Comparison of retrograde intrarenal surgery and mini-percutaneous nephrolithotomy in children with moderate-size kidney stones: results of multi-institutional analysis.

OBJECTIVE: To compare the outcomes of miniaturized percutaneous nephrolithotomy (mini-perc) and retrograde intrarenal surgery (RIRS) in children for 10- to 30-mm renal calculi by evaluating operative data, stone-free rates, and associated complications.

METHODS: The records of 201 pediatric patients who underwent mini-perc (n = 106) or RIRS (n = 95) for intrarenal stones of 10- to 30-mm size were reviewed retrospectively. The χ(2) test was applied to compare the success rates, postoperative complications, and blood transfusion rates, and the Mann-Whitney U test was used to compare the means of hospital stay, fluoroscopy, and operative time for mini-perc and RIRS.

RESULTS: The stone-free rate was 84.2% for the RIRS group and 85.8% for the mini-perc group after a single procedure (P = .745). These percentages increased to 92.6% and 94.3% with adjunctive therapies for RIRS and mini-perc, respectively. Minor complications classified as Clavien I or II occurred in 17% and 8.4% in mini-perc and RIRS, respectively. No major complications (Clavien III-V) occurred in either group. Overall complication rates in mini-perc were higher, but the differences were not statistically significant (P = .07). However, 7 patients in the mini-perc group received blood transfusions, whereas none of the children in the RIRS group were transfused (P = .015). The mean hospital stay, fluoroscopy, and operation times were significantly longer in the mini-perc group.

CONCLUSION: This study demonstrates that RIRS is an effective alternative to mini-perc in pediatric patients with intermediate-sized renal stones. Operative time, radiation exposure, hospital stay, and morbidities of percutaneous nephrolithotomy (PNL) can be significantly reduced with the RIRS technique.