Objective: A porcine model was established to investigate the effect of indwelling duration of ureteral stents on formation and pathological characteristics of ureteral stricture after laser thermal injury.

Methods: Pigs were randomly divided into 2 groups, A and B, with 15 pigs in each group. Holmium laser was used to cauterize the bilateral ureters at 5, 10, 15, and 20 cm from the Ureteropelvic Junction. Ureteral stents were indwelled for 4 weeks in Group A and 10 weeks in Group B. Ureteroscopy was performed 3 months after stents removal. Pigs were sacrificed to detect the damage point stricture. The cauterization tissue was harvested for pathological analysis.

Results: Group A included 13 pigs and group B included 14 pigs. The incidence of ureteral stricture in group A was higher than that in group B (P < 0.001). The percentages of inflammatory cell infiltration (P = 0.001), epithelial necrosis (P < 0.001), and epithelial hyperplasia (P < 0.001) were higher in Group A than in Group B. The proportion of muscle necrosis in Group A was lower than in Group B (P < 0.001). The percentage of the fibrosis area in group A was lower than that in group B (P = 0.001).

Conclusion: Compared with 4 weeks, 10 weeks of ureteral stent placement after laser thermal injury can reduce the risk of ureteral stricture, but may increase the risk of ureteral muscularis cell damage and tissue fibrosis. However, further clinical studies and animal experiments are required to confirm our results.

Keywords: Animal model; Pathological characteristics; Thermal injury; Ureteral stent; Ureteral stricture.

© 2025. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.

目的： 建立一个猪模型，以研究尿管支架留置时间对激光热损伤后尿道狭窄形成及病理特征的影响。

方法： 将15头猪随机分为A组和B组。使用钬激光在距离肾盂输尿管连接部5厘米、10厘米、15厘米和20厘米处烧灼双侧尿道。A组留置尿道支架4周，B组则为10周。3个月后移除支架并进行尿道镜检查，以检测损伤点狭窄情况，并采集烧灼组织进行病理分析。

结果： A组有13头猪和B组有14头猪完成实验。A组的尿道狭窄发生率高于B组（P

结论： 相比于4周，激光热损伤后留置尿道支架10周可以降低尿道狭窄的风险，但可能会增加尿道肌层细胞损伤和组织纤维化的风险。然而，需要进一步的临床研究和动物实验来验证这些结果。

关键词： 动物模型；病理特征；热损伤；尿道支架；尿道狭窄。