带蒂大网膜修复严重输尿管损伤及其机制的实验研究

Repairing effect of pedicle omentum in severe ureteral injury

目的探讨带蒂大网膜修复严重输尿管损伤的作用机制。方法20只健康成年杂种犬随机分为实验组及对照组，每组10只，均建立严重输尿管损伤动物模型，端端吻合输尿管后实验组采用带蒂大网膜包裹损伤输尿管，对照组未采用大网膜包裹。术后不定期观察有无尿瘘及输尿管坏死。术后12周观察术侧输尿管损伤愈合情况，取吻合口及周围组织行病理学检查，镜下观察血管再生情况，免疫组化检测血管内皮生长因子（VEGF）及其受体KDR的表达。结果术后实验组无尿瘘，对照组2只因尿瘘反复腹腔感染死亡。术后12周实验组输尿管吻合口处黏膜及平滑肌层完全再生，血管再生现象明显，VEGF及KDR表达阳性细胞密度分别为（12．65±0．02）％和（10．23±0．03）％。对照组吻合口愈合不良并狭窄，患侧肾严重积液（脓），无明显血管再生，VEGF及KDR表达阳性细胞密度仅为（1．54±0．03）％、（2．65±0．04）％，明显低于实验组（均P〈0．05）。结论带蒂大网膜有促进严重输尿管损伤修复作用，可能通过VEGF及KDR表达升高促进血管再生而实现。

Objective To evaluate the repairing effect of pedicle omentum on severe ureteral injury. Methods Twenty healthy dogs were randomized into the experiment group and the control group. Firstly the model of severe ureteral injury was made. In experimental group, the pedicle omenturn were used to wrap up the severe injured ureter, but which was no done in control group. Urinary fistula and ureteral necrosis were observed. At 12 weeks postoperatively,the models were re-operated to investigate whether the severe injured ureters had healed. Angiogenesis, VEGF and its receptor KDR were also examined in stoma and surrounding tissue histopathologically. Results No urinary fistula was observed in experimental group, but 2 cases in control group were dead because of recurrent abdominal cavity infection after the formation of urinary fistula. The mucosa and smooth muscle of stoma were completely regenerated,and the blood vessels were regenerated more significantly in experimental group than in the control group. In experimental group, the VEGF and KDR were over-expressed, and the positive cell rates were （12. 65±0.02）% and （10. 23±0. 03）%. But in control group,the stoma were not healed,and severe ureteral strictures were observed in all dogs. Angiogenesis was not significant, the VEGF and KDR positive cell rates were （1. 54 ± 0. 03）% and （2.65± 0.04）%, respectively. Conclusions Pedicled omentum can promote the repair of severe ureteral injury. The mechanism may be the over expression of VEGF and KDR in prompting angiogenesis.