Thoracic Aortic Aneurysm Flashcards
Define thoracic aortic aneurysm
Dilation of the thoracic aorta.
Is generally considered at greater than 4.5cm in the ascending aorta and greater than 3.5cm in the descending aorta.
True aneurysm is a dilation of all three layers.
What is the aetiology of thoracic aortic aneurysm?
Neural crest cells give rise to smooth muscle cells in the thoracic aorta.
Abnormalities in the structural integrity of the wall can predispose to aneurysm formation - apoptosis or reductions in elastin, collagen and glycosaminoglycans.
MMPs, inflammation, RAAS and immune cells can all play a role in this process.
What are the risk factors for thoracic aortic aneurysm?
Marfan syndrome + Ethlers Dandlos syndrome
Familial bicuspid aortic valve syndrome
HTN
Smoking
Male
Increased age
Existing cardiovascular disease
What are the signs and symptoms for thoracic aortic aneurysm?
Typically are clinically silent until rupture or dissection.
Rupture presents with - hemodynamic instability and collapse, back pain, chest pain and aortic valve insufficiency.
Pre-rupture symptoms - compression on nearby structures - horseness of voice (recurrent laryngeal nerve), SOB/wheezing, coughing (left bronchus) and dysphagia (oesophagus), hiccups (phrenic nerve).
What is the medical treatment for thoracic aortic aneursym?
Titrate beta-blockers and ARBs to help reduce BP/HR
What is meant by a thoracoabdominal aortic aneurysm?
When a thoracic aneurysm extends below the diaphragm continuing into the abdominal aorta
Occurs in 10% of cases.
How is thoracic aortic aneurysm typically diagnosed?
Incidentally - CXR?CT - widened mediastinal section, enlarged arotic knuckle.
Screening process in patients with Elthlers Dandlos/marthan/loeys-dietz or first/second degree relative with sudden unexplained cardiac-related death and family history of aneurysmal disease.
What is the conservative management for a thoracic aortic aneurysm?
Avoid isometric exercise - can inc intra-thoracic pressure.
Stop smoking
Health diet and exercise
Optimise the management of HTN, DM and hyperlipidemia.
Transthoracic echo at diagnosis
CT angiogram - for whole aorta - inc prob of dilation elsewhere
Monitor at 6 months, then annually.
If aneurysm enlarges to within 0.5cm of size recommended for surgery then inc surveillance to twice yearly.
What surgical management is used for a thoracic aortic aneurysm?
Aortic resection and inter-position graft - open surgery
Thoracic endovascular aortic repair (TEVAR) - inserts a stent
Norm when ascending or root reaches 5.5cm or grows more than 0.5cm in a year.
If connective tissue disorder recommended at 5cm (4.5cm if other high risk features such as family history of young age sudden cardiac death).
What are some common complications of a TAA?
Aortic dissection
Ruptured aneurysm
Aortic regurgitation
What is the typical description of pain of an aortic dissection?
Acute, severe tearing sensation central in the chest
Reach maximum intensity within minutes.
