Objective: We present our series of surgically treated cystic vestibular schwannomas (CVSs), review postoperative morbidity and facial nerve outcomes, and propose a classification system for CVSs based on cyst location, which might be useful for guiding surgeons in the management of these tumors and for optimizing surgical results. Study Design: Retrospective chart review. Setting: Tertiary care facility. Patients: Patients were included in this study if they had a CVS and were surgically treated at our institution between January 1998 and May 2008 (96 patients). Facial nerve outcomes were assessed in a subpopulation of these patients (57) who had ≥1-year follow-up. Intervention: Fifty-six of the 57 patients underwent the enlarged translabyrinthine approach with transapical extension (type I), and 1 patient underwent a transcochlear/transzygomatic approach. Main Outcome Measure: Facial nerve function was assessed using the House-Brackmann facial nerve grading scale twice: (1) during preoperative evaluation and (2) at the most recent long-term follow-up appointment. Results: Of the 1416 patients who underwent vestibular schwannoma resection at our institution from January 1998 to May 2008, 96 (6.8%) underwent resection of some form of CVS. Among the 57 CVS patients with ≥1-year follow-up, 29 were men and 28 were women. The average age was 51 years (median, 50 years; range, 27–80 years), and the average length of follow-up was 23.8 months (median, 16 months; range, 12–66 months). Favorable House-Brackmann facial nerve grades (I–III) were observed in 46 (81%) CVS patients, and unfavorable grades (IV–VI) were seen in 11 (19%) patients. A comparison of tumor size and 1-year facial nerve grades showed a significant, moderate to strong Pearson's correlation (0.38). Although 2 patients who underwent subtotal resection had grade V facial nerve outcomes—because the tumor was adherent to the facial nerve and a dissection plane could not be developed between the cyst wall and the nerve—only subtotal resection could offer the CVS patients a normal facial nerve outcome. Conclusions: Complete resection should be anticipated in the majority of CVS cases. However, when thin-walled, adherent cystic tumors are confronted and the surgeon is unable to develop a sufficient dissection plane, we advocate subtotal resection, leaving cyst wall remnants anteriorly versus the facial nerve and/or medially versus the brainstem, and versus the posterior fossa vasculature to improve facial nerve results and reduce vascular complications.
No takes yet. Share an insight, caveat, or question.
Wiet et al. (2009) studied this question.