Peripheral aneurysms, a weakened area of a blood vessel with abnormal bulging or expansion, affect arteries other than the aorta.
Most peripheral aneurysms develop on the backside of the lower thigh and knee, in the area of the popliteal artery (a continuation of the femoral artery).
A peripheral aneurysm can also form in the femoral artery in the groin, the carotid artery in the neck or occasionally in the arms.
Symptoms
A peripheral aneurysm can go undetected, but it’s something your primary care physician can discover during a routine physical. Tell your doctor if you feel a pulsating mass in the groin or behind a knee. Ultrasound and other radiologic studies can also reveal a peripheral aneurysm.
Possible symptoms:
- Cramping with exercise.
- A limb that weakens or fatigues easily.
- Swelling or numbness in a leg.
- Numbness or radiating pain a leg or arm.
- Ulcers or sores on a hand or foot that don’t heal.
- Gangrene (dead tissue) from a severe blockage in a limb.
- Foot pain while sleeping.
- Abdominal pain.
- Fainting.
- Discolored, painful toe (evidence of a small blood clot).
A ruptured aneurysm, though rare, will cause sudden swelling of the groin or knee accompanied by a loss of circulation downstream from the affected area.
Causes
Peripheral aneurysms are often attributed to atherosclerosis, a disease marked by plaque buildup that causes narrowing or hardening of the arteries. When the cholesterol, fat and other substances that constitute plaque accumulate on the interior walls the narrowed or hardened walls restrict blood flow. If not enough blood reaches body tissue, the condition is called ischemia. Injury, infection and aging also have been linked to peripheral aneurysms.
Risk factors:
- You’ve already had an aneurysm.
- Family history of aneurysms, or heart/vascular disease.
- Smoking.
- High blood pressure.
- High cholesterol.
- Obesity.
Treatment
Your doctor will evaluate the size and location of the clots and whether they have blocked the aneurysm entirely before recommending treatment. If you experience no symptoms with a popliteal aneurysm blocked by blood clots – in the popliteal artery at the back of the lower thigh and knee -- your doctor might forgo surgery.
Instead, you could be asked to concentrate on controlling the risks of atherosclerosis, the narrowing or hardening of the arteries:
- High blood pressure.
- High cholesterol.
- Diabetes.
- Smoking.
- Excess body weight.
- Sedentary lifestyle.
- Poor nutrition.
A small peripheral aneurysm poses no danger. Your doctor will monitor it with periodic ultrasound tests. (You should also have an abdominal ultrasound to check for an aortic aneurysm.)
A large aneurysm requires surgery:
Femoral aneurysm (groin): The artery is replaced with a synthetic graft placed inside the vein, sealing off the aneurysm.
Popliteal aneurysm (back of leg, knee): If repair isn’t possible, the artery is bypassed so that blood is rerouted around the aneurysm. At that point, your doctor can remove the aneurysm or otherwise isolate it so that blood no longer flows into it.