Abstract

Introduction:Recurrences following operations of lumbar disc herniations cannot be completely avoided. The rates are up to 8%, depending on the operation technique. Revision is mainly more demanding as an increased risk of injury exists due to the cicatrisation with frequently occurs. For this reason, more extensive resection of osseous parts may be necessary in order to achieve scar-free areas. As a minimally-invasive alternative to conventional techniques, there is the possibility of operating disk herniations full-endoscopically. The objective of the prospective study was the comparison of a full-endoscopic (Group 1) with the microsurgical (Group 2) revision in recurrent lumbar disc herniations in patients with conventional previous operations.Material and Methods:40 patients with recurrent lumbar disc herniation after microsurgical operation were revised in the full-endoscopic interlaminar technique (12 times) and lateral transforaminal technique (8 times) or conventional microsurgical technique (20 times) in 2003/2004. Apart from specific inclusion criteria for the lateral transforaminal or interlaminar full-endoscopic approach, there were no technical exclusion criteria. All the patients had a MRI-diagnosed disc herniation and, after a free interval, new occurrences of leg pains. New 7 mm endoscopes with intra-endoscopic 4.2 mm working canal were used. Follow-up lasted 12 months. 39 patients (20 full-endoscopic, 19 microsurgical) could be followed. Additionally to general parameters validated scores were used.Results:No patients suffered injuries to the dura or neural structures. 3 patients in Group 1 and 4 patients in group 2 had a transient dysaesthesia. The mean operating time in Group 1 was 29 minutes (33 minutes interlaminar, 24 minutes transforaminal), in Group 2 57 minutes. In Group 1, resection of osseous sections was not necessary in any cases, in Group 2 in 16 cases. The postoperative pain symptoms and rehabilitation were significantly reduced in Group 1. The results showed a satisfactory result subjectively in 91% of the cases, without significant differences between the two groups. This also corresponded to the constant results of the scores.Conclusion:The full-endoscopic interlaminar and lateral transforaminal revision of the recurrent lumbar disc herniation in patients with conventional previous operations is an alternative to microsurgical procedure. Advantages can result from quicker operating times, reduced osseous resections and lower traumatisation with reduced postoperative pain and shorter rehabilitation. In particular, the transforaminal procedure enables reaching of the epidural space from ventral, avoiding the scars. The disadvantage is the technical impossibility of occlusion of injuries to the dura, which can always occur in preoperated patients.