To investigate the feasibility and safety of percutaneous nephrolithotomy combined with ureteroscopic lithotripsy in first-stage operation in the prone "split-leg" position for complex renal calculi.

The 154 patients with complex renal calculi were admitted to our hospital from October 2017 to March 2020 with complicated renal calculi. All those patients were matched and divided into observation group and control group and were treated by percutaneous nephrolithotomy (PCNL) combined with flexible ureteroscopic lithotripsy. Patients in observation group were in the prone "split-leg" position but patients of control group were in oblique supine and lithotomy position. The operation time, intraoperative blood loss, postoperative hospital stay, nephrostomy tube extubation time, stone clearance rate, postoperative pain and 30-day postoperative complications were compared and analyzed between the two groups.

The surgery was completed successfully in all the 154 cases. The operation time (122±37) minutes, nephrostomy tube extubation time (2.1±0.4) days, postoperative hospital stay (4.3±1.2) days, VAS score (1.9±0.2) and postoperative complications (6.5%) were significantly lower than that in the control group. There was no significant difference in intraoperative blood loss [22.2%(8/36) vs 58.3%(21/36), P<0.05] and stone clearance rate (93.5% vs 88%, P>0.05) between two groups.

Percutaneous nephrolithotomy combined with ureteroscopic lithotripsy in prone "split-leg" position is convenient, safe and effective with high stone clearance rate and quick recovery for complex renal calculi.