OzEMedicine - Wiki for Australian Emergency Medicine Doctors

see also:

• vascular surgery
• aortic dissection
• abdominal aortic aneurysm (AAA)
• ANZSVS patient information on TAAs and AAAs

• aneurysm of the thoracic aorta is much less common than abdominal aortic aneurysm (AAA) and mainly occurs in those over the age of 60 yrs, although may occur in patients younger than 40yrs if they have a predisposing condition
• they are rare, occurring in approximately 6-10 per every 100,000 people.
• a dilated thoracic aorta is defined as having a diameter greater than 3.5cm, however in young or small adults, the descending aorta upper limit may be regarded as being 2.3cm, while in larger adults or the elderly, the upper limit for the ascending aorta may be regarded as being 4.3cm
• a diameter greater than 4.5cm is regarded as aneurysmal and needs 6-12 monthly monitoring
  • some place these patients on statins, ACE inhibitors and beta adrenergic blockers to try to slow the rate of dilatation
• surgery is offered when the risk of rupture is greater than the risk of the operation
  • thoracic aneurysms are much more difficult to repair and carry much greater risks from treatment than do abdominal aortic aneurysm (AAA)
  • elective surgical repair carries a 5% mortality rate
  • those larger than 6cm should be considered for endovascular or surgical intervention as they have much higher risks of rupture
  • those with Marfan's are often advised to have surgery once it reaches 4.5cm or if one is undergoing heart valve surgery

• 10-20% are familial
• risk is higher if:
  • aneurysms elsewhere
  • PH aortic dissection or blunt trauma
  • age > 65yrs
  • male (3x risk)
  • smoker
  • hypertension
  • hyperlipidaemia
  • connective tissue (CT) disorders
  • Loeys-Dietz Syndrome
  • Turner Syndrome
  • syphilis
• ascending aorta
  • usually in younger patients with:
    • connective tissue (CT) disorders such as Marfan's, Ehler's Danlos, or Loeys-Dietz Syndrome and Turner Syndrome
    • following an aortic dissection or blunt trauma
• aortic arch
  • atherosclerosis and primary prevention
  • following an aortic dissection
  • inflammatory such as syphilis, Salmonella
• descending thoracic aorta
  • usually in elderly patients due to atherosclerosis and primary prevention

• most are asymptomatic and found incidentally on CXR, echo or CT scan
• as they enlarge, some may cause:
  • chest pains, back pains, cough, SOB
  • dysphagia due to compression of the oesophagus
  • hoarse voice due to stretching of the recurrent laryngeal nerve
• those with an impending potentially fatal complication such as rapid enlargement, tear or dissection
  • may present with severe chest pain as per aortic dissection
  • some may present with epigastric pain rather than chest pain
  • once bleeding occurs, the patient may present with hypotension, shock, raised inflammatory markers including raised C reactive protein (CRP) which may mimic septic shock, and may also cause nausea, vomiting, dizziness, clamminess and even haemoptysis (aorto-bronchial fistula), or haematemesis (aorto-oesophageal fistula)
  • once rupture occurs, mortality is 70-80%
    • some cease bleeding temporarily or survive long enough to allow emergency Open Aneurysm Repair which has a high rate of complications and only a 50% survival rate albeit with a prolonged recovery with lengthy ICU care being required. ¹⁾

• refer back to GP to arrange:
  • non-urgent CT aortogram (or perhaps echocardiogram)
  • referral to vascular surgeon as needed, especially if either:
    • greater than 6cm diameter, or,
    • cardiac valve surgery being considered, or,
    • Marfan's syndrome and diameter > 4.5cm
  • otherwise if greater than 4.5cm diameter:
    • 6-12 monthly surveillance
    • consider statins, ACE inhibitors and beta adrenergic blockers to try to slow the rate of dilatation

• urgent CT aortogram to exclude complications
• if dissection or rupture evident, see as for aortic dissection
• if no complication evident but symptomatic, discuss with vascular surgeon