Popliteal artery aneurysm

Overview

A popliteal artery aneurysm is a bulge in the wall of the artery behind the knee joint. It is a type of lower extremity aneurysm. Sometimes, a popliteal artery aneurysm develops a blood clot and blocks blood flow to the leg. Rarely, the blood clot may break open. Treatment may include regular health checkups, medicines and surgery.

Symptoms

You might not notice any symptoms. If you do, the first may be pain in the lower leg when walking, called claudication. Other symptoms of a popliteal artery aneurysm include:

• Knee pain.
• Lower leg pain.
• Swelling behind the knee.
• Pulsing feeling behind the knee.
• A sudden drop in blood flow to the legs, called acute limb ischemia.

Causes

A weak spot in an artery wall causes an aneurysm. Blood pushes against this weak spot, causing it to balloon out.

Many different things can cause the popliteal artery wall to become weak, including:

• A buildup of fats, cholesterol and other substances in and on the artery walls, called atherosclerosis.
• High blood pressure.
• Wear and tear of the popliteal artery from repeated use of the knee joint.
• A very bad leg injury.
• Smoking.

Risk factors

Popliteal artery aneurysms are rare. They are more common in men than in women.

Popliteal artery aneurysm often happens in men with abdominal aortic aneurysm (AAA). An abdominal aortic aneurysm is a ballooning of the wall of the body's main artery, called the aorta. Anyone diagnosed with popliteal artery aneurysm should be checked for AAA.

Other risk factors for popliteal artery aneurysm include:

• Older age.
• High blood pressure.
• Smoking.
• Having aneurysms anywhere in the body.
• A family history of aneurysms.

Complications

Complications of popliteal artery aneurysm include blood clots. Blood clots can slow or block blood flow in the lower leg.

If blood flow is blocked, you might have:

• A change in skin color in the lower leg.
• No pulse behind the knee or in the foot.
• Cold skin in the lower leg.
• Numbness or pain in the leg.
• No ability to move the foot.

If there is little to no blood flow to the leg, the leg doesn't get enough oxygen. This can cause tissue to die. If that happens, surgery may be needed to improve blood flow to the leg. Rarely, amputation may be needed if surgery doesn't help. Amputation is the surgical removal of a body part, such as a leg or foot.

Another complication of popliteal artery aneurysm is an aneurysm rupture. This means the aneurysm breaks out. It can cause blood to leak out of the artery into the leg, called internal bleeding. But the risk of popliteal artery aneurysm rupture is low.

Prevention

To prevent a popliteal artery aneurysm, take steps to keep the heart and blood vessels healthy.

Try these tips:

• Do not smoke.
• Eat healthy foods.
• Stay active and get regular exercise.
• Keep a healthy weight.
• Manage blood pressure, cholesterol and blood sugar.

Diagnosis

To diagnose popliteal artery aneurysm, a healthcare professional usually examines you and checks your legs for:

• Pulses in the back of the knee.
• Pulses in your feet.
• Swelling.
• Tenderness.
• Changes in skin color or temperature on the lower leg and behind the knee.

You may be asked questions about your health history and habits, such as smoking.

Tests

Imaging tests can help tell if you have a popliteal artery aneurysm. Tests may include:

• Duplex ultrasound. This test uses sound waves to see how blood flows through the arteries and veins. It also lets the healthcare professional measure the size of the popliteal artery. It's a simple and quick way to diagnose popliteal artery aneurysm. For the test, a healthcare professional gently moves a hand-held ultrasound device on the skin behind and around the knee.
• CT angiography or magnetic resonance (MR) angiography. These tests take detailed images of blood flow in the arteries. Before the images are taken, a solution called contrast is injected into a blood vessel. The contrast helps the arteries show up more clearly on images taken during the test.

Treatment

Popliteal artery aneurysm treatment depends on:

• The size of the aneurysm.
• The symptoms.
• Your age and overall health.

Treatment may include:

• Regular health checkups. You get checkups and ultrasound tests to check the aneurysm, particularly if the aneurysm is small. This also may be called "watchful waiting."
• Medicines. People with popliteal artery aneurysm usually get aspirin. If you have high blood pressure or high cholesterol, your healthcare professional may also give you medicines to treat those conditions.
• Surgery. Surgery to fix the damaged artery is usually done for any popliteal artery aneurysm that is 0.8 inches (2 centimeters) or larger. But surgery also is typically suggested for any sized popliteal artery aneurysm if you have symptoms. During surgery, a surgeon replaces the artery with a piece of vein or an artificial artery. Rarely, endovascular repair may be done. During this treatment, a doctor places a tube called a stent inside the popliteal artery to keep it open.