An aortic aneurysm is a balloon-like bulge in the aorta, the body’s largest artery that carries oxygen-rich blood from the heart. This condition often develops and grows silently, without symptoms, making it serious. When aortic walls weaken, the force of blood can cause bulging. This article focuses on infrarenal aortic aneurysms, a common type located in the abdomen.
Understanding Infrarenal Aortic Aneurysms
An aneurysm is an artery enlargement greater than 1.5 times its normal size. The aorta extends from the heart through the chest and into the abdomen. An infrarenal aortic aneurysm occurs in the abdominal aorta below the arteries supplying blood to the kidneys. This location is the most common site for aortic aneurysms, accounting for approximately 60% of all abdominal aortic aneurysms.
Aneurysms are classified by their shape: fusiform or saccular. A fusiform aneurysm, more common, bulges on all sides of the blood vessel. In contrast, a saccular aneurysm bulges on only one side of the affected artery. Constant blood pressure exerts stress on the weakened aortic wall, leading to expansion.
Identifying Risk Factors and Symptoms
Several factors increase the likelihood of developing an infrarenal aortic aneurysm. Age over 65 is a significant risk, with prevalence increasing each decade. Men are about four times more likely to develop an abdominal aortic aneurysm than women at any age.
Smoking history, defined as at least 100 cigarettes, is a major risk factor, increasing with tobacco use. High blood pressure, high cholesterol, and atherosclerosis (hardening of the arteries due to plaque buildup) are additional contributing factors. A family history of abdominal aortic aneurysms also plays a role; 10% to 20% of individuals with a first-degree relative affected may develop one.
If an aneurysm grows larger or ruptures, symptoms may appear suddenly and require immediate medical attention. Signs of a ruptured aneurysm include severe, sudden, persistent pain in the abdomen or lower back, potentially spreading to the groin or legs. Other indicators of a rupture include dizziness, fainting, clammy skin, a rapid heart rate, and a drop in blood pressure. These symptoms signal a life-threatening emergency, and prompt medical care is necessary.
Diagnosis and Treatment Approaches
Infrarenal aortic aneurysms are often detected incidentally during imaging for other health concerns or through screening. Ultrasound is a common screening tool, particularly recommended for men aged 65 to 75 who have a history of smoking, as it can accurately measure the aorta’s diameter. If an aneurysm is suspected, further imaging like CT scans or MRI provides detailed information on size, shape, and location. An abdominal aortic aneurysm is generally diagnosed when the abdominal aorta’s diameter is 3 centimeters or greater.
Treatment decisions are based on the aneurysm’s size, its rate of growth, and the patient’s overall health. For smaller aneurysms, typically those less than 5.5 centimeters in diameter for men and 5.0 centimeters for women, a “watchful waiting” approach is often recommended. This involves regular monitoring with ultrasound or CT scans, usually every 6 to 12 months, to track any changes in size or shape. During this period, lifestyle modifications and medications to control blood pressure and cholesterol are often prescribed to slow aneurysm growth.
Surgical intervention is recommended when an aneurysm reaches 5.5 cm or larger, grows rapidly (0.5 cm+ over 6 months, or 1.0 cm+ over a year), or becomes symptomatic. Open surgical repair involves a large abdominal incision to access the aorta. The weakened section of the aorta is clamped, removed, and replaced with a synthetic graft, which is then sewn into place. This procedure is extensive and requires a longer recovery period, typically several weeks to a few months.
Endovascular Aneurysm Repair (EVAR) is a less invasive alternative, now the primary treatment for many infrarenal aortic aneurysms. This procedure uses small groin incisions to guide catheters to the aneurysm. A stent-graft, a fabric tube supported by a metal mesh frame, is then deployed inside the aorta to reinforce the weakened area and divert blood flow away from the aneurysm. EVAR typically results in less pain and a faster recovery compared to open surgery, with many patients returning home the day after the procedure.
Living with an Infrarenal Aortic Aneurysm
After diagnosis or treatment of an infrarenal aortic aneurysm, ongoing management is important. For individuals under watchful waiting, strict adherence to lifestyle modifications is advised. This includes maintaining healthy blood pressure through medication and stress management, as high blood pressure can increase the risk of aneurysm worsening. Quitting smoking is especially important, as it significantly reduces the risk of aneurysm growth and rupture.
A heart-healthy diet, rich in fruits, vegetables, whole grains, and lean proteins, along with regular physical activity, supports cardiovascular health and helps prevent arterial disease progression. For those who have undergone repair, recovery from EVAR typically involves a quicker return to activities, often within 1 to 2 weeks, while full recovery from open surgical repair can take 2 to 3 months. Regardless of repair method, long-term follow-up with regular imaging (CT scans or ultrasounds) is necessary to monitor the graft and detect complications like endoleaks or graft movement. Adherence to prescribed medications, such as aspirin, blood pressure medications (beta-blockers, ACE inhibitors, ARBs), and statins, is also important to manage cardiovascular risks and help prevent future issues. The prognosis for individuals with infrarenal aortic aneurysms is generally favorable with early detection and successful management, emphasizing the importance of ongoing medical care and a healthy lifestyle.