Cost Analysis Between Mini-percutaneous Nephrolithotomy with and Without Vacuum-assisted Access Sheath

Purpose: To perform a cost analysis between vacuum-assisted percutaneous nephrolithotomy (vmPCNL) and minimally invasive PCNL (MIP) and explore potential predictors of costs associated with the procedures.

Methods: We analyzed data from 225 patients who underwent vmPCNL or MIP at a single tertiary referral academic center between January 2016 and December 2020. We collected patients' demographics, peri-and postoperative data and detailed expense records. After propensity score matching, 108 (66.7%) vmPCNL and 54 (33.3%) MIP procedures were analyzed. Descriptive statistics assessed differences in clinical and operative parameters. Univariable and multivariable linear regression models tested the association between clinical variables and costs.

Results: Operative time (OT) was shorter for vmPCNL, and the use of additional instruments to complete litholapaxy was more frequent in MIP (all p ≤ 0.01). Length of stay (LOS) was longer for MIP patients (p = 0.03) and the stone-free (SF) rate was higher after vmPCNL (p = 0.04). The overall instrumentation cost was higher for vmPCNL (p < 0.001), but total procedural costs were equivalent (p = 0.9). However, the overall cost for the hospitalization was higher for MIP than vmPCNL (p = 0.01). Univariable linear regression revealed that patient's comorbidities, OT, any postoperative complication and LOS were associated with hospitalization costs (all p < 0.001). Multivariable linear regression analysis revealed that LOS and OT were associated with hospitalization costs (all p < 0.001), after accounting for vmPCNL procedure, patients' comorbidities, and complications.

Conclusion: vmPCNL may represent a valid option due to clinical and economic benefits. Shorter OT, the lower need for disposable equipment and the lower complication rate reduced procedural and hospitalization costs.