Abstract: Objective To study the efficacy and safety of flexible ureteroscopy holmium laser lithotripsy (FURS) in the treatment of urinary tract stones of different sizes and positions.Methods A retrospective analysis was conducted on the clinical data of 121 patients with upper urinary tract stones from January 2021 to December 2023.According to the size of the stones,they were divided into the diameter ≤20 mm group (n=98) and the 20mm＜diameter≤40 mm group (n=23).According to the location of the stones,19 cases were divided into the renal pelvis stone group and 102 cases were non renal pelvis stones.The surgical related indicators and incidence of complications were compared between the groups.Result The operation time of the group with diameter ≤20 mm and the group with diameter 20 mm < diameter ≤40 mm was (44.13±12.6) minutes and (57.52±20.98) minutes,respectively.The hospitalization periods were (4.55±1.54) days and (5.74±2.00) days,respectively.There were statistically significant differences between the two groups (P<0.05).The stone clearance rates in the group with diameter ≤20 mm and the group with 20 mm < diameter ≤40 mm were 84.69% and 78.26%,respectively.There was no statistically significant difference between the two groups (P>0.05).The operation time of the subcalyx kidney stone group and the non-subcalyx kidney stone group was (44.05±11.08) minutes and (47.17±16.19) minutes respectively,the hospital stay was (4.74±1.52) days and (4.78±1.73) days respectively,and the ESWL selection rates after the operation were 5.26% and 10.78% respectively.The stone recurrence rates were 15.79% and 4.90% respectively,and there was no statistically significant difference between the two groups (P>0.05).The stone clearance rates in the subcalyx kidney stone group and the nonsubcalyx kidney stone group were 63.16% and 87.25%,respectively.There was a statistically significant difference between the two groups (P<0.05).There was no statistically significant difference in the incidences of urosepsis,fever,low back pain,hematuria and total complications between the 20 mm < diameter ≤40 mm group and the diameter ≤20 mm group (P>0.05).There was no statistically significant difference in the incidences of urosepsis,fever,low back pain,hematuria and total complications between the noninferior calyx stone group and the inferior calyx stone group (P>0.05).Conclusion FURS treatment for upper urinary tract stones with a diameter of ≤20 mm has shorter surgical and hospitalization times compared to patients with a diameter of ≤40 mm.ESWL and lower stone recurrence rates are also preferred after surgery.FURS treatment for non lower renal calyx stones has a higher stone clearance rate compared to lower renal calyx stones.The safety of FURS treatment for upper urinary tract stones of different sizes and positions is equivalent.

Key words: upper urinary tract stones, holmium laser lithotripsy, therapeutic effect, security