The learning curve in vestibular schwannoma surgery

Objective: This study aimed to examine the effect of surgical team experience on facial nerve function and complication rate in vestibular schwannoma surgery. Study Design: The study design was a retrospective analysis of a case series. Setting: The study was conducted at a tertiary referral center. Patients: One hundred sixty consecutive patients undergoing vestibular schwannoma excision participated. Intervention: Surgical excision of vestibular schwannoma via a translabyrinthine, middle cranial fossa, suboccipital, or combined approach was performed. Main Outcome Measures: Facial nerve function (House-Brackmann score) and complication rates including cerebrospinal fluid leak and meningitis compared by groups of 20 patients were measured. Results: There was a statistically significant improvement in the number of patients achieving a House-Brackmann grade 1 result between the first 20 patients (35% House-Brackmann grade 1) and the ensuing 7 groups of 20 patients (74% House-Brackmann grade 1) by χ² analysis. When considering House grades I and II together, there was no statistically significant difference in facial nerve function in the first 20 patients (80%) compared to the last 7 groups of 20 patients (88%) by Tukey's pairwise comparisons (p = 0.245). Mean tumor size was not significantly different in the groups studied (p = 0.54). The total cost of patient care declined over the study period; however, the wide case-to-case variance made it so that this trend was not statistically significant (p = 0.448). Conclusions: A learning curve of 20 patients was demonstrated by this study to have been necessary for attaining acceptable standards in the surgical removal of vestibular schwannomas by a new surgical team. The findings of this study may have implications for patient care and surgeon training.