Minimally invasive surgery for lumbar disc herniation: a systematic review and meta-analysis

Assessing the benefits of surgical treatments for sciatica is critical for clinical and policy decision-making. To compare minimally invasive (MI) and conventional microdiscectomy (MD) for patients with sciatica due to lumbar disc herniation. A systematic review and meta-analysis of controlled clinical trials including patients with sciatica due to lumbar disc herniation. Conventional microdiscectomy was compared separately with: (1) Interlaminar MI discectomy (ILMI vs. MD); (2) Transforaminal MI discectomy (TFMI vs. MD). Outcomes: Back pain, leg pain, function, improvement, work status, operative time, blood loss, length of hospital stay, complications, reoperations, analgesics and cost outcomes were extracted and risk of bias assessed. Pooled effect estimates were calculated using random effect meta-analysis. Twenty-nine studies, 16 RCTs and 13 non-randomised studies (n = 4,472), were included. Clinical outcomes were not different between the surgery types. There is low quality evidence that ILMI takes 11 min longer, results in 52 ml less blood loss and reduces mean length of hospital stay by 1.5 days. There were no differences in complications or reoperations. The main limitations were high risk of bias, low number of studies and small sample sizes comparing TF with MD. There is moderate to low quality evidence of no differences in clinical outcomes between MI surgery and conventional microdiscectomy for patients with sciatica due to lumbar disc herniation. Studies comparing transforaminal MI with conventional surgery with sufficient sample size and methodological robustness are lacking.