Gourgiotis et al Figure 2 Computed tomographic angiogram ﬁndings with bilateral popliteal artery entrapment syndrome. period, they had been followed clinically, unless they express complains associated with popliteal vessel troubles. All the patients were cured of their symptoms. Discussion The popliteal fossa is a diamond-shaped depression at the posterior of the knee that is bordered by biceps femoris tendon superolaterally, semimembranosus muscle supero- medially, and medial and lateral hands of the gastrocnemius muscle inferiorly. The popliteal artery normally courses between the median and lateral heads of gastrocnemius muscle. Popliteal artery might be entrapped by neighbour- ing muscles and tendons due to variations that occur during embryologic development of the muscles and arteries (Elias et al 2003). Several classiﬁcations of a number of anatomical variants of PAES have been described (Insua et al 1970; Whelan 1976; Bouhoutsos and Daskalakis 1981; Hoelting et al 1997). In the commonest of these, the popliteal artery enters the popliteal 86 fossa by curving medial to the medial head of gastrocnemius. The artery then courses laterally, deep to the medial head, between the latter and the underlying medial condyle of the femur. In other variants, a slip of gastrocnemius, a ﬁbrous band or the popliteus muscle may cause constriction of the artery. It is also possible for the popliteal artery to undergo compression without an embryological anomaly being present. This condition, termed physiological PAES, may be due to a hypertrophied gastrocnemius, soleus, plantaris, or semimembranosus muscle causing vascular compression and is sometimes seen in highly trained athletes (Gibson et al 1977; Erdoes et al 1994; Akkersdijk et al 1995). So PAES is most commonly found in young sportsmen or soldiers with well-developed muscles. Therefore, military surgeons have taken a special interest in this disorder, which has increased the diagnostic rate of PAES in military personnel (Love and Whelan 1965; Rich et al 1979; Rich 1982). PAES must always be included in the list of differential diagnoses in young patients presenting with symptoms Vascular Health and Risk Management 2008:4(1)