Popliteal Artery Entrapment
Popliteal artery entrapment syndrome (PAES) is a rare vascular disease in which muscle and tendons near the knee are positioned in such a way that they compress the main (popliteal) artery that runs through and behind the knee. This most often occurs in the legs of young athletes, as training over time can lead to an enlarged calf muscle that compresses the popliteal artery, restricting blood flow to the lower leg, and sometimes damaging the artery.
Young athletes aren’t the only ones at risk, however. Patients with PAES may simply be born with the condition due to a defect in the development of their calf muscle and popliteal artery.
The main symptom of PAES is pain during exercise, many times in the same leg and at the same point during the activity. This is known as intermittent claudication, or walking pain. Inflammation, numbness, fatigue, and cramping in the calf during exercise are also signs of the condition. These symptoms typically subside after three to five minutes of rest.
Because symptoms of popliteal artery entrapment are similar to another condition called adventitial cystic disease. it is essential to seek medical help for an accurate diagnosis so appropriate treatment can be received.
Large muscles compressing the artery due to athletics or in rare cases, a birth defect, are behind most cases of PAES. It is most often seen in male athletes under 30 years of age, but it can occur in young female athletes as well. Runners and those who play soccer, football or rugby are typically most at risk. PAES can sometimes be considered an overuse injury since it is tied to muscle growth over time. As muscles next to the popliteal artery get larger, there is a greater chance of compression.
f aA vascular specialist can best diagnose PAES. Initially, we will perform a physical exam which includes checking the pulse in your foot and popliteal artery. If PAES is present, we may feel the pulses while you are at rest, but they may be harder to detect when you exercise, or extend or flex your foot. For this reason, diagnostic tests are also done to measure blood flow through the leg, knee, and foot. These can include:
- Ankle brachial pressure assessment – this measures the blood pressure in the arms and legs before and after exercise.
- Duplex Ultrasound – sound waves are used to provide an image of the artery and measure blood flow.
- Computed tomographic angiography (CTA) – this is a type of CT scan which uses injected dye to reveal areas around the knee with narrowed arteries or poor blood flow.
- Magnetic Resonance Angiography (MRA) –a process using radio wave energy pulses and magnetic fields to provide images of tendons and muscles and the blood vessels within them.
A surgical procedure can release the popliteal artery by correcting the problem with muscles or tendons. Once compression of the artery from the muscles is eliminated, it will allow for normal blood flow to the leg.
In advanced cases when the popliteal artery is actually blocked and not just pinched, a bypass around the blocked section of the artery may need to be performed to restore blood flow.