Ultra-Mini Percutaneous Nephrolithotripsy and Retrograde Intrarenal Surgery in Treatment of Less than 2 cm Kidney Stones: Comparative Efficacy and Safety

Background. Renal stones of ≤ 2cm size occur most commonly, with several treatment options currently available that include remote shockwave lithotripsy, percutaneous nephrolithotripsy (PCNL) and retrograde intrarenal surgery (RIRS). The choice of treatment for ≤ 2 cm kidney stones remains a relevant and hotly debated issue.Aim. A study of the efficacy, safety, advantages and disadvantages of ultra-mini percutaneous nephrolithotripsy (ultra-mini PCNL) and retrograde intrarenal surgery (RIRS) in treatment of ≤ 2 cm kidney stones.Materials and methods. Treatment outcomes in urology patients of the Botkin Hospital were analysed retrospectively for years 2017–2022. The patients were divided between cohorts: cohort 1 consisted of patients who underwent ultra-mini PCNL; cohort 2 included 41 patients with RIRS.Results and discussion. The incidence of complete stone absence on the day after surgery was significantly higher in cohort 1 (39; 92.8 %) vs. 2 (33; 80.4 %). Mean operation time was significantly less in cohort 1 (55 [30–80] min) vs. 2 (78 [30–125] min). Mean hospital stay did not differ significantly between the cohorts: 3 (1–5) vs. 2.8 (2–4) days in cohorts 1 and 2, respectively. Haematuria was statistically more severe in cohort 1 (7 cases; 16.6 %) vs. 2 (4 cases; 9.7 %); mean postoperative haemoglobin decrease was also significantly higher in cohort 1 (11.6) vs. 2 (6.4 g/L).Conclusion. Both ultra-mini PCNL and RIRS are effective, safe and complementary procedures in treatment for ≤2 cm renal stones. Ultra-mini PCNL is more effective over RIRS in terms of single-intervention complete stone removal and shorter operation time, whereas the overall complications rate did not significantly differ between cohorts.