[Microendoscopic decompression via unilateral approach for lumbar spinal stenosis].

OBJECTIVE: To investigate the effectiveness and safety of microendoscopic decompression via unilateral approach for lumbar spinal stenosis. METHODS: Between May 2006 and June 2009, 79 patients with lumbar stenosis were treated and divided into 2 groups: posterior lamina fenestration decompression (group A, n = 37), endoscopic decompression via unilateral approach (group B, n = 42). There was no significant difference in age, sex, segment level, and disease duration between 2 groups (P > 0.05). The clinical outcomes were assessed by using the visual analogue scale (VAS) score and Oswestry Disability Index (ODI). The operation time, blood loss, complications were compared between 2 groups. RESULTS: Operations were successfully performed in all cases. The operation time, blood loss, and drainage volume were (75.0 +/- 25.7) minutes, (140.3 +/- 54.8) mL, and (46.5 +/- 19.7) mL in group A, were (50.4 +/- 18.2) minutes, (80.2 +/- 35.7) mL, and (12.7 +/- 5.3) mL in group B; there were significant differences between 2 groups (P < 0.05). All the wounds healed by first intention. All patients were followed up 12-39 months (mean, 16 months). In group A, 1 patient suffered from intervertebral space infection after operation and recovered after conservative treatment; 4 patients had lumbar instability after operation and recovered after lumbar interbody fusion combined with spine system internal fixation. In group B, 2 patients suffered from spinal dural rupture during operation and recovered after corresponding treatment, and no lumbar instability was found. There was no significant difference in VAS score and ODI between 2 groups at preoperation (P > 0.05). Both VAS score and ODI were significantly improved at early stage after operation and last follow-up when compared with preoperation in each group (P < 0.05). Comparing with group A, there was significant improvement in VAS score at 24 hours postoperatively and in ODI at 1 month postoperatively in group B (P < 0.05), but no significant difference was observed at last follow-up (P > 0.05). According to clinical evaluation of ODI improvement rate, the excellent and good rate was 89.2% in group A and 92.9% in group B, showing no significant difference (chi2 = 0.896, P = 0.827). CONCLUSION: Comparing with posterior decompression surgery, microendoscopic decompression via unilateral approach is one of effective method to treat lumbar stenosis, with less trauma of fenestration yield and good early outcomes.