Question

A patient presents with thigh and calf pain and is able to walk a claudication distance of 500 meters. No palpable pulses are present in the affected limb, but pulses in the opposite limb are normal. Where is the disease most likely located?

• A. External iliac stenosis
• B. Supra renal aorta
• C. Infra renal aorta
• D. Popliteal occlusion

Hint:

PAD Localization Rules:
- Calf pain + Normal femoral pulse = Superficial Femoral Artery (SFA) or Popliteal disease.
- Thigh/Calf pain + Absent femoral pulse unilaterally = Iliac Artery disease.
- Bilateral Buttock pain + Absent femoral pulses bilaterally + Impotence = Aortoiliac disease (Leriche Syndrome).

Answer 1

The Correct Option is A

Concept:
The clinical scenario requires the clinician to anatomically localize an atherosclerotic occlusion in Peripheral Arterial Disease (PAD) based purely on the patient's symptomatic muscle groups and physical pulse examination.
Explanation:
• In peripheral arterial disease, intermittent claudication (ischemic muscle pain brought on by exercise) classically occurs in the muscle bed immediately distal to the arterial stenosis or occlusion.

• The patient complains of pain in both the thigh and the calf on one side.

• Thigh claudication indicates disease proximal to the Deep Femoral Artery (Profunda Femoris), while calf pain indicates disease proximal to the Superficial Femoral Artery.

• Therefore, the occlusion must be higher up, in the aortoiliac segment.

• The physical exam reveals completely absent pulses throughout the affected limb (including the common femoral pulse in the groin), but completely normal pulses in the opposite limb.

• This unilateral presentation rules out aortic disease (Supra-renal or Infra-renal aorta). Aortic occlusions (like Leriche syndrome) produce bilateral buttock/thigh claudication, bilateral absent femoral pulses, and erectile dysfunction.

• A popliteal occlusion would cause isolated calf claudication, but importantly, the femoral pulse in the groin would remain completely normal and palpable.

• The external iliac artery supplies the entire lower limb on one side; an occlusion here perfectly explains unilateral absent femoral/distal pulses and unilateral thigh/calf claudication.
Final Answer:
Unilateral thigh and calf claudication with unilaterally absent pulses localizes the atherosclerotic disease to the ipsilateral external iliac artery.