Percutaneous Endoscopic Lumbar Discectomy Via Partial Pedicle Approach For High-grade Down-migrated Disc Herniation

Objectives: To investigate the safety,feasibility and clinical outcome of percutaneous endoscopic lumbar discectomy(PELD)via partial pedicle approach for high-grade down-migrated disc herniation.Methods: From July 2014 to January 2016,21 patients suffering from high-grade down-migrated lumbar disc herniation were treated by this method.(including 3 cases of L3/4,15 cases of L4/5 and 3 cases of L5/S1).These patients were treated with non-surgery methods for 3 weeks,and the curative effect was poor.To remove the herniated disc materials and complete the compression,a portion of the upper margin and medial border of the vertebral pedicle could be removed under visual control.The operation time and complications were recorded.The Visual analogue scale(VAS)and Oswestry disability index(ODI)were recorded to evaluate the postoperative improvement of the patients.the results of treatment were evaluated according to the Macnab's criteria.Results: All the patients tolerated the operation.The operation time was 93±10min.Only one case was found complicated with paresthesia of leg at the first day of postoperation,which relieved by conservative therapy.The rest patients presented with no infection,vascular,neurological or dural injury.Patients were followed up for 12 months.The VAS was 7.57±1.09 prior to surgery,2.90±0.52(1-day after surgery),2.24±0.52(1-month after surgery),1.86±0.63(3-month after surgery),1.38±0.48(6-month after surgery),and 1.19±0.49(12-month after surgery),which were improved significantly compared with preoperative(p<0.01).The ODI score improved from 54.86±12.67 at preoperation to 11.80±1.73 at last follow-up,The ODI scores at different follow-up time after surgery that also showed significant differences(p<0.01).According to Macnab's criteria,15 patients had excellent results,4 patients had good results,2 patient had fair results,and no patient had a poor result;satisfactory results were obtained in 90.47% of the cases.Conclusion: The percutaneous endoscopic lumbar discectomy via partial pedicle approach could be safe,feasible and effective for high-grade down-migrated disc herniation.