Perioperative Outcomes and Adverse Events of Minimally Invasive versus Open Posterior Lumbar Fusion: Meta-Analysis

Abstract

Introduction The perioperative outcomes and adverse events of minimally invasive surgery (MIS) for lumbar fusion remain unclear. The purpose of this systematic review and meta-analysis is to summarize the perioperative outcomes and adverse event rates for MIS transforaminal or posterior lumbar interbody fusion (TLIF/PLIF) compared with traditional open midline techniques. Materials and Methods A systematic review of Medline, EMBASE, PubMed, Web of Science, and Cochrane databases were performed. A hand search of reference lists was performed. Studies were reviewed by two independent assessors to identify randomized controlled trials or comparative cohort studies including ≥ 10 patients undergoing MIS or open TLIF/PLIF for degenerative lumbar spinal disorders and reporting at least one of the following: clinical outcome measure; perioperative surgical performance or outcome measure; radiographic outcome; or adverse events. Study quality was assessed using the GRADE protocol. When appropriate, a meta-analysis of outcomes data was conducted. Results The systematic review and reference list search identified 3,306 articles, with 26 meeting study inclusion criteria. All studies, including one randomized controlled trial, were of low or very low quality. No significant difference regarding age, gender, surgical levels, or diagnosis was identified between the two cohorts ( n = 856 MIS/ n = 806 open). Meta-analysis revealed changes in the perioperative outcomes of mean estimated blood loss, time to ambulation, and length of stay favoring an MIS approach by 260 mL ( p < 0.00001), 3.5 days ( p = 0.0006) and 2.9 days ( p < 0.00001), respectively. Operative time was not significantly different between the surgical techniques ( p = 0.78). There was no significant difference in surgical adverse events ( p = 0.97); however, MIS cases were significantly less likely to experience medical adverse events (RR [95% CI] MIS vs. open = 0.39 [0.23–0.69], p = 0.001). No difference in nonunion ( p = 0.97) or reoperation rates ( p = 0.97) was observed. Mean Oswestry Disability Index scores were slightly better in the patients with MIS at a median follow-up time of 24 months (mean difference MIS [ n = 346] vs. open [ n = 346] = 3.32, p = 0.001). Conclusion The quality of the current comparative evidence is low to very low with significant inherent bias. The result of this quantitative systematic review of clinical comparative effectiveness research examining MIS versus open TLIF/PLIF for degenerative lumbar pathology suggests equipoise in patient reported clinical outcomes. Furthermore, meta-analysis of adverse event data suggests equivalent rates of surgical complications with lower rates of medical complications in patients undergoing MIS TLIF/PLIF compared with open surgery.