Aegisy型可回收性下腔静脉滤器的动物实验研究

An Experimental Study of Aegisy Retrievable Inferior Vena Cava Filter in Animal Models

目的探讨Aegisy型下腔静脉滤器（inferior vena cava filters，IVCF）放置于成年羊的下腔静脉后不同时点内滤器附着处静脉内膜增生情况，评估其临床应用的安全性及可回收时间。方法18只成年羊（体重23～51kg，平均39．6kg）随机分为A、B组，每组9只羊，每只羊置入1枚IVCF，按滤器留置时间分为2、3、4周组，每组3只。观察期满后造影观察滤器有无移位及血栓形成，A组滤器回收，B组为观察滤器附着处静脉内膜的增生情况而不回收滤器。所有羊无痛处死，取出置入滤器处下腔静脉段，行病理检查，评估滤器置入处下腔静脉内膜增生和损伤情况。结果18只羊成功置入滤器，滤器无移位及血栓形成。A组中2周组滤器均成功回收，3周组1只滤器回收成功，2只滤器未能回收，4周组滤器均未能回收。2组滤器未成功回收的病理结果显示：2周组新生内膜开始轻度增生，3周组新生内膜中度增生，4周组滤器周围有袖套样新生内膜显著增生。结论Aegisy滤器在置入羊体内后2周时滤器支撑丝和倒刺部位轻度内膜增生，可安全回收，对于Aegisy滤器在延长回收时间窗后能否安全的回收仍需要进行大量研究并准确评估。

Objective to detect the intimal hyperplasia conditions at the implantation sites of Aegisy inferior vena cava filters （IVCF） and evaluate the safety of the filter＇s clinical application and the retrieval time points from the inferior vena cava （IVC） in animals. Methods A total of 18 adult sheep with an average weight of 39.6 kg （range, 23 -51 kg） were selected. All the sheep were divided into Group A and Group B at random with 9 sheep for each group. Each sheep was implanted with one IVCF. According to the implantation time of the filter, every group was divided into 2-week, 3-week, and 4-week subgroups, respectively, with 3 sheep in each subgroup. After the observation, an IVC venography was performed to observe the displacement and thrombosis of filters. Filters of Group A were retrieved and those of Group B were not retrieved. All sheep were killed to pick up the filters. Pathological examinations were conducted. And the intimal hyperplasia and damage conditions of IVC at the part of implantation were evaluated. Results All the 18 sheep were implanted with filters successfully. No displacement of filter or thrombosis were detected. In Group A, filters for 2-week were retrieved successfully. Among filters for 3-week, 1 filter was successfully retrieved and 2 failed to be retrieved. Among filters for 4-week, all filters failed to be retrieved. Pathological results of specimens of the filters which were not successfully retrieved showed slight hyperplasia of neointima at 2-week, moderate hyperplasia of neointima at 3-week, and remarkable hyperplasia like oversleeve around filters at 4-week, respectively. Conclusions After Aegisy filter has been implanted into sheep for 2 weeks, slight hyperplasia of neointima will be found at the filter support wire and agnall part, but the filter can be retrieved safely. After this retrieved window, the safety of retrieval needs further investigation based on a large number of cases.