Popliteal artery entrapment syndrome (PAES)
is a rare vascular condition that may result in the compression or occlusion of
the popliteal artery. It occurs when the muscle and tendons near the knee are
positioned so that they compress the popliteal artery, which is the main artery
that runs through and behind the knee. Compression of the artery restricts
blood flow to the lower leg and can damage the artery.
PAES often affects the legs of young athletes. About 60% of patients with the disorder are sportsmen under 30 years old. It is estimated that men are 15 times more likely to develop PAES than women.
From the perspective of anatomy, PAES can
be classified into five types:
- Type 1
This type occurs because of an abnormal
relationship of the popliteal artery with the medial head of gastrocnemius
- Type 2
In this condition, there is no deviation of
the popliteal artery. But the MHG inserts more towards the side than usual and
the artery goes beneath the muscle.
- Type 3
There is an abnormal muscle bundle from the MHG that surrounds and constricts the popliteal artery.
- Type 4
Here, the popliteal artery lies deep in the popliteal fossa and is entrapped by the popliteus muscle.
- Type 5
In this type, both the popliteal artery and the vein are entrapped.
The proper cause of PAES is unclear. Excessive
exercising and pressure on the calf may result in the problem. Hypertrophy of
the musculotendinous structures may also lead to the condition. Risk factors
for PAES include:
- Age and profession
If you are an athlete between the ages of 25-40, particularly runners or soccer players under 30 years old, you are at higher risk of getting PAES.
Less than 3% of people are born with a
defect that can lead to PAES, but most people with the condition never develop
Men are at greater risk to be affected than
Generally, signs and symptoms of PAES are
quite similar to those of adventitial cystic disease. They include:
- Pain and numbness in the legs
- Frequent occurrence of cramps or tiredness in the calf when exercising
- Swelling of the legs
Though the symptoms may go away in three or five minutes with resting, you should pay attention if you have risk factors for PAES.
Differential diagnosis is quite important for PAES because many other conditions can cause similar signs and symptoms, such as adventitial cystic disease, cystic adventitial disease of the popliteal artery, thrombosed popliteal artery aneurysm, muscle strain or medial tibial stress syndrome.
For diagnosing PAES, your doctor will first
ask about your medical history and symptoms. Then, he or she will carry out a
physical exam. During the exam, the doctor will check if there are diminished
pulses with active foot plantar flexion or passive foot dorsiflexion and
coolness of posterior calf.
Imaging tests are very effective to
diagnose PAES. They include:
- Radiographs, which is the most normal one
- Doppler ultrasound to detect changes in pulse when active plantar
flexion or passive dorsiflexion is performed
- Arteriogram to confirm the diagnosis, which is close to 100%
- MRI and CT scan to help detect abnormalities in the legs
If you experience only mild symptoms and the
cause of your PAES is rigorous exercise, you may need nothing but activity
modification and observation. For more severe cases and complex causes,
surgical treatment is required. Different operative options include:
- Bypass surgery, or saphenous vein graft to restore blood flow to the leg
- Dividing the anomalous musculotendinous tissue to release the popliteal artery when it is still intact
- Vascular reconstruction together with the division of the anomalous musculotendinous structure when the popliteal artery is occluded, stenotic, or aneurysmal
Keyword: popliteal artery entrapment syndrome (PAES).