Petroclival meningiomas: the risk of post-operative cranial nerve deficits among different surgical approaches-a systematic review and meta-analysis

Background: The surgical resection of petroclival meningiomas (PCMs) remains a challenge. Both the relationship with neurovascular structures and the deep location of the tumor can affect the extent of resection and the rate of post-operative morbidity. Methods: The authors performed a systematic review and meta-analysis of the literature examining the rate of new cranial nerve (CN) deficits after resection of PCM. A systematic search of two databases was performed for studies published between 1990 and 2018. Random-effect meta-analysis was used to pool the rate of post-operative CN deficits, mortality rate, and rate of radical resection. Results: We included twelve studies and 334 patients harboring PCM. The overall rate of complete resection was 68% (95% CI 57.9-78.2%; p < 0.01; I2 = 83%). The rate of early and late post-operative CN deficits was the following: 3.8 and 2.7% (III CN), 6.6 and 3% (IV), 7.3 and 5.5% (V CN), 8 and 3.6% (VI CN), 8.9 and 8.9%% (VIII), and 4 and 2.7% (IX-XI CNs) (I2 = 0%, and p < 0.01 for all analyses). The risk of post-operative deficit of the IV CN was higher among the petrosal group (7.6%; I2 = 0% vs 2.1%; I2 = 0%), whereas the impairment of VII CN function was higher among retrosigmoid group (16.6%; I2 = 64.6% vs 11.4%; I2 = 52.8%), but it was transient in the majority of cases. Conclusions: This systematic review and meta-analysis provides a detailed overview of post-operative CN deficits ensuing surgical resection of PCMs. These findings should be acknowledged when counseling patients with PCMs regarding the more appropriate approach for their tumor.