Spinal ependymomas. Part 1: Intramedullary ependymomas

OBJECT Ependymomas represent the most common intramedullary tumor in adults. Despite their usually well-defined dissection plane, surgical morbidity has been documented to be considerably higher compared with other intramedullary entities. This study presents an analysis of risk factors for surgical morbidity and data on long-term results for intramedullary ependymomas. METHODS Among 1447 patients with tumors of the spinal canal treated between 1980 and 2014, 309 patients presented with intramedullary tumors. One hundred patients with intramedullary ependymomas underwent 102 operations. Mean age was 44 +/- 15 years (range 8-74 years). Patients were followed by outpatient visits and questionnaires, with a mean follow-up of 77 +/- 91 months. Short-term results were determined for individual symptoms and the McCormick Scale, whereas tumor recurrence rates were calculated with Kaplan-Meier statistics. RESULTS Compared with cervical ependymomas, those of the thoracic spine were associated with more severe motor deficits and gait problems at presentation. A total of 86.3% of patients with intramedullary ependymomas underwent gross-total resection (GTR). A low preoperative McCormick grade and first surgery were the strongest predictors for a GTR. Postoperatively, 67.6% of patients demonstrated a worse neurological state at discharge from the hospital. This deterioration was transient for 40.1% of the patients and permanent for 27.5%. In the long term, the McCormick grade remained unchanged from the preoperative grade in 74.5% of patients, while it was improved in 5.9% of patients and increased after surgery in 19.6% of patients. According to a multivariate analysis, the risk of permanent morbidity increased with a thoracic level of the ependymoma, advanced age, a long clinical history, presence of a tumor hemorrhage, and surgery on a recurrent tumor. In the long term, tumor recurrence rates correlated significantly with the amount of resection (4.2% and 18.5% in 20 years after GTR and partial resections, respectively). Postoperative neuropathic pain syndromes affected 37.0% of patients, whereas 4% demonstrated a postoperative myelopathy related to cord tethering at the level of surgery. CONCLUSIONS Intramedullary ependymomas are tumors best treated surgically. A complete resection indicates cure for the overwhelming majority of these patients. Surgery should be performed early by neurosurgeons who deal with these lesions on a regular basis to achieve high GTR rates. Permanent surgical morbidity varies most according to tumor location and patient age.