Presented by: Kevin Wymer MD
Mayo Clinic

Introduction

Although PCNL is the standard for management of stones >2cm, the approach has technical barriers and often requires advanced training. Conversely, ureteroscopy alone can prove ineffective. The CVAC aspiration system (Calyxo, Inc.) has shown promising results as an adjunct to URS. Herein, we assess the economic and quality of life impact of the CVAC system.

Materials

A decision-analytic Markov model was used to assess the cost-effectiveness of URS alone, URS + CVAC, and PCNL for the treatment of 2-3cm renal stones. The model included stone free rates, retreatment, auxillary procedures, complications, and residual stone events. Primary outcomes included Medicare costs, effectiveness (quality adjusted life years (QALYs)), and incremental cost-effectiveness ratios (ICERs) with a willingness-to-pay (WTP) threshold of $100,000/QALY. Univariable and multivariable sensitivity analyses were performed.

Results

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At 3 years following the index procedure, costs per patient were $6,259, $9,741, and $11,343 for URS, URS+CVAC, and PCNL, respectively. Similarly, URS resulted in the lowest QALYs (2.89), followed by URS+CVAC (2.93), and PCNL (2.94). Although more effective, both URS+CVAC (ICER= $108,505) and PCNL (ICER= $112,905) were not cost-effective relative to URS alone. However, with an ICER near the WTP threshold, the model was sensitive to slight changes in multiple variables. Specifically, URS+CVAC became cost-effective if the SFR with CVAC was 22% higher than URS alone (base difference of 20%) or if the cost of CVAC decreased by 3%. On multivariable analysis with 100,000 microsimulations, URS was most commonly favored (42%), followed by URS+CVAC (30%), and PCNL (28%) (Figure).

Conclusion

Based on a Markov model, URS+CVAC led to higher quality of life relative to URS alone and lower costs relative to PCNL- occupying a middle ground between these two procedures for patients with large (2-3cm) sized stones. Such models can be used to help guide patient, provider, health system, and reimbursement-level decision making for these complex patients.

Funding

No Funding 

Co-Authors

Daniel Heidenberg, MD
Mayo Clinic

Victoria Edmonds, MD
Mayo Clinic

Nicolette Payne, MD
Mayo Clinic

Mouneeb Choudry, MD
Mayo Clinic

J. Stuart Wolf, MD
Mayo Clinic

Karen Stern,
Mayo Clinic