Abstract: Objective To explore the efficacy of flexible suction sheath (FSS) combined with disposable flexible ureteroscope (fURL) in the treatment of non-lower calyx renal calculi ≤ 3cm.Methods A total of 112 patients with non-lower calyx renal stones who underwent surgical treatment at Lishui People's Hospital,Nanjing,from April 2020 to February 2023,were divided into two groups according to the surgical method:percutaneous nephrolithotomy (PCNL) group (54 patients) and FSS-fURL group (58 patients).The PCNL group received PCNL treatment,while the FSS-fURL group underwent FSS combined with disposable fURL treatment.Postoperative stone clearance rate,24-hour urinary calcium,24-hour urinary uric acid,24-hour urinary creatinine,and renal cortex thickness changes were compared between the two groups.A 24-month follow-up was performed to record the recurrence rate of renal stones.Results The stone clearance rate in the FSS-fURL group (96.55%) was higher than that in the PCNL group (85.19%) (P<0.05).At 1 week after surgery,the 24-hour urinary calcium in the FSS-fURL group [(8.09±0.61) mmol] was higher than that in the PCNL group [(7.84±0.59) mmol] (P<0.05).At 1 month after surgery,the 24-hour urinary calcium in the FSS-fURL group [(6.86±0.65) mmol] was lower than that in the PCNL group [(7.12±0.48) mmol] (P<0.05).At 1 week and 1 month after surgery,the 24-hour urinary creatinine in the FSS-fURL group [(19.81±3.75) mg/kg and (20.83±3.62) mg/kg] was higher than that in the PCNL group [(17.32±2.89) mg/kg and (18.96±3.05）mg/kg] (P<0.05).At 1 month,6 months,and 12 months post-surgery,the renal cortex thickness in the FSS-fURL group [(14.06±0.53),(14.05±0.57) and (13.92±0.53)] was higher than that in the PCNL group [(13.75±0.48),(13.02±0.69) and (12.77±0.85)] (P<0.05).Postoperatively,the FSS-fURL group had lower levels of C-reactive protein,interleukin-6,procalcitonin,norepinephrine,and cortisol [(1.41±0.37) mmol/L,(50.81±11.03) ng/L,(0.97±0.23) ng/L,(291.63±47.29) μg/L and (227.18±40.92) μg/L] than the PCNL group [(1.02±0.25) mmol/L,(45.05±12.96) ng/L,(0.75±0.19) ng/L,(256.31±39.26) μg/L and (205.32±50.19) μg/L] (P<0.05).At the end of the follow-up,15 cases of recurrence were recorded in the PCNL group,with a recurrence rate of 27.78%,while 6 cases of recurrence were recorded in the FSS-fURL group,with a recurrence rate of 10.34%.The recurrence rate in the FSS-fURL group was lower than that in the PCNL group (P<0.05).Conclusion FSS combined with disposable fURL for the treatment of 3cm non-lower calyx renal stones can improve postoperative stone clearance rate,reduce postoperative renal function damage,lower the long-term recurrence rate of stones,and has good safety.

Key words: flexible suction sheath, ureteroscope, renal calyx stones, minimally invasive, recurrence rate, renal cortex thickness