Lightning Learning: Abdominal Aortic Aneurysm
AAA is the enlargement of the aortic diameter >1.5 times normal, or any infrarenal aorta >3 cm diameter. Often an incidental finding!
Normal infrarenal diameter: 1.5cm in women, 1.7cm in men
Risk factors include: Male gender, Smoking, Age, Obesity, Family history, Connective tissue disease
Suprarenal: visceral artery involvement
Pararenal: renal artery involvement
Infrarenal: begins below renal arteries (85% of AAAs)
Usually asymptomatic until rupture. 85-99% mortality. BEWARE ATYPICAL PRESENTATIONS!
Sudden onset abdominal and back pain
Palpable abdominal mass
Features of lower limb ischaemia
Low threshold for consideration in all elderly patients with sudden onset abdominal, back or flank pain.
Bedside ultrasound can be useful to assess aortic size.
Early surgical involvement is important.