Optical scattering analysis for the determination of the physicochemical properties of blood clots

forthcoming

Venous thromboembolism (VTE) is a common and serious disease in which a blood clot forms in the venous system. When a blood clot forms in the deep veins of the leg (deep vein thrombosis, DVT) and migrates through the bloodstream, to lung arteries, it creates a pulmonary embolism (PE). VTE encompasses DVT and PE and causes more than 30000 annual deaths in Europe. After clinical investigation, nearly half of the events can be explained (immobilisation, cancer, inherited thrombophilia), the other half of VTE cases have no known origin (called idiopathic VTE). Among the patients developing idiopathic, about 30% of them would have a recurrent thromboembolic event, 70% would not be subjected to any recurrence. This leads to difficult decisions in the population of idiopathic VTE; if the anticoagulation therapy used to treat VTE is very efficient it also has major side effects, such as bleeding events, that can be deadly. A balance must be struck between the risks of recurrent thrombosis if anticoagulant treatment is stopped versus the risks of bleeding associated with continued anticoagulation therapy that can go up to the course of decades. Physico-chemical properties of clots seem to be relevant parameters to describe their mechanical resistance and to develop risk assessment models. Currently, the most investigated methods in the literature are based on turbidimetry, rheology and permeation. Therefore, the development of optical approaches seems particularly interesting. In addition to their ease of implementation, their non-invasive and non-contact features, they would allow access to information related to the clot density, fibrin fibre arrangement, and dynamic changes during clot formation. These techniques are promising, but an integration of the different results from various methods is necessary to get a comprehensive understanding of clot properties.