Comparative Clinical And Economic Outcomes Of Minimally Invasive Surgery For Posterior Lumbar Fusion: A Systematic Review And Meta-Analysis

Presented at SMISS Annual Forum 2014
By Y. Rampersaud MD, FRCS9(C)
With Christina Goldstein MD, FRCSC, Kevin Macwan BHSc, Kala Sundararajan BSc, MSc,

Disclosures: Y. Rampersaud MD, FRCS9(C) Consulting Fees: Medtronic Christina Goldstein MD, FRCSC None, Kevin Macwan BHSc None, Kala Sundararajan BSc, MSc None,

Introduction:
The comparative effectiveness and economic benefit of minimally invasive surgery (MIS) for lumbar fusion remains unclear.

Aims/Objectives:
The main objective of this systematic review and meta-analysis is to summarize the results of comparative effectiveness and economic research comparing MIS transforaminal lumbar interbody fusion (TLIF) to traditional open midline techniques.

Methods:
A systematic review of Medline, EMBASE, Pubmed, Web of Science, and Cochrane databases was performed. A hand search of reference lists was performed. Studies were reviewed by 2 independent assessors to identify randomized controlled trials or comparative cohort studies including ≥10 patients undergoing open or MIS TLIF for degenerative pathology and reporting at least one of: clinical outcome measure; perioperative outcome measure; radiographic outcome; complications; or economic analysis. Study quality was assessed using the GRADE protocol. A meta-analysis was conducted on outcomes data when appropriate.

Results:
The systematic review and reference list search identified 3,306 articles, of which 26 met our inclusion criteria. All studies were of low or very low quality. The cohorts (n=856 MIS / n=806 open) were comparable in age, gender, surgical levels and diagnosis. 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 260ml (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 medial adverse events (RR[95% CI] MIS vs. open = 0.39[0.23-0.69], p=0.001). No difference in non-union (p=0.97) or reoperation rates (p=0.97) was observed. At a median follow-up time of 24 months mean Oswestry Disability Index scores were slightly better in the MIS patients (mean difference MIS vs open = 3.32, p = 0.001). Limited economic comparisons (3 studies) consistently showed decreased direct hospital costs associated with an MIS technique (range = 10.6 - 23.9%).

Conclusions:
Pooled analysis of the current literature comparing MIS to open TLIF for degenerative lumbar pathology suggests improved clinical and perioperative outcomes associated with decreased direct health care costs. Thus, there appears to be value associated with the performance of MIS lumbar fusion in this patient population.