Aortic Dissection

• What occurs during aortic dissection?


  A tear in the tunica intima leads to blood collecting between the intima and media layers of the aorta.
• What are the risk factors for aortic dissection?


  Risk factors include hypertension, connective tissue diseases, and cocaine or amphetamine usage.
• How are dissections classified?

  Dissections are classified as Stanford Type A or B.
• What does Stanford Type A dissection involve?


  Stanford Type A involves the ascending aorta and possibly the aortic arch.
• What is the typical presentation of aortic dissection?


  The typical presentation is tearing chest pain that radiates to the back.
• What is the usual diagnostic investigation for aortic dissection?


  CT angiography is the usual diagnostic investigation.
• What is the management approach for aortic dissection?


  Management involves medical management of hypertension, analgesia, and urgent referral to the vascular team.
• How do Type A and Type B dissections differ in treatment?


  Type A dissections are typically treated surgically, while Type B may be treated with TEVAR.
• What are some complications of aortic dissection?


  Complications include acute aortic valve regurgitation, cardiac tamponade, stroke, and myocardial infarction.
• What is the most common risk factor for aortic dissection?


  Hypertension is the commonest risk factor, seen in 50-75% of patients.
• What are the other risk factors for aortic dissection?

  • Smoking
  • Hypercholesterolaemia
  • Male sex
  • Older age
  • Pregnancy
  • Sudden increase in blood pressure (e.g., cocaine abuse, weightlifting)
  • Bicuspid aortic valve
  • Coarctation of the aorta
  • Connective tissue disorders (e.g., Ehlers-Danlos or Marfan's Syndrome)
  • History of cardiac surgery
• What does the DeBakey classification system for aortic dissection include?


  DeBakey classification includes Type I, Type II, and Type III dissections.
• What is the classic symptom of aortic dissection?


  The classic symptom is sudden onset "tearing" or "ripping" chest pain that radiates to the back.
• What percentage of patients may present without pain during aortic dissection?


  1. 15% of patients may present without pain.
• What are the other symptoms of aortic dissection?


  • Syncope
  • Acute leg weakness or sensory loss
  • Abdominal pain due to mesenteric ischaemia
  • Anginal pain due to coronary artery involvement
  • Limb ischaemia (e.g., pallor, loss of sensation)
  • Symptoms of a stroke (e.g., dysphasia)
  • Haematuria due to renal artery involvement
• What are the signs on examination for aortic dissection?


  • Hypertension (hypotension may occur later)
  • Radio-radial delay
  • Blood pressure differential between arms (>20mmHg is significant)
  • Diastolic murmur due to acute aortic regurgitation
  • Neurological signs (e.g., weakness, paraesthesia)
• What is a differential diagnosis for aortic dissection?


  Myocardial infarction may be mistaken for aortic dissection due to chest pain.
• Why is it critical to differentiate myocardial infarction from aortic dissection?


  Misdiagnosis can lead to catastrophic consequences if treated with thrombolysis or antiplatelet therapy.
• What are some bedside tests for aortic dissection?


  ECG, blood gas, and echocardiography are bedside tests for aortic dissection.
• What is the key investigation for diagnosing aortic dissection?


  A CT angiogram is the key investigation.
• What blood tests are performed for aortic dissection?


  • Full blood count to check haemoglobin
  • U&Es for renal impairment
  • LFTs for liver dysfunction
  • Coagulation screen for coagulopathy
  • Crossmatch for blood transfusion
  • Troponin for myocardial ischaemia
  • D-dimer to rule out dissection in low-risk patients
• What imaging techniques are used for aortic dissection?


  • CT angiogram (urgent diagnosis)
  • Chest X-ray (to look for differentials)
  • MRI angiogram (higher sensitivity and specificity)
• What is the conservative management for aortic dissection?


  • Urgent referral to the vascular team
  • Cardiac monitoring for ischaemic changes
  • Arterial line for invasive blood pressure monitoring
  • Cautious fluid resuscitation if required
• What is the first-line medical management for aortic dissection?


  IV beta-blockers (labetolol) are the first-line treatment for hypertension and tachycardia.
• What is the target systolic blood pressure for aortic dissection management?


  The target systolic blood pressure is 100-120 mmHg.
• What surgical intervention is required for Stanford Type A dissections?


  Urgent cardiothoracic surgery is required for Stanford Type A dissections.
• What does surgical management for Stanford Type A dissections involve?


  • Removal of the ascending aorta and replacement with a synthetic graft
  • Possible aortic arch replacement
  • Re-implantation of involved aortic branches into the graft
• What is the first-line treatment for Stanford Type B dissections?


  Thoracic endovascular aortic repair (TEVAR) is the first-line treatment for Type B dissections.
• When might Type B dissections require open surgery?


  Type B dissections may require open surgery in cases of organ ischaemia, refractory pain, or rapidly expanding aortic diameter.
• What are the complications of aortic dissection?

  • Myocardial infarction
  • Cardiac tamponade
  • Aortic regurgitation
  • Mesenteric ischaemia
  • Renal failure
  • Stroke
  • Limb ischaemia
  • Paraplegia
  • Aortic rupture
  • Aortic aneurysm formation
  • Death
• What is the mortality rate from aortic dissection if treatment is delayed?


  Mortality increases by 1-2% per hour if treatment is delayed.
• What percentage of patients die before reaching the hospital due to aortic dissection?


  Over 20% of patients die before reaching the hospital.
• What is the mortality rate if the aorta ruptures?


  The mortality rate is 80% if the aorta ruptures.
• What may develop in patients with stable Type B dissections?


  Patients may develop aortic aneurysm, occurring in approximately 25% of patients.