Comparison of flexible ureteroscopy and mini-percutaneous nephrolithotomy in the treatment for renal calculi larger than 2 cm: a matched-pair analysis

To compare the effectiveness and safety of flexible ureteroscopy and mini-percutaneous nephrolithotomy for renal calculi > 2 cm and perform subgroup analysis of stone length and age. Patients received mini-percutaneous nephrolithotomy or flexible ureteroscopy in Qilu Hospital of Shandong University from 2016.01 to 2021.03 with renal calculi > 2 cm were retrospectively analyzed. Propensity score matching was performed to get comparable patients. The postoperative hospital days, operation time, complication rate, and stone free rate were compared. The age and stone length were analyzed by subgroup. 162 in 313 patients were finally included. Each group had 81 cases. Outcomes such as intraoperative transfusion, stone free rate show no difference either. Flexible ureteroscopy had shorter postoperative hospital days (3.2 days vs 7.2 days, P < 0.001) and fewer complications (9, 11.1% vs 25, 30.9%, P = 0.002) compared to mini-percutaneous nephrolithotomy. The postoperative hospital days, and complication of the flexible ureteroscopy were significantly lower than those in the mini-percutaneous nephrolithotomy for renal stones ≤ 2.5 cm; when the stone length > 2.5 cm, the stone free rate of flexible ureteroscopy was lower than that of the mini-percutaneous nephrolithotomy group, but not statistically significant. The complications of flexible ureteroscopy in the young group (18–39 years old) were significantly lower than those in the mini-percutaneous nephrolithotomy group. For 2–2.5 cm renal stones, flexible ureteroscopy can achieve a similar stone free rate with shorter hospital stay, and lower complications. For larger stones, flexible ureteroscopy performed poorly. Flexible ureteroscopy may be a better option for younger patients with fewer complications.