Abstract 23: Immediate Reconstruction of Oncologic Spinal Wounds Is Cost Effective Compared to Conventional Primary Wound Closure

Abstract

PURPOSE: Several studies have demonstrated a reduced wound complication rate when immediate soft tissue reconstruction is performed at the time of oncologic spine surgery. Most authors document the use of bilateral paraspinous muscle flaps in this clinical scenario, demonstrating good outcomes. Despite the clear clinical advantages, the cost-effectiveness of this technique is not known. We hypothesized that immediate reconstruction of oncologic spine wounds using bilateral paraspinous muscle flaps would be a cost-effective strategy compared to the standard of care (oncologic spine surgery with conventional primary wound closure). METHODS: We employed a decision tree model to evaluate the cost-utility, from the perspective of a hospital/insurer, of immediate reconstruction with bilateral paraspinous muscle flaps relative to primary incision closure after oncologic spine surgery. A systematic review of the literature on oncologic spine surgery and immediate and delayed spinal wound reconstruction was performed to estimate health state probabilities. Costs were estimated using 2014 Center for Medicare and Medicaid Services data for relevant associated CPT and DRG codes. Overall expected cost and quality-adjusted life years (QALYs) were assessed using a Monte Carlo simulation and sensitivity analyses. RESULTS: Bilateral paraspinous muscle flaps performed in conjunction with oncologic spine surgery had an expected cost of $81,458.90 and an expected average QALY of 24.19, whereas primary wound closure (no reconstruction) had an expected cost of $83,434.34 and an expected average QALY of 24.17, making immediate soft tissue reconstruction the dominant, most cost-effective strategy. Monte Carlo sensitivity analysis demonstrated that immediate soft tissue reconstruction was the preferred and most cost-effective option in a statistically significantly greater number of iterations (81.3 percent vs. 18.7%; p<0.001), supporting its overall greater cost-utility. Even when the willingness-to-pay threshold varied from $0 to $100,000 per QALY, immediate soft tissue reconstruction remained the dominant strategy across all iterations. CONCLUSION: This cost-utility analysis suggests that performing bilateral paraspinous muscle flaps in conjunction with oncologic spine surgery is more cost-effective than primary spine incision closure alone.