输尿管软镜治疗肾下盏结石术后清石率的预测模型构建及验证

doi:10.3969/j.issn.1006-5725.2025.13.006

Abstract

Abstract:

Objective To explore the risk factors of the stone-free rate after flexible ureteroscopy for lower pole calculi， develop a predictive model based on these identified factors， with subsequent validation and evaluation of the established model. Methods A retrospective analysis was conducted on 154 patients with lower pole renal calculi who underwent flexible ureteroscopy （FURS） at Guangdong Provincial Hospital of Traditional Chinese Medicine from 2020 to 2024. Based on postoperative stone clearance status， patients were categorized into a stone-free group and a residual stone group. Univariate analysis was performed to screen potential risk factors， while Pearson correlation coefficients and variance inflation factor （VIF） were employed to assess multicollinearity， retaining the indicator with the highest area under the curve （AUC）. Independent predictors were identified through multivariate logistic regression analysis， and a nomogram model was constructed. Internal validation was conducd using the bootstrap resampling method. The predictive performance and clinical utility of the model were evaluated using receiver operating characteristic （ROC） curves and decision curve analysis （DCA）. Results Univariate analysis demonstrated that largest stone diameter （LSD）， cumulative stone diameter （CSD）， stone volume （SV）， stone surface area （SA）， mean stone density （MSDE）， and infundibular pelvic angle （IPA） were significantly associated with stone-free rate （SFR） following flexible ureteroscopy （FURS） for lower pole calculi （all P < 0.05）. After collinearity diagnostics， LSD （area under the curve ［AUC］= 0.724） was retained as the optimal stone burden parameter. Multivariate logistic regression analysis confirmed LSD， MSDE， and IPA as independent predictors of postoperative SFR. The nomogram model exhibited robust predictive performance with an AUC of 0.786 （sensitivity： 79.6%， specificity： 71.0%）. Internal validation via 1000 bootstrap resamples yielded an AUC of 0.792， and decision curve analysis （DCA） confirmed clinical utility with net benefit across threshold probabilities of 4% — 75%. Conclusions The nomogram model developed in this study， which incorporates both stone characteristics and renal anatomical parameters， demonstrates effective prediction of stone-free rate （SFR） following flexible ureteroscopy for lower pole calyceal stones. With stable predictive performance and high clinical applicability， this model provides a reliable tool for preoperative personalized decision-making in endourological management.

Key words: lower pole calculi, flexible ureteroscopy, stone-free rate, predictive model, logistic regression

CLC Number:

R692.4

Huangjunqing LIAO,Jiadong CAO,Zhichao WANG,Qiuhong ZHANG,Jianfu ZHOU,Songtao XIANG. Establishment and validation of a predictive model for the stone⁃free rateafter flexible ureteroscopy for lower pole calculi[J]. The Journal of Practical Medicine, 2025, 41(13): 1979-1986.

Figures/Tables 8

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References 41

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项目	结石残留（n = 54）	结石清除（n = 100）	t/χ²/Z值	P值
年龄（x ± s）/岁	56.07 ± 12.02	54.89 ± 13.44	-0.54	0.587
性别/［例（%）］			0.00	0.986
男	28（51.85）	52（52.00）
女	26（48.15）	48（48.00）
肾积水程度/［例（%）］			12.11	0.070
0	23（42.59）	47（47.00）
1	5（9.26）	19（19.00）
2	6（11.11）	9（9.00）
3	13（24.07）	24（24.00）
4	7（12.96）	1（1.00）
结石数量/［例（%）］			0.465	0.502
1	45（83.33）	87（87.00）
2	8（14.81）	12（12.00）
3	1（1.85）	1（1.00）
最大结石直径/mm	14.18（11.78，17.77）	11.09（8.73，14.08）	-4.578	< 0.001
累计结石直径/mm	15.91（12.10，18.50）	11.77（9.05， 15.35）	-4.250	< 0.001
结石体积/mm³	635.75（433.36，958.13）	302.33（178.77，644.29）	-4.485	0.002
结石表面积/mm²	91.15（68.31，142.52）	67.36（38.40，104.74）	-3.779	0.001
平均结石密度（x ± s）/HU	798.90 ± 209.58	678.55 ± 228.98	-3.098	0.003
IPA（x ± s）/ °	36.52 ± 10.61	43.55 ± 13.65	3.283	0.002
IL/mm	18.77（17.03，21.93）	15.63（13.45，18.24）	-0.744	0.597
IW/mm	5.52（4.32，6.88）	5.33（4.49，6.43）	-0.441	0.611
CPH/mm	15.63（13.45，18.24）	14.98（11.62，17.49）	-0.896	0.532

变量	SV	SA	LSD	CSD
SV	1	0.867	0.761	0.699
SA	0.867	1	0.816	0.831
LSD	0.761	0.816	1	0.741
CSD	0.699	0.831	0.741	1

变量	方差膨胀因子
SV	4.217
SA	7.274
LSD	3.256
CSD	3.401

变量	B	标准误差	P值	OR值	95%CI	VIF
LSD	0.178	0.052	0.001	1.195	1.079 ~ 1.323	1.09
MSDE	0.002	0.001	0.026	1.002	1 ~ 1.004	1.074
IPA	-0.047	0.016	0.004	0.954	0.924 ~ 0.985	1.018

Establishment and validation of a predictive model for the stone⁃free rateafter flexible ureteroscopy for lower pole calculi

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