Revision lumbar surgery in elderly patients with symptomatic pseudarthrosis, adjacent-segment disease, or same-level recurrent stenosis. Part 2. A cost-effectiveness analysis ; Clinical article

Object. Despite advances in technology and understanding in spinal physiology, reoperation for symptomatic adjacent-segment disease (ASD), same-level recurrent stenosis, and pseudarthrosis in elderly patients continues to occur. While revision lumbar surgery is effective, attention has turned to questions on the utility and value of the revision decompression and fusion procedure. To date, an analysis of the cost and health state gain associated with revision lumbar surgery in elderly patients with symptomatic pseudarthrosis, ASD, or same-level recurrent lumbar stenosis has yet to be performed. The aim of this study was to assess the long-term outcomes and cost-effectiveness of revision surgery in elderly patients with recurrent or persistent back and leg pain. Methods. After reviewing their institutional database, the authors found 69 patients 65 years of age and older who had undergone revision decompression and instrumented fusion for back and leg pain associated with pseudarthrosis (17 patients), same-level recurrent stenosis (24 patients), or ASD (28 patients) and included them in this study. Total 2-year back-related medical resource utilization and health state values (quality-adjusted life years [QALYs], calculated from the EQ-5D, the EuroQol-5D health survey, with US valuation) were assessed. Two-year resource use was multiplied by unit costs based on Medicare national allowable payment amounts. The mean total 2-year cost per QALY gained after revision surgery was assessed. Results. The mean (±standard deviation) time between the index surgery and revision surgery was 3.51 ±3.63 years. A mean cumulative 2-year gain of 0.35 QALY was observed after revision surgery. The mean total 2-year cost of revision surgery was $28,256 ±$3000 (ASD: $28,829 ±$3812, pseudarthrosis: $28,069 ±$2508, same-level recurrent stenosis: $27,871 ±$2375). Revision decompression and extension of fusion was associated with a mean 2-year cost of $80,594 per QALY gained. Conclusions. Revision decompression and fusion provided a significant gain in health state utility for elderly patients with symptomatic pseudarthrosis, same-level recurrent stenosis, or ASD, with a mean 2-year cost of $80,594 per QALY gained. When indicated, revision surgery for symptomatic ASD, same-level recurrent stenosis, and pseudarthrosis is a valuable treatment option for elderly patients experiencing persistent back and leg pain. Findings in this study provided a value measure of surgery that can be compared with future cost-per-QALY-gained studies of medical management or alternative surgical approaches.