Abstract: Objective  To explore the curative effect of different surgical methods and analysis of curative effect-related factors in patients with inferior calyx stones with different infundibulum angles of the renal pelvis.
Methods  A retrospective analysis of the case data of 198 patients with inferior calyx stones admitted to the Department of Urology in our hospital from June 2019 to June 2020 was divided into two groups according to the IPA angle.Group A IPA>30°,Group B IPA≤30 ° group,divided into 4 subgroups according to the operation method of each group,A1 group(70 cases) was treated with microchannel percutaneous nephrolithotomy(MPCNL),and A2 group(62 cases) was treated with ureteroscopy holmium laser Lithotripsy(FURS) was used for treatment.Group B1(23 cases) was treated with FURS,and group B2(43 cases) was treated with FURS combined with MPCNL.The curative effect and complications of each group were compared,and the factors affecting the curative effect of lower calyx stones were analyzed.
Results  There was no statistically significant difference in operation time,postoperative hospital stay,stone removal rate,and complication rate between group A1 and group A2(P>0.05);group B1 and group B2 had no significant difference in operation time,postoperative hospital stay,There was no statistically significant difference in the incidence of complications(P>0.05),but the stone clearance rate in group B2 was higher than that in group B1,and the difference was statistically significant(P<0.05).Among the 198 patients,167 had complete stone removal(the removal group),and 31 cases had incomplete stone removal(uncleared group).The body mass index(BMI) <25 kg/m2 of the cleared group was higher than that of the uncleared group,the angle of the renal pelvic funnel(IPA) was higher in the cleared group,and the length of the renal pelvic funnel(IL) and stone diameter were lower than those of the uncleared group.The differences were statistically significant(P<0.05).Multivariate logistic regression showed that high BMI,small IPA,long IL,and large calculus diameter were independent risk factors that led to poor postoperative efficacy of inferior calyx stones(P<0.05).
Conclusion  In the renal calculus with IPA>30°,MPCNL and FURS have little difference in stone removal effect,but with IPA≤30°,the FURS calculus removal effect is limited,and the combined application with MPCNL can obtain better treatment effect;Moreover,high BMI,small IPA,long IL,and large calculus diameter are independent risk factors that lead to poor postoperative efficacy of inferior calyx stones.

Key words: infundibulum of the renal pelvis, calculus in the lower renal calyx, curative effect, related factors