We believe, from our direct experience, that patients who test positive for COVID-19 could experience a hypercoagulable state that could increase the incidence and extension of native arterial occlusion. Previous (pre–COVID-19) studies have reported that the overall incidence of ALI has declined significantly in the past decade and that the presence of a hypercoagulable state is an uncommon etiology among the broad population presenting with ALI.2 , 10 However, in our early experience, we have evaluated a significantly greater number of patients with from ALI compared with the same period in 2019 before COVID-19. If the pandemic continues as predicted, this emergency will extend until the end of the calendar year. Undoubtedly, this will translate into the evaluation and surgical intervention of ∼171 cases. This would be greater than 30% of the projected total interventions or a fivefold increase if compared with all of 2019 (Fig 4 ). Additionally, although a hypercoagulable state has been preferentially associated with venous thromboembolism, our patients with COVID-19 had both arterial and venous vascular system involvement.2 Multiple patients had a diagnosis of extensive deep venous thrombosis, in addition to ALI, and massive pulmonary embolism has been reported to be frequently found during autopsy in these patients (Chen, unpublished data, 2020). Third, we are expecting to perform better analyses of the thrombus specimens. However, macroscopically, they appear quite different from specimens before COVID-19, with a typical gelatinous consistence. Finally, although young age and female gender have been found to be more frequently associated with known hypercoagulable disorders, in our series, this hypercoagulability state was observed in both younger and older patients, with a male predominance. These latter two findings suggest that the hypercoagulability in our patients is not related to well-known blood disorders but, rather, that native arterial thrombosis might be triggered by COVID-19 infection. This is only a preliminary, although totally new, observation. Viral-related ALI has been described anecdotally in reported studies but was not associated with venous thromboembolism or hypercoagulability.11
Fig 4 Estimated projection of patients with acute limb ischemia (ALI) in 2020 compared with those treated in 2019 at the same center.