7.TB can sometimes lead to thoracic aortic aneurysm.
Degenerative changes in the wall of the aorta lead to cystic medial necrosis. This causes damage to collagen and elastin, loss of smooth muscle cells and increased amounts of basophilic ground substance in the medial (elastic) layer of the aorta. The ascending TAA is usually more affected by cystic medial necrosis. Descending aortic aneurysm is a primary consequence of Atherosclerosis .
In Marfans syndrome fibrillin gene mutation is responsible for this structural lipoprotein changes causing dilatation of aortic wall.
75% of bicuspid aortic valve have evidence of cystic medial necrosis.
Usually aneurysms of Fusiform nature is true aneurysm .In this all the layer of aorta is involved.
In pseudoaneurysm-saccular type a small blister or bleb present on the side of aorta .
If symptoms occurs ,it may be due to copression of trachea causing wheezing, dyspnea, cough, hemoptysis, or recurrent pneumonitis.
Compression of esophagus causes dysphagia .
Compression of recurrent laryngeal nerve causing hoarseness of voice.
Vascular consequences include aortic regurgitations due to dilatation of aortic root,Thromboembolism causing stroke, lower extremity ischemia, renal infarctions, or mesenteric ischemia also can occur .
Angina sometimes occurs in one quarter of patients due to direct compressions of intra thoracic structures or erosions into bones.Typicaly the pain is steady, deep, boring and at times severe .
X-Ray chest- Mediastinal widening .
CT -Less accurate .
MRI -Very accurately detect and size thoracic aneurysms.
Transthoracic aorta is an excellent modality for imaging the aortic root.
Trans esophageal echo is an excellent for Visualization for entire aorta. Not usually done because of it semi invasive nature .
CONTRAST AORTOGRAPHY is the best investigation for Aneurysm of aorta .
Long term Beta blocker therapy.And control of hypertension.
Operative repair with placement of prosthetic graft is indicated in patients with symptomatic thoracic aortic aneurysm and in patients with aortic diameter of >5.5 to6 cm or has increasing by>1cm per year .
Surgical repair with synthetic graft or own blood vessel graft can be done.