GHOST BLOOD- A NOVEL FLUID FOR VISUAL MONITORING OF COAGULATION IN AN OCCLUSION SYSTEM

• Published in: International journal of artificial organs 2023-07, Vol.46 (7), p.401
• Main Authors: Hefer, P, Schuermann, B J, Luisi, C, Yin, X, Steinseifer, U, Sedaghat, A, Clauser, J
• Format: Article
• Language: English
• Subjects: Additives; Aorta; Aortic valve; Blood clots; Blood coagulation; Blood flow; Blood plasma; Coagulation; Electromagnetic absorption; Erythrocytes; Fluid flow; Glycerol; Glycerol-Water; Heart valves; Hemoglobin; Medical devices; Medical equipment; Mixtures; Occlusion; Pseudoplasticity; Rheological properties; Rheology; Thrombosis; Viscosity; Xanthan
• ISSN: 0391-3988; 1724-6040

Objectives: Water-glycerol mixtures are primarily used as blood-substitute fluids for in-vitro studies of flow dynamics in the investigation of biomedical devices. Although such fluids have the advantage of full transparency, they cannot reproduce the natural rheology and coagulation of blood. With our new approach of using a mixture of erythrocytes with reduced hemoglobin content (ghost cells) and blood plasma, we were able to mimic the rheology and coagulation properties of whole blood. Methods: The coagulation properties were tested by thromboelastometry (ROTEM), and the dynamic viscosity was measured at high shear rates from 2650 s-1 down to 5 s-1 in exponential steps by a cone-plate rheometer at 22 °C and 37 °C, both analyses showed similar behavior compared to whole blood. Results: However, ROTEM results regarding natural coagulation indicate accelerated coagulation at the same clot strength. The typical pseudoplastic property of blood was achieved at 22 °C without any additives, but at 37 °C, xanthan had to be added to increase the viscosity, especially at low shear rates < 50 s-1. In addition, the so-called "ghost blood" showed an approximately 120-fold reduction in light absorption. For this purpose, a model of the left atrial appendage was used to visualize the occlusion during PIV measurements. Thus, we were able to visualize the forming of a thrombus in an occlusion system in real-time during perfusion. Conclusions: The increased transparency and blood-like behavior in terms of coagulation and rheology opens new possibilities for studying the flow dynamics in blood-carrying medical devices that are designed to shield the blood flow in specific areas. In the future, the ghost blood allows for the investigation of other thrombus-prone regions due to stagnation such as aneurysm occluders, left atrial appendage occluders, or the neo-sinus after transcatheter aortic valve implantation.