FEBAIR microsurgical principles in meningiomas and recurrence: a long-term follow-up series.

Objective and background: Meningiomas are the most prevalent type of primary intracranial tumor. It is essential to conduct an extensive follow-up period to assess the effectiveness of any treatment method. In this study, we present a long-term follow-up series (average ~14 years) of surgical treatments for meningiomas and evaluate the aspects related to their recurrence. Methods: This is a retrospective study focusing on surgeries performed on 99 patients with 102 meningiomas. The study reviews the patients' medical records, operative reports, radiologic examinations, and follow-up data. The surgeries aimed to achieve the most complete and safest removal of the meningiomas, considering the patients' medical conditions and comorbidities. Postoperative CT and MRI scans were obtained for all patients during the follow-up period. Results: The group comprised 79 women and 20 men with a median age of 56 years (range 27-87 years). The mean follow-up period was 171 months (120-280 months). Simpson grades zero, I and II resections were obtained in ~83%. Twenty cases presented recurrence during the follow-up period (~20%). In the non-recurrent group of patients (n=82), Simpson grades "zero, " I, and II were obtained in 86.6% of cases. In the recurrent group (n=20), Simpson grades III and IV were obtained in 80% of cases. Meningiomas were WHO grade 1 in 95.1% of cases, 2 in 3.9%, and 3 in ~1%. Eight recurrent cases (40%) were originally giant meningiomas (>5cm). Previously irradiated accounted for 7% of cases. Mortality rate during the follow-up period was 7%. The Karnofsky Performance Status (KPS) score of 100 and 90 was 87%. Conclusions: This retrospective series has shown that the recurrence of meningiomas after surgery depends on the Simpson grade of resection, which is linked to incomplete tumor removal. The principles of meningioma surgery can help achieve a higher grade of resection while preserving patients' quality of life. Long-term follow-up is essential to verify the effectiveness of any treatment method for meningiomas, and proper surgical treatment provides a high rate of cure and control over 10 years. This retrospective series has determined that the recurrence of meningiomas after surgery depends on the Simpson grade of resection. Technical principles can help improve the extent of resection during surgery while maintaining patients' quality of life, thereby lowering the risk of recurrence. Using advanced microsurgical techniques in combination with new technologies is essential to achieving these outcomes.