Surgery for posterior fossa meningioma: elevated postoperative cranial nerve morbidity discards aggressive tumor resection policy

Radical excision of meningioma is suggested to provide for the best tumor control rates. However, aggressive surgery for meningiomas located at the posterior cranial fossa may lead to elevated postoperative morbidity of adjacent cranial nerves which in turn worsens patients' postoperative quality of life. Therefore, we analyzed our institutional database with regard to new cranial nerve dysfunction as well as postoperative cerebrospinal fluid (CSF) leakage depending on the extent of tumor resection. Between 2009 and 2017, 89 patients were surgically treated for posterior fossa meningioma at the authors' institution. Postoperative new cranial nerve dysfunction as well as CSF leakage were stratified into Simpson grade I resections with excision of the adjacent dura as an aggressive resection regime versus Simpson grade II-IV tumor removal. Simpson grade I resections revealed a significantly higher percentage of new cranial nerve dysfunction immediately after surgery (39%) compared with Simpson grade II (11%, p = 0.01) and Simpson grade II-IV resections (14%, p = 0.02). These observed differences were also present for the 12-month follow-up (27% Simpson grade I, 3% Simpson grade II (p = 0.004), 7% Simpson grades II-IV (p = 0.01)). Postoperative CSF leakage was present in 21% of Simpson grade I and 3% of Simpson grade II resections (p = 0.04). Retreatment rates did not significantly differ between these two groups (6% versus 8% (p = 1.0)). Elevated levels of postoperative new cranial nerve deficits as well as CSF leakage following radical tumor removal strongly suggest a less aggressive resection policy to constitute the surgical modality of choice for posterior cranial fossa meningiomas.