To investigate the feasibility and efficacy of flexible ureteroscope combined with holmium laser lithotripsy in the treatment of the upper urinary tract calculi in infants aged <2 years old.

Clinical data of 62 infants diagnosed with the upper urinary tract calculi (77 sides) receiving flexible ureteroscope in our department from January 2016 to February 2018 were retrospectively analyzed. Among them, 37 cases were male and 25 female. All patients were Uyghur nationality, aged 8-24 months. Forty-seven cases had unilateral and 15 patients suffered from bilateral upper urinary tract calculi. The upper urinary tract calculi were detected on 19 sides, renal pelvic calculi on 31 sides, upper renal caliceal calculi on 18 sides and lower renal caliceal calculi on 9 sides. The maximum diameter of calculi was ranged from 8 to 25 mm. During the Stage I operation, double J stent was placed in all children for passive ureteral dilatation for 2 weeks. In the Stage II surgery, wire-guided flexible ureteroscope insertion combined with 200 μm holmium laser lithotripsy at a laser power of 20-30 W was performed. Double J stent was retained for 2-3 weeks after operation.

Flexible ureteroscope was successfully inserted in 62 cases. Fifty-one patients underwent lithotripsy for one time (6 cases of bilateral upper urinary tract calculi), 9 patients with bilateral upper urinary tract calculi underwent lithotripsy twice, and 2 patients were still under observation because the lower caliceal calculi were not detected. The patients were hospitalized for 3-5 d after operation. At postoperative 8 weeks, the calculi on 67 sides were thoroughly removed with a removal rate of 87.0% (67/77). The average operation time was 35 min (20-55 min).

Flexible ureteroscopy combined with holmium laser lithotripsy is an efficacious and safe treatment of the infantile upper urinary tract calculi, which yields a high removal rate.