There is evidence that statin use may reduce the size of aneurysms, even in patients without hypercholesterolemia, possibly due to statins’ anti-inflammatory properties.22,29 ACE inhibitors may also be beneficial in reducing AAA growth and in lowering blood pressure. Antiplatelet medications are important in general cardiovascular risk reduction in the patient with AAA. Aspirin is the drug of choice.27,29
Surgical Repair
AAAs are usually repaired by one of two types of surgery: endovascular repair (EVR) or open surgery. Open surgical repair, the more traditional method, involves an incision into the abdomen from the breastbone to below the navel. The weakened area is replaced with a graft made of synthetic material. Open repair of an intact AAA, performed under general anesthesia, takes from three to six hours, and the patient must be hospitalized for five to eight days.30
In EVR, the patient is given epidural anesthesia and an incision is made in the right groin, allowing a synthetic stent graft to be threaded by way of a catheter through the femoral artery to repair the lesion (see Figure 2). EVR generally takes two to five hours, followed by a two- to five-day hospital stay. EVR is usually recommended for patients who are at high risk for complications from open operations because of severe cardiopulmonary disease or other risk factors, such as advanced age, morbid obesity, or a history of multiple abdominal operations.1,2,4,19
Prognosis
Patients with a ruptured AAA have a survival rate of less than 50%, with most deaths occurring before surgical repair has been attempted.3,31 In patients with kidney failure resulting from AAA (whether ruptured or unruptured, an AAA can disrupt renal blood flow), the chance for survival is poor. By contrast, the risk for death during surgical graft repair of an AAA is only about 2% to 8%.1,12
In a systematic review, EVR was associated with a lower 30-day mortality rate compared with open surgical repair (1.6% vs 4.7%, respectively), but this reduction did not persist over two years’ follow-up; neither did EVR improve overall survival or quality of life, compared with open surgery.1 Additionally, EVR requires periodic imaging throughout the patient’s life, which is associated with more reinterventions.1,19
Patient Education
Clinicians should encourage all patients to stop smoking, follow a low-cholesterol diet, control hypertension, and exercise regularly to lower the risk for AAAs. Screening recommendations should be explained to patients at risk, as should the signs and symptoms of an aneurysm. These patients should be instructed to call their health care provider immediately if they suspect a problem.
Conclusion
The incidence of AAA is increasing, and primary care providers must be prepared to act promptly in any case of suspected AAA to ensure a safe outcome. For aneurysms measuring greater than 5.5 cm in diameter, open or endovascular surgical repair should be considered. Patients with smaller aneurysms or contraindications for surgery should receive careful medical management and education to reduce the risks of AAA expansion leading to possible rupture.