Cost per quality-adjusted life year gained of revision neural decompression and instrumented fusion for same-level recurrent lumbar stenosis: defining the value of surgical intervention.

Object: Despite advances in technology and understanding in spinal physiology, reoperation for symptomatic same-level recurrent stenosis continues to occur. Although revision lumbar surgery is effective, attention has turned to the question of the utility and value of revision decompression and fusion procedures. To date, an analysis of cost and heath state gain associated with revision lumbar surgery for recurrent same-level lumbar stenosis has yet to be described. The authors set out to assess the 2-year comprehensive cost of revision surgery and determine its value in the treatment of same-level recurrent stenosis.

Methods: Forty-two patients undergoing revision decompression and instrumented fusion for same-level recurrent stenosis-associated leg and back pain were included in this study. Two-year total back-related medical resource utilization, missed work, and health state values (quality-adjusted life years [QALYs], calculated from the EQ-5D with US valuation) were assessed. Two-year resource use was multiplied by unit costs based on Medicare national allowable payment amounts (direct cost), and patient and caregiver workday losses were multiplied by the self-reported gross-of-tax wage rate (indirect cost). Mean total 2-year cost per QALY gained after revision surgery was assessed.

Results: The mean (± SD) interval between prior and revision surgery was 4.16 ± 4.64 years. Bone morphogenetic protein was used in 7 cases of revision arthrodesis (16.7%). A mean cumulative 2-year gain of 0.84 QALY was observed after revision surgery. The mean total 2-year cost of revision fusion was $49,431 ± $7583 (surgery cost $21,060 ± $4459; outpatient resource utilization cost $9748 ± $5292; indirect cost $18,623 ± $9098). Revision decompression and extension of fusion was associated with a mean 2-year cost per QALY gained of $58,846.

Conclusions: In the authors' practice, revision decompression and fusion provided a significant gain in health state utility for patients with symptomatic same-level recurrent stenosis, with a 2-year cost per QALY gained of $58,846. When indicated, revision surgery for same-level recurrent stenosis is a valuable treatment option for patients experiencing back and leg pain secondary to this disease. The authors' findings provide a value measure of surgery that can be compared with the results of future cost-per-QALY-gained studies of medical management or alternative surgical approaches.