic neuroma treated at the Department of Neurosurgery, The First Affiliated Hospital of Wannan Medical College, between January 2021 and June 2024, were retrospectively analyzed. All patients underwent surgery via the retrosigmoid approach. Facial nerve function was evaluated using the House-Brackmann (H-B) grading system at 1 week and 6 months postoperatively. Patients were divided into 2 groups based on H-B grades: I to II (good prognosis) and III to IV (poor prognosis). Statistical methods were used to identify and analyze relevant risk factors.

At 1 week postoperatively, facial nerve function was graded as I to II in 30 cases and III to IV in 17 cases. At 6 months postoperatively, 39 cases showed grade I to II function, while 8 cases were graded III to IV. Univariate analysis identified several factors significantly associated with poor facial nerve function at 1 week, including a tumor diameter >3.0 cm, absence of intraoperative electrophysiological monitoring, tight adhesion to the facial nerve, rich blood supply, and the presence of cystic changes in the acoustic neuroma ( P <0.05). At 6 months, poor facial nerve function was similarly associated with tumor diameter >3.0 cm, lack of electrophysiological monitoring, and a rich blood supply ( P <0.05). Further analysis through multivariate regression identified the absence of electrophysiological monitoring, tight adhesion to the facial nerve, and a greater blood supply as significant predictors of facial paralysis at 1-week postsurgery ( P <0.05). In addition, larger tumor diameter and the absence of electrophysiological monitoring were found to significantly increase the risk of facial paralysis at 6 months ( P <0.05). These associations were statistically significant.

The absence of intraoperative electrophysiological monitoring, tight adhesion to the facial nerve, and richer tumor blood supply were associated with poorer facial nerve function prognosis 1 week after surgery. In addition, a larger tumor diameter and the absence of electrophysiological monitoring were linked to worse outcomes for facial nerve function at 6 months postoperatively.