From cellular function to global impact: the vascular perspective on COVID-19.

Since COVID-19 was declared a pandemic a year ago, our understanding of its effects on the vascular system has slowly evolved. At the cellular level, SARS-CoV-2 - the virus that causes COVID-19 - accesses the vascular endothelium through the angiotensin-converting enzyme 2 (ACE-2) receptor and induces proinflammatory and prothrombotic responses. At the clinical level, these pathways lead to thromboembolic events that affect the pulmonary, extracranial, mesenteric, and lower extremity vessels. At the population level, the presence of vascular risk factors predisposes individuals to more severe forms of COVID-19, whereas the absence of vascular risk factors does not spare patients with COVID-19 from unprecedented rates of stroke, pulmonary embolism and acute limb ischemia. Finally, at the community and global level, the fear of COVID-19, measures taken to limit the spread of SARS-CoV-2 and reallocation of limited hospital resources have led to delayed presentations of severe forms of ischemia, surgery cancellations and missed opportunities for limb salvage. The purpose of this narrative review is to present some of the data on COVID-19, from cellular mechanisms to clinical manifestations, and discuss its impact on the local and global surgical communities from a vascular perspective.