Management of spheno-orbital en plaque meningiomas: clinical outcome in a consecutive series of 40 patients

Objective. The clinical results of combined surgical-radiosurgical treatment of the spheno-orbital en plaque meningiomas in a consecutive series of 40 patients are presented. The clinical outcome is evaluated in terms of surgical morbidity, tumour control, visual function and cosmetic result. Methods. Forty patients harbouring spheno-orbital en plaque meningiomas were treated. Forty-two surgical procedures were performed through a fronto-temporal craniotomy. The reconstruction of the orbital walls was performed using a titanium mesh. In case of sub-total resection, the patients underwent Gamma-Knife radiosurgery on residual tumour. Visual function was evaluated considering visual acuity tested with a Snellen chart, funduscopy and Goldmann perimetry for visual field defects. Proptosis was quantified on CT scans. Results. Total or gross-total tumour resection was achieved in 56.1% of cases. Permanent morbidity was recorded in three patients after surgery. Visual acuity and visual field defect both improved in 66.7% of patients; improvement of proptosis was recorded in 92.7% of cases. Eighteen patients were treated with Gamma-Knife radiosurgery for residual tumour after surgery and four patients for tumour relapse at follow-up. The mean follow-up period was 72.6 months. Conclusions. Surgical treatment of spheno-orbital en plaque meningiomas is safe and effective: a low morbidity rate was recorded and visual function improved in about two-thirds of patients. Reconstruction of the orbital walls with titanium mesh provides for good functional and cosmetic results. In case of superior orbital fissure and cavernous sinus invasion, the combined surgical-radiosurgical treatment allows to minimise surgical morbidity and to achieve tumour control.