Iliac Artery Stress Test
A patient was evaluated for complaints of right lower extremity claudication that had persisted for 2 years. Ankle-brachial index was normal in both legs but Doppler evaluation detected a stenosis at the origin of the right common iliac artery. Angiography revealed a complex stenosis of intermediate severity (Figure, A). The pressure gradient across the lesion under basal conditions was 6 mm Hg (mean arterial pressure [MAP] was 99 mm Hg in the aorta and was 93 mm Hg in the right common femoral artery). After administration of 400 μg of nitroglycerin, the pressure gradient increased to 22 mm Hg and the MAP in the right femoral artery decreased significantly (MAP in aorta and right common femoral artery were 90 and 68 mm Hg, respectively). A 9 mm×18 mm stent was placed at the site of the lesion (Figure, B), with resolution of the pressure gradient.
In this case, nitroglycerin was used to increase flow in the iliac artery in an attempt to simulate the hemodynamic changes that would occur with exercise. There was a small pressure drop across the lesion under basal conditions, but the gradient increased and the MAP in the common femoral artery decreased significantly in the setting of increased flow. This case suggests that hemodynamic evaluation of iliac disease under high-flow conditions can provide additional useful information to that obtained under basal conditions, especially in patients whose complaints occur solely during exertion.
The editor of Images in Cardiovascular Medicine is Hugh A. McAllister, Jr, MD, Chief, Department of Pathology, St Luke’s Episcopal Hospital and Texas Heart Institute, and Clinical Professor of Pathology, University of Texas Medical School and Baylor College of Medicine.
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