Aortoiliac occlusive disease (AIOD) occurs commonly in patients with PAD. Significant lesions in the aortoiliac arterial segment are exposed easily by palpation of the femoral pulses. Any diminution of the palpable femoral pulse indicates that a more proximal obstruction exists. Obstructive lesions may be present in the infrarenal aorta, common iliac, internal iliac (hypogastric), external iliac, or combinations of any or all of these vessels. Occasionally, degenerated nonstenotic atheromatous disease exists in these vessels and may manifest by atheroembolism to the foot, the "blue toe" or "trash foot" syndrome. Generally, patients with aortoiliac PAD have a poorer general prognosis than those with more distal PAD.