Open Transcranial Resection of Small (<35 mm) Meningiomas of the Anterior Midline Skull Base in Current Microsurgical Practice

Abstract

Objective: Despite technical surgical advance, the ultimate management of midline anterior skull base meningiomas remains to be defined. Open transcranial surgery is usually the first treatment option for large meningiomas, while less invasive techniques such as endoscopic surgery or radiosurgery might represent an alternative to open microsurgery for smaller lesions. The aim of our study is to investigate the outcome of open transcranial microsurgery in the resection of small (<35 mm) meningiomas of the midline anterior cranial base.

Methods: Clinical and surgical data from 43 patients affected by small midline anterior skull base meningiomas operated via an open transcranial approach were retrospectively reviewed.

Results: The tumor diameter on its major axis ranged from 12 to 35 mm, with a mean diameter of 28 mm. Gross total resection (Simpson grades I-II) was achieved in 100% of cases through a pterional approach. Postoperative overall morbidity was 9%. It was 3% among patients <70 years. No mortality was reported. Postoperative visual outcome was significantly associated with preoperative visual performance (P = 0.02), but not with preoperative optic nerve compression as detected by magnetic resonance imaging (P = 0.116). Age >70 years was associated with postoperative visual impairment, although not significantly (P = 0.06). Visual function was preserved or improved in 95% of cases, in 100% of patients <70 years, and in 71% of patients with preoperative visual impairment.

Conclusions: In our experience, open transcranial surgery proved safe and effective for midline anterior skull base meningiomas smaller than 35 mm in all patients <70 years and in patients >70 years without preoperative visual deficit. Our data are consistent with the literature. Conversely, the standard of treatment for the subgroup of patients >70 years with preoperative visual deficit has not yet been defined. This specific subgroup of patients offers a topic for further investigation.

Keywords: Endoscopic; Microsurgery; Midline anterior fossa meningiomas; Skull base; Small meningiomas; Surgical outcome.