Transforaminal Percutaneous Endoscopic Lumbar Discectomy Via Superior Border Of Inferior Pedicle Approach For Severe Down-migrated Disc Herniations

Objective: To approach the feasibility of transforaminal percutaneous endoscopic lumbar discectomy via superior border of inferior pedicle approach for severe down-migrated intracanal disc herniations.Method: From November 2012 to August 2015,a total of 14 patients with severe down-migrated disc herniations were treated transforaminal percutaneous endoscopic lumbar discectomy via superior border of inferior pedicle approach in hospital.1 case had L2/3 disc herniation and 1 had L3/4 disc herniation,8 L4/5,4 L5/S1.Among them1 case was reherniation after open window decompression.Remove partial vertebral pedicle with abrasive drilling via superior border of inferior pedicle approach.The pulposus was removed under direct vision.The data of JOA,back/leg pain VAS and ODI of before surgery,postoperationscore immediately,the 2nd day after operation and last follow-up was collected and analysised.The clinical effect was elevated with Macnab standard.Result: The mean operation time was 105 min,ranged from 65 min to 210 min.1cases had right leg numbness,and was recovered after conservative treatment.1 patient suffered form left thumb dorsal extension asthenia and fully recovered 1 month latter.No surgery complications were noted in other patients.The preoperative VAS of backand leg pain was 6.0±2.1,7.4±1.9 respectively,and the 2nd day after surgery was2.1±0.8,1.8±1.1 respectively.The ODI before surgery,2nd day after operation and last follow-up was 19.3% ± 7.4%,10.5% ± 4.1% and 6.5% ± 2.3% respectively.According to Mac Nab classification,12 cases was excellent and 2 cases was good on the 2nd day after operation.At the most recent follow-up,13 cases got excellent and 1got good results.Conclusion: Transforaminal percutaneous endoscopic lumbar discectomy via superior border of inferior pedicle approach is an effective and safe alternative for severe down-migrated disc herniations.