Defined as a dilated aorta more than150% greater than its normal diameter.
More than 4.5 cm in diameter is considered a thoracic aneurysm.
May affect the ascending, arch or descending thoracic aorta.
Approximately 25% of such patients have a concomitant abdominal aortic aneurysm.
Most frequently from degeneration of the media of the aortic wall.
There is an increase in incidence of thoracic aortic aneurysm, which is commonly an incidental finding on imaging studies form for various reasons.
Degeneration of the media leads to cystic medial necrosis with damage to the collagen, and elastin with smooth muscle cell loss, and increased ground substance in the medial layer.
The ascending aorta is most affected by cystic medial necrosis.
The descending thoracic aneurysms are related primary due to atherosclerosis.
Many patients have mutations in the gene responsible for lipoprotein abnormality found in Marfan’s syndrome but don’t have the Marfan’s syndrome.
Up to 75% of patients with a bicuspid aortic valve have evidence of cystic medial necrosis.
Thoracic aneurysm-inherited forms of medial degeneration are associated with defects in genes for fibrillin.
Inherited forms of medial degeneration are associated with defects in genes for fibrillin.
The onset of symptoms may indicate an expanding thoracic aortic aneurysm, with eminent serious complications such as dissection and rupture.
Surgical intervention is indicated for a symptomatic thoracic aortic aneurysm to minimize complications, regardless of the diameter of the aneurysm.
Treatment of asymptomatic thoracic aortic aneurysm involves weighing the risk of complications with expanding thoracic aortic aneurysm against the risk of prophylactic surgical intervention.
Presently the cut off guideline for prophylactic surgical intervention in patients with asymptomatic thoracic aneurysm of based on observational studies and is not definitive.
In a study of elective thoracic aortic aneurysm repair repair it was found there was a lower in hospital mortality and morbidity compared to when there is a clinical presentation of an aneurysm associated acute aortic syndrome (Elbadawi,A).