In Vivo Experiment Of A New Retrievable Inferior Vena Cava Filter For Protection From Pulmonary Embolism In Canine Model

Objectiveâ‘ To establish a new canine model of pulmonary embolism that be suit for the study of imaging diagnosis and therapy, and to evaluate the technique feasibility.â‘¡To evaluate the validity, safety and feasibility of a new retrievable inferior vena cava filter for the prevention of pulmonary embolism in an animal model.Methodsâ‘ The model of deep ilio-femoral venous thrombosis was established in 12 experimental dogs. The deep venous thrombosis was made to fall off directly in control group (6 dogs) and with a implanted filter in inferior vena cava in experimental group (6 dogs). The thrombus-trapping efficacy of filter was evaluated by angiography of pulmonary artery, measurement of the mean pressure of pulmonary artery and arterial oxygen saturation before and after the deep venous thrombosis falling off.â‘¡Eight dogs were divided into four groups at random according to the time (10 days, 2 weeks, 3 weeks, 4 weeks ) after the new retrievable inferior vena cava filter were deployed, with two dogs in each group. The filter was placed in inferior vena cava through femoral vein in all dogs. The influence of the filter on inferior vena cava was evaluated by angiography and microscope. Resultsâ‘ All filters implanted in the experimental dogs can successfully capture clot coming from deep venous thrombosis. There was no case with pulmonary embolism in experimental group. On the other hand, pulmonary embolism occurred following falling off from deep venous thrombosis in all dogs of control group.â‘¡There were no complicationsrelated to filter implantation in all dogs. Filters were successfully retrieved at 10,14 days. It is difficult to retrieve the filters at 3, 4 weeks after implantation. There was had slight neointimal proliferation at 10, 14 days, and moderate or severe neointimal proliferation at 3, 4 weeks.Conclusionâ‘ The model of acute pulmonary embolism in dog with interventional technique is simple and microinvasive. The method dose serve as a useful model for the early medical imaging diagnosis and therapy of acute pulmonary embolism.â‘¡The retrievable inferior vena cava filter can effectively prevent from the pulmonary embolism falling off from deep venous thrombosis. The process of implantation and retrieval of the new retrievable inferior vena cava filter is relatively simple and easy. The filter can be reliable and safely retrieved at 2 weeks after implantation in dog.