Comparison of Mini-Percutaneous Nephrolithotomy and Flexible Ureteroscopy for Treating 1–2 cm Single Stones in Solitary Kidney: Outcomes and Renal Function Impact

TL;DR

This study compares two kidney stone treatments in patients with one kidney, finding that flexible ureteroscopy offers similar stone removal with better safety and kidney function preservation.

Contribution

The study provides a comparative analysis of mPCNL and f-URS in solitary kidney patients with 1–2 cm stones, focusing on renal function outcomes.

Findings

f-URS showed comparable stone-free rates to mPCNL but with less blood loss and shorter hospital stays.

f-URS resulted in greater improvements in serum creatinine and eGFR at one month.

All transfusion-related complications occurred in the mPCNL group.

Abstract

Objective: The optimal surgical approach for 1.0–2.0 cm renal stones in solitary kidney patients remains controversial. This retrospective study compared mini-percutaneous nephrolithotomy (mPCNL) and flexible ureteroscopy (f-URS) outcomes in this vulnerable population. Methods: Between June 2018 and April 2024, 50 patients with solitary kidneys and 1.0–2.0 cm renal stones underwent either mPCNL (n = 26) or f-URS (n = 24). Outcomes included 3-month stone-free rate (SFR), complications (Clavien–Dindo classification), and renal function (serum creatinine, eGFR by CKD-EPI equation) at the baseline, 72 h, and 1 month. Results: Stone-free rates were comparable (mPCNL 96.2% vs. f-URS 91.7%, p = 0.157). The f-URS group demonstrated significantly less hemoglobin decline (2.2 ± 0.9 vs. 5.7 ± 2.4 g/dL, p < 0.001) and shorter hospitalization (4.1 ± 1.1 vs. 7.8 ± 1.6 days, p < 0.001). All Grade II complications (8.3%, requiring transfusion) occurred in the mPCNL group. At 1 month, serum creatinine decreased more with f-URS (15.4 ± 7.96 vs. 8.7 ± 4.23 μmol/L, p < 0.001), with greater eGFR improvement (16.7 ± 4.7 vs. 15.4 ± 5.2 mL/min/1.73 m2, p = 0.023). Conclusions: In this retrospective cohort, f-URS achieved comparable stone clearance to mPCNL alongside a superior early safety profile and better short-term renal functional preservation. These preliminary findings suggest that f-URS represents a viable nephron-sparing option for this high-risk population. However, these results are considered hypothesis-generating, and further prospective, long-term studies are required to evaluate the durability of these functional benefits.

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