Clinical Application Of The Unilateral Hemilaminectomy Approach For Microsurgical Treatment In The Spinal Cord Tumors

Background and Purpose: Spinal cord tumors, also known as intraspinal tumors,accounting for15%of the tumors of the central nervous system.According to theirlocation spinal cord tumors can be divided into the intramedullary tumors andextramedullary tumors.Subdural extramedullary tumors in the spinal cord tumors sharethe largest proportion of about60%to70%, more common in schwannomas andmeningiomas; epidural tumors were malignant metastatic; the intramedullary tumorsaccount for about20%, mainly as astrocytoma and ependymoma.Surgery is the mosteffective treatment of spinal cord tumors. Laminectomy surgery is the previous meansfor the management of spinal cord tumors, which bring about great trauma to the spine,postoperative spinal stability will be influenced usually, scar adhesions affect thelong-term clinical efficacy. Hemilaminectomy surgery in recent years is a newminimally invasive surgery for the management of spinal cord tumors. This studyapplying retrospective analytic process analyzed90cases of spinal cord tumors byhemilaminectomy surgery from our department since2008, aimed at investigating thestrengths and weaknesses, clinical indications, clinical efficacy and impact on thestability of the spine by the hemilaminectomy microsurgical treatment of spinal cordtumors.Research Methods: The authors retrospectively analyzed clinical data of90patientswith spinal cord tumors surgically treated through hemilaminectomy from February2008to December2012；85patients with spinal cord tumors removed through totallaminectomy approach during the same period were chosen as comparative group．Wecompared two group patients with operative time, surgical exposure and resection of the tumor, the mean postoperative hospital stay, and get ting out of bed time; Recentclinical efficacy was evaluated by symptoms after one week compared with thepre-operative in patients; All surgical cases carried out the regular follow-up.UsingMcCorick clinical classification standards evaluated the long-term clinical efficacy ofthe patients.The spinal stability of two group patients were evaluated for medicalimaging data before and after surgery.All datas are analyzed statistically by using SPSSsoftware.Surgical methods: The lesion segments are positioned with X-ray before surgery.Methylene blue is injected in the spinous process as a marker. The patients take theprone position after general anesthesia. Location mark as the center take the posteriormidline longitudinal incision where the the lesions range exceeds about2cm. We cutthe skin, subcutaneous tissue, fascia, separate to the spinous process and supraspinous.Paraspinal muscles are separated in the side of the lesion subperiosteal by thehemilaminectomy group.We reveal the lamina of pathological segment which does notexceed the zygapophysial lateral border. Laminectomy retractor retractors theparaspinal muscles in order to assist exposing. We remove unilateral laminectomy witha laminectomy rongeur or cutter, bite yellow ligament and expose dural. Some casesare precisely positioned with intraoperative ultrasound again. We cut dural near thesurface of the tumors, then resect the tumors under the microscope piecemeal, stanchbleeding thoroughly and suture the dural tightly. Paraspinal muscles are sutured oninterspinous ligament, we suture fascia, subcutaneous and skin layer by layer. Thetotal laminectomy surgery bites off the spinous process, supraspinous ligament,interspinous ligament and bilateral laminectomy. The dura is slit along the posteriormidline longitudinal. We stitch on each floor hierarchically after the removal of thetumor. Drainage tubes are placed in the epidural. Intramedullary tumors arelongitudinally incised along the median sulcus of spinal cord, then the tumors are resected piecemeal under the neurophysiological custody.Results:90tumors of the hemilaminectomy group and85tumors of the laminectomygroup were totally removed, the short-term clinical efficacy was satisfactory in the twogroups(P>0．05). The operation time of the two groups were not statistically significantdifferences, the postoperative hospital stay of the laminectomy group was significantlyshorter.You can get out of bed early, the difference between the two groups wasstatistically significant (P <0.05). The period of follow-up was ranged from3monthsto61months(mean29.50months), The spinal stability was excellent and there was nospinal deformity in the hemilaminectomy group. There were11patients with spinalstability changed in the total laminectomy group(P <0.05). The long-term clinicalefficacy of hemilaminectomy group had improved the85cases, while the totallaminectomy group was66cases. Hemilaminectomy group was significantly superiorto total laminectomy group. The difference was statistically significant (P <0.05).Conclusion:With many advantages of minimal trauma,the shorter postoperativehospital stay, getting out of bed early,significant short-term and long-term clinicalefficacy and lower incidence of spinal instability,hemilaminectomy for surgicalresection of spinal cord tumors can be used for the majority of extramedullary spinalcord tumors. Notwithstanding the restricted exposed shortcomings block the resectionof the tumor tissue, operating space is sufficient with the microscope. Combined withintraoperative ultrasound and electrophysiological monitoring technology, thehemilaminectomy surgical resection is even better than the total laminectomy approachfor the small lesions and clear borderline of intramedullary tumors.