Comparison of Stone-Free Rates and Systemic Inflammatory Response Between Intelligent Pressure-Controlled and Conventional Mini-Percutaneous Nephrolithotomy in Patients With Kidney Stones.

BACKGROUND

Elevated intrarenal pressure during mini-percutaneous nephrolithotomy (mini-PCNL) may worsen systemic inflammation and affect stone clearance. This study compared stone-free rates and incidence of systemic inflammatory response syndrome (SIRS) between intelligent pressure-controlled and conventional mini-PCNL after propensity score matching (PSM).

METHODS

This retrospective cohort study included patients undergoing primary mini-PCNL for kidney stones (April 2022-April 2025). After PSM, patients were divided into a conventional mini-PCNL group (n = 136) and an intelligent pressure-controlled group (n = 136). Primary outcomes included stone-free rates (residual fragments <4 mm) at postoperative day 1, month 1, and month 3, and SIRS incidence. Secondary outcomes included operative time, blood loss, hospital stay, pain scores, inflammatory markers, and complications.

RESULTS

The intelligent pressure-controlled group had a significantly higher immediate stone-free rate (p < 0.001), lower SIRS incidence (p = 0.040), shorter operative time (p = 0.006), less blood loss (p = 0.002), shorter hospital stay (p = 0.022), lower pain scores (p = 0.008), and lower postoperative C-reactive protein and procalcitonin levels (all p < 0.001). Total complication rate was lower in the intelligent pressure-controlled group than in the conventional group (11.76% vs. 25.00%, p = 0.005).

CONCLUSIONS

Intelligent pressure-controlled mini-PCNL was associated with higher immediate stone-free rates, lower SIRS incidence, and better perioperative outcomes than conventional mini-PCNL in this retrospective matched comparison. Causality cannot be inferred due to the retrospective, non-randomised design. Findings warrant confirmation in prospective randomised trials.