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Popliteal Artery Entrapment Syndrome (PAES)

Popliteal artery entrapment syndrome (PAES) is a rare vein condition in the leg. It happens when tendons and muscles squeeze the knee's main (popliteal) artery, limiting blood flow to the lower leg. PAES tends to affect male athletes under 30, largely runners. It causes symptoms — most often during a workout — such as pain, numbness, or cramping in the calf.

Left untreated, PAES can cause lasting nerve or muscle damage. But, you’re in good hands at the UPMC Division of Vascular Surgery. Our surgeons are experts at treating PAES.

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What Is Popliteal Artery Entrapment Syndrome (PAES)?

Popliteal artery entrapment syndrome, also called PAES, is a rare vascular disease.

The popliteal artery is the main artery that runs through and behind the knee.

PAES occurs when nearby tendons and muscles squeeze — or compress — the popliteal artery. This limits blood flow, leading to symptoms in the lower leg.

Types of PAES

There are six different types of PAES:

  • Type I — happens because of an abnormal course of the popliteal artery.
  • Type II — happens because of an abnormal position of a nearby muscle.
  • Type III — happens because of an accessory slip of a nearby muscle and fibrous bands of tissue.
  • Type IV — happens when the popliteal artery passes underneath the popliteus muscle.
  • Type V — includes compression of the popliteal artery and the popliteal vein.
  • Type VI — includes other variations.

PAES causes and risk factors

PAES is often a congenital problem, meaning you're born with the condition. An enlarged calf muscle can also cause PAES to form over time.

PAES is most common in young athletes, largely those who play soccer, football, rugby, or vigorously lift weights.

Men are more at risk to get PAES than are women.

PAES complications

In some cases, compression can damage and narrow the wall of the popliteal artery.

In severe cases, permanent muscle or nerve damage can occur due to compression or loss of blood flow to the lower leg.

For an appointment with a UPMC vascular surgeon, complete an appointment request form or call 1-855-876-2484 (UPMC-HVI).

Popliteal Artery Entrapment Syndrome (PAES) Symptoms and Diagnosis

Symptoms of PAES

PAES symptoms can include:

  • Pain, numbness, tiredness, or cramping in the calf during exercise
  • Swelling
  • Coolness in the foot and calf
  • Discoloration of the toes and nails

Often, symptoms improve after a few minutes of rest but return during exercise.

Diagnosing PAES

To diagnose PAES, your UPMC vascular surgeon will:

  • Ask you about your symptoms.
  • Learn about your medical history.
  • Perform a physical exam.

Your doctor may also use the following tests to confirm a diagnosis of PAES:

  • Ankle-brachial index with exercise — measures blood pressure in your arms and legs before and after exercise.
  • Ultrasound — uses sound waves to make pictures of the blood flow through your blood vessels.
  • Computerized tomography (CT) angiography — uses cross-sectional x-rays and a computer to create detailed 3D images.
  • Magnetic resonance angiography(MRA) — uses a large magnetic field, radio waves, and computers to make detailed pictures.

Popliteal Artery Entrapment Syndrome (PAES) Treatment

Your UPMC vascular surgeon can treat PAES through open surgery to release the compression of the popliteal artery.

Most people only spend one to two days in the hospital after surgery and don't need physical therapy once they return home.

The majority of patients make a full recovery within four weeks.