Prominent Bronchopulmonary Vascular Anastomoses in Fatal Childhood Asthma

The role of vasculature and angiogenesis in respiratory diseases

In European countries, nearly 10% of all hospital admissions are related to respiratory diseases, mainly chronic life-threatening diseases such as COPD, pulmonary hypertension, IPF or lung cancer. The contribution of blood vessels and angiogenesis to lung regeneration, remodeling and disease progression has been increasingly appreciated. The vascular supply of the lung shows the peculiarity of dual perfusion of the pulmonary circulation (vasa publica), which maintains a functional blood-gas barrier, and the bronchial circulation (vasa privata), which reveals a profiled capacity for angiogenesis (namely intussusceptive and sprouting angiogenesis) and alveolar-vascular remodeling by the recruitment of endothelial precursor cells. The aim of this review is to outline the importance of vascular remodeling and angiogenesis in a variety of non-neoplastic and neoplastic acute and chronic respiratory diseases such as lung infection, COPD, lung fibrosis, pulmonary hypertension and lung cancer.

Prominent Intrapulmonary Shunt Vessels and Altered Lung Development in Infants With Sudden Unexplained Infant Death

The purpose of this study was to evaluate intrapulmonary arteriovenous shunts in patients with and without sudden unexplained infant death. We identified open intrapulmonary bronchopulmonary anastomoses as potential pathways for right-to-left shunt in a subset of infants with sudden unexplained infant death.

Intrapulmonary bronchopulmonary anastomoses in COVID-19 respiratory failure

The spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has led to a devastating and worldwide pandemic disease known as coronavirus disease 2019 (COVID-19). COVID-19 causes acute hypoxic respiratory failure (COVID-ARF), a major cause of mortality and morbidity, with an incompletely understood pathophysiological mechanism. Gattinoniet al. [1] noted that COVID-19 patients with acute hypoxic respiratory failure have lung disease that is often characterised by a remarkable dissociation between relatively well-preserved lung mechanics, including lung compliance, and severe hypoxaemia. These findings are consistent with the concept that profound hypoxaemia occurring in ventilated patients with highly compliant lungs could be due to the loss of regulation of lung perfusion and impaired hypoxic pulmonary vasoconstriction. Early autopsy studies suggest that the lung circulation is a major target of coronavirus infection, which leads to striking pulmonary vascular disease due to variable degrees of thrombosis, apoptosis, oedema, inflammation and angiogenesis [2–4]. These changes contribute to dysregulation of the pulmonary vasculature, which induces perfusion abnormalities and contributes to the physiological phenotypes reported in COVID-19 pneumonia. Further, computed tomography suggests a unique “tree in bud” appearance of small pulmonary arteries [3] and transcranial agitated saline microbubble doppler studies of COVID-19 patients with hypoxaemia have demonstrated intrapulmonary shunting of these bubbles, and that the presence and degree of transpulmonary bubble transit correlates with the degree of hypoxaemia [5]. Despite these studies, histopathological correlates of severe hypoxaemia and shunt in the setting of relatively normal lung compliance in COVID-19 patients are largely lacking.

Open intrapulmonary bronchopulmonary anastomoses (IBA) were identified in COVID-19 patients who died of respiratory failure. IBA may be the microanatomical basis of intrapulmonary right to left shunt leading to severe hypoxaemia in COVID-19.https://bit.ly/3e2GajO