[Popliteal artery entrapment syndrome]

Popliteal artery entrapment syndrome (PAES) is a cause of exertional calf pain, predominantly affecting young athletic patients without pre-existing vascular disease. Although the condition is generally rare, the number of undetected asymptomatic cases is thought to be substantial. In up to two thirds of cases the PAES is bilateral. Pathophysiologically, it results from external compression of the popliteal artery within the popliteal fossa. The classification distinguishes between anatomical variants (types I-V), which arise from embryological maldevelopments of muscular and tendinous insertions, most commonly involving the medial head of the gastrocnemius muscle and functional entrapment (type VI), which is caused by muscle hypertrophy. Chronic compression leads to intimal damage, fibrosis, occlusions and poststenotic aneurysms. In addition to the clinical angiological examination, the diagnostics are based on duplex ultrasonography, magnetic resonance (MR) or computed tomography (CT) angiography and invasive angiography. For anatomically driven PAES (types I-V), surgical intervention is indicated due to the risk of permanent vascular damage. If the artery is intact, myotomy alone yields excellent long-term results; however, if stenoses or occlusions are already present, arterial reconstruction is required. For symptomatic functional PAES (type VI), botulinum toxin injections offer a nonsurgical alternative to myotomy.