Mini-percutaneous nephrolithotomy in surgery of nephrolithiasis

The present study aimed to assess the effectiveness and safety of mini-percutaneous nephrolithotomy (mPNL) in comparison with standard percutaneous nephrolithotomy (sPNL) for the treatment of complex nephrolithiasis. Methods. During the period from 2012 to 2020, 1021 patients with solitary (10.0-30.0 mm), staghorn and multiple renal calculi were retrospectively divided into two groups: sPNL (500 patients) and mPNL (521 patients). The groups were compared by the stone-free rate (%, SFR), the duration of the surgery, complications and hospital stay. Results. SPNL and mPNL were highly effective procedures for the treatment of nephrolithiasis. The mPNL group had longer operative times (81.0±15.5 vs 69.1±13.9 min, p<0.001) and higher frequency tubeless/totally tubeless procedures (41.1 vs 6.8%, p<0.001). mPNL showed a higher SFR (96.4 vs 91.8%, р=0.002 in patients with complete staghorn (90.1 vs 77.3%, p<0.05) and multiple kidney stones (89.5 vs 70.8%, p=0.03). Postoperative decrease in hemoglobin was lower in mPNL group 1.1±0.34 vs 2.1±0.26 g/dl (p<0.001). The incidence rate of urinary tract infections and postoperative hospital stay was lower in the mPNL group: 7.3 vs 13.2%, p=0.03 and 1.9±0.6 vs 4.3±2.4 days, р<0.001. Conclusions. MPNL is a safe and effective treatment for patients with complex renal stones with an improved stone-free rate and lower complication rate and shorter hospital stay. Smaller diameter tract in mPNL procedures was associated with a longer duration of surgery.