Can cystinuria decrease the effectiveness of RIRS with high-power ho:yag laser in children? Outcomes from a tertiary endourology referral center.

Cystinuria, which is the cause of cystine urolithiasis, accounts for 2-6% of all urinary stones in children, has a low prevalence with a high recurrence rate, making this metabolic disorder a therapeutic challenge in pediatric population. The aim of this work is evaluate the efficacy and safety of retrograde intra-renal surgery (RIRS) in pediatric patients with cystinuria and kidney stones smaller than 2 cm. Prospective study of 64 stones treated in 22 retrograde intra-renal surgeries (RIRS) in cystinuric pediatric patients with renal or proximal ureteral stones less than 2 cm. Average age of 9.5 years. The following data were analyzed: demographics, stone characteristics and surgical data with intra- and postoperative complications. Location of the stones was 68.7% in the calyces, 20.3% in the renal pelvis, and 9.3% in the ureteropelvic junction; 41% of cases had multiple locations. The average cystinuria level before the procedure was 825 mg/dL. The anatomy of 73% of the interventions increased the difficulty of flexible ureteroscopy and decreased stone free rates, because distorted renal anatomy was present: sclerosis of the pelvis or infundibulum, abnormal calyceal dilations, or excluded calyces. Intraoperative complications occurred in 18.2% of the procedures. Reno-vesical ultrasound was performed in all patients in the first postoperative month, with an SFR of 59%. Cystinuric patients are a challenge for pediatric urologists, decreasing the effectiveness of RIRS. However, it could be better treatment than SWL and with fewer complications than PCNL in the pediatric population with this disease.

Urolithiasis. 2022 Jan 27 [Epub ahead of print]

Yesica Quiroz Madarriaga, Almudena Badenes Gallardo, Erika Llorens de Knecht, Guilherme Motta Lang, Joan Palou Redorta, Anna Bujons Tur

Urology Department, FundaciĆ³ Puigvert, Carrer de Cartagena, 340-350, 08025, Barcelona, Spain. ., Urology Department, FundaciĆ³ Puigvert, Carrer de Cartagena, 340-350, 08025, Barcelona, Spain.