Symptoms such as fever, dry cough, shortness of breath, and muscle pain are commonly reported in patients with COVID-19[22]. There was no distinct COVID-19 symptom in this patient, and he had normal SVT symptoms such as swelling and pain sensitivity. While he had no risk factors for SVT, paraclinical tests and CT scans of the chest showed COVID-19, which was also confirmed by a laboratory kit.
Studies have shown that the most important and stable hemostatic disorders associated with COVID-19 include mild thrombocytopenia[23] and an increase in D-dimer amount[24]. Numerous studies have shown that thrombotic abnormalities, along with abnormalities in the function of various organs in patients with COVID-19[25] lead to higher mortality, but there are few reports of SVT and its side effects in patients with COVID-19. In a 2020 study on a patient with COVID-19, CT images of angiography showed signs of acute cerebral infarction and DVT in both lower limbs[26].
According to the Chinese National Health Commission, patients with severe COVID-19 are defined based on one of the following symptoms[20]: (a) acute respiratory syndrome, in which patient is able to breathe through mechanical ventilation, (b) shock, and (c) dysfunction of organs or other systems of the body. In addition, studies have shown that patients with COVID-19 are prone to DVT. Pathophysiologically, patients with COVID-19 have been shown to be candidates for venous thrombosis, usually due to diarrhea, hypotension, recurrent long-term infections, and dehydration[20]. Therefore, in patients with coronavirus, assessing the risk of DVT and SVT are essential to reduce complications and mortality risk. Studies have shown that patients prone to DVT usually have one of the following criteria: age over 75, respiratory and heart failure, history of previous thrombosis, acute onset of chronic pulmonary obstruction, acute cerebral infarction, malignant tumor, limb varicose veins, obesity, chronic kidney disease, inflammatory bowel disease, and more than 3 days of bed rest[27].
In our study, the patient was at first suspected of having thromboembolism because of similar lesions on his leg, but after a CT scan of his chest, he was diagnosed with COVID-19 and there was no evidence of pulmonary thromboembolism. The physicians at the hospital also suspected SVT and DVT due to numbness, swelling, and pain in the right leg, which were examined by Doppler ultrasound of all blood vessels, including the common iliac, small saphenous, and greater saphenous. As many studies have reported respiratory distress along with other clinical evidence of venous thrombosis, the pulmonary embolism should be suspected[28, 29].
A recent study of patients with coronavirus found that the rate of thrombotic disorders in these patients was 31%. Medical imaging has also shown that 27% of thrombosis is due to venous thromboembolism and 3.7% to arterial thrombosis. 81% related to pulmonary embolism, which is the most common complication of thrombosis. The study also found that coronavirus disease may be associated with myocardial damage, renal dysfunction, and myocardial infarction due to hospitalization and coagulation disorders[30]. The possible reasons for venous thrombosis may include the fact that the COVID-19 attacks the human body via the 2-angiotensin converting enzyme, which is found in various blood vessels and organs of the body[31]. Ultimately, coronaviruses cause cytokine waterfalls, including IL2, IL7, IL10, GCSF, IP10, MCP1, MIP1A, and TNFα in the body, which can increase the risk of complications such as blood clots. This cytokine storm can be related to the severity of the disease and its negative consequences[21, 32]. Blood clots formed in deep vein thrombosis may have a variety of causes, including vascular damage, surgery, special medications, and limited mobility,[33] but the exact cause of COVID-19-induced deep vein thrombosis is still a mystery[34].
In summary, in this case report, we present one patient with mild COVID-19 who was hospitalized with a thrombosis in his right greater saphenous vein at one of the hospitals in Sanandaj, Iran. The risk classification of deep vein thrombosis and superficial vein thrombosis are of fundamental importance for predicting the side effects of coronavirus.