A 60-year-old white man with a history of hyperlipidemia, hypertension, and anxiety presented with complaints of abdominal pain, localized to an area left of the umbilicus. He described the pain as constant and rated it 6 on a scale of 1 to 10. He said the pain had been present for longer than three weeks.
The man said he had been seen by another health care provider shortly after the pain began, but he did not think the provider took his complaint seriously. At that visit, antacids were prescribed, blood work was ordered, and the man was told to return if there was no improvement. He felt that because he was being treated for anxiety, the provider believed he was just imagining the pain.
At the current visit, the review of systems revealed additional complaints of shakiness and nausea without vomiting, with other findings unremarkable. The persistent pain did not seem related to eating, and the patient had no history of any surgeries that might help explain his current complaints. He had smoked a pack of cigarettes daily for 40 years and had a history of heavy alcohol use, although he denied having consumed any alcohol during the previous five years.
His prescribed medications included gemfibrozil 600 mg per day, hydrochlorothiazide 25 mg each morning, and diazepam 5 mg twice daily, with an OTC antacid.
The patient’s recent laboratory results were normal; they included a complete blood count, comprehensive metabolic panel, liver enzyme levels, and a serum amylase level. The patient weighed 280 lb and his height was 5’10”; his BMI was 40. His temperature was 97.7°F, with a regular heart rate of 88 beats/min; blood pressure, 140/90 mm Hg; and respiratory rate, 18 breaths/min.
The patient did not appear to be in acute distress. A bruit was heard in the indicated area of pain. No mass was palpated, and the width of his aorta could not be determined because of his obesity. His physical exam was otherwise normal.
Abdominal ultrasonography (US) revealed a 5.5-cm abdominal aortic aneurysm (AAA), and the man was referred for immediate surgery. The aneurysm was repaired in an open abdominal procedure with a polyester prosthetic graft. The surgery was successful.
Discussion
AAA is a permanent bulging area of the aorta that exceeds 3.0 cm in diameter (see Figure 1). It is a potentially life-threatening condition due to the possibility of rupture. Often an aneurysm is asymptomatic until it ruptures, making this a difficult illness to diagnose.1
Each year, an estimated 10,000 deaths result from a ruptured AAA, making this condition the 14th leading cause of death in the United States.2,3 Incidence of AAA appears to have increased over the past two decades. Causes for this may include the aging of the US population, an increase in the number of smokers, and a trend toward diets that are higher in fat.
Prognosis among patients with AAA can be improved with increased awareness of the disease among health care providers, earlier detection of AAAs at risk for rupture, and timely, effective interventions.
Symptomatology
In about one-third of patients with a ruptured AAA, a clinical triad of symptoms is present: abdominal and/or back pain, a pulsatile abdominal mass, and hypotension.4,5 In these cases, according to the American College of Cardiology/American Heart Association (ACC/AHA),4 immediate surgical evaluation is indicated.
Prior to the rupture of an AAA, the patient may feel a pulsing sensation in the abdomen or may experience no symptoms at all. Some patients report vague complaints, such as back, flank, groin, or abdominal pain. Syncope may be the chief complaint as the aneurysm expands, so it is important for primary care providers to be alert to progressive symptoms, including this signal that an aneurysm may exist and may be expanding.6
Pain may also be abrupt and severe in the lower abdomen and back, including tenderness in the area over the aneurysm. Shock can develop rapidly and symptoms such as cyanosis, mottling, altered mental status, tachycardia, and hypotension may be present.1,4
Since symptoms may be vague, the differential diagnosis can be broad (see Table 14,7,8), necessitating a detailed patient history and a careful physical examination. In an elderly patient, low back pain should be evaluated for AAA.9 In addition, acute abdominal pain in a patient older than 50 should be presumed to be a ruptured AAA.8
Risk Factors
A clinician should be familiar with the risk factors for AAA so that diagnosis can be made before a rupture occurs. Male gender and age greater than 65 are important risk factors for AAA, but one of the most important environmental risks is cigarette smoking.9,10 Current smokers are more than seven times more likely than nonsmokers to have an aneurysm.10 Atherosclerosis, which weakens the wall of the aorta, is also believed to contribute to the risk for AAA.11