Animal experimental study of safety for a self-made vena cava stent-filter
- VernacularTitle:自制下腔静脉支架式滤器安全性的动物实验研究
- Author:
Dingwen QIN
;
Haibin SHI
;
Sheng LIU
;
Linsun LI
- Publication Type:Journal Article
- Keywords:
Vena cava filter;
Animal experiment;
Self-made
- From:
Journal of Interventional Radiology
2001;0(05):-
- CountryChina
- Language:Chinese
-
Abstract:
Objective To evaluate the safety of a self-made vena cava stent-filter(VCSF)for prevention of pulmonary embolism.Methods Fusiform unmbrella-like vena cava filter was made of Nitinol wires and stainless steel metal pole,and then ten mongrel dogs were implanted with these self-made filters and divided into 5 groups according to the different periods(2,3,4,5 and 6 w) of filter placement,with 2 dogs in each group.After the VCSFs were placed in inferior vena cava via the right femoral vein approach,the dogs in each group were bred for 2-6 weeks,respectively.The blood flow of inferior vena cava and the position of the filters were inspected by inferior vena-cavography according to the indwelling periods.Finally the metal pole was retrieved via the femoral vein,leaving the VCSF as permanent venous stent.The feasibility of retrieval and the free state of filter net with the adhering vascular wall were evaluated.Laparotomies were performed to remove the inferior vena cava from the animals for gross and electron microscopic examinations of the inferior vena cava intimal changes of the involved segment.Results All 10 VCSFs were placed at the right positions of the dogs successfully.Angiography showed patent inferior vena cava without filter thrombosis at 2-6 weeks.There were no tilting and migration of the filter and all the metal poles were successfully retrieved.The superior and inferior extremities of filter nets could be set free with all the filters turning into venous stents.Postmortem displayed retroperitoneal hemorrhage and caval thrombosis.The barbs of the filters penetrated over the caval adventitial coat.Under electron microscope,a thin layer of neointima already covered the braiding net of VCSFs at 2 weeks after the deployment.The tunica intima became slightly thick at 3-4 weeks and with moderate proliferation at 5-6 weeks.Conclusions The self-made vena cava stent-filter possesses rather long indwelling period according to the necessity of treatment with simultaneously keeping patent caval flow,stability of the position and easy for displacement and retrieval.
