Mini Percutaneous Nephrolithotomy Is a Noninferior Modality to Standard Percutaneous Nephrolithotomy for the Management of 20–40mm Renal Calculi: A Multicenter Randomized Controlled Trial

High quality of evidence comparing mini percutaneous nephrolithotomy (mPNL) with standard percutaneous nephrolithotomy (sPNL) for the treatment of larger-sized renal stones is lacking. To compare the efficacy and safety of mPNL and sPNL for the treatment of 20–40mm renal stones. A parallel, open-label, and noninferior randomized controlled trial was performed at 20 Chinese centers (2016–2019). The inclusion criteria were patients 18–70 yr old, with normal renal function, and 20–40mm renal stones. Percutaneous nephrolithotomy PNL was performed using either 18 F or 24 F percutaneous nephrostomy tracts. The primary outcome was the one-session stone-free rate (SFR). The secondary outcomes included operating time, visual analog pain scale (VAS) score, blood loss, complications as per the Clavien-Dindo grading system, and length of hospitalization. The 1980 intention-to-treat patients were randomized. The mPNL group achieved a noninferior one-session SFR to the sPNL group by the one-side noninferiority test (0.5% [difference], p