可回收式下腔静脉支架动物实验研究

Experimental study of a new retrievable stent in inferior vena cava

目的本研究旨在通过动物实验评价一款新型可回收式下腔静脉支架置入及回收的可行性和安全性,为其进一步应用于临床提供依据.方法 24头健康幼年家猪按照完全随机法分为4组,每组6头,分别于支架置入3、7、11、15d后回收.全麻下经右侧颈内静脉途径行支架置入术,支架主体跨越肝右静脉;造影观察下腔静脉及肝右静脉通畅情况,测量支架释放前后肝右静脉压力.按设计时间回收支架,支架回收前后均造影复查下腔静脉及肝右静脉情况,测量支架取出前肝右静脉压力.术毕处死动物,取支架段下腔静脉血管组织行病理学检查等.正态分布的计数资料采用均值±标准差(Mean±SD)表示,多组间均数比较用单因素方差分析,组间比较采用Bonferroni或Dunnett T3法;多个不同时间点进行测量的均数比较用重复测量方差分析.结果 24头实验猪均成功置入可回收式下腔静脉支架,技术成功率为100%,所有支架展开良好,无移位或脱落.各实验组测得不同时间点的肝右静脉压力并组内进行比较,差异无统计学意义(F=0.17,P>0.05;F =0.41,P >0.05;F =0.50,P>0.05;F=0.62,P>0.05).3d组及7d组支架均顺利取出,11d组及15d组支架无法取出.3、7、11及15 d组支架段下腔静脉新生内膜厚度分别为(41.82 ±7.15)、(200.32±66.67)、(416.32 ±21.22)、(646.38±37.53)μm,结果显示随着支架放置时间延长,新生内膜增生程度更为明显,差异有统计学意义(F =260.52,P<0.01).增殖细胞核抗原(PCNA)平均吸光度值分别为(8.25±1.63)、(19.77±3.59)、(40.52 ±5.23)、(59.38±3.58),各组间差异有统计学意义(F=209.46,P<0.01).结论该款可回收式下腔静脉支架在动物实验中表现了良好的可行性及安全性,支架在短期内不会影响肝静脉血流,且7d内均可顺利回收.

Objective To evaluate the feasibility and safety of the implantation and recovery of a new retrievable inferior vena cava stent by animal experiment, and to provide evidence for further clinical application. MethodsA total of 24 miniature pigs were divided into four groups randomly according to the observation time (3, 7, 11 and 15 days) after the retrievable inferior vena cava stent was deployed, with 6 pigs in each group. The retrievable stent placement was performed under general anesthesia via the right jugular vein with the right hepatic vein covered by the stent. Angiography of inferior vena cava and right hepatic vein and measurement of right hepatic vein pressure was conducted before and after the stent was released. On the basis of a pre-determined time, the retrievable inferior vena cava stent was removed. Right hepatic vein pressure was measured before the stent was taken out. Inferior vena cava and right hepatic vein were evaluated by venography before and after the stent was removed. The tissue of vessel with stent placement underwent pathological examination. ResultsTwenty-four stents were successfully implanted in inferior vena cava of the animals, the technical success rate was 100%, and all stents expanded great. For comparison of right hepatic vein pressures measured at different time points within the group, there was no significant difference (F=0.17, P>0.05;F=0.41, P>0.05;F=0.50, P>0.05;F=0.62, P>0.05). Stents were successful retrieved at 3rd and 7th day. It was difficult to retrieve the stents at 11th and 15th day after implantation. Under the microscopic examination, the thickness of neo-endothelialization of the inferior vena cava segments where the stent was implanted was (41.82±7.15),(200.32±66.67),(416.32±21.22) and (646.38±37.53)μm respectively, which had statistically significant difference among the four groups (F=260.52, P<0.01). The proliferating cell nuclear antigen (PCNA) mean optical density was (8.25±1.63),(19.77±3.59),(40.52±5.23) and (59.38±3.58) respectively in four group, with the difference being significant among four groups (F=209.46, P<0.01). ConclusionThe retrievable inferior vena cava stent is safe and feasible to implant in the animal model, it will not change the hemodynamics of hepatic vein in the short term and can be safely retrieved within 7 days after implantation.