OBJECTIVE:Although intramedullary spinal cord ependymomas are amenable to surgical total resection, some ependymomas have been associated with severe surgical morbidity. The aim of this study is to determine what factors affect surgical morbidity.METHODS:Thirty-six consecutive patients who underwent surgical removal of an intramedullary spinal cord ependymoma between September 1980 and June 1998 were studied retrospectively. This series includes 19 women and 17 men between the age of 12 and 67 years (mean age, 41.2 yr). The location of the tumors was cervical in 24 cases, cervicothoracic in 3 cases, thoracic in 7 cases, and conus in 2 cases. At surgery, complete removal was achieved in 34 patients and subtotal removal was performed in the remaining 2.RESULTS:There has been no tumor recurrence in any patient except one who had an anaplastic ependymoma after a mean follow-up period of 56 months. The surgery improved neurological status in 14 of the 36 patients (39%). However, five patients (14%) experienced persistent deteriorations in clinical grade caused by surgery. Four of the five patients harbored benign ependymomas in the thoracic cord and characteristically demonstrated arachnoid scarring and cord atrophy at surgery, indicating that tumors had been present for a long time.CONCLUSION:Surgical removal of intramedullary ependymomas is beneficial to patients. However, the thoracic cord may be susceptible to surgical manipulations for intramedullary ependymomas. In addition, intraoperative findings of arachnoid scarring and cord atrophy are ominous for surgical morbidity.