Recurrent systemic embolism caused by thoracic aortic thrombus

A 49-year-old man was admitted for abdominal pain. His previous medical history included metabolic syndrome, cholecystectomy, a motorcycle accident several years ago and ongoing tobacco smoking. Physical examination was normal aside from right lower quadrant abdominal pain on palpation. Laboratory tests showed renal insufficiency (serum creatinine = 1.7 mg/dL) and elevated acute phase reactants consistent with an inflammatory syndrome (C-reactive protein = 44 mg/dL). Laboratory analyses for thrombophilia were unremarkable. Abdominal ultrasound and a non-contrast computed tomography (CT) scan were normal; however, a computed tomographic angiogram (CTA) showed complete right renal infarction resulting from right renal artery thrombosis (Panel A). A second CTA (Panel B) and transesophageal echocardiography (TEE) revealed a 7 cm mobile pedunculated thrombus located within the distal aortic arch.

Panel A Panel B

Despite effective anticoagulation treatment with intravenous heparin, the patient developed recurrent, now left-sided, abdominal pain related to incomplete splenic infarction, which was confirmed by CTA (Panel C). The patient was referred for surgery and underwent replacement of the aortic isthmus and the initial segment of the descending thoracic aorta by an 8 cm aortoaortic tube graft. The procedure was performed via a left posterolateral thoracotomy under partial cardiopulmonary bypass via right femoral arteriovenous access. Macroscopic examination of the aorta revealed an atheromatous, thickened and calcified aortic wall with two pedunculated mural thrombi (Panel D). At 5 months’ follow-up, he had no recurrent thrombo-embolic events. Unfortunately, renal failure was still present due to a single functional left kidney and persistent contrast-induced kidney injury resulting from repeated CTA examinations.

Panel C Panel D

Aortic mural thrombi have been found to represent 5–10% of the causes of peripheral arterial embolic events. ¹ They predominantly occur in pathological aortic segments at the site of aneurysm, atherosclerotic plaque or dissection. ¹ Some cases have been reported in patients with macroscopically normal aorta, generally associated with underlying pathologies such as coagulopathies or malignancy. ² Various aortic locations have been described but the abdominal aorta is the most frequent. Accordingly, aortic imaging with TEE, CTA or magnetic resonance imaging should be performed in patients without an identifiable cardiac source of peripheral embolization. While optimal treatment remains controversial, systemic anticoagulation is widely accepted as the first-line therapy – with surgical thrombectomy or endovascular thrombus exclusion with stent grafting as options for patients with recurrent events. ²

‘Images in vascular medicine’ is a regular feature of Vascular Medicine. Readers may submit original, unpublished images related to clinical vascular medicine. Submissions may be sent to: Heather L Gornik, Editor in Chief, Vascular Medicine, via the web-based submission system at http://mc.manuscriptcentral.com/vascular-medicine