Anterior Skull Base Meningiomas with Optic Pathway Involvement: Retrospective Analysis of Factors for Visual and Overall Outcome

Objective: Technical details in microsurgery of anterior skull base meningiomas with optic pathway compromise like unroofing of the optic canal face controversy in the literature. In our group, unroofing of the optic canal was indicated by the surgeon intraoperatively after tumor removal outside the canal depending on the pathoanatomical situation in the individual patient. The result of this individualized, surgeon-based decision strategy was analyzed.

Methods: We retrospectively analyzed the medical files of 33 patients treated microsurgically from February 2010 till October 2015. Analyzed factor with potential influence on visual and overall outcome were: age, gender, location of the meningioma, surgical approach, WHO grade, prior surgery (recurrence status), Simpson grade, preoperative and postoperative visual function, optic canal decompression, the surgeon, complication rate, surgical revision rate and coagulation disorder.

Results: Visual compromise led to surgery in 23 patients (unroofing in 14/22), 10 patients only had radiological involvement of the visual pathways (unroofing in 5/10). Deterioration of vision occurred in 2 out of 33 patients (6%, one patient each with and without preop visual decline), but not in the optic canal unroofing group (not significant). Visual improvement occurred in 12/33 patients (36%). Complication rate was 9/33 (27%; 2 CSF fistula, 3 subdural hematoma, 3 epidural hematoma, 1 seizure; no mortality) and surgical revision rate 6/33 (18%). The surgeon (p: 0.027), coagulation disorder (p: 0.043) and age (p: 0.045) significantly affected revision rate (nominal-logistic regression chi-square test) with higher revision rate in patient pretreated with warfarin and elderly patients. Surgical approach, grade of resection or WHO grade did not influence visual outcome, complication rate or revision rate significantly.

Conclusion: Surgeons experience, warfarin pretreatment and patient age affect surgical revision rate in perioptic anterior skull base meningioma patients. Unroofing of the optic canal did not deteriorate visual function, but improvement of vision was not linked statistically to optic canal decompression.