Letter to the Editor Unexplained thrombosis of the aortic arch with distal embolization in a patient with altered fibrin clot properties Tomasz Ciurus1, Anetta Undas2, Malgorzata Lelonek1 1Department of Cardiology, Chair of Cardiology and Cardiac Surgery, Medical University of Lodz, Poland 2Institute of Cardiology, Jagiellonian University School of Medicine, Krakow, Poland Submitted: 18 January 2011 Accepted: 26 July 2011 Arch Med Sci 2012; 8, 4: 733-735 DOI: 10.5114/aoms.2012.30298 Copyright © 2012 Termedia & Banach The pathophysiology of arterial thrombosis in young patients remains unclear. Traditional cardiovascular risk factors explain not more than 50% of cases of arterial thrombosis [1]. It is known that arterial inflammation, autoimmune diseases, endothelial dysfunction, atherosclerosis, blood flow abnormalities, and finally, altered platelet function, coagulation or fibri- nolysis predispose to arterial thrombosis. The common thrombophilic fac- tors, factor V Leiden and prothrombin G20210A polymorphism, are incon- sistently associated with arterial thrombosis [2]. Growing evidence indicates that the structure of a fibrin clot composed of compact thin fibrin net- works can predispose to arterial thrombosis [3]. However, a role of abnor- mal fibrin clot characteristics in arterial thrombosis different from coro- nary artery thrombosis is unknown. Aortic arch thrombosis (AAT) is a rare pathology and generally is associated with diffuse atherosclerosis of the aortic arch in elderly patients, aortic aneurysm or dissections [4]. Howev- er, mobile thrombi in the aortic arch have also been reported in younger patients [5]. We report here a young man who developed unexplained AAT and sub- sequent emboli to the lower limbs and, importantly, we detected novel prothrombotic fibrin alterations that may be behind this thrombosis. A 35-year-old man, with no medical history (normal arterial, diabetes mellitus, lipid disorders, no smoking, normal weight) was admitted to the hospital due to paresis of the lower extremities. The patient was para- plegic; femoral and distal pulses were nonpalpable. Computed angiogra- phy showed an intraaortic mass which straddled the aortic bifurcation and extended to just below the renal arteries, indicative of a thrombus. Urgent embolectomy and fasciotomy in both lower extremities were performed. An electrocardiogram showed a regular sinus rhythm at 70 beats/min, with no history of atrial fibrillation. Routine laboratory investigations did not show any abnormalities, with a normal value of blood lipids. C-reac- tive protein level was 2.82 mg/l and fibrinogen 4.11 g/l. Thrombophilia screening, including prothrombin gene 20210A mutation, factor V Leiden, lupus anticoagulant, antiphospholipid antibodies, protein C, free protein S and antithrombin, yielded negative results. Interestingly, his mother underwent embolectomy of the aortic arch and brachiocephalic trunk, when she was 42 years. In search for causes of arterial thrombosis one month after surgery, transoesophageal echocardiography was performed and revealed in the aortic arch a pedunculated mass of 2.6 cm × 1.3 cm, with no visible ath- erosclerotic plaques. Cardiac magnetic resonance imaging (MRI) showed Corresponding author: Assoc. Prof. Malgorzata Lelonek MD, PhD, FESC Department of Cardiology Chair of Cardiology and Cardiac Surgery Medical University of Lodz 1/3 Sterling 91-425 Lodz, Poland Phone/fax: +48 42 636 44 71 E-mail: mlelonek@poczta.fm