Occlusive Disease: Aorta & Iliac Arteries

Key Features

Essentials of Diagnosis

• Claudication: cramping pain or tiredness in the calf, leg, or hip while walking

• Diminished femoral pulses

• Tissue loss (ulceration, gangrene) or rest pain

General Considerations

• Pathologic changes of atherosclerosis may be diffuse, but flow-limiting stenoses occur segmentally

• In the lower extremities, stenoses classically occur in three anatomic segments

  • The aorto-iliac segment

  • The femoral-popliteal segment

  • The infrapopliteal, or tibial, segment of the arterial tree

• Lesions in the distal aorta and proximal common iliac arteries often occur in relatively young men, age 50–60 years, who are smokers

• Disease progression may lead to complete occlusion of one or both common iliac arteries, which can precipitate occlusion of the entire abdominal aorta to the level of the renal arteries

• Atherosclerosis of the femoro-popliteal segment usually

  • Occurs about a decade following the development of aorto-iliac disease

  • Is evenly distributed between men and women

Demographics

• Prevalence of peripheral artery disease (PAD) is 30% in patients who are

  • 70 years old without other risk factors

  • 50 years old with risk factors such as diabetes mellitus or tobacco use

Clinical Findings

Symptoms and Signs

• About two-thirds of patients with PAD are either asymptomatic or do not have classic symptoms

• Intermittent claudication (pain with ambulation)

  • Occurs from insufficient blood flow relative to demand

  • Severe and cramping in quality

  • Usually located in the calf muscles

  • May be bilateral

  • Severity varies day by day

• The pain from aorto-iliac lesions may extend into the thigh and buttocks

• Weakness in the legs when walking or simply extreme limb fatigue

• Symptoms relieved with rest

• Erectile dysfunction common with bilateral common iliac disease

• Femoral and distal pulses are absent or very weak

• Bruits may be heard over the aorta, iliac, and femoral arteries

Differential Diagnosis

• Vascular disease of the femoral or popliteal arteries

• Lumbar spinal stenosis

• Degenerative joint disease of the hips

Diagnosis

Imaging Studies

• CT angiography and magnetic resonance angiography can identify the anatomic location of disease

• Duplex ultrasound has a limited role in imaging the aortoiliac segment because of overlying bowel

• Imaging is required only when symptoms necessitate intervention, since vascular testing should identify the involved levels of the arterial tree

Diagnostic Procedures

• Doppler examination

  • Ratio of systolic blood pressure at ankle compared with brachial artery of upper arm is reduced to below 0.9 (normal ratio is 0.9–1.2)

  • This difference is exaggerated by exercise

• Segmental wave-forms or pulse volume recordings

  • Obtained by strain gaze technology through blood pressure cuffs

  • Demonstrate blunting of the arterial inflow throughout the leg