Ahmed MNA. et al., 2025: Extracorporeal shock wave lithotripsy vs percutaneous nephrolithotomy, complication rate and recurrence rate in management of pediatric renal stone, a prospective randomized trial.

Mahmoud Nader Abdel-Razik Ahmed, Gamal Ibrahim Selmy, Hazem Abdelsabour Deif, Adel Elatreisy, Ahmed Farag Wahsh, Emadeldeen Salah
Arch Ital Urol Androl. 2025 Oct 29:14286. doi: 10.4081/aiua.2025.14286. FREE ARTICLE

Abstract

Background: The mini-percutaneous nephrolithotomy (PNL) technique has introduced notable advantages, establishing it as a compelling option compared to extracorporeal shock wave lithotripsy (SWL) in managing renal stones in the pediatric population. We aimed to compare the outcomes of both techniques as regards effectiveness, morbidity, and stone recurrence.

Methods: A prospective, randomized superiority trial included 128 pediatric patients with a solitary renal stone measuring 10-20 mm. Group I included patients who underwent mini-PNL (n=65), while Group II included those managed with SWL (n=63). The primary endpoint was the stone-free rate (SFR) eight weeks after the procedure, while the secondary endpoints were operative time, hospital stay, and postoperative complications. The stone recurrence rate was assessed at 2-year follow-up.

Results: The mean age of the patients ± SD was 8.48±4.08 years, and the mean size of the stones was 17.13±2.45 millimeters. The study arms had comparable demographics and stone characteristics. The mean operative time was significantly lower in Group I than in Group II (51.38±14.02 min vs 63.70±16.90 min, respectively; p=0.001). We reported a perioperative complication rate of 26.2% in Group I, compared to 20.6% in Group II, with a statistically insignificant difference (p=0.461). SFR was 93.8% and 41.3% for groups I and II, respectively (p<0.001). The stone recurrence was reported in 4 cases (6.1%) in Group I compared to 10 cases (15.8%) in Group II (p=0.005).

Conclusions: Our study demonstrates that Mini-PNL has a higher stone-free rate than SWL for managing renal stones of 10-20 mm in children. While both techniques have comparable complication rates, mini-PNL has higher intraoperative complications and longer hospital stays. Additionally, stone recurrence is more common after SWL compared to mini-PNL.

Comment Peter Alken

At a quick look, this prospective randomized study seems to be a valuable contribution. However,

34 % of all stones were radiolucent, e.g. they did not have a high density. In children these are frequently not the typical uric acid stones but relatively brittle Ca-Phosphate stones.  That does not fit to the density value of 1308.04 ± 245.5 HU given for all stones. Unfortunately, the stone analyses announced in the method section are not reported. Shock wave treatment exclusively done under ultrasound control with a Richard Wolf PiezoLith 3000Plus lithotripter was not very effective: “Three SWL sessions were performed for 52 cases (82.5%), two sessions for 9 cases (14.3%), and only one session for 2 cases (3.2%).  37 cases of the ESWL group were finally treated with PNL.

What I miss in this and similar papers with repeat sessions or additional or adjunctive procedures is that not the sum of procedures to treat the single case is presented. E.g.  if 52 (82,5%) cases of the ESWL group need three sessions and 37 of all 63 ESWL cases needed PNL. The comparison of an operative time of 51.38 ± 14.02 min for PNL with 63.70 ±16.90 min for ESWL is relatively meaningless. But even the gaps in a work encourage reflection on how it can be improved.

Peter Alken