Safety and feasability of ureteroscopy for pediatric stone, in children under 5 Years (SFUPA 5): A French multicentric study

Abstract

Ureteroscopy (URS) can be proposed as first-line therapy for the management of pelvic stones from 10 to 20mm and for lower ureteric stones in children. However, little is known about the success and the morbidity of URS in young children. Ureteroscopic treatment may present matters in young children because of the small size of the pediatric kidney and the small size of the collecting system. To assess safety and efficacy of URS for the treatment of urinary stones in children aged of 5 years or less. After the institutional ethical board approval was obtained, we conducted a retrospective, analytic, multicentric study that included all URS performed between January 2016 and April 2022 in children aged of 5 years or less. In this non-comparative case series, anonymized pooled data were collected from 7 tertiary care centers of pediatric patients. Endpoints were the one-session SFR at 3 months and per and postoperatives complications. Descriptive statistics were applied to describe the cohort. Eighty-three patients were included. For them, 96 procedures were performed at the median age of 3.5 years (IQR: 0.8-5) and median weight of 14Kg (6.3-23). Median stone size was 13mm (4-45). There were 65 (67 %) renal stones treated with flexible URS, most of which were in the renal pelvis (30 %) and in the lower calix (33 %). A ureteral access sheath was used in 91% procedures. Preoperative ureteral stent was placed in 52 (54 %) of patients. None of patients had ureteral dilatation. The single-session SFR was 67.4 % (56.3 and 89.2% for flexible URS and semi-rigid URS respectively) and children require 1.4 procedures to achieve complete stone clearance. The overall complication rate was 18.7 %, most of them were minor (Clavien I-II). Intraoperative perirenal extravasation (Clavien IIIb) due to forniceal rupture was documented in 6.2% of cases, related to an increased intrapelvic pressure (IPP) performed in a closed pelvicalyceal system. Pediatric urologists should be aware of forniceal rupture based on the presence of extravasation of contrast during endourological procedures especially when they have difficulties to reach lower caliceal stone in small patient. URS in patients aged of 5 years or less, is a complex minimally invasive procedure with reasonable efficacy and low morbidity. Intrarenal stones treated by RIRS in young children carries the risk of additional procedures to complete stone clearance.