Purpose: The extracorporeal shockwave lithotripsy (ESWL) remains the most common first line of treatment for renal stones in the pediatric population. The purpose of this study is to evaluate and compare the outcomes of the ESWL and mini-percutaneous nephrolithotomy (mini-PCNL).

Patients and methods: A total of 108 patients younger than 12 years of age with 1-2 cm single renal stone (pelvic or calyceal) were randomized into two groups, each containing 54 patients. Patients in group A were subjected to mini-PCNL using 16.5 Fr percutaneous sheath while those in group B underwent ESWL using Dornier Compact Sigma.

Results: The stone-free rate (SFR) after first session was 88.9% (48 cases) and 55.6% (30 cases) for groups A and B, respectively. The difference is highly statistically significant P = 0.006. Two patients (3.7%) in group A needed 2nd session of PCNL, while 18 patients (33.3%)in group B needed a 2nd session, of theses 18 patients six patients needed a 3rd session of ESWL. After the third session of ESWL and second look PCNL the stone-free rates were 92.59% (50 cases) and 88.89% (48 cases) for groups A and B, respectively, (P = 0.639), which is statistically insignificant. The mean hospital stay and fluoroscopy exposure were significantly longer in the mini-PCNL group. The complication rate in groups A and group B were (22.2%) and (14.8%), respectively, which is statistically insignificant (P = 0.484).

Conclusions: According to Clavien grade of complications mini-PCNL is a safe procedure, and after three session of ESWL, mini-PCNL has a similar stone-free rate with a lower retreatment rate. However, the mini-PCNL has more radiation exposure, and requires a longer hospital stay.