Vacuum-Assisted Mini-PCNL is Associated with Lower Postoperative SIRS: A Real-World Cohort Study.

BACKGROUND

Postoperative systemic inflammatory response syndrome (SIRS) remains a key complication after mini-percutaneous nephrolithotomy (mini-PCNL) and is often related to elevated intrarenal pressure and bacterial translocation. Vacuum-assisted mini-PCNL (VmPCNL) has been developed to mitigate this risk through active pressure control.

OBJECTIVE

To evaluate the association between VmPCNL and postoperative SIRS and to identify the independent predictors of SIRS in a real-world cohort.

MATERIALS AND

METHODS

A retrospective cohort study was conducted of patients undergoing mini-PCNL at a tertiary referral center between January 2021 and May 2025. Patients were stratified into standard mini-PCNL (SmPCNL) and VmPCNL groups. The primary endpoint was SIRS within 48 hours post-surgery. Secondary outcomes included operative time, stone-free rate (SFR), and length of hospital stay (LOS). Multivariable logistic regression was used to identify independent predictors of SIRS.

RESULTS

A total of 136 patients were included in the study (SmPCNL, n = 78; VmPCNL, n = 58). The incidence of postoperative SIRS was significantly lower in the VmPCNL group (8.6% vs 21.8%, p = 0.036). VmPCNL was also associated with shorter operative time (median 90 minutes vs 115 minutes, p = 0.038) and reduced LOS (p = 0.012). Stone-free rates were comparable between the groups, indicating no compromise in procedural efficacy. In the multivariable analysis, VmPCNL was independently associated with a lower risk of SIRS (adjusted OR [aOR] 0.44, 95% CI 0.19-0.98, p = 0.041), while a positive preoperative urine culture was an independent risk factor (aOR 2.60, 95% CI 1.01-6.60, p = 0.045).

CONCLUSION

In this real-world cohort, VmPCNL was associated with a lower SIRS incidence and improved perioperative efficiency without compromising stone-free outcomes. The mechanism may involve improved intraoperative outflow dynamics through active suction, although direct measurement of intrarenal pressure is needed to confirm this hypothesis.