Endofibrosis is a rare cause of lower extremity claudication in a healthy young adult.¹ Given the increase in the number of high-intensity athletes during the past decade, the prevalence of endofibrosis is steadily increasing, making this disease relevant to the practice of the modern vascular surgeon. The pathology involves hypertrophy of the intimal layer of the iliac vessels, seen usually in runners or cyclists, and results in intimal thickening that leads to stenosis and decreased blood flow during heavy exercise.² Symptoms occur only at maximal exertion.

Diagnosis has previously been described by provocative duplex examinations and angiography, sometimes with pressure gradients obtained across the proposed lesion with vasodilators to mimic the exercise state.³ Angiographic findings are generally subtle, and often, pharmacologically stimulating the high level of exercise needed to induce symptoms in these patients may not be possible. The patient consented to the publication of this report in which we found the use of intravascular ultrasound (IVUS) imaging as a diagnostic tool to aid in the diagnosis of endofibrosis. We believe that IVUS imaging is superior to the other traditional modalities used for the diagnosis of this disease. In this report, we introduce the use of IVUS to definitively diagnose intimal thickening and endofibrosis, which leads to appropriate operative planning and surgical treatment.