A 23-year-old competitive athlete comes to the primary health care facility complaining about progressively worsening pain and cramps in his left buttock and lower leg over the last 3 months. The pain has been so severe during exercise that he could not participate in the last competition. He mentions that pain is exacerbated by running or vigorous cycling and usually is relieved after 2 minutes of rest. Two years ago, he underwent surgical repair for a femoral shaft fracture. He is otherwise healthy except for the use of omeprazole occasionally for gastroesophageal reflux disease (GERD) symptoms. Clinical examination revealed an audible 2/6 murmur in left common iliac artery and pain exacerbation in left thigh, buttock and calf after hip hyperflexion. A computed tomography angiography (CTA) was ordered and detected a 90% stenosis of proximal segment of left common iliac artery with collateral blood flow and considerable stenosis of left external iliac artery. The patient was referred to a sports medicine specialist and underwent a surgical repair of the stenotic artery and returned to his previous level of performance within 2 months.
Which of the following risk factors have mainly contributed to disease manifestation?
The correct answer is: C. Endurance exercise (i.e. cycling)
Pain in the left buttock and leg that is related to exercise intensity and subsides after few minutes of rest indicates symptoms of vascular origin. This patient is a competitive athlete with no other cardiovascular risk factors. This clinical presentation in combination with age and the type of activity (i.e. cycling), raises the suspicion for kinking of the iliac artery due to endofibrosis.
Iliac artery endofibrosis is a rare clinical entity that is found primarily in young endurance exercise athletes and especially in cyclists.1,2 The position of the cyclist and psoas hypertrophy contribute to the development of this condition.1 The most predominant symptoms are pain or numbness at the thigh, buttock or calf ipsilaterally to the affected side.1,2 The patient often stops the exercise to relieve his symptoms.
Clinical examination may reveal an audible bruit over common or external iliac arteries.1 Arterial pulses are usually palpable in peripheral vasculature.1,2 Resting ankle-branchial pressure index being measured 5 minutes after stopping exercise is a noninvasive useful examination and can detect potential flow restriction to lower limb. Imaging studies with duplex ultrasonography, CTA or magnetic resonance angiography (MRA) are used to confirm the diagnosis.1,2
A conservative therapeutic approach could be an option, suggesting withdrawal from cycling and any activities that include hip hyperflexion. However, open surgical treatment remains the mainstay of treatment with excision and release of fibrotic segments.1,2
Femoral shaft fracture (Answer A), atherosclerotic lesions (Answer B) and vessel wall inflammation (Answer E), considering the age and general health status of the patient, are less likely to be the causes of his symptoms. Imaging studies could help differentiate between different vascular etiologies of the patient's current condition.
Protein supplement (Answer D) consumption with sulfur amino acids have been reported in rare cases of young athletes with iliac artery endofibrosis. However, no clear association has been established yet.1
Iliac artery endofibrosis represents an underecognized condition that is characterized by intimal thickening of iliac artery. It is most often found in young cyclists that complain about leg pain and weakness during maximal strength. Abstinence from exercise and open surgical approach in refractory cases are the proposed treatment approaches.1,2
Peach G, Schep G, Palfreeman R, Beard JD, Thompson MM, Hinchliffe RJ. Endofibrosis and kinking of the iliac arteries in athletes: a systematic review. Eur J Vasc Endovasc Surg 2012;43:208-17.
Veraldi GF, Macrì M, Criscenti P, et al. Arterial endofibrosis in professional cyclists. G Chir 2015;36:267-71.