We analyzed factors that might affect outcome in terms of success and incidence of complications in children up to 17 years after undergoing percutaneous nephrolithotomy. The data of 346 renal units (294 patients) were analyzed in terms of postoperative outcome. Factors investigated that might affect outcome were patient gender, age, stone laterality, largest stone size, stone burden, number of stones, location of a single stone, previous intervention and instrument size. Mean ± SD patient age was 8.51 ± 4.91 years, and male-to-female ratio was 209:137. Mean ± SD stone burden was 3.49 ± 3.3 cm(2). Stone-free rates after a single procedure were 84.4% and 73.1% in patients with and without clinically insignificant residual stones, respectively. On univariate and multivariate analyses stone burden and number of stones affected the stone-free rate. Complications consisted of bleeding in 41 patients (11.8%), postoperative urinary tract infection in 21 (6%), urosepsis in 4 (0.1%) and hydrothorax in 4 (0.1%). One patient died of multiple organ failure. Through the years blood transfusion and complication rates decreased, and the use of smaller instruments increased significantly. Although bleeding occurred less often in cases where a 14Fr sheath was used rather than a larger sheath (5% vs 12%, p = 0.142), the difference was not significant. No significant factor affecting complication rates was detected. As in adults, percutaneous nephrolithotomy can be used in children with acceptable complication rates and good success rates for surgical treatment of complex renal stones. Number of stones and stone burden are predictive of postoperative stone-free rate.

Purpose: To investigate the factors that predict the success and complication rates of semi-rigid ureteroscopy (URS) in pediatric population. Materials and Methods: This is a retrospective analysis of the database including 182 patients who underwent URS between 2001 and 2016. The possible factors that might affect the outcome were age, gender, stone laterality, largest stone size, number of stones, stone location, orifice dilatation status, and caliber of ureteroscope. Results: The mean age was 68.1 (7–204) months, and male-to-female ratio was 94:88. Operative side was left for 97, right for 82, and bilateral for 3 patients. One hundred and forty-four patients had a single stone, and 38 patients had multiple stones. The median largest stone size was 7 (2–20) mm. Postoperative ureteral stenting was performed in 150 (86.2%) patients. The overall success rate was 84.6%, while 81.6% and 85.4% in 8F URS and 4.5F URS groups, respectively ( p = 0.560). Stone-free rate was higher among patients who were older than 36 months, distal ureteral stones and single stones ( p = 0.012, 0.002, and 0.009, respectively). Complication rate was higher for proximally located stones ( p = 0.029). The mean follow-up was 23.9 ± 32.5 months. Conclusion: URS is a safe procedure with acceptable success rates in the pediatric population. Younger age, multiple stones, and proximal location are the predisposing factors for failure, whereas proximal location was the only factor for complication occurrence. Therefore, semi-rigid ureteroscopy should not be the first choice in the treatment of proximal ureteral stones, and alternative methods should be preferred, if available.