Development of synthetic thrombus models to simulate stroke treatment in a physical neurointerventional training model

In an ischaemic stroke, a blood clot (thrombus) occludes one of the arteries supplying the brain with oxygen. In such cases, a prompt and safe removal of the thrombus by interventional physicians is of high importance. The procedure of mechanical thrombectomy is mainly trained on animal models or simple flow models with animal- or human-based thrombi. The aim of this study is to develop a completely blood free thrombus model for use in an existing physical neurointerventional simulation model. Based on requirements established with treating physicians and supplemented by a broad literature review, a systematic material selection based on mechanical properties was performed by means of a material database. Selected materials, as well as other materials from a literature search and structural additive manufactured clots, were produced and selectively narrowed down, by means of functional property testing. Based on a pre-selection by a simple test set-up, the main tests were carried out on the existing simulation model by interventional physicians under realistic test conditions in a clinical angiography suite. As a result, four different types of thrombi varying in elasticity, solidity and fragmentation, were obtained by material combinations based on agarose and silicone in different concentrations and with further additives.