Minimally invasive approach to far lateral lumbar disc herniation: technique and clinical results.

To describe our minimally invasive technique for the surgical treatment of far lateral lumbar disc herniation (FLLDH) using MetRx tissue dilators system and a surgical microscope; and to report our experience with this method. Retrospective analysis of data of all patients with FLLDH treated by minimally invasive discectomy. Outcome assessment was performed using neurological status, the visual analog scale (VAS) for back pain and leg pain, and the Short Form-36 Health Survey Questionaire (SF-36). Thirty-one patients were included in this study. The mean follow-up time was 25.16 months. Muscle weakness improved in all patients. Sensory deficits disappeared in 22 patients and improved in the other five patients. The mean VAS for radicular pain showed significant improvement from 8.6 preoperatively, to 3.8 in the immediate postoperative period (P-value <.01), and 0.6 at the last follow-up. The mean VAS for back pain also showed significant improvement from 5.8 preoperatively, to 4.8 in the immediate postoperative period and 0.7 at the last follow-up visit. The SF 36 data showed significant improvement in all the eight domains: the physical functioning improved from 9.68 preoperatively to 76.33 at 6-month follow-up and SF 36 bodily pain index improved from 6.71 before surgery to 79.53 at 6-month follow up. Complications included two cases of incidental dural tear, without postoperative CSF leakage and one case of residual sequestered disc that was successfully removed by a second minimally invasive procedure. Our results suggest that this minimally invasive technique is safe and efficacious for the management of FLLDH and might be an alternative to open microsurgical approaches.