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Essentials of Diagnosis
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Most aortic aneurysms are asymptomatic until catastrophic rupture
80% of abdominal aortic aneurysms measuring 5 cm are palpable; the usual threshold for treatment is 5.5 cm
Back or abdominal pain with aneurysmal tenderness may precede rupture
Hypotension
Excruciating abdominal pain that radiates to the back
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General Considerations
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The aorta of a healthy young man measures approximately 2 cm
An aneurysm is considered present when the aortic diameter exceeds 3 cm
Aneurysms rarely cause rupture until diameter exceeds 5 cm
90% of abdominal atherosclerotic aneurysms originate below the renal arteries
Aortic bifurcation is usually involved
Common iliac arteries are often involved
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Most asymptomatic aneurysms are discovered on ultrasound or CT imaging as part of a screening program or during the evaluation of unrelated abdominal symptoms
Symptomatic aneurysms
Mild to severe midabdominal pain due to aneurysmal expansion often radiates to lower back
Pain may be constant or intermittent, exacerbated by even gentle pressure on aneurysm sack, and may also accompany inflammatory aneurysms
Inflammatory aneurysms have an inflammatory peel, similar to the inflammation seen with retroperitoneal fibrosis, surrounds the aneurysm and encases adjacent retroperitoneal structures, such as the duodenum and, occasionally, the ureters
Ruptured aneurysms
Severe pain
Palpable abdominal mass
Hypotension
Free rupture into the peritoneal cavity is lethal
Most aneurysms have a thick layer of thrombus lining the aneurysmal sac
Embolization to lower extremities is rarely seen
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Differential Diagnosis
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Perforated viscus, eg, peptic ulcer, appendix, gallbladder, diverticulitis
Pancreatitis or pancreatic pseudocyst
Urinary calculi
Pyelonephritis
Gastritis
Intestinal ischemia
Bowel obstruction
Musculoskeletal pain
Sudden death due to other causes, eg, ventricular fibrillation, myocardial infarction, pulmonary embolism
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Hematocrit will be normal, since there has been no opportunity for hemodilution
Patients with aneurysms may have the following coexisting conditions, which typically occur in older men who smoke or have smoked cigarettes:
Coronary artery disease
Carotid disease
Kidney impairment
Emphysema
Preoperative testing may indicate the presence of these comorbid conditions
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Abdominal ultrasonography
Recommend screening in men 65–75 years old with exposure to 100 or more lifetime cigarettes
Conflict on whether women with the same exposure should be screened
Do not recommend repeated screening if the aorta shows no enlargement
While patients are monitored, smoking cessation and treatment of underlying hypertension, hyperlipidemia, and diabetes should be considered
Abdominal or back radiographs: curvilinear calcifications outlining portions ...