Fibrin Network Formation and Thrombolysis using a Birefringence Measuring

Abstract

Background: Fibrin is a fibrous plasma protein, which is known as precursor of clot. The polymerized fibrin network together with platelets forms a thrombus which causes fatal thromboembolism especially in the extracorporeal circulation using heart-lung machine or dialyzer. Because the length of fibrin is shorten than visible ray wavelength, we cannot detect fibrin using an optical microscope. Objective: To develop early phase thrombus detection system, we proposed fibrin imaging method using the birefringence properties. In this study, the relationship between fibrin network formation/resolution and optical birefringence properties was evaluated. Method: Birefringence imaging system was consisted of halogen light source, red light interference filter, polarizer, quarter wave plate, optical condenser, sample flow pass, ×10 objective lens, and CCD image sensor. Experimental plasma, which was kept at temperature of 36°C and coagulated gradually, was set in flow tube and guided by continuous flow pump to the sample flow pass. The retardation of the sample plasma was calculated from CCD images which was obtained by system at every 5 seconds. After confirming sufficient aggregation of fibrin, heparin was injected to the sample flow pass so as to activate fibrinolytic system of blood. Result: The retardation of plasma increased over time within 5 minutes. In contrast, fibrinolytic system reduced phase differences by melting aggregated fibrin within 6 minutes.