Introduction: Retrograde intrarenal surgery (RIRS) is an option for pediatric kidney stone upto 1cm in EAU guidelines and many urologist do RIRS for > 1 cm stones as well if they have sufficient experience. We aim to assess the outcomes of pre-stenting versus non-pre-stenting in a pediatric population undergoing RIRS for intrarenal stones in different age groups and locations . Methods: Data collected on Children/adolescents with kidney stones undergoing RIRS in 9 centers between 2015-2020 were retrospectively reviewed. Exclusion criteria: ureteral lithotripsy, bilateral procedures. Stone-free status was evaluated at 3-month and deemed as a single residual fragment (RF) =2 mm/absence of multiple fragments. Patients were divided into two groups (Group 1 no pre-stenting , Group 2 pre-stented). Student’s, Chi-square and Fisher’s exact test was used to assess difference between groups. Univariable and multivariable logistic regression analysis were performed to predict RF. Statistical signicance: p-value <0.05. Results: 389 children/adolescents were included (192 patients in Group 1). Pre-stented patients were younger compared with non-presented (mean age 8.30±4.93 vs 10.43±4.30 years, p<0.001). There were no differences in stone characteristics (number, size, locations). Lasing and total surgical time were similar. Urinary tract infections (Clavien grade 2) were more prevalent in Group 2 (10.7%) compared to Group 1 (3.7%, p=0.016). Sepsis (Clavien grade 4) occurred in 2.1% of patients in Group 2 and no patient in Group 1 (p=0.146). 30.7% patients in Group 1 and 26.4% in Group 2 had RF (p=0.322). Multivariate logistic regression analysis showed that stone size was associated with RF (OR 1.20 95% CI 1.08-1.36, p=0.001). Conclusions: RIRS showed similar stone-free rate in pre and non-pre-stented children/adolescents, In this multicenter study, we found that preoperative positioning of ureteral stent had no effect in clearing stones but a higher incidence of postoperative infections. Whilst routine pre-stenting cannot be recommended it becomes imperative that the child's guardian is counseled appropriately about pros and cons of prestenting including need for additional anaesthesia. SOURCE OF Funding: NIL
