Surgery of intramedullary spinal cord tumors

The diagnosis and management of intramedullary spinal cord tumors have been significantly influenced by new diagnostic and surgical tools such as MRI, ultrasonic aspiration, intraoperative ultrasound, and evoked potential monitoring. In this study we compared the surgical results of our earlier cases using conventional methods with more recent cases using these new methods. We report our experience based on 44 adult cases. Histologic diagnosis revealed ependymoma (20 cases), astrocytoma (15 cases), glioblastoma multiforme (1 case), and other histologic diagnoses (8 cases). We performed 20 gross total resections, 19 partial resections, and 5 biopsies. The mean follow-up period was 25.8 months (3 months-10 years). Surgical results were improvement in 11 patients (25%), stabilization in 24 (54%), and deterioration in 9 (20%). The first 28 cases (group A) were diagnosed using conventional myelography and CT myelography. The more recent 16 cases (group B) were diagnosed with MRI and operated on using techniques such as ultrasonic aspiration, intraoperative monitoring and ultrasound imaging. Radical surgery (total excision) was performed in 36% (n = 10) of group A, while it was possible in 62% (n = 10) of group B. Deterioration after operation was noted in 28% (n = 8) of group A, but only 6.2% (n = 1) of group B. These results stress the importance of a preoperative MRI scan and the positive effects of intraoperative ultrasound imaging, ultrasonic aspiration, and evoked potential monitoring on surgical results. With the help of these tools, most intramedullary spinal cord tumors may be diagnosed and treated surgically with significantly decreased risk. Radical surgery was possible in as many as 62% of our more recent patients. Partial resection with radiotherapy should be confined to patients with high-grade astrocytomas.