++
A 60-year-old woman with hypertension and a 40 pack-year smoking history presented to the emergency department with acute onset of right leg numbness and pallor. She also related long-standing burning and cramping in her hips and buttocks after walking about 50 yd. She had difficulty climbing stairs because she felt extremely weak after walking up 2 to 3 stairs.
++
On examination she had no palpable pulses in her lower extremities, including the femoral arteries. She had monophasic signals via a Doppler probe in her femoral and pedal arteries. Her skin envelope over both feet was intact, and she had normal motor function in both feet. Her right foot was slightly cooler than the left. She was started on heparin and admitted for further management of her acute and chronic presentation of peripheral vascular disease.
+++
Aortoiliac Occlusive Disease
++
Often found in conjunction with multilevel disease involving the femoropopliteal or infrageniculate arteries.
Patients with isolated aortoiliac occlusive disease (AIOD) tend to be younger with a significant smoking history and hypercholesterolemia.1
Patients with multilevel disease are older, diabetic, and hypertensive.1
A particularly aggressive form of AIOD is seen in younger female patients who are smokers, in that they have not only the occlusive disease but small or hypoplastic aortoiliac segments. These patients tend to fare worse because the durability of their repair is compromised due to the small arteries.2
+++
ETIOLOGY AND PATHOLOGY
++
AIOD, like many other forms of vascular disease, begins at branch points where the laminar flow is disrupted and turbulence arises.
++
This occurs at the aortic bifurcation and origins of the common iliac arteries.
Thrombosis or extension of the disease typically progresses in retrograde fashion into the aorta and the contralateral iliac.3
++
It is rare for patients with multilevel disease to have involvement of the visceral segment of the aorta or the renal arteries, and simultaneous procedures are rarely needed during lower extremity revascularization.
++
If the onset of thrombosis is gradual, collateralization is possible, and therefore the limb ischemia symptoms are not as dramatic as those with acute aortoiliac occlusion. Sources of collateralization include
Lumbar arteries via the circumflex iliac into the femoral, and profunda arteries (Figure 1-1).
Internal mammary artery, which continues as the inferior epigastric artery into the femoral artery.
Superior mesenteric artery continues into the inferior mesenteric artery (IMA) and hemorrhoidal artery pathway via the arc of Riolan and the meandering mesenteric artery.
All of these collaterals are important sources of flow to the lower extremity and should be preserved during interventions4 (Figure 1-2).
++