Minimally Invasive Versus Open Laminectomy for Lumbar Stenosis

STUDY DESIGN: Systematic review with meta-analysis. OBJECTIVE: To assess the relative merits of minimally invasive unilateral laminectomy for bilateral decompression (ULBD) versus open laminectomy, a systematic review and meta-analysis of all available evidence was performed. SUMMARY OF BACKGROUND DATA: Lumbar spinal stenosis is one of the most common pathologies in the increasingly elderly population that results in claudication, back and leg pain, and disability. The conventional approach for decompression is open laminectomy. In recent years, there has been a surge in microendoscopic procedures, which aim to minimize invasiveness. Despite the increasing use of these minimally invasive techniques, few studies have directly compared the safety, efficacy, and outcomes of these procedures with conventional laminectomy. There is a lack of robust clinical evidence, with most reports limited to single-center, inadequately powered, noncomparative studies. METHODS: Relevant articles were identified from six electronic databases. Predefined endpoints were extracted and meta-analyzed from the identified studies. RESULTS: Satisfaction rates were significantly higher in the minimally invasive group (84% vs. 75.4%; P = 0.03), whereas back pain Visual Analog Scale scores were lower (P < 0.00001). Minimally invasive laminectomy operative duration was 11 minutes longer than the open approach (P = 0.001), however this may not have clinical significance. However, there was less blood loss (P < 0.00001) and shorter hospital stay (2.1 days; P < 0.0001). Dural injuries and cerebrospinal fluid leaks were comparable, but reoperation rates were lower in the minimally invasive cohort (1.6% vs. 5.8%; P = 0.02); however this was not significant when only randomized evidence was considered. CONCLUSION: The pooled evidence suggests ULBD may be associated with less blood loss and shorter stay, with similar complication profiles to the open approach. These findings warrant verification in large prospective registries and randomized trials. LEVEL OF EVIDENCE: 1.