Popliteal artery entrapment syndrome


The popliteal artery entrapment syndrome is a rather uncommon pathology, which results in claudication and chronic leg ischemia. The popliteal artery may be compressed behind the knee, due to congenital deformity of the muscles or tendon insertions of the popliteal fossa. This repetitive trauma may result in stenotic artery degeneration, complete artery occlusion or even formation of an aneurysm.

Classification

Love and Whelan proposed a classification of this pathology into four types, according to the various relationships between the popliteal artery and the muscles of the popliteal space. Rich and Hughes described popliteal vein compression, thus adding a fifth type into the former classification. The functional type of the popliteal vessel compression was first described by Rignault et al. in 1985 and labeled by Levien as type VI of the popliteal vessels entrapment syndrome.

Cause

Diagnosis

Differential diagnosis

Exercise induced lower leg pain includes chronic exertional compartment syndrome, unresolved muscle strain , medial tibia stress syndrome, fibular and tibial stress fractures, fascial defects, nerve entrapment syndrome, vascular claudication and referred pain from lumbar disc herniation.

Epidemiology

In the general population, popliteal artery entrapment syndrome has an estimated prevalence of 0.16%. It is most commonly found in young, physically active males. In fact, sixty percent of all cases of this syndrome occur in athletically active males under the age of 30. The predilection of this syndrome presents in a male to female ratio of 15:1. This discrepancy in prevalence may be partially attributed to the findings that males are generally found to be more physically active than females or because a large portion of the data accumulated for PAES is from military hospitals that treat mostly male populations. The prevalence of PAES varies through different populations; it increases in those who participate in running, soccer, football, or rugby. During embryonic development, the medial head of gastrocnemius migrates medially and superiorly. This migration can cause structural abnormalities, such as irregular positioning of the popliteal artery, and can account for the rare instances of entrapment caused by the popliteus muscle. Less than 3% of all people are born with this anatomical defect that progresses into PAES, and of those who are born with the anatomical defect, the majority never develop symptoms. Bilateral presentation of PAES is found in approximately 25% of cases.

History

The syndrome was first described in 1879 by Anderson Stuart, a medical student, in a 64-year-old male. Hamming and Vink in 1959 first described the management of the popliteal artery syndrome in a 12-year-old patient. The patient was treated with myotomy of the medial head of the gastrocnemius muscle and endarterectomy of the popliteal artery. They later reported four more cases and claimed that the incidence of this pathology in patients younger than 30 years old with claudication was 40%. Servello was the first to draw attention to diminished distal pulses observed with forced plantar- or dorsiflexion in patients suffering from this syndrome. Bouhoutsos and Daskalakis in 1981 reported 45 cases of this syndrome in a population of 20,000 Greek soldiers. During recent years the increasing frequency with which popliteal artery entrapment is reported, strongly suggests a greater awareness of the syndrome.