Name : Hamidreza
Affiliation : Radiology department,ShohadaTajrish Hospital,SBMU
Academic Degree: Associate professor of Radiology
Resident : Ramin Pourghorban
Gender : Female
Age : 47
47 year old female with left upper limb ischemia
Imaging Procedures and Findings
CT angiogram after contrast medium injection via the right upper extremity (combined images 1-4) reveals a 22*8 mm thrombosis in anterior left side of the aortic arch distal to the origin of left CCA. The floating clot is well depicted in the aortic arch and extends into the left subclavian artery where it causes complete occlusion shortly after the origin of artery. The arterial run off in the left axillary artery is evident. Also noted is the extension of the colt into the left vertebral artery till the level of the mandibular angle. Notice the filling defect in the left vertebral artery compared to the right side. Three days after, the patient experienced loss of consciousness and brain MRI (images 6-10) obtained. Multiple iso T1 and high T2 signal intensities with restricted diffusion are detected in right thalamus, left basal ganglia, both parietal lobes and both cerebellar hemispheres. These findings are consistent with acute brain infarcts due to emboli from the above mentioned clot.
Floating thrombus in the aortic arch is an unusual source of systemic embolism. Surgical removal of the thrombus is a therapeutic option, because thrombolytic therapy carries the risk of partial lysis and repeat embolization. Formation of friable floating thrombus, especially in the proximal aortic arch, creates a life-threatening risk of stroke, as well as peripheral embolization. Treatment is mandatory, once the diagnosis is established. When the floating thrombus is near the branches of the aortic arch, special thought must be given to therapeutic strategy. Many factors, such as atherosclerosis, dissection, trauma, malignancy, and coagulopathies, have been associated with aortic mural thrombi. Even though some collected cases of mural thrombus in the ascending aorta and the proximal aortic arch have been reported, there have been only a few reported cases of friable floating thrombus in the aortic arch, and in those the base of the thrombus was the aortic isthmus or the ligamentum arteriosum. Thrombolysis has been suggested as a promising therapy for aortic thrombus, and in some cases heparin and warfarin have led to complete resolution in 3 months. However, long-term anticoagulation for the complete resolution of a floating, friable thrombus carries unacceptable risk of partial lysis and distal embolization. A thrombus in the distal aortic arch can be removed under extracorporeal circulation while the heart is beating, but a more conservative surgical option is necessary for the excision of thrombi in the proximal or middle aortic arch.
Floating clot in the aortic arch with extension into the left subclavian and left vertebral arteries and subsequent brain infarcts due to emboli
Choi JB, Choi SH, Kim NH, Jeong JW. Floating thrombus in the proximal aortic arch. Tex Heart Inst J. 2004; 31(4):432-4.