Cellular and Molecular Mechanisms Leading to Air Travel-Induced Thrombosis

Venous thromboembolism, characterized by deep vein thrombosis and pulmonary embolism, is the third cardiovascular disease in the world. Deep vein thrombosis occurs when a blood clot forms in areas of impaired blood flow, and it is significantly affected by environmental factors. Local hypoxia, caused by venous stasis, plays a critical role in deep vein thrombosis under normal conditions, and this effect is intensified when the Po₂ decreases, such as during air travel or high-altitude exposure. The lower oxygen levels and reduced pressure at high altitudes further contribute to deep vein thrombosis development. These conditions increase the pro-coagulant activity of neutrophils, platelets, and red blood cells, which interact on the surface of activated endothelial cells, promoting clot formation. Understanding the mechanisms involved in thrombus formation when Po₂ is reduced, with or without pressure reduction, is crucial for preventing the development of venous thromboembolisms in such conditions and identifying innovative therapeutic targets. This literature review explores the mechanisms involved in thrombus formation related to high-altitude conditions and discusses the pro-coagulant consequences induced by environmental disturbances.