Clinoidal meningiomas present specific characteristics related to their peculiar site of anatomic origin. Clinical series focusing on pure clinoidal meningiomas are not numerous. We performed a systematic review and meta-analysis, including our own case series, of the available literature to better identify the specific features of these tumors.
A systematic review and meta-analysis were performed for surgically treated pure clinoidal meningiomas using PubMed, Cochrane, and Embase databases. A retrospective review of a cohort of 18 consecutive patients treated between 2010 and 2018 in our department was also included in this meta-analysis.
A total of 1208 patients were included in the analysis. With a weighted mean follow-up of 48.1 months, the pooled rate of gross total resection was 64.2% (95% confidence interval [CI], 57.3%-71.0%) in the overall population, 11.8% (95% CI, 2.4%-21.1%) in the Al-Mefty I subgroup, 92.6% (95% CI, 88.9%-96.3%) in the Al-Mefty II subgroup, and 84.2% (95% CI, 70.8%-97.6%) in the Al-Mefty III subgroup. Overall visual improvement after treatment was found in 48% (95% CI, 38.6%-57.4%) of patients with a pooled deterioration rate of 4.5% (95% CI, 3%-6%). Pooled overall recurrence was observed in 8.9% of patients (95% CI, 6.0%-11.8%) and mortality occurred in 1.2% (95% CI, 0.6%-1.8%).
The rate of gross total resection is proportional to the dural origin of these tumors, which is intimately related to critical neurovascular structures. Complementary radiosurgery could represent a valid treatment strategy. Postoperative visual improvement remains less satisfying compared with other suprasellar meningiomas. The introduction of skull-base techniques, such as extradural anterior clinoidectomy, has enabled improvements in visual outcome without any increase in approach-related morbidity.