Correct Answer: B. Aortoiliac bifurcation
The clinical triad of impotence, bilateral resting leg pain, and bilateral leg findings is pathognomonic for Leriche syndrome — aortoiliac occlusive disease. This syndrome results from thrombotic occlusion at the aortoiliac bifurcation, which is the most common site of atherosclerotic occlusion in the lower limb vasculature. The aortoiliac bifurcation is a natural narrowing point where flow turbulence and atherosclerotic plaque preferentially accumulate. Impotence occurs because the internal iliac arteries (which arise from the aortic bifurcation) are compromised, reducing penile perfusion pressure. Bilateral resting pain and claudication occur because both legs lose their primary blood supply distal to the occlusion. The bilateral symmetry of findings is the key discriminator — it indicates proximal, central pathology rather than peripheral arterial disease. In Indian vascular surgery practice, aortoiliac disease is increasingly recognized in middle-aged smokers and diabetic patients. The diagnosis is confirmed by duplex ultrasound or CT angiography, and management ranges from conservative therapy (smoking cessation, antiplatelet agents) to endovascular intervention (aortoiliac stenting) or surgical reconstruction (aortofemoral bypass), depending on symptom severity and anatomy.
Why the other options are wrong
A. Bilateral popliteal arteries — Popliteal artery occlusion causes claudication in the calf and foot, but impotence is not a feature because the internal iliac arteries remain patent. Bilateral popliteal disease would present with calf pain on walking, not resting pain, and would spare sexual function. This option misses the proximal nature of the pathology. C. Bilateral femoral arteries — Femoral artery occlusion causes thigh and calf claudication but does not impair penile perfusion because the internal iliac arteries (which supply the penis via pudendal arteries) remain patent. Impotence is the discriminating feature that points to aortoiliac disease, not femoral disease. Bilateral femoral occlusion would not explain the erectile dysfunction. D. Bilateral internal iliac arteries — While internal iliac occlusion would cause impotence, it would not typically cause bilateral resting leg pain because the external iliac arteries (which supply the legs) remain patent and provide adequate perfusion. Isolated internal iliac disease is rare and usually unilateral. The combination of impotence AND bilateral leg ischemia points to aortoiliac bifurcation involvement, not isolated internal iliac disease.
High-Yield Facts
- Leriche syndrome = aortoiliac occlusion presenting with impotence + bilateral claudication/resting pain + absent femoral pulses.
- Aortoiliac bifurcation is the most common site of atherosclerotic occlusion in lower limb vascular disease due to flow turbulence and plaque predilection.
- Internal iliac arteries arise from the aortic bifurcation; their occlusion causes erectile dysfunction via reduced penile perfusion (pudendal artery compromise).
- Bilateral symmetry of leg findings is the key to recognizing proximal (aortoiliac) rather than peripheral arterial disease.
- Resting pain (not just claudication) indicates critical limb ischemia and demands urgent vascular imaging and intervention to prevent tissue loss.
Mnemonics
LERICHE = Aortoiliac Lower limb claudication + Erectile dysfunction + Resting pain + Internal iliac compromise + Critical ischemia + High bifurcation pathology + Exam shows absent femoral pulses. Use this when you see impotence + bilateral leg pain. IBF Rule: Impotence + Bilateral + Femoral pulse absent If a patient has impotence AND bilateral leg ischemia AND no femoral pulses, think aortoiliac bifurcation occlusion. This triad is pathognomonic for Leriche syndrome.
NBE Trap
NBE pairs impotence with femoral or popliteal disease to trap students who forget that penile perfusion depends on the internal iliac arteries (which branch from the aortic bifurcation). The key discriminator is the combination of impotence + bilateral leg ischemia, which only aortoiliac disease explains.
Clinical Pearl
In Indian vascular clinics, Leriche syndrome is increasingly seen in middle-aged smokers and diabetic patients presenting with "impotence" as the chief complaint — vascular surgeons must always ask about leg pain and check femoral pulses in such patients. Early recognition and aortoiliac stenting can restore both sexual function and limb perfusion.
_Reference: Bailey & Love Ch. 52 (Vascular Surgery); Harrison Ch. 246 (Peripheral Arterial Disease)_