Floating aortic thrombus is a rare condition defined as a non-adherent thrombus floating in the aortic lumen or partially attached to the inner wall of the aorta with a floating component [1,2]. It is usually associated with an aortic aneurysm or atherosclerosis, but can also occur in healthy patients, associated with various favourable factors, such as haematological disorders and other hypercoagulable states (malignancy, trauma, etc) [2,3]. Despite its high morbidity and mortality in symptomatic cases, it is an under-recognised disease in medical practice [3,4]. Floating thrombus of the aorta is responsible for embolic events during which the diagnosis is usually made. It can also be discovered accidentally or post mortem [1,3-5]. With the emergence of coronavirus 2019 (Covid-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2), there has been the issue of venous and then arterial thrombosis, making it a factor in recent thromboembolic events . An association of arterial thromboembolism with Covid-19 has been reported in the literature; however, to the best of our knowledge, few reports have addressed floating aortic thrombus in Covid-19 disease. This case aims to raise awareness of this entity among medical practitioners and radiologists.
This is a 62-year-old male soldier who was admitted to the emergency department with chest pain, polypnoea-like dyspnoea, febrile syndrome and worsening cough. The onset of symptoms was 7 days ago. He was hypertensive and had no comorbidities or history of thromboembolic events. D-dimer was elevated (1895 ng/ml) and the PCR test was positive. Imaging was ordered for suspected pulmonary embolism. A chest CT scan with contrast showed a non-adherent thrombus 13 mm long at the level of the aortic arch (Figures 1, 2) and revealed diffuse parenchymal condensations in a peripheral and basal bilateral arrangement, with neighbouring ground-glass areas and discrete traction bronchiectasis (Figures 3,4). The patient was treated with an anticoagulant for the thrombus and symptomatic treatment for the Covid-19 lesions. A two-week check-up showed that the thrombus had disappeared and the lung parenchymal lesions had almost completely regressed.
Floating aortic thrombus is rare in clinical practice, its exact incidence uncertain and most cases are diagnosed incidentally during imaging for embolic complications or at autopsy [1,2,4,5].
The pathophysiology of aortic floating thrombus remains poorly understood; however, the literature suggests that the onset of thrombus formation during Covid-19 disease will be secondary to a state of hypercoagulability due to severe haemostatic disturbances caused by severe inflammatory states associated with the disease [7,8].
The diagnosis of floating aortic thrombus in Covid-19 disease is challenging as the clinical presentation of FAT is variable and may be asymptomatic or consist of symptoms related to organic or peripheral embolism, sometimes cerebral embolism . In most cases, these thrombi were discovered during imaging studies for embolic complications, others were discovered incidentally during routine workup or autopsy [2,5].
Trans-oesophageal echocardiography is inexpensive and available. It has its place as a first-line procedure for the detection of floating aortic thrombi. It allows characterisation of atheromatous plaques, visualisation of mobile or sessile thrombi and their insertion zones [3,5]. However, a limitation is the non-visualisation of the upper portion of the ascending aorta, including the origin of the vertebral arteries [3,5].
CT with contrast is considered the examination of choice because it can clearly show a thrombus and also visualise a haematoma, aortic dissection or atherosclerosis in different segments of the aorta . It can also make the differential diagnosis of other intraluminal masses by assessing their enhancement [3, 5].
MRI angiography provides a good exploration of the aorta as does CT, although it may have false positives due to circular turbulence. But it has advantages in distinguishing aortic thrombus from vascular tumour mass [3,5].
The most unfortunate complication of floating aortic thrombus is embolism, which can lead to cerebral (stroke), limb or mesenteric ischaemia. Several authors have reported cases of perforation .
Treatment of floating aortic thrombus should be initiated promptly after detection because of the high risk of massive systemic embolism. The optimal approach to its treatment remains unclear. There are several options for treatment of thrombus: use of anticoagulants, thrombolytics and thrombectomy. However, the literature suggests surgery rather than other treatment options .
Currently, there are no clear guidelines for the optimal treatment of floating aortic thrombus in Covid-19 [6,9].
Conflict of Interest: The authors declare that they have no conflicts.