Comment on Comparison of super-mini-PCNL and flexible ureteroscopy for the management of upper urinary tract calculus (1–2 cm) in children

Abstract

I congratulate the authors for their study entitled “Comparison of super-mini-PCNL and flexible ureteroscopy for the management of upper urinary tract calculus (1–2 cm) in children” [1]. In this study, the stone-free rates for supermini-PCNL (SMP) and flexible ureteroscopy (f-URS) group in postoperative first day were 94.4% and 52%, respectively. The stone-free rates for SMP and f-URS group in first month control were 94.4% and 60%, respectively. The authors stated that SMP was better procedure than f-URS in terms of stone-free rate and postoperative complications. However, this conclusion is controversial. Stone localizations in f-URS group and SMP group were not the same in this study. The rate of the stones located in renal pelvis was 69.4% and 44% in SMP and f-URS groups, respectively. Therefore, the comparison for these two groups is not appropiate [1]. If the stone localisations were the same in two groups, the results would be different as shown in the study by Resorlu et al. [2]. In this multicenter study, the outcomes of miniaturized percutaneous nephrolithotomy (mini-perc) and retrograde intrarenal surgery (RIRS) in children for 10to 30-mm renal calculi in terms of operative data, stone-free rates and associated complications were compared. The stone-free rates for the RIRS group and the mini-perc group after a single procedure were 84.2% and 85.8%, respectively. Minor complications classified as Clavien I or II occurred in 17% and 8.4% in mini-perc and RIRS, respectively [2]. PCNL is always an invasive procedure even if miniaturized devices are used. In the present study, 12 and 14 F sheaths were used. It is well-known that urinary tract stone disease in children and adults has a high reccurence rate up to 40–50% [3]. Therefore, repeated surgical treatment sessions are likely required in the patients with urinary tract stone disease. This is very important point to be considered in these group of the patients. As a result, the repeated PNL sessions are expected to be harmful for the kidneys even if miniaturized devices are used. Considering the long life expectancy in children, possible future intervention needs should be considered when treating children with upper urinary tract stone disease. Urinary stone disease in pediatric patients is always a challenge for surgeons. The etiology of the stone disease is very important to decide the type of the treatment option. Is there any metabolic or anatomic reason for the etiology of the stone disease in the present study? The outcomes of this study should not be generalized. It is well known that f-URS is a very succesful procedure if it is performed by the well-experienced urologists [4–6]. Therefore, expertise, equipments available, underlying etiology and patient’s preference should be considered in the choose of the technique in children with upper urinary tract stone disease.