Learning Curves of Flexible Ureteroscopy (275 Cases) and Prone Percutaneous Nephrolithotomy (73 Cases) in Pediatric Stones: Data from 348 Children

Objectives: To evaluate learning curves in pediatric flexible ureteroscopy (FURS) and pediatric prone percutaneous nephrolithotomy (PCNL) by a single surgeon with experience in adult endourologic procedures. Materials and Methods: Children who were found to have nephrolithiasis and treated with PCNL or FURS from June 2014 to April 2019 were analyzed. Patient demographics, stone characteristics, stone-free rate (SFR), and complication rate (CR) were reported. Learning curves were generated to estimate the effect of a surgeon's experience on outcomes. Results: Seventy-three children underwent PCNL on 86 sides in 77 operations and 275 children underwent FURS on 320 sides in 288 operations. The SFRs were 88.1% (282/320) for FURS procedures and 89.5% (77/86) for PCNL procedures. CRs were 19.8% (57/288) and 35.1% (27/77), respectively. Learning curves showed that the SFRs of the two procedures increased with the accumulation of cases. There was an apparent improvement of SFR for PCNL procedures after ∼60 surgeries. A favorable SFR of FURS could be achieved at the start of learning. No apparently decreased CRs were observed for either PCNL or FURS. Conclusions: Both PCNL and FURS could achieve satisfactory SFRs and accepted CRs in pediatric stones. Increased surgical experience was associated with improved SFRs of both PCNL and FURS procedures, and the surgeon's experience of adult FURS translating to that of pediatric FURS was better than adult PCNL translating to pediatric PCNL. A surgeon needs ∼60 cases of PCNL to achieve competence. For FURS, a favorable SFR could be achieved at the start of learning.