The Bronchial Circulation in COVID-19 Pneumonia

The primary life-limiting pulmonary morbidity of severe coronavirus disease (COVID-19) is characterized by pulmonary endothelialitis, microangiopathy, and aberrant angiogenesis (1). Although numerous studies have highlighted the pronounced microangiopathy in pulmonary circulation, the impact of the bronchial vascular system has not been fully elucidated. Therefore, we comprehensively analyzed complete lung lobes from three male patients (age, 63.7 ± 14.2 years; hospitalization time, 22 ± 1 days, mechanically ventilated) who succumbed to severe COVID-19 using conventional computed tomography, histology, microvascular corrosion casting, and hierarchical phase-contrast tomography (2). We used three control lungs from body donors (age, 78.3 ± 13.6 yr; nonventilated, two females and one male died from cerebral stroke or uterine carcinoma).