Innovative experimental animal models for real‐time comparison of antithrombogenicity between two oxygenators using dual extracorporeal circulation circuits and indocyanine green fluorescence imaging

• Published in: Artificial organs Vol. 47; no. 1; pp. 77 - 87
• Main Authors: Sakurai, Hironobu, Fujiwara, Tatsuki, Ohuchi, Katsuhiro, Hijikata, Wataru, Inoue, Yusuke, Maruyama, Osamu, Tahara, Tomoki, Yokota, Sachie, Tanaka, Yui, Takewa, Yoshiaki, Mizuno, Tomohiro, Arai, Hirokuni
• Format: Journal Article
• Language: English
• Published: United States Wiley Subscription Services, Inc 01.01.2023
• Subjects: Animal models; Animals; antithrombotic comparison; Blood clots; Carotid arteries; Carotid artery; Circuits; Continuous flow; COVID‐19; dual extracorporeal circulation; Equipment Design; Evaluation; experimental animal model; Extracorporeal membrane oxygenation; Extracorporeal Membrane Oxygenation - methods; Fluorescence; Imaging; Indocyanine Green; indocyanine green fluorescence imaging; Jugular vein; Models, Animal; Optical Imaging; Oxygenation; oxygenator; Oxygenators; Oxygenators, Membrane - adverse effects; pulsatile flow; Surgical apparatus & instruments; Swine; Thrombosis; Thrombosis - etiology; Veins; COVID-19; dual extracorporeal circulation; indocyanine green fluorescence imaging; experimental animal model; oxygenator; extracorporeal membrane oxygenation; antithrombotic comparison; pulsatile flow
• ISSN: 0160-564X; 1525-1594
• DOI: 10.1111/aor.14380

Background Antithrombogenicity of extracorporeal membrane oxygenation (ECMO) devices, particularly oxygenators, is a current problem, with numerous studies and developments underway. However, there has been limited progress in developing methods to accurately compare the antithrombogenicity of oxygenators. Animal experiments are commonly conducted to evaluate the antithrombogenicity of devices; however, it is challenging to maintain a steady experimental environment. We propose an innovative experimental animal model to evaluate different devices in a constant experimental environment in real‐time. Methods This model uses two venous–arterial ECMO circuits attached to one animal (one by jugular vein and carotid artery, one by femoral vein and artery) and real‐time assessment of thrombus formation in the oxygenator by indocyanine green (ICG) fluorescence imaging. Comparison studies were conducted using three pigs: one to compare different oxygenators (MERA vs. CAPIOX) (Case 1), and two to compare antithrombotic properties of the oxygenator (QUADROX) when used under different hydrodynamic conditions (continuous flow vs. pulsatile flow) (Cases 2 and 3). Results Thrombi, visualized using ICG imaging, appeared as black dots on a white background in each oxygenator. In Case 1, differences in the site of thrombus formation and rate of thrombus growth were observed in real‐time in two oxygenators. In Case 2 and 3, the thrombus region was smaller in pulsatile than in continuous conditions. Conclusions We devised an innovative experimental animal model for comparison of antithrombogenicity in ECMO circuits. This model enabled simultaneous evaluation of two different ECMO circuits under the same biological conditions and reduced the number of sacrificed experimental animals. We developed an innovative experimental animal model in which two veno‐arterial ECMO circuits were attached to one animal in combination with ICG fluorescence imaging for real‐time comparison of antithrombogenicity between oxygenators. Thrombi appeared as black dots on a white background. Differences in site of thrombus formation and rate of thrombus growth could be observed. This model allowed simultaneous evaluation of two circuits under the same biological conditions, thus reducing the number of sacrificed animals.