Epidemiology

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Etiology

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• Risk factors
  • Smoking (most important risk factor)
  • Advanced age
  • Male sex
  • Atherosclerosis (ASCVD)
  • Hypercholesterolemia and arterial hypertension
  • Positive family history
• Localization
  • Infrarenal: below the renal arteries
    • Most common location

Pathophysiology

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Characteristic	Abdominal Aortic Aneurysm (AAA)	Aortic Dissection
Definition	Localized dilation of abdominal aorta >3cm	Tear in aortic wall creating false lumen
Risk Factors	Smoking (most important), male, hypertension, age >65, family history	Hypertension (most important), Marfan syndrome, bicuspid valve, pregnancy
Pathophysiology	Progressive weakening of arterial wall due to elastin degradation and inflammation; atherosclerosis leads to oxidative stress and matrix metalloproteinase activation	Intimal tear allows blood to enter media, creating false lumen; can be triggered by hypertensive crisis or inherited connective tissue disorders
Onset	Gradual	Sudden, acute
Pain	Usually asymptomatic; may have dull abdominal/back pain	Severe, tearing chest/back pain; migrating
Physical Exam	Pulsatile abdominal mass	Unequal pulses, BP differences between arms
Complications	Rupture with hemorrhagic shock	Organ ischemia, tamponade, aortic rupture
Imaging	Ultrasound, CT with contrast	CT angiogram, TEE
Treatment	Endovascular repair (EVAR) or open surgery if >5.5cm	Emergency surgery (Type A), medical management (Type B)
Mortality	80% if ruptured; 5% with elective repair	50% at 48h without treatment (Type A)

Clinical features

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Diagnostics

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Treatment

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