Ependymomas of the spinal cord and cauda equina: An analysis of 26 cases and a review of the literature

Study design: Retrospective review. Objectives: To clarify the clinical features of patients with spinal ependymomas and to compare the clinical results between the patients in whom microsurgical technique and spinal cord monitoring were used intraoperatively and the patients in whom they were not used. Setting: Keio University Hospital, Tokyo, Japan. Methods: Twenty-six consecutive patients with spinal ependymomas were treated surgically between 1958 and 1995. All patients underwent tumor resection through a posterior approach. Complete tumor resection was possible in 15 patients (57.7%), and subtotal tumor resection (more than 90%) was done in two patients (7.7%). Only a partial tumor resection (less than 90%) was performed in the remainder of the patients (34.6%). The operative results of the patients were evaluated by the Japanese Orthopaedic Association Scoring SS stem (JOA score) and its recovery rate. Results: The overall average recovery rate was 18.3%. The mean recovery rate was 14.4% in cervical lesion, 11.1% in thoracic lesion and 40% in lumbar lesion. The recovery rate of eight patients with cervical ependymomas who underwent tumor resection under both microscopic surgical procedure and intraoperative spinal cord monitoring was 37.1% although the recovery rate of the rest of the patients was -1.6%. There was a statistical difference between the two groups (P < 0.02). The survival rate of patients following complete excision was statistically better compared to that of patients after incomplete resection. Conclusion: Both microsurgical technique and spinal cord monitoring are indispensable to achieve total removal of ependymomas and to obtain improvement of neurological recovery.