Purpose: to determine the characteristics of the surgeon training curve in the development of percutaneous nephrolithotripsy (PNТ).
Materials and methods: The first 125 PNТs performed by one team of surgeons were investigated. In chronological order, five groups of 25 operations were formed. The assessment was carried out according to the following parameters: the duration of the operation; the number of perioperative complications; stone free rate (SFR).
Results: With the advanced training of the surgical team, the duration of the operation tended to decrease; after 50 PNТ the time decreased from 164±12 to 113±11 minutes. The duration of the next 50 PNТ conducted in the third and fourth groups remained unchanged – 105±10 and 103±12 minutes. In the fifth group, a decrease in time to 99±9 minutes had no significant differences with the third and fourth groups. The frequency of complications tended to decrease up to the 75th operation, followed by a plateau. The structure was dominated by complications related, according to the modified Clavien-Dindo classification, to Grade I and Grade II. With the accumulation of surgeons’ experience, there was a tendency towards an increase in SFR: in the 1st group – 72%, in 2 – 84%, in 3 and 4 – 88%, in 5 – 92% (p<0,05).
Conclusions: in order to achieve the average indicators of the duration and effectiveness of PNТ, the surgical team must have experience of at least 50 such operations. Due to the long training process, it is advisable to use PNТ in organization with an estimated number of such operations of at least 30 per year.

Keywords: urolithiasis, percutaneous nephrolithotripsy, learning curve, duration of operation, complications of percutaneous nephrolithotripsy, stone free rate