Surgery of Vestibular Schwannomas with Peritumoral Edema

Introduction: The presence of peritumoral edema in meningiomas correlates with complexity of surgery and outcome. Its significance in vestibular schwannomas (VS) has not yet been evaluated systematically. Methods: Retrospective study of patients’ series. Correlative analysis of presence of edema to: radiological tumor characteristics, operative difficulty, tumor adhesion, vascularity, presence of capsule, functional outcome, and complication rate. The findings were compared with those in a matched control group without peritumoral edema (group B). Results: A total of 30 patients (30/605 patients or 5%) presented with peritumoral edema. Patients with edema had more frequently tinnitus and hydrocephalus. At surgery these VS were more frequently hypervascular. No major difference in the operative difficulty in patients with/without edema in regards to difficulty of tumor dissection and presence of arachnoid plane was found. Complete resection was achieved in all patients in group A (vs.97% in the control group B); the facial nerve was preserved in 97% (vs.98%). Functional outcome in both groups was similar. However, the postoperative hemorrhage rate was higher in the current control Group (10 vs. 3%). Conclusion: VS with perifocal edema are more frequently hypervascular. This may lead to a higher rate of postoperative hemorrhages in the tumor bed and should always be considered. With adequate microsurgical technique, however, the presence of peritumoral edema does not influence the rate of complete tumor removal and the functional outcome.