To compare the cost-effectiveness of simultaneous vs staged percutaneous nephrolithotomy (PCNL) during treatment of patients with large, bilateral stone burden.

A decision-analytic Markov model was used to assess the cost-effectiveness of simultaneous and staged PCNL for large, bilateral stone burden. Model probabilities and outcomes for index procedures were drawn from a large-volume, single-center cohort. Primary outcomes included costs from a Medicare standpoint with the addition of operative time, length-of-stay costs, effectiveness (quality adjusted life years, QALYs), and incremental cost-effectiveness ratios with a willingness-to-pay threshold of $100,000/QALY.

At 1year following the index procedure, costs per patient were $52,585 and $61,687 for simultaneous and staged PCNL, respectively. In addition to being less costly, simultaneous PCNL resulted in slightly higher QALYs (0.982) compared to staged PCNL (0.977). On one-way sensitivity analyses, staged PCNL became cost-effective if the stone-free rate increased from 56% to 88% (40% greater per renal unit relative to simultaneous PCNL) or the cost of unilateral PCNL decreased approximately 50% to $4699 ($16,266 less than simultaneous PCNL).

Even when assuming a modest reduction in stone-free rate and slightly higher major and minor complication rates at index procedure, simultaneous bilateral PCNL was both less costly and more effective at 1year follow up relative to staged bilateral PCNL. This offers further support of simultaneous bilateral PCNL in the proper clinical setting.