Even patients who do not have symptoms from their AAAs may eventually require surgical intervention because the result of medical management in this population is a mortality of 100% over time as a consequence of rupture. In addition, these patients have a potential for limb loss from peripheral embolization.
The decision to treat an unruptured AAA is based on operative risk, the risk of rupture, and the patient’s estimated life expectancy. In 2009, the Society for Vascular Surgery (SVS) published a series of guidelines for the treatment of AAAs based on these principles. [20]
Operative risk is based on patients’ comorbidities and hospital factors (see Table 1 below). Patient characteristics, including age, sex, renal function, and cardiopulmonary disease are perhaps the most important factors. However, lower-volume hospitals and surgeons are associated with higher mortality. [21]
Table 1. Operative Mortality Risk With Open Repair of Abdominal Aortic Aneurysm (Open Table in a new window)
Lowest Risk |
Moderate Risk |
High Risk |
Age <70 y |
Age 70-80 y |
Age 80 y |
Physically active |
Active |
Inactive, poor stamina |
No clinically overt cardiac disease |
Stable coronary disease; remote MI; LVEF >35% |
Significant coronary disease; recent MI; frequent angina; CHF; LVEF < 25% |
No significant comorbidities |
Mild COPD |
Limiting COPD; dyspnea at rest; O2 dependency; FEV1</td></tr> |
... |
Creatinine 2.0-3.0 mg/dL |
... |
Normal anatomy |
Adverse anatomy or AAA characteristics |
Creatinine >3 mg/dL |
No adverse AAA characteristics |
... |
Liver disease (↑PT; albumin </td></tr> |
Anticipated operative mortality, 1-3% |
Anticipated operative mortality, 3-7% |
Anticipated operative mortality, at least 5-10%; each comorbid condition adds ~3-5% mortality risk |
AAA = abdominal aortic aneurysm; CHF = chronic heart failure; COPD = chronic obstructive pulmonary disease; FEV1 = forced expiratory volume in 1 second; LVEF = left ventricular ejection fraction; MI = myocardial infarction; PT = prothrombin time. |
Abdominal ultrasonography can provide a preliminary determination of the aneurysm’s presence, size, and extent. Rupture risk is in part indicated by the size of the aneurysm (see Table 2 below).
Table 2. Abdominal Aortic Aneurysm Size and Estimated Annual Risk of Rupture (Open Table in a new window)
AAA Diameter (cm) |
Rupture Risk (%/y) |
<4 |
0 |
4-5 |
0.5-5 |
5-6 |
3-15 |
6-7 |
10-20 |
7-8 |
20-40 |
>8 |
30-50 |
AAA = abdominal aortic aneurysm. |
In addition to aneurysm diameter, factors such as sex, aneurysm expansion rate, family history, and chronic obstructive pulmonary disease (COPD) also affect the risk of rupture (see Table 3 below).
Table 3. Factors Affecting Risk of Abdominal Aortic Aneurysm Rupture (Open Table in a new window)
Factor |
Low Risk |
Average Risk |
High Risk |
Diameter |
<5 cm |
5-6 cm |
>6 cm |
Expansion |
<0.3 cm/y |
0.3-0.6 cm/y |
>0.6 cm/y |
Smoking/COPD |
None, mild |
Moderate |
Severe/steroids |
Family history |
No relatives |
One relative |
Numerous relatives |
Hypertension |
Normal blood pressure |
Controlled |
Poorly controlled |
Shape |
Fusiform |
Saccular |
Very eccentric |
Wall stress |
Low (35 N/cm2 |
Medium (40 N/cm2 |
High (45 N/cm2) |
Sex |
... |
Male |
Female |
COPD = chronic obstructive pulmonary disease. |
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Radiograph shows calcification of abdominal aorta. Left wall is clearly depicted and appears aneurysmal; however, right wall overlies spine.
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On radiography, lateral view clearly shows calcification of both walls of abdominal aortic aneurysm, allowing diagnosis to be made with certainty.
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CT demonstrates abdominal aortic aneurysm (AAA). Aneurysm was noted during workup for back pain, and CT was ordered after AAA was identified on radiography. No evidence of rupture is seen.
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Arteriography demonstrates infrarenal abdominal aortic aneurysm. This arteriogram was obtained in preparation for endovascular repair of aneurysm.
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Lateral arteriogram demonstrates infrarenal abdominal aortic aneurysm. Demonstration of superior mesenteric artery, inferior mesenteric artery, and celiac artery on lateral arteriogram is important for complete evaluation of extent of aneurysm.
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Arteriogram after successful endovascular repair of abdominal aortic aneurysm.
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Ultrasonogram from patient with abdominal aortic aneurysm (AAA). This aneurysm was best visualized on transverse or axial image. Patient underwent conventional AAA repair.
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MRI of 77-year-old man with leg pain believed to be secondary to degenerative disk disease. During evaluation, abdominal aortic aneurysm was discovered.
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Age is risk factor for development of aneurysm.
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Inflammation, thinning of media, and marked loss of elastin.
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Pulsatile abdominal mass.
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Aneurysm with retroperitoneal fibrosis and adhesion of duodenum.
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Aortic endoprosthesis (Cook aortic and aortobi-iliac endograft).
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Endoaneurysmorrhaphy
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Endovascular grafts.
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Atheroemboli from small abdominal aortic aneurysms produce livedo reticularis of feet (ie, blue toe syndrome).
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Enhanced spiral CT scans with multiplanar reconstruction and CT angiogram.
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Angiography is used to diagnose renal area. In this instance, endoleak represented continued pressurization of sac.