Approach

Patients most commonly lack any symptoms and their aneurysm is noted on physical examination or imaging studies performed for other reasons.

History

In the minority of patients who experience symptoms, abdominal, back, and groin pain are typical. Medical history is directed toward risk factors:

  • Development (i.e., hyperlipidemia, connective tissue disorder, COPD, and hypertension)[1][5][13][15][22][58][59][63][70]​​

  • Expansion (i.e., previous cardiac or renal transplant, previous stroke, advanced age [>70 years], and severe cardiac disease)[71][72][73]

  • Rupture (i.e., female sex, previous cardiac or renal transplant, hypertension).[13][54][55][73]​​[74][75]​​

A history of cigarette smoking increases a patient's risk of AAA development, expansion, and rupture.[5][13][22][23][43][75]​​​​ In men who have never smoked, important risk factors for AAA include older age and a first-degree relative with AAA.[3][4]

A history of previous abdominal surgery or previous endovascular aortic aneurysm repair can be elicited as well as family history of AAA.

Physical examination

The abdomen can be palpated for a pulsatile abdominal mass and abdominal tenderness. Physical exam should include an assessment for peripheral artery aneurysm (femoral and popliteal).[76]

Aneurysm palpation on clinical examination has only been shown to be sensitive in thin patients and those with AAA >5 cm, with an overall sensitivity and specificity of 68% and 75%, respectively.[1][77] Detection rates are affected by aortic diameter, clinician experience, and body habitus of the patient.[3] The sensitivity of abdominal palpation for detecting AAA decreases in patients with an abdominal girth more than 100 cm.[77]​​​

The classic triad of a pulsatile abdominal mass with hypotension and abdominal and/or back pain is present in about 50% of patients with a ruptured AAA.[3]

The presence of fever may increase suspicion for infectious AAA in the appropriate clinical setting.

Key tests

Suspected ruptured or symptomatic AAA is a medical emergency; immediate review from a vascular surgeon is required. See Management approach. Urgent imaging with bedside aortic ultrasound is needed to confirm the diagnosis; however, clinical diagnosis and management of a ruptured AAA should not be delayed while waiting for the results of imaging.[76][78]​​​​

The ultrasound is performed perpendicular to the aortic axis as oblique views may overestimate the true aortic diameter.​[2]​​[5][79]​​ Unfortunately, ultrasound offers little utility in imaging aneurysms close to the origins of, or proximal to, the renal arteries.[80][81] In selected patients, CT scan is recommended as a first-line investigation to evaluate patients thought to have AAA presenting with recent-onset abdominal or back pain, particularly in the presence of a pulsatile epigastric mass or significant risk factors for AAA.[76]​​

Other investigations

Once the diagnosis is made, further imaging with computed tomography angiography (CTA) is used to exclude rupture and for anatomic mapping to assist with operative planning (open or endovascular).[78]​​[79][82]​​​

Elevated erythrocyte sedimentation rate and C-reactive protein support a diagnosis of possible inflammatory AAA.[5]​

Leukocytosis and a relative anemia on complete blood count with positive blood cultures are indicative of infectious AAA.[12]

Positron emission tomography-computed tomography (PET-CT) is used for the diagnosis and follow-up of aortic pathologies associated with inflammatory aneurysm, aortic infection (including mycotic AAAs), infected prostheses, and stent grafts.[3][83]

Predictors of rupture risk include AAA expansion rate, increase in intraluminal thrombus thickness, wall stiffness, wall tension, and peak AAA wall stress.[10][76][84]​​​

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