Introduction: Spinal tumors rarely occur with an incidence of 10 per 100,000 people. Neurinoma (schwannoma) and meningioma are the most common types of intraduralextramedullary tumors (IDEM). In recent years there have been a number of studies investigating the excision of IDEM tumors with hemilaminectomy. Compared with the traditional surgical approach, hemilaminectomy is relatively safer with less trauma, and helps maintain spine stability. In this study, we describe our experience of 8 cases with hemilaminectomy for IDEM tumors, along with a review of the literature. Case Report :We performed eight cases of hemilaminectomy for IDEM tumors from January 2017 to December 2019. In the case of cervical IDEM (Case-1) 60-year-old male with weakness of all four limbs for 1 year, with 3/3 right and 4/4 left motoric strength, pain and numbness on both hands, neck and urination disorders, MRI examination of cervical spine with contrast showed visible extramedularintradural mass as high as C3-C5 in right dorsolateral, histopathological report is meningioma, we performed right-sided hemilaminectomyon the level of C3-C5. Two weeks post operative, normal motor function was achieved and pain disappears, one year follow up after surgery, no signs of spine instability both clinical and imaging.Case of IDEM in the thoracal (Case-2) 53-year-old woman with complaints of weakness on both lower limbs since 6 months, right left motoric power 5/3, history of back pain radiating to both limbs since 1 year ago, dysesthesia on both limbs, MRI examination of thoracal spine contrast showed intraduralextramedullary mass on the right ventrolateral as high as thoracal 8, we performed right hemilaminectomy on Th 8. The histopathological report is schwannoma. Two weeks post operation, normal motor function was achieved and pain disappeared, follow-up 1.5 years postoperatively did shows signs of instability in spine both clinical and imaging.30-year-old woman (Case-3) came with complaints of weakness on both lower limbs for 6 months, motoric strength of 5/2retention of urine was found, a history of back pain radiating to the lower limbs, a thoraco-lumbar MRI was performed, with results of anterior located mass on the Th-9, suspicious of a mengioma which stick to the anterior dura mater. In this case bilateral laminectomy was. After surgery maximum motor function improvement occurs after 8 months and the urinary catheter can be removed after 2 months. Discussion: 90% of complete resection can be performed, with a 10% surgical complication rate and 1.5% surgical fatality rate. Levi et al. also reported similar results for 66 patients with a 9% surgical complication rate and 1.5% mortality rate. Various studies have investigated IDEM tumors excision with hemilaminectomy, which is relatively safe with minimal trauma, and can maintain spinal stability. The advantage of hemilaminectomy is that reducing postoperative pain, prevents instability, avoids the use of postoperative external bracing and allows early mobilization of patients, less blood loss during surgery, better wound healing and reduced postoperative infections and shorter hospital stays than traditional total laminectomy. In our cases of eight operations, no tumor was found extending to the foramen. no unilateral facetectomy was needed. Two years of follow-up no spinal instabilitywas found, all cases have motor improvement postoperative. Only one case was carried out by bilateral laminectomy. Our study group is too small and the follow-up period is too short to make a definite statement with respect to the applicability of the hemilaminectomy approach to intradural-extramedullary spinal cord tumors. Conclusion: Intradural-extramedullary spinal cord tumors that are not extended to the vertebral foramen can be resected safely and completely by hemilaminectomy approach. Hemilaminectomy approach is an optimal approach for providing sufficient exposure of spinal cord tumors. We have demonstrated the possibility of completely resectingintradural-extramedullary spinal cord tumors safely with the reductions of postoperative back pain, instability, degenerative changes and operative blood loss.
