1. Aortic Aneurysm and Dissection

📄 Definitions

  • Aortic Aneurysm: Pathological dilatation of the aorta (>1.5× normal diameter).

    • Abdominal Aortic Aneurysm (AAA): Most common; below renal arteries.

    • Thoracic Aortic Aneurysm (TAA): Less common; higher rupture risk.

  • Aortic Dissection: Tear in intima causes blood to track between layers.

    • Stanford Type A: Ascending ± descending aorta (surgical emergency)

    • Stanford Type B: Descending aorta only (medical management)

🔍 Risk Factors – Mnemonic: BAD AORTA

  • Blood pressure (hypertension)

  • Atherosclerosis

  • Disorders connective tissue (Marfan, Ehlers-Danlos)

  • Age >65

  • Obstructive vascular disease

  • Renal disease

  • Tobacco use

  • Aortic valve disease / bicuspid valve

🩺 Clinical Features

Aneurysm (AAA)

  • Often asymptomatic (screening important)

  • Pulsatile abdominal mass

  • Abdominal/back pain

  • Sudden collapse if ruptured (triad: pain + hypotension + mass)

Dissection

  • Sudden tearing chest/back pain

  • Pulse deficit or BP discrepancy

  • Syncope, stroke signs, limb ischaemia

  • Murmur of aortic regurgitation

  • Shock (if rupture or tamponade)

Investigations

🥇 First-Line

  • AAA: Bedside abdominal ultrasound

  • Dissection: CT angiography (CTA) – gold standard

🥈 Second-Line

  • ECG – rule out MI

  • Chest X-ray – widened mediastinum (dissection)

  • Bloods: FBC, U&Es, troponin, d-dimer (may be raised)

  • Echo – transoesophageal (TOE) for proximal dissection

Management – Mnemonic: DISSECT

  • Drop BP (IV beta-blocker – e.g. labetalol)

  • Imaging urgently (CTA)

  • Surgical consult – Type A = surgery, Type B = medical

  • Stabilise – IV access, fluids cautiously

  • ECG + labs

  • Control pain (opiates)

  • Treat complications (tamponade, MI, stroke)

⚠️ Complications

  • AAA rupture → fatal haemorrhage

  • Aortic dissection → cardiac tamponade, stroke, renal failure

  • Ischaemic bowel or spinal cord infarction

🔺 Last updated in line with NICE NG156 – Abdominal aortic aneurysm: diagnosis and management

Published: March 2020 • Last updated: August 2022

  • PARA-aligned, reviewed February 2026


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Educational platform. Not medical advice.

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