Facial paralysis and vestibular Schwannoma surgery: new classification system for assessing non-total tumor resection.

Objective: To compare the outcomes of vestibular schwannoma surgeries over the past decade, focusing on surgical approach, facial nerve function, tumor recurrence, and to standardize a classification system for the extent of tumor resection.

Study design: A retrospective cohort study involving 197 patients who underwent vestibular schwannoma surgery between January 2014 and December 2023.

Methods: Data on demographics, tumor characteristics, surgical approach, and facial nerve function were collected. Facial nerve function was monitored intraoperatively, and facial palsy was graded using the House-Brackmann scale. Postoperative MRI was used to assess residual tumor and guide follow-up care. Tumor volumes (preoperative and postoperative) were estimated by measuring the largest diameters in the axial, coronal, and sagittal planes A new classification for the extent of tumor resection was proposed, incorporating both the surgeon's intraoperative impression and post-surgery MRI results. Statistical analysis was performed using SPSS v.25. A p-value < 0.05 was considered statistically significant.

Results: Of the 197 patients, 84.8% had total resection, and 15.2% had non-total resections. Non-total resections were associated with better facial nerve outcomes. Tumor regrowth occurred in 6 patients (3%). Statistical analysis showed that the extent of resection (p = 0.004), preoperative tumor volume (p = 0.018), and year of surgery (p = 0.005) were significant predictors of facial paralysis.

Conclusions: Our policy remains focused on total tumor resection; however, when the tumor is attached to the facial nerve, we advocate for a non-total resection to preserve the integrity of the facial nerve. Based on our study, this approach does not increase the risk of tumor recurrence or the need for revision surgeries in our population.