Abstract No. 372: Animal models in interventional radiology

Abstract

Animal models are useful for testing and development of devices and drugs, including efficacy, safety and creation of disease models. Our objective is to present the criteria for animal selection including the anatomic similarities to humans, vascular system size, coagulation parameters and reproduction of diseases and problems affecting humans. Twenty-one animal studies were retrospectively reviewed looking into the type of study, type of animal used, utilization of temporary or permanent device, drug or cell therapy and simulation of human diseases. The animals used were swine, canine and rodents. Devices tested included stents in the peripheral circulation and carotids, covered stents in the peripheral circulation and abdominal and thoracic aortic aneurysm model, angioplasty balloons, thrombectomy devices, IVC filters, venous valves, embolic materials, including particles, spheres and several types of coils. Drugs for angiogenesis and coagulation were also tested. Liver and kidney ablation with a variety of devices were performed. Human disease simulation included creation of renal artery stenosis, IVC stenosis, ureteral and biliary duct stenosis. Large animals such as swine were adequate for testing human size devices, such as stents, balloons, IVC filters, thrombectomy and venous valves, however, exuberant fibrin formation and intimal hyperplasia posed problems for permanent implants. Embolic materials can be tested in any size animal simulation of human diseases are best tested in larger animals. Drug therapy and angiogenesis can use medium size animals or large size animals. Simulation of AAA and pseudoaneurysms is better executed in medium to large size animals. The capacity of fibrin development and intrinsic fibrinolytic mechanisms are variable among animals used for research and the animal model needs to match the device to be tested. Several examples will be presented. Animal models are useful for training and for the testing and development of interventional radiology devices and drugs. Selection of the animal size, coagulation profile of the animal and anatomy target of the device or drug study is important for the success of the experiment.