VCAM1 and endothelial dysfunction: Although the above studies supported postoperative BBB dysfunction, Moazzen et al. (2024) (n = 788, mixed surgical cases) examined preoperative plasma levels of markers of endothelial dysfunction (including asymmetric and symmetric dimethylarginine, ICAM-1, VCAM-1, vWF) and did not find an association with POD risk, suggesting that the link between endothelial and BBB dysfunction with POD may be dynamic.