Adventitial Microcirculation Is a Major Target of SARS-CoV-2-Mediated Vascular Inflammation.

We report the case of a 77-year-old woman affected by coronavirus disease-19 (COVID-19) who developed an occlusive arterial disease of the lower limb requiring a left leg amputation. We studied the mechanisms of vascular damage by SARS-CoV-2 by means of a comprehensive multi-technique in situ analysis on the diseased popliteal arterial district, including immunohistochemistry (IHC), transmission electron microscopy (TEM) and miRNA analysis. At histological analyses, we observed a lymphocytic inflammatory infiltrate, oedema and endothelialitis of adventitial vasa vasorum while the media was normal and the intima had only minor changes. The vasa vasorum expressed the ACE2 receptor and factor VIII; compared with the controls, VEGFR2 staining was reduced. TEM analyses showed endothelial injury and numerous Weibel-Palade bodies in the cytoplasm. No coronavirus particle was seen. IL-6 protein and mRNA, together with miR-155-5p and miRs-27a-5p, which can target IL-6, were significantly increased compared with that in the controls. Our case report suggests an involvement of adventitial artery microcirculation by inflammation in the course of COVID-19. Without evident signs of current infection by SARS-CoV-2, endothelial cells show a spectrum of structural and functional alterations that can fuel the cardiovascular complications observed in people infected with SARS-CoV-2.

Is it Possible to Safely Maintain a Regular Vascular Practice During the COVID-19 Pandemic?

OBJECTIVE: This study aimed to evaluate the protocol adopted during the emergency phase of the COVID-19 pandemic to maintain elective activity in a vascular surgery unit while minimising the risk of contamination to both patients and physicians, and the impact of this activity on the intensive care (IC) resources. METHODS: The activity of a vascular surgery unit was analysed from 8 March to 8 April 2020. Surgical activity was maintained only for acute or elective procedures obeying priority criteria. The preventive screening protocol consisted of nasopharyngeal swabs (NPS) for all patients and physicians with symptoms and for unprotected contact infected cases, and serological physician evaluations every 15 days. Patients treated in the acute setting were considered theoretically infected and the necessary protective devices were used. The number of patients and the possible infection of physicians were evaluated. The number and type of interventions and the need for post-operative IC during this period were compared with those in the same periods in 2018 and 2019. RESULTS: One hundred and fifty-one interventions were performed, of which 34 (23%) were acute/emergency. The total number of interventions was similar to those performed in the same periods in 2019 and 2018: 150 (33, of which 22% acute/emergency) and 117 (29, 25% acute/emergency), respectively. IC was necessary after 6% (17% in 2019 and 20% in 2018) of elective operations and 33% (11) of acute/emergency interventions. None of the patients treated electively were diagnosed with COVID-19 infection during hospitalisation. Of the 34 patients treated in acute/emergency interventions, five (15%) were diagnosed with COVID-19 infection. It was necessary to screen 14 (47%) vascular surgeons with NPS after contact with infected colleagues, but none for unprotected contact with patients; all were found to be negative on NPS and serological evaluation. CONCLUSION: A dedicated protocol allowed maintenance of regular elective vascular surgery activity during the emergency phase of the COVID-19 pandemic, with no contamination of patients or physicians and minimal need for IC resources.