thoracic aortic aneurysm

Question 1

what is an aneurysm?

Answer 1

a persistent, abnormal dilatation of an artery to 1.5 times its normal diameter.

Question 2

what parts of the vessels can a thoracic aortic aneurysm involve, which is the most common and which has the highest mortality?

Answer 2

ascending aorta (most common)
aortic arch
descending aorta
thoracoabdominal aorta

thoracic aneurysms have the highest mortality

Question 3

how do thoracic aortic aneurysms occur?

Answer 3

develop due to degradation of the tunica media, the layer of the artery which provides tensile strength and elasticity to the wall.

artery loses structural integrity and dilates, and as the diameter increases, the wall tension rises and further increases the diameter in a vicious cycle.

Question 4

what are the main causes of a thoracic aneurysm ?

Answer 4

• CT disease e.g mafans and Ehlers danlos
• bicuspid aortic valve
• trauma
• aortic dissection
• aortic arteritis
• dissected aneurysm

Question 5

what are the risk factors for a thoracic aortic aneurysm?

Answer 5

• FH
• hypertension
• atherosclerosis
• smoking
• high BMI
• male
• advancing age

Question 6

what are the clinical features of TAA?

Answer 6

asymptomatic generally and found incidentally

• Pain location shows location of aneurysm

ascending aorta = anterior chest
aortic arch = neck
descending aorta = between the scapulae

also get

• back pain secondary to spinal compression
• hoarse voice from arch aneurysms on left recurrent laryngeal nerve
• distended neck veins due to SVC compression
• symptoms of HF from aortic valve involvement
• dyspnoea or cough secondary to tracheal/bronchial compression

if acute, pain is sudden onset

Question 7

what are your differentials for a TAA?

Answer 7

usually found incidentally on imaging

if symptomatic, present with chest pain, can suggest

• ACS
• PE
• pneumothorax
• aortic dissection

Question 8

what investigations are done into TAA?

Answer 8

• routine bloods (FBC, U&Es, clotting)
• ECG
• CXR

imaging
- CT chest scan with contrast if preferred

• Transoesophageal echocardiography (TOE) can be used to further detect any concurrent aortic insufficiency or dissection
• CXR will show but isn’t sensitive enough for definitive diagnosis

Question 9

how is a TAA managed medically?

Answer 9

start on medical management

• Statin and anti platelet therapy to decrease MI risk
• BP control
• smoking cessation

Question 10

when would a TAA be managed surgically?

Answer 10

depends on location of aneurysm

If suffering from CT disorder or have a previous aortic thoracic dissection, threshold for intervention are usually lower

for Asending aorta and aortic arch, once aneurysm is >5.5cm, surgery is considered for replacement with graft

descending aorta, intervention is indicated after 6cm