Does Simpson 1 Resection of Spinal Meningiomas Lead to Lower Tumor Relapse or Increase of CSF Leaks? A 40-year Single-Center Experience.

Objective: To evaluate the risk of tumor relapse after Simpson grade 1 resection of spinal meningiomas compared to other Simpson grades. Furthermore, to evaluate incidence of cerebrospinal fluid (CSF) leak after resection of affected dura and use of a patch for dural repair.

Methods: We retrospectively analyzed a consecutive series of patients who underwent resection of a spinal meningioma at our department between 1980 and 2020.

Results: Overall, 153 patients were included, and Simpson grade 1, 2, 3, and 4 resection was achieved in 13%, 75%, 9%, and 3%, respectively. The median time of radiologic follow-up was 28.5 (1-261) months. Tumor relapse occurred in a total of 8 patients (5.2%) after a median time of 54.5 (22-219) months and was significantly associated with Simpson grade (P = 0.004). CSF leaks occurred in a total of 5 patients and were not associated with dural resection and use of a patch for dural repair compared to primary dural suture (P = 0.470).

Conclusions: Gross total resection including the affected dura may reduce the risk of tumor relapse and is not associated with a higher rate of CSF leaks in dorsal spinal meningiomas. Resection of only the inner dural layer is a valid alternative to achieve Simpson 1 resection.