The recent description of exercise-induced intimal fibrosis affecting mainly the iliac artery (and therefore usually described as external iliac artery endofibrosis) has dramatically changed the diagnostic approach of unexplained recurrent lower limb exercise pain, especially in cyclists. Because arterial disease is often associated with the aftereffect of various concomitant musculotendinous lesions, several months may pass before an arterial origin is suspected. The arterial origin of the pain must not be eliminated on normal ankle-to-arm index or normal Doppler velocity profiles at rest. Ultrasound examinations taken at rest may show the lesions in 80% of endofibrotic patients and allow for the diagnosis of popliteal entrapment syndrome during dorsiflexion of the foot. However, the hemodynamic consequences of a stenosis on the aortoiliofemoral axis can only be proved by measurement of the ankle-to-arm index after exercise. A cutoff of this index <0.5 provides an 85% sensitivity in the detection of endofibrosis. Invasive investigations (arteriography or angioscopy) will confirm the diagnosis before surgery is discussed. Although long-term results in endofibrosis are unknown, most of the surgically treated patients return to competition.

Atherosclerosis and inflammatory arterial diseases are rare in young people. Since the early 1980s, an increasing incidence of iliac arterial stenosis in competition cyclists has been reported. Histological findings in these individuals are specific, with fibrosis of the intimal wall on histology and no atherosclerotic or inflammatory lesions. Clinical consequences of this arterial endofibrosis are usually described as an exercise-related subjective sensation of swollen thigh in one or both (15%) legs, with normal clinical and Doppler investigations at rest. Following maximal exercise, ankle-to-brachial systolic pressure index is lower than 0.5 in 85% of individuals with disease and is used as a key argument for diagnosis before deciding upon arteriography. Surgery (recalibrated saphenous grafts or angioplasty-endofibrosectomy) seems to be efficient to allow an early return to competition, but its long term results are still to be evaluated. The physiopathology of this disease and its possible relationship with atherosclerosis are unknown.