Pulmonary artery thrombosis as one of the crucial pathonorphological signs of COVID-19: results of 7 autopsies and literature review

Pulmonary artery thrombosis is one of the crucial mechanisms of severe COVID-19 development. Histological examination reveals widespread microvascular thrombosis in 87 % and large branches pulmonary artery thrombosis in 13 % of deceased patients. Caused by viral and immune cytotoxic effect thrombotic lung vasculopathy appears to be the main trigger of pulmonary artery thrombosis. In this study we examined 7 lungs obtained from patients who died from COVID-19. Thrombotic lung vasculopathy was typical sign of all 7 lungs. Endothelial cell destruction, media fibrinoid necrosis, neutrophil and lymphocytic infiltrates of the arterial wall and perivascular tissues were the basic histological changes in the lung arteries of different diameters. All this fatal changes developed independently of the therapeutic and prophylactic anticoagulation.