Abdominal aortic aneurysm

Background

• Infrarenal diameter >3cm or >50% increase in size of diameter
• Rupture Risk
  • <4cm: low risk for rupture
  • 4-5cm: 5 year risk 3-12%
  • >5cm: 25-41%
  • Rupture poss at any size, most commonly >5cm

Risk Factors

1. Age
   1. Prevalence is negligible in age < 50 yrs
2. Smoking
   1. Risk factor most strongly assoc with AAA
   2. Also promotes the rate of aneurysm growth
3. Family history
4. HTN

Diagnosis

• May be asymptomatic or abdominal/back pain
• Pain + AAA = rupture until proven otherwise
• Acute abdomen + BP = possible rupture

Workup

• US (cannot see rupture)
• CT Noncon (if stable)

Treatment

1. Rupture-EMERGENT SURG/Endovasc
   1. Do not waste time for stablization --> OR
   2. T&C x 6-10U PRBCs, 4U FFP and 4U platelets
   3. Maintain BP high enough to keep asymptomatic end organ (like penetrating tauma)
   4. Do not lower BP if R/O rupture (chronic ok)
2. Asymptomatic-Incidental finding: f/u Vascular

Source

Donaldson, Bessen, H-N, UpToDate