Skip to Main Content

++

Essential Features

+

  • • Permanent aortic dilation (at least 50%)

    • Classified by etiology (degenerative, inflammatory, mechanical, congenital, dissecting) and by shape (saccular, fusiform)

    • Up to 25% of patients have symptoms of aortoiliac occlusive disease as well

    • Most are infrarenal; decreased vasa vasorum and elastic lamellae may predispose to aneurysm formation

    • Rupture risk correlates with size, following law of LaPlace

    • Average expansion rate of 0.4 cm/y depends on aneurysm size, diastolic blood pressure, and chronic obstructive pulmonary disease (COPD)

    • For AAA measuring 5.0–5.5 cm, rupture risk is 40% at 5 years

    Suprarenal: Uncommon; extends proximal to renal arteries; low risk for rupture until exceeds 6–7 cm

    Ruptured: Most often ruptures posterolaterally to left; if exsanguination delayed, likely contained rupture that eventually becomes free rupture

    Inflammatory: Characterized by inflammatory response external to aneurysmal wall, with inflammation usually confined to anterior aorta; 25% have ureteral obstruction, which results in dense, shiny fibrotic reaction enveloping adjacent viscera

    Infected (mycotic): Bacterial contamination of preexisting aneurysm (different from Salmonella causing false aneurysm); gram-negative infections result in higher rupture rates

++

Epidemiology

+

  • • Ruptured AAA is the 13th leading cause of death in the United States (15,000 deaths yearly)

    • Present in 2% of population and incidence is increasing

    • More men affected than women (4:1)

    • 5% of patients with coronary artery disease have AAA

    • 50% of patients with femoral or popliteal aneurysms have AAA

    • 19% incidence among first-degree relatives

    Rare causes:

    • –Marfan syndrome

      –Ehlers-Danlos syndrome

      –Behçet disease

      –Syphilis

      –Long-term sequelae of aortic dissection

    Risks:

    • –Smoking

      –Hypertension (HTN)

      –COPD

    • Diabetes appears to exert protective effect

    • Increased incidence of rupture during fall and winter months

    Strep, Haemophilus, Staph, E coli, other gram-negative pathogens, and fungi identified in infected AAA

++

Clinical Findings

++

Symptoms and Signs

+

  • • Rarely produces symptoms if intact

    • Painless, pulsatile abdominal mass above umbilicus; may be uncomfortable on palpation

    • Palpation may be difficult in obese patients

    • Rarely produces back pain from pressure on nerves

    • Severe paincaused by inflammatory or ruptured AAA or acute expansion

    • Congestive heart failure from aortocaval fistula, GI bleed from duodenal erosion, and pyelonephritis from ureteral obstruction are rare

    • Rupture causes sudden, severe abdominal/back pain radiating to back or inguinal area, faintness or syncope, shock; often tender pulsatile mass present

    Triad for rupture: Pain, pulsatile abdominal mass, hypotension found in < 67% of patients

    Inflammatory: Abdominal pain, tender AAA

    Infected: Rapidly enlarging tender pulsatile mass, fever

++

Laboratory Findings

+

  • • CBC abnormal

++

Imaging Findings

+

  • Abdominal x-ray: 20% calcifications in outer aortic wall on lateral view

    US

    • –Inexpensive screening test, measures size and position

      –Used in cases of groin pseudoaneurysm to evaluate proximal anastomosis in abdomen

    CT scan

    • –Diagnostic, accurate sizing, and provides information about anatomy: renal ...

Want remote access to your institution's subscription?

Sign in to your MyAccess profile while you are actively authenticated on this site via your institution (you will be able to verify this by looking at the top right corner of the screen - if you see your institution's name, you are authenticated). Once logged in to your MyAccess profile, you will be able to access your institution's subscription for 90 days from any location. You must be logged in while authenticated at least once every 90 days to maintain this remote access.

Ok

About MyAccess

If your institution subscribes to this resource, and you don't have a MyAccess profile, please contact your library's reference desk for information on how to gain access to this resource from off-campus.

Subscription Options

AccessSurgery Full Site: One-Year Subscription

Connect to the full suite of AccessSurgery content and resources including more than 160 instructional videos, 16,000+ high-quality images, interactive board review, 20+ textbooks, and more.

$995 USD
Buy Now

Pay Per View: Timed Access to all of AccessSurgery

24 Hour Subscription $34.95

Buy Now

48 Hour Subscription $54.95

Buy Now

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.