Thoracic Aortic Aneurysm

The Common Vein Copyright 2007

Ashley Davidoff MD

Aortic aneurysym is a condition characterized by a bulging of the aortic wall and associated symptoms. 2-5% of aneurysms occur in the thoracic aorta

Cause

Caused by arteriosclerosis, aortic trauma, aortic inflammation, heredity, and syphilis. atherosclerosis destroys medial elements

Pathogenesis

atherosclerosis causes weakening of wall aorta dilates tension increases acceleration of the process Laplace’s Law: tension is proportional to the product of pressure and radius)

Result

Dilation can occur anywhere along the thoracic aorta Most common sites are the arch and descending aorta

Natural History

Five year survival in one study was 27% for symptomatic and 58% for asymptomatic thoracic aneurysms

Complications

Rupture of an aneurysm is heralded by the dramatic onset of excruciating pain Aneurysms greater than 7 cm are more prone to rupture than smaller ones and symptomatic ones are more prone to rupture than asymptomatic ones

Diagnosis

Clinical

Symptoms are secondary to impingement on adjacent structures Tracheal deviation , stridor, hemoptysis, dyspnea, pneumonitis from compression of the tracheobronchial tree, hoarseness from compression of the laryngeal nerve, dysphagia from esophageal compression, SVC syndrome, and pain is due to compression and erosion on musculoskeletal structures and is usually steady and may be severe

Imaging

Treatment

Elective resection is recommended for thoracic aneurysms greater than 6 and in some institutions 7 cm in diameter, 2 times normal diameter, or if symptomatic Major operative complications include paraplegia from inadvertent interruption of the spinal cord’s arterial blood supply (5%) and those secondary to associated arteriosclerosis (MI, CVA, renal failure, etc.)