Popliteal Artery Entrapment Syndrome

Olya Polishchuk

Mary Wyers, M.D.

Children's Memorial Hospital

Abstract

16 year old female with calf claudication with exercise

popliteal entrapment, MRI, 220

Publication Date: 2004-07-30

16 year old female with calf claudication with exercise

The axial T1 weighted sequences demonstrate a very prominent part of the medial head of the gastrocnemius muscle which extends anteriorly into the intercondylar region and compresses the popliteal artery against the lateral femoral condyle. This muscle slip does not extend in between the popliteal artery and vein. This finding is bilateral and appears symmetric.

Gadolinium enhanced MRA in rest position shows a patent popliteal artery. In the stress position, the popliteal artery is occluded on the right and narrowed on the left at the level of the knee joint (demonstrated both on the gradient echo axial source images (images 9-17) and in the reconstructed images (18-20). Note how the bright signal in the right popliteal artery disappears at the level of the knee joint due to the abnormal muscle slip of the medial head of the gastrocnemius muscle.

Popliteal artery entrapment syndrome is an uncommon entity typically affecting young athletic males who present with symptoms of calf claudication. It is caused by an anomalous relationship of the gastrocnemius muscle and artery in the popliteal fossa resulting in extrinsic arterial comression. The anomalous anatomic relationship for compression of the popliteal artery is caused by abnormal embryologic development of the popliteal fossa. The muscle or the artery can be responsible for the abnormal anatomy, and numerous variations can result. Repetitive insult to the popliteal artery can cause arterial damage and lead to aneurysm, thromboembolism, and arterial thrombosis. This aggressice natural history warrants early diagnosis and treatment.

Although conventional angiography has been traditionally used to confirm the diagnosis, cross-sectional imaging also has an important role. MRI and MR angiography have emerged as promising imaging modalities for the diagnosis of popliteal artery entrapment syndrome. MRI can show the abnormal anatomy responsible for the entrapment, and dynamic compression can be shown with MR angiographic techniques.

The definitive treatment for popliteal artery entrapment syndrome is surgical intervention. Because of progressive nature of this entity, even asymptomatic limbs should have surgical correction to prevent irreversible change.

Macedo, T.A., et. al., "Popliteal Artery Entrapment Syndrome: Role of Imaging in the Diagnosis", AJR, 2003; 181: 1259-1265.