Asymptomatic Giant Dissecting Aortic Aneurysm

Abstract

INTRODUCTION: Giant ascending aortic aneurysm is a rare finding, defined as an aneurysm in the ascending aorta that is more than 10 cm in diameter. Etiological factors include atherosclerosis, MarfanaTMs syndrome, giant cell arteritis, tuberculosis, syphilis, HIV-associated vasculitis, hereditary hemorrhagic telengectasia, and medial agenesis. We report a unique case of giant dissecting aortic aneurysm discovered in an asymptomatic outpatient. CASE PRESENTATION: A 33-year old asymptomatic Brazilian male with no significant prior medical history was referred to our institution for an outpatient 2D Echocardiogram after his primary physician heard a diastolic murmur on a routine office visit. To our surprise, the transthoracic echocardiogram revealed a severely dilated proximal ascending aorta with effacement of aortic valve and aortic root. An immediate transesophageal echocardiogram was performed that revealed a proximal ascending aortic aneurysm of 13.0 cm in maximal diameter with well-defined dissection flaps on either side causing severe aortic insufficiency (Fig 1). However, aortic arch and descending aorta dimensions were within normal limits with preserved left ventricular systolic function. Findings were confirmed with CT angiography. Retrospectively when interviewed, patient endorsed family history significant for MarfanaTMs in his mother. On physical examination, the patient was noted to have some Marfanoid features like buffalo hump and long arm span. On physical examination , there was a diastolic murmur, 3/6 in intensity in the aortic area. Rest of the examination was normal. The patient was then admitted to the hospital and underwent successful Bentall procedure constituting reconstruction of ascending aorta, aortic valve replacement and re-implantation of coronaries (Fig 2). DISCUSSION: The average rate of growth of thoracic aneurysms is 0.1-0.2 cm/year. Giant aneurysms can have varied presentation. The most feared complications include dissection and rupture. The risk of rupture depends on the size and the rate of growth of the aneurysm. However, an asymptomatic giant thoracic aneurysm in a young patient is extremely rare. Conservative treatment is reserved for asymptomatic aneurysms less than 6 cm in diameter. However surgery is the modality of choice for larger aneurysms.