Comparison of Efficiency and Safety of Retrograde Intrarenal Surgery and Micro-Percutaneous Nephrolithotomy in Pediatric Kidney Stones Smaller Than 2 cm: A Prospective Cohort Study

Objective: To compare the safety and efficacy of two minimally invasive surgical techniques used for pediatric stone disease: retrograde intrarenal surgery (RIRS) and micropercutaneous nephrolithotomy (micro-PCNL). Materials and Methods: A prospective study was designed to include children aged <15 years with a single stone <20 mm. Sixty-four patients were assigned to undergo either an RIRS or a micro-PCNL (1:1 ratio). Demographic parameters, stone size, location, operative data, complications, stone-free status, and efficacy quotient were compared. Results: Due to anatomic considerations, seven patients were shifted to the micro-PCNL arm, thus resulting in 39 micro-PCNLs performed vs 25 RIRS in the end. Because of the deviation from planned surgery that was significantly higher in the RIRS group (p = 0.011), the analysis was done in a prospective cohort comparison. Stone-free rates were similar for micro-PCNL and RIRS groups (80% vs 82.2%). The operative (median 60 vs 90 minutes, p < 0.001), fluoroscopy (median 15 vs 30 seconds, p = 0.004), and lithotripsy times (median 15 vs 25 minutes, p = 0.007) were shorter in the RIRS group. However, despite the larger stone size, the efficiency quotient was significantly higher in the micro-PCNL group (82.1% vs 54.1%; p = 0.009). None of the patients experienced significant hematuria requiring blood transfusion, as well as no ureteral orifice obstructive complication was detected within the follow-up period. Conclusion: RIRS and micro-PCNL techniques in children have similar stone-free and complication rates. The operative, fluoroscopy, and lithotripsy times were shorter, deviation from the planned surgery, and the number of sessions under anesthesia was higher in the RIRS group. Despite the larger stone size, efficacy quotient was significantly higher in the micro-PCNL group.