内皮祖细胞种植支架在经颈静脉肝内门体分流术中应用的实验研究

目的 评价内皮祖细胞(EPC)种植支架在经颈静脉肝内门腔分流(TIPS)家猪动物模型中减少分流道再狭窄的疗效.方法 体外分离、培养、鉴定家猪外周血内皮祖细胞,并构建内皮祖细胞种植支架.15头家猪行TIPS介入手术,采用随机区组设计分为EPC种植支架组9头(实验组),裸支架组6头(对照组).术后14 d行直接门静脉造影,然后处死动物,作病理分析及免疫组织化学检查,记录分流道狭窄及阻塞率,并用图像处理软件计算TIPS分流道假性内膜厚度及面积.计数资料用Fisher精确概率法,计量资料行t检验,作统计学分析.结果 15头猪TIPS手术均成功.实验组分流道通畅5头,狭窄2头(狭窄率50%、70%),阻塞2头(共9头).对照组狭窄1头(狭窄率80%),阻塞5头(共6头).2组通畅率差异有统计学意义(P=0.03).实验组假性内膜增生的厚度(肝静脉、肝实质、门静脉段)显著小于对照组[分别为(1.0 ±0.6)、(0.9±0.5)、(1.0±0.4)mm和(1.2±0.4)、(1.3±0.5)、(1.5±0.4)mm,P值均＜0.05].免疫组织化学显示实验组中通畅的分流道有完整的内皮形成;再狭窄分流道的假性内膜主要由胶原纤维组成,而通畅分流道的假性内膜主要由细胞成分组成.结论 体外构建EPC种植支架是可行的,置入后促进了家猪模型TIPS分流道内皮化形成,可以提高分流道的通畅性.

Experimental study of an endothelial progenitor cell coated stent in transjugular intrahepatic portosystemic shunt

Objective To evaluate the efficacy of a self-expandable metal stent coated with autologous endothelial progenitor cells(EPCs)for prevention of restenosis in transjugular intrahepatic portosystemic shunt(TIPS)in a swiue model.Methods EPCs were coated on the metal stents using fibrin gel before TIPS procedure.TIPS was performed in 15 young adult pigs,using an autologous EPC-seeded stent(treatment group,n=9)or a conventional bare metal stent(control group,n=6).All pigs were sacrificed at 2 weeks after TIPS procedure.Portography was performed immediately before the euthanasia.Gross and microscopic pathological exams and immunohistochemical exams of the TIPS track specimens were performed.Fisher test and t test were used to analyse the data.Results TIPS was performed successfully in all the 15 swine.On day 14 of follow-up,direct portography and necropsy demonstrated that 5 shunts remained patent,2 shunts stenosed,and the remaining 2 shunts occluded in the treatment group(n=9);while 5 shunts were occluded and one shunt was stenotic in the control group(n=6).The patency rate was 56%vs 0(P=0.03)between the two groups.Histological analyses showed a greater pseudo-intimal hyperplasia in the TIPS track of the control group than that of the treatment group(pseudointimal thickness at hepatic vein,hepatic parenchyma and portal vein site was(1.2±0.4),(1.3±0.5),(1.5±0.4)mmvs(1.0±0.6),(0.9±0.5),(1.0±0.4)mm respectively(P＜0.05).Conclusion The EPC-coated metal stent is feasibly constructed in vitro and improves the patency in TIPS in a porcine model.