Iliac Artery Endofibrosis in Athletes: A Case Series

Abstract

Introduction Endofibrosis of the external iliac arteries (IE) occurs in some high-performance athletes, particularly female cyclists, and causes leg pain on extreme exertion. Establishing the diagnosis in these cases is challenging, because a vascular cause is often not suspected initially. The anatomic lesion of IE is difficult to detect with B-mode ultrasound because of the characteristic smooth and diffuse thickening of the arterial wall. Standard treadmill testing can be equivocal in these athletes, but more intense or “extended” treadmill exercise can demonstrate the physiological abnormalities. Case Report This report describes our experience with 6 limbs of 4 patients found to have IE and who also underwent surgical intervention to relieve symptoms. All patients had normal resting ankle/brachial indices, except one, who also had iliac artery thrombosis. Duplex scanning showed diffusely increased velocities throughout external iliac segments. The treadmill exam was modified, with speeds ranging from 2.5 to 5.8 mph and exercise times up to 15 minutes required to provoke a significant decrease in ankle pressure. Monophasic, high-velocity postexercise Doppler flow waveforms helped to localize the site of the responsible lesions. Results All 6 limbs were treated by enlarging the affected external iliac artery with a vein patch angioplasty (thrombectomy was also performed in one patient). Inspection of the arterial lumen at surgery revealed a smooth, fibrous-appearing lesion with diffuse wall thickening. The 5 limbs, which had postoperative treadmill tests, all had normal results and these patients resumed athletic training. Among 5 limbs with postoperative duplex scans, 2 showed normal vessel diameter, and 3 had a dilated lumen. Conclusion Although the mechanism of IE is not known, the typical history and location of the lesions suggests that repetitive stress or bending of the vessels and high flow during extreme exercise leads to thickening of the arterial wall. Awareness of this entity and a modified vascular testing protocol are essential to establishing the diagnosis.