Either subtype may lead to aneurysm or pseudoaneurysm formation, thrombosis or distal thromboembolism [5-8,15-19]. EIAE is a rare cause of performance-limiting claudication that occurs primarily in endurance athletes. Although EIAE typically occurs in cyclists, it has been described in other groups of elite endurance athletes. Symptoms include lower-extremity weakness, thigh pain, and symptom resolution after cessation of exercise [20]. Its etiology is poorly understood and may be multifactorial. Suggested mechanisms include repeated mechanical Reprint requests to: publications@acr.org Nonatherosclerotic Peripheral Arterial Disease trauma upon the external iliac artery by a hypertrophied psoas muscle during hip flexion with subsequent arterial kinking [21] and vasospasm [22]. Arterial-brachial pressure indexes typically decrease following exercise [20]. Connective tissue diseases are multisystem disorders, several of which profoundly involve the vascular system. MS is an autosomal-dominant (AD) connective tissue disorder caused by a mutation in the FBN1 gene that codes for fibrillin-1 and occurs in 1 in 20,000 individuals. The systems typically affected by MS are cardiovascular, ocular, and skeletal. MS is classically associated with aortic root aneurysms and dissection; however, the dissection flap may extend into the iliac arteries resulting in pain, pallor, paresthesias, and pulselessness [1,24]. LDS results from an AD heterozygous mutation in either of the genes that encode transforming growth factor beta. LDS has a much more aggressive clinical course than MS, with a mean survival of 26 years. Like MS, LDS is associated with aortic root aneurysm and dissection [3]. Vascular EDS, formerly known as EDS type IV, is an AD disease caused by a heterozygous mutation in the COL3A1 gene that encodes type III collagen. Vascular EDS can affect any vessel and carries a poor prognosis that is due to risk of life-threatening arterial rupture [4].
Nonatherosclerotic Peripheral Arterial Disease. Either subtype may lead to aneurysm or pseudoaneurysm formation, thrombosis or distal thromboembolism [5-8,15-19]. EIAE is a rare cause of performance-limiting claudication that occurs primarily in endurance athletes. Although EIAE typically occurs in cyclists, it has been described in other groups of elite endurance athletes. Symptoms include lower-extremity weakness, thigh pain, and symptom resolution after cessation of exercise [20]. Its etiology is poorly understood and may be multifactorial. Suggested mechanisms include repeated mechanical Reprint requests to: publications@acr.org Nonatherosclerotic Peripheral Arterial Disease trauma upon the external iliac artery by a hypertrophied psoas muscle during hip flexion with subsequent arterial kinking [21] and vasospasm [22]. Arterial-brachial pressure indexes typically decrease following exercise [20]. Connective tissue diseases are multisystem disorders, several of which profoundly involve the vascular system. MS is an autosomal-dominant (AD) connective tissue disorder caused by a mutation in the FBN1 gene that codes for fibrillin-1 and occurs in 1 in 20,000 individuals. The systems typically affected by MS are cardiovascular, ocular, and skeletal. MS is classically associated with aortic root aneurysms and dissection; however, the dissection flap may extend into the iliac arteries resulting in pain, pallor, paresthesias, and pulselessness [1,24]. LDS results from an AD heterozygous mutation in either of the genes that encode transforming growth factor beta. LDS has a much more aggressive clinical course than MS, with a mean survival of 26 years. Like MS, LDS is associated with aortic root aneurysm and dissection [3]. Vascular EDS, formerly known as EDS type IV, is an AD disease caused by a heterozygous mutation in the COL3A1 gene that encodes type III collagen. Vascular EDS can affect any vessel and carries a poor prognosis that is due to risk of life-threatening arterial rupture [4].