Abstract:Abstract: Objective?To investigate the efficacy and safety of retrograde intrarenal surgery (RIRS) in treatment of residual kidney stones after PCNL in patients with cast kidney stones.?Method?From July 2015 to August 2018, 68 patients with cast renal calculi underwent multi-stage lithotripsy were retrospectively analyzed. They were divided into two groups according to the choice of the patients and their families. The patients in PCNL group were 36 patients with PCNL in the second stage of operation. The RIRS group consisted of 32 patients with RIRS in the second stage of operation. The clinical effects of 68 patients were observed.?Result?All the operations were successfully completed and no serious complications occurred. Good stone clearance rate was obtained in the two groups, which were 87.50% in RIRS group and 91.67% in PCNL group, respectively. There was no significant difference between the two groups (P?>?0.05). The average hospitalization time, the amount of intraoperative bleeding, the average decrease of hemoglobin 24 hours after operation and the pain score of 24 hours after operation in RIRS group were significantly better than those in PCNL group (P?0.05). In terms of operation time, the operation time in RIRS group was longer than that in PCNL group (P?0.05). After operation, there were 4 patients in RIRS group who needed further treatment, the treatment rate of ESWL in third stage operation was 12.50%, 3 patients in ESWL group needed further treatment, and the rate of three stage operation/ESWL treatment was 8.33%, there was no significant difference (P?>?0.05). Finally, 1 month after treatment, no residual stones were found in the two groups of abdominal CT.?Conclusion?RIRS compared with the second phase of single channel/multi-channel PCNL, RIRS with intraoperative bleeding, small surgical trauma, less postoperative pain, and shorter postoperative hospital stay, less complications, such as advantages, particularly suitable for treatment of residual kidney stones of upper renal pelvis and middle renal pelvis after PCNL in patients with cast kidney stones.