Archived case 183 · September 3-September 10, 2015
Ascending Aortic Aneurysm related to Bicuspid Aortic Valve
53 yo man with Chest Pain
The question posed to readers
What are the pertinent imaging findings? What is the likely etiology in this case?
Images
Imaging findings
Radiologic Findings: Selected axial and coronal images of the chest demonstrate aneurysmal dilation of the ascending aorta measuring to 52 mm at the level of the main pulmonary artery (Figure 1). More inferiorly, marked calcific plaque deposition is seen within the left coronary cusp and right coronary cusp of the aortic valve (Figure 2). The ascending aorta at the sinuses of Valsalva also demonstrates dilatation to 47 mm (Figure 3) (write-up provided by Daniel Chu; VCU department of Radiology) Answer Diagnosis: Ascending Aortic Aneurysm related to Bicuspid Aortic Valve
Diagnosis
Ascending Aortic Aneurysm related to Bicuspid Aortic Valve
Discussion: An aortic aneurysm is an abnormal, irreversible dilatation of the aorta to greater than 50% of normal size. These can occur in either the thorax or abdomen and can be classified as true aneurysms (involving all 3 layers of the aortic wall) or false aneurysms (pseudoaneurysms). Most thoracic aneurysms involve the descending aorta and are the result of atherosclerosis. However, multiple other infectious, rheumatologic, congenital, traumatic, or iatrogenic etiologies are also responsible.
On average, the diameter of the ascending aorta (extending from the aortic root to the origin of the right brachiocephalic artery) normally measures 31 +/- 4mm. The diameter of the aortic root (the portion of the ascending aorta containing the aortic valve, annulus, and sinuses of Valsalva) normally measures 37 +/- 3mm. Imaging findings can be varied. Often, chest radiographs will demonstrate a widened superior mediastinum, abnormal contour of the aorta, elevation of the aortic-pulmonary stripe, or extrinsic compression of the trachea, bronchi, or esophagus. CT can often show the extent of dilation, presence/absence of thrombus, and complications such as dissection or rupture.
Most patients with thoracic aortic aneurysms are asymptomatic. Some may present with chest, shoulder, or back pain. Compression of adjacent mediastinal structures may also produce characteristic symptoms such as dyspnea, stridor, or hoarseness.
Bicuspid aortic valvular disease is the most common congenital heart defect. Depending on the severity of disease, complications may be seen from childhood throughout adulthood (typically before the age of 65). Dilation of the proximal ascending aorta is the most common associated finding. Other associated complications include aortic stenosis, aortic insufficiency, and endocarditis. Imaging findings may demonstrate calcification of the aortic valve leaflets, cardiomegaly, left ventricular hypertrophy, and post-stenotic dilatation of the ascending aorta.
Selected Readings:
• Parker MS, Rosado de-Christenson ML, Abbott GF. Adult Cardiovascular Disease: Thoracic Aorta Aneurysm. In: Chest Imaging Case Atlas, Thieme New York 2012; 655-662.
• Parker MS, Rosado de-Christenson ML, Abbott GF. Adult Cardiovascular Disease: Aortic Stenosis: Bicuspid Aortic Valve. In: Chest Imaging Case Atlas, Thieme New York 2012; 682-685.
Siu SC, Silversides CK. Bicuspid Aortic Valve Disease. J Am Coll Cardiol. 2010;55(25):2789-2800.
Original case written by its authors at Virginia Commonwealth University and published at this address as part of a weekly teaching collection. Reproduced here as an archive.