Coronavirus disease-19 (COVID-19) caused by SARS-CoV-2 first appeared in December 2019 in China (1) and has remained a hot topic for the past 3 years. Currently, it is considered a multi-systemic disease associating a hypercoagulable state responsible for thrombotic complications in seriously affected patients. Acute COVID-19 infection causing micro thrombi called immune thrombi.

Among the complications, acute limb ischemia is rarer than coronary heart disease, which explains the absence of clear and consensual guidelines allowing cardiologists to diagnose and treat acute limb ischemia in the context of the Covid 19 pandemic.

A 60-year-old man suffering from hypertension, hyperlipidemia, a history of smoking and chronic obstructive pulmonary disease (COPD) presented to our hospital with a febrile state for a week associated with respiratory distress syndrome (dyspnea) which gradually got worse. He had a productive cough and severe pain in his right leg since 6 p.m.

The clinical and paraclinical constants are as follows, tachypnea (48 parmin cycles), tachycardia (FC123bpm), blood pressure 140/90 mmhg and hyperpyrexia (39.2°).

Examination of the lower limbs showed a decrease in sensitivity of the right foot, The abolition of the posterior tibial and right dorsal pedal pulses. The distal toes were cyanotic and cold.

Laboratory results found a positive PCR for COVID-19, an elevated D-dimer level (8300ng per ml), a positive CRP and an elevated fibrinogen level.

Oxygen saturation was 80% without oxygen (in the open air).

Figure 1: Front chest x-ray on admission showing pulmonary condensation syndrome. Results compatible with viral pneumonia.

Doppler echocardiogram: finds good LV function with an EF of 65% and good global and segmental contractility. We performed an arteriovenous Doppler ultrasound of the lower limbs and found a thrombus in the distal right popliteal artery, minimal flow in the distal posterior tibial artery. There was no clear sign of collateral flow or sign of thrombus in deep veins

In addition to antibiotic and corticosteroid treatment, he was treated with an IV infusion of unfractionated heparin (UFH) with a target control of 1.5 × −3 × TCA.

Unfortunately on day 2 of his hospitalization his condition worsened with severe saturation where he was discharged, intubated and ventilated.

On day 6 of his hospitalization, the patient died of fatal septic shock.

Thrombotic complications (3) of COVID-19 are thought to be due to a hyperinflammatory response caused by the virus. Several complications have been described in the literature. These include acute limb ischemia, abdominal and thoracic aortic thrombosis, mesenteric ischemia, myocardial infarction, venous thromboembolism, acute stroke, and disseminated intravascular coagulation.

-Pathophysiology: SARS-CoV-2 is a single-stranded RNA virus that belongs to the Coronaviridae family, which it shares with severe acute respiratory syndrome coronavirus 1 (SARS-CoV-1) and respiratory syndrome coronavirus from the Middle East (MERS-CoV) [ 3,4].SARS-CoV-1, MERS, and SARS-CoV-2 all bind to angiotensin-converting enzyme 2 (ACE-2), which is a crucial counter-regulatory enzyme that converts angiotensin I to angiotensin II [5, 6]. ACE-2 is present in almost all human tissues, Angiotensin I, when not broken down by ACE-2, promotes an inflammatory state in the body and causes vasoconstriction, sodium retention and fibrosis throughout the body [ [7,8,9] ]. Recent studies have evaluated the role of inflammation in creating hypercoagulable states, possibly via activation of endothelial cells, platelets and leukocytes inducing tissue factor (TF), then triggering the coagulation system through binding to coagulation factor VIIa [10,11].

  Interestingly, an autopsy study of the lungs in 10 COVID-19 patients revealed platelet-rich microvascular deposits in the small vessels of the lungs reminiscent of thrombotic microangiopathy [13].

Acute limb ischemia is an important consideration in patients with COVID-19 [ 14 ]. There have been more than a dozen case reports and case series of AMI (Acute Limb Ischemia) described in the literature [ [15] , [16] , [17] , [18] , [19 ], [20], [21], [22], [23], [24], [25], [26], [27], [28], [29]. These patients often have multiple thromboses involving different vessels throughout their body. Many of these patients do not have existing peripheral arterial disease. Acute limb ischemia can even occur in patients already receiving thromboprophylaxis [22, 25, 27, 29].

Symptoms may include sharp pain in the limbs [15, 18, 20], focal hypothermia [15, 18, 22, 28], skin mottling [14, 15, 18, 23, 28], absent pulse [15, 15, 18, 23, 28]. 18, 22, 28], or toe necrosis [27]. Patients usually have elevated D-Dimer [19, 21, 25, 26, 28] and may also have elevated C-reactive protein (CRP) [18]. Although computed tomographic angiography (CTA) of the extremity is often performed, clinicians should consider adding CTA of the aorta to evaluate for concomitant aortic thrombosis [ 15 , 25 , 28 ]. Treatment involves vascular surgery and interventional radiology consultation, as well as empiric systemic anticoagulation [ 29 , 30 ]. A study of 20 patients found that surgical treatment was performed in 17 patients and successfully saved the limb in 12 (70.6%) [20]

Several internal and external factors make the treatment of acute ischemia more difficult during the COVID-19 pandemic. Diagnosis and management in COVID-19 patients may not be fully consistent with current guidelines. . COVID-19 is associated with a significant inflammatory response, increasing the risk of arterial and venous thrombosis. These complications can increase the risk of morbidity and mortality and include acute limb ischemia, abdominal and thoracic aortic thrombosis, mesenteric ischemia, myocardial infarction and acute coronary syndrome, venous thromboembolism, acute stroke and disseminated intravascular coagulation. Knowledge of these COVID-19-related conditions may improve emergency medicine clinicians' recognition and management of these thrombotic complications. Peripheral arterial thrombosis with or without AMI is a rare and unpredictable complication of COVID-19 infection requiring rapid and adequate management. Treatment is essentially based on curative anticoagulation associated or not with surgery despite the risk of re-thrombosis.