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Primary study objective:

To explore the current indications, efficacy and safety of the PCNL in renal stones treatment.

Secondary study objectives:

To assess the intra- and postoperative complications of PCNL by using the Clavien –Dindo system

To define risk factors for intraoperative and postoperative complications following PCNL

To compare the efficacy of miniaturized PCNL techniques compared to standard PCNL according to stone size

The different variables will be included for statistical analysis to determine the effect on the outcome of the PCNL and on the complications of the procedure.

Patient preoperative variables – age, comorbidities, BMI, anticoagulation medications, type of stones, the presence of solitary functioning kidney, congenital abnormalities

Preoperative imaging methods for planning type of the procedure, stone density, stone size, number etc.

Preoperative urinary tract infection (frequency, type of bacteria), preoperative antibiotic treatment (type, duration)

Patient position, imaging methods for creating of the percutaneous access, size and the dilatation method (balloon, metal telescopic, one-shot etc.)

Type and size of the access sheath, instruments and procedure (micro, mini, supermini, ultra-mini, standard PCNL)

The type of the lithotripsy method and method for extracting and evacuating the stone fragments

Exiting strategies (totally tubeless, tubeless, nephrostomy (type, size), time for extracting drainage and postoperative hospital stay.

Morbidity of the procedure, complications classified according to the Clavien-Dindo system and treatment of complications