The Learning Curve with Vestibular Schwannomas

Introduction: Early career skull base surgeons face unique challenges when handling vestibular schwannomas, including ethical decisions in patient selection, surgical approach, cerebrospinal fluid management, and intraoperative safety. With adequate training, wise choices, and self-reflection, they can achieve successful outcomes. We evaluate a surgeon's learning curve and analyze the nuanced treatment decisions in managing these cases.

Methods: The author retrospectively analyzed the initial 120 consecutive acoustic neuroma surgeries in their practice. A blinded review analysis was then performed, and the cases were categorized into early and later groups for a thorough comparison of patient care aspects, aiming to pinpoint areas for improvement.

Results: On average, lesions measured 3.1cm, and a retrosigmoid approach was used in 92% of cases. Six months post-surgery, 90% of patients had favorable facial nerve outcomes (House Brackmann 1 or 2). Of the patients with good preoperative hearing, 31% had successful hearing-preserving surgery, with an average lesion size of 2.4cm. Comparing the initial group (n=60) with the second group (n=60, similar tumor size and Koos grade), significant improvements were observed in hearing preservation, extent of resection, and hospital stay duration (all p< 0.05). Facial nerve outcomes trended towards improvement but this was not statistically significant. With increasing case numbers, there was a reduced need for early cerebrospinal fluid drainage (via methods such as lumbar drain, lumbar puncture, or external ventricular drain) (p < 0.05). The length of surgery improved by over 20% in the second group compared to the first group (p < 0.05). Notably, a multivariate analysis revealed that cerebrospinal fluid drainage during surgery and subtotal resection correlated with worse facial nerve outcomes (p < 0.05).

Conclusion : Today, early career skull base neurosurgeons can achieve proficiency in managing vestibular schwannomas, even for tumors larger than 3cm, with positive patient outcomes. Key elements include rigorous training, wise decision-making, careful intraoperative choices, and learning from experiences. Important surgical lessons involve safeguarding venous drainage, preserving tumor capsule layers, using endoscopic support, and understanding the pros and cons of aggressive cerebrospinal fluid drainage.