gms | German Medical Science

Objective: Microsurgical resection is the primary treatment of skull base meningiomas. The goal is maximal resection combined with best functional outcome and quality of life. Outcome is usually measured by recurrence free survival, relieve of neurological deficits as well as surgical morbidity. Further, it is of paramount importance to pinpoint factors indicating a higher incidence of recurrence, to identify patients at risk. Our goal was therefore to investigate a consecutive series of patients presenting with skull base meningiomas, which were treated in our department. In our analysis we especially focused on the extent of resection, functional outcome and the frequency of recurrence.

Methods: We investigated 226 skull base meningioma patients (170 female; 56 male) with a mean age of 58.7 years. Anatomically, 29.2% presented with olfactory groove tumors, 22.6% medial sphenoid ridge, 13.6% tentorial, 8.4% petroclival, 7.1% clival, 5.8% cerebellopontine angle, 4.9% tuberculum sellae and foramen magnum respectively, as well as 3.5% lateral and middle sphenoid ridge. Infiltration of venous sinus or the adjacent bone structures was investigated by analyzing the preoperative MRI and CT scans. Extent of resection was rated according to the Simpson scale. Quality of life was measured by the Karnofsky performance score (KPS), neurological deficits were quantified using the Neurological Severity Score (NSS).

Results: The extent of resection was graded as follows; I: 26.1%, II: 36.7%, III: 11.5% IV: 23.0% and V: 2.7%. Mortality and morbidity rate was 2.7% and 32.3% respectively with intracranial hemorrhage (10.6%) and csf fistula (10.2%) the most frequent complications. Infiltration of the venous sinus was detected in 21.2%, bone infiltration in 48.2%. The median KPS was 90, at follow-up 12.4% of all patients showed an improved KPS. The NSS was improved significantly at follow-up (p < 0.001), 52.7% of all patients experienced a relief of focal neurological deficits. Recurrence occurred in 15.5%, uni- and multivariate analyses revealed tumor size, bone- and venous sinus infiltration, WHO grade, high MIB-1 labeling index and poor extent of resection as risk factors for recurrence (p < 0.001).

Conclusions: Although a challenging disease, modern surgical treatment of skull base meningiomas can improve neurological impairment and quality of life. Risk factors for recurrence such as bone or venous sinus infiltration need to be considered for the postoperative management.