Popliteal artery entrapment syndrome.

Popliteal artery entrapment syndrome (PAES) is a rare cause of exercise-induced leg pain. Entrapment occurs because of an abnormal relationship between the popliteal artery and the surrounding myofascial structures in the popliteal fossa. Arterial insufficiency in the affected limb arises with entrapment of the artery, commonly giving leg symptoms with exertion. The true incidence of PAES in the general population is not known. The aetiology of PAES has an embryological basis related to the development of the popliteal artery and the surrounding musculature. Many different classification schemes have been developed to differentiate the various types of abnormal anatomy that are associated with the syndrome. Repeated popliteal artery compression causes trauma to the arterial wall, leading to premature localised atherosclerosis. The pathology of PAES is believed to be progressive, with arterial thrombosis occurring in some individuals as a natural progression of the disease process. Acute ischaemia can occur if there is an occlusion of the artery or thrombosis within an aneurysm. Clinically, up to 85% of individuals diagnosed with the syndrome are males. The mean age of individuals in a large series was 28 years. The condition can be found bilaterally in 25% of cases. Most individuals present with exercise-induced leg pain, the remainder presenting with acute or chronic ischaemia. The condition can result in significant functional loss for active individuals. Surgery has been advocated to prevent the progression of the disease that is believed to be the natural history of untreated PAES. However, the little research that has been done to determine the prognosis for individuals who have undergone surgery has focused on the patency rate of the arteries after surgery and the presence or absence of complications. Research needs to be done to look at the natural history of untreated PAES and the functional status of athletes after undergoing PAES surgery.