Introduction
Coronavirus Disease of 2019 (COVID-19) is a novel coronavirus declared a pandemic by the World Health Organization in March 2020. Like other viruses (HIV, CVM…) and bacteria (Staphylococcus aureus), COVID-19 has increased the risk of venous and arterial thromboembolic events [1,2].
Arterial and venous thromboses are associated with severe complications and a high mortality risk.
We report a case of COVID-19 infection complicated by multiple arterial thromboses.

Figure 1c: CT angiography of the aorta and iliofemoral arteries showed: Complete occlusion of the right popliteal artery

Discussion
Multiple arterial thromboses are a vascular surgery emergency. They can lead to severe morbidity and mortality. Many reviews suggest that COVID-19 patients are predisposed to arterial thrombosis. Tang et al. found that 74 % of patients who died of COVID-19 had disseminated intravascular coagulopathy [3]. Cheruiyot et al. reported that arterial thrombotic events can occur in up to 4 % of critical patients with COVID-19, sometimes affecting multiple territories [4]. In a few patients, arterial thromboembolic complications have been observed with increasing frequency in the vasculature of the brain, lungs, spleen, and limbs [5].

In Emilio Ribas Institue of Infectious Diseases in Brazil, from March to July 2020, approximately 350 patients with COVID-19 were admitted. Only 0,3 % of them were diagnosed with spleen infarction. An apparent increase in infarction prevalence was noticed, with other manifestations of ischemic events involving the abdominal viscera [6]. Most cases of arterial thrombose in SARS-CoV2 positives patients were elderly and had chronic diseases. A recent review by Putko M. et al. noticed that most patients had cardiovascular comorbidities and diabetes mellitus [7]. Our patient was a 58-year- old man without medical history. However, diabetes was newly diagnosed on admission.

The mechanism of thrombotic events may be multifactorial. It associates cytokine storm, increased procoagulant factors, stasis, hypoxia, and endothelial dysfunction.

Our patient presented with complete thrombosis of the abdominal aorta with extension to both common iliac arteries, a spleen infarction, occlusion of the right popliteal artery, the left tibiofibular trunk, and the left anterior tibial artery. This topography suggested that the emboli originated from a thrombus in the aorta, detached from the aorta, and caused multiple arterial thromboses.

In the literature, several cases of aortic thrombosis are reported in patients with severe COVID-19[8,9]. Gomez-Arbelaez D et al. has reported four cases of aortic thrombosis and ischemic complications in patients with severe SARS-CoV2 infection despite the antithrombotic prophylaxis: Two patients had an aortic occlusion, and the others had an aortic floating thrombus. All the patients had other ischemic complications like acute limb ischemia, acute mesenteric ischemia, and stroke [10].

In the literature, multiple ischemias usually affect the lower limbs. In the Putko M et al. review, 47 patients with COVID-19 were diagnosed with lower limb ischemia, and 6 patients had bilateral ischemia [11]. Monteiro L et al. reported a case of a 61-year-old man with a medical history of diabetes mellitus and dyslipidemia who had severe SARS- CoV2 pneumonia. A few hours after admission, he complained about intense pain in the lower limbs. The CT angiography revealed an intramural aortic thrombosis with more than 50 % stenosis of the descending thoracic aorta, complete occlusion of the lower abdominal aorta, and extension to both common iliac arteries. Left renal infarction was also found. Despite adequate medical treatment, the patient died [12].

The most important indicators of the cytokinin storm are D-dimer, platelets, ferritin, LDH, prothrombin time, fibrinogen, and IL-6. [13]. D-dimer was frequently elevated. In China, a study of 1099 patients showed that 46,4 % of patients had a high level of D-dimer (≥500 μg/l), and 60% of them had severe forms of COVID-19 infection [14]. Tang et al. showed that abnormal coagulation results, significantly elevated D-dimer and fibrinogen, are common in deaths with COVID- 19 infection [15].

Because of the hemostatic derangements in these patients, some clinicians use a variety of prophylactic, intermediate, or therapeutic doses of heparin for routine care of patients with COVID-19 pneumonia [16].

Many authors suggest using heparins at therapeutic doses in patients with COVID-19 from admission [17]. The timing of thrombosis diagnosis and treatment is intriguing [17]. In a retrospective study of COVID-19 patients with limb vascular ischemia, the median time from the onset at the clinic consistent with coronavirus infection to the development of limb ischemia was 19 days [18].

In the three cases presented by Baeza C, surgical treatment associated with curative anticoagulation has allowed the rescue of patients with extensive aortic thrombosis [18]. So, this case aims to reinforce the difficulty of managing multiple thromboses despite a therapeutic dose of LMWH or UFH. But, prophylaxis, prompt diagnosis, and initiation of medical therapy or even surgery are the mainstay of managing these complications [19].