General Session: Endoscopic Surgery
Presented by: Y. Gu
(1) Zhongshan Hospital Fudan University, Orthopaedics, Shanghai, China
Introduction: Although nearly all kinds of disc herniations are accessible for TESS of outside disc-inside technique directly into spinal canal, complexity of C-arm guided orientation, difficulty to find the optimal trajectory for target and more steps of surgical manipulation leaded to much exposure of X-ray, long duration of operation, and steep learning curve. We designed an easy posterolateral transforaminal endoscopic decompression technique, termed PTES, for radiculopathy secondary to lumbar disc herniation. We found that the entrance point was located at the corner of flat back turning to lateral side, and as high as, or more cranially or slight more caudally than the horizontal line of target disc, which was similar to "All roads lead to Rome (herniated fragment)". This has never been mentioned by other scholars, and we named this entrance point after "Gu's Point". In PTES, press-down enlargement of foramen could make it easy to advance the working cannula into the spine canal between the dura and disc even if the angle of puncture was 45° and to remove the fragments underneath the nerve root and the central dura, even the contralateral nerve root.(Figure 1) The purpose of study is to describe the technique of PTES and evaluate the efficacy and safety for treatment of recurrent, missed lumbar disc herniations and adjacent disc herniations after previous intervention; and to report outcome and complications.
Materials and Methods: PTES was performed to treat 57 cases of 40 recurrent herniations and 7 missed fragments after previous intervention at the index level and 9 adjacent disc herniations after decompression and fusion. One case of L4/5 herniation after transforaminal endoscopic discectomy for L5/S1 also was included. There were 29 laminectomy & discectomies, 11 endoscopic discectomy, 14 decompression & fusion, 2 radiofrequency ablation, and 1 ozone injection. Preoperative and postoperative leg pain was evaluated using visual analog scale (VAS) and the results were determined to be excellent, good, fair, or poor according to the MacNab classification at 2-year follow-up.
Results: The mean duration of the operation was 50.2±8.4 minutes per level. The mean frequency of intraoperative fluoroscopy was 5(4-14) times per level. The mean blood loss was 5(2-20) ml per level. The mean stay in the hospital was 3(2-4) days. The patients were followed for an average of 27.4±3.2months. The VAS score of leg pain significantly dropped from 9(6-10) before operation to 1(0-3) (P< 0.001) immediately after the operation and to 0(0-3) (P< 0.001) 2 years after operation. At 2-year follow-up, 98.2% (56/57) of the patients showed excellent or good outcomes, 1.8% (1/57) fair and 0% (0/57) poor. No patients had any form of permanent iatrogenic nerve damage and a major complication, although there was 1 case of recurrence from injury 2 months after the operation.
Conclusion: PTES for recurrent, missed lumbar disc herniations and adjacent disc herniations after previous intervention is an easy, effective and safe technique with simple orientation, easy puncture, reduced steps and little X-ray exposure. The learning curve is no longer steep for surgeons.
Keywords: Lumbar disc herniation, Transforaminal, Endoscopic discectomy, Minimally invasive surgery