Prognostic factors of efficacy and safety for percutaneous nephrolithotripsy of large and staghorn stones of solitary kidney

The actuality of this study is defined by the lack of knowledge in the area of treatment of large or staghorn stones of solitary kidney. Materials and methods. Eighty patients with large (>20 mm) and staghorn stones of anatomically or functionally solitary kidney were included. Among them, 58 were operated on using percutaneous nephrolithotripsy (PCNL), 22 - using open interventions. Stone-free state or presence of residual fragments of no more than 3 mm were considered as effective procedure, safety was evaluated using the Clavien-Dindo grading of intra-and postoperative complications. The following factors were under consideration with regard to efficacy and safety: number of access points, tubus diameter, using the access sheath, lithotripsy type, stone size, stone density, stone type and chemical composition. Results. PCNL showed a better safety profile compared to open surgery, given the same efficacy. Stone recurrence was detected in 10.4% and 18.2% after PCNL and open interventions, respectively. PCNL resulted in significant improvement of renal function, open surgery - in deterioration of the renal function. PCNL efficacy depends on the stone type and size and type of lithotripsy: it is 7.5 times better by large stones compared to staghorn, 4.6 times better - for stones ≤ 5 mm compared to larger ones, 2.2 times better in case of ultrasound lithotripsy compared to other types. Safety of PCNL depends on the tubus diameter, sheath use, number of accesses, lithotripsy type and stone type: it is 3.6 times better for tubus diameter 24 Ch compared to >24 Ch, 3.2 times better when sheath is not used, 3 times better by single access, 2.7 times better if the ultrasound lithotripsy is used and 2.1 times better in case of large compared to staghorn stones. Conclusions. The information obtained could be used for optimization of the treatment in patients with large and staghorn stones of solitary kidney.