Sports-related flow limitations in the iliac arteries in endurance athletes : aetiology, diagnosis, treatment and future developments

Approximately one in five top-level cyclists will develop sports-related flow limitations in the iliac arteries. These flow limitations may be caused by a vascular lumen narrowing due to endofibrotic thickening of the intima and/or by kinking of the vessels. In some athletes, extreme vessel length contributes to this kinking. Endofibrotic thickening is a result of a repetitive vessel damage due to haemodynamic and mechanical stress. Atherosclerotic intimal thickening is seldom encountered in these young athletes. This type of sports-related flow limitation shows no relationship with the classical risk factors for atherosclerosis like smoking, hypercholesterolaemia or family predisposition for arterial diseases. The patient's history is paramount for diagnosis. If an athlete reports typical claudication-like complaints in a leg at maximal effort, which disappear quickly at rest, approximately two out of three will have a flow limitation in the iliac artery. In current (sports) medical practice, this diagnosis is often missed, since a vascular cause is not expected in this healthy athletic population. Even if suspected, the routinely available diagnostic tests often appear insufficient. Definite diagnosis can be made by a combination of the patient's history and special designed tests consisting of a maximal cycle ergometer test with ankle blood pressure measurements and/or an echo-Doppler examination with provocative manoeuvres like hip flexion and exercise. Conservative treatment consists of diminishing or even completely stopping the provocative sports activity. If conservative treatment is insufficient or deemed unacceptable, surgical treatment might be considered. As surgery needs to be tailored to the underlying lesions, a detailed analysis before surgery is necessary. Standard clinical tests, used for visualising atherosclerotic diseases, are inadequate to identify and quantify the causes of flow limitations. Echo-Doppler examination and magnetic resonance angiography with both flexed and extended hips have ...