Surgical Technique and Clinical Outcomes for Primary Intradural Extramedullary Spinal Tumors

Abstract

Background: Primary intradural extramedullary spinal tumors are rare and comprise nerve sheath tumors, meningiomas, and other rare pathologies. Clinical symptoms of these tumors are often nonspecific and are usually not obvious until neurological deterioration occurs. A delay in surgical treatment can lead to permanent neurological deficits. The aim of this study is to assess the clinical manifestations and surgical results of patients diagnosed with primary intradural extramedullary spinal tumors. Methods: From September 1999 to June 2014, patients who underwent surgery for primary intradural extramedullary spinal tumors at the orthopedic departments of authors' institutes were included in this study. Surgical procedures included laminectomy and midline durotomy for adequate exposure, total excision of tumors, and primary closure of durotomy by non-absorbable sutures. Spinal instrumentation and fusion was performed to prevent postlaminectomy kyphosis in only one patient whose tumor located in upper thoracic spine. The data were gathered retrospectively from medical records and included clinical presentation, tumor location, histopathology, postoperative complications and outcomes. Results: There were 11 patients, 5 males and 6 females, included in this study. The mean age of the patients was 52.8 (between 25 and 75) years. Preoperative symptoms included back pain in all cases, Brown-Sequard syndrome in the 3 cases of thoracic lesions, and sciatica-type of symptoms in 8 cases of lumbar lesions. The histopathologic results were meningiomas for 2 cases, schwannomas for 6 cases, paraganglioma for 1 case, ependymoma for 1 case, and mesenchymal chondrosarcoma for 1 case. Meningiomas and mesenchymal chondrosarcoma were located in the thoracic spine. Three schwannomas located at the level of conus medullaris. Paraganglioma, ependymoma, and the other three schwannomas located at the level of cauda equina. The case of mesenchymal chondrosarcoma received radiotherapy after surgery for the malignant nature of the tumor. All patients recovered well from preoperative symptoms after surgery. Persistent CSF leakage needed revision of dural repair was noted in one case. Iatrogenic spondylolisthesis at the operated levels was noted in one case but the patient declined the suggestion of additional spinal fusion because the clinical symptoms were minimal. No recurrence of tumor was found in the follow-up period. Conclusion: Although malignant lesions have been reported sporadically in the literature, intradural extramedullary tumors are usually benign. There is no typical presentation of clinical symptoms, therefore early-stage intradural extramedullary tumors are difficult to detect. Complete excision of these tumors is usually achievable and the neurologic prognosis after surgical excision is often better than the other spinal neoplasia.