gms | German Medical Science

Objective: Aim of this retrospective study was to show the results of the facial nerve following vestibular schwannoma surgery after failed radiosurgery. Radiosurgery has been increasingly used as an alternative treatement for VS. Currently there is a controversial discussion whether previous radiation may lead to more difficult surgery of VS and thereby increase the risk for the facial nerve.

Methods: In a series of 250 surgical cases of VS, a total of 9 patients, who had received previous radiosurgery were investigated. All 9 patients presented with growing tumors at MRI investigations. Surgical and clinical records were studied, and follow-up investigations were performed.

Results: In the total series of 250 VS, complete tumor resection was achieved in over 95%, and facial nerve function was preserved in 98% of the cases. Among the 9 patients with previous radiosurgery, four patients had incomplete tumor removal. Postoperative facial function was classified acording to House and Brakmann method as follows: Grade I and II (good facial function), 4 patients, Grade III (significant palsy), 3 patients, Grade V (severe palsy) 2 patients. There was no mortality in this series.

Conclusions: Tumor removal after radiosurgery will not necessarily result in facial palsy. However, there is an increased risk of injuring the facial nerve during tumor dissection, due to the increased tumor tissue consistency, the increased adherence between tumor surface and nerves, and due to the lack of a soft arachnoidal plane. In addition, an irradiated facial nerve's regeneration potential seems to be diminished. We recommend that patients, who require microsurgical excision following radiosurgery have a more conservative approach compared to non-irradiated cases.