A 70-year-old man presents to the clinic with worsening loss of sensation on the right foot for 6 months. His medical history includes type 2 diabetes mellitus and hypertension which are treated with metformin, atorvastatin, and lisinopril. He has a history of smoking 1 pack of cigarettes per day for 40 years. Vital signs include blood pressure 145/83 mmHg and pulse of 87 beats/minute. Random blood sugar is 187 mg/dL. Physical examination shows that the lower back, hips and knees have full range of movement. Peripheral pulses in the upper and lower limbs are palpable and 2+. There is motor weakness in right foot plantar flexion and decreased plantar sensation on the right. Further investigation with doppler ultrasound shows an arterial aneurysm behind the right knee, and it is concluded that it causes compression of the tibial nerve.
Which of the following is the correct order of arterial vessels feeding this aneurysm?
The correct answer is:
B) External iliac artery, common femoral artery, superficial femoral artery, popliteal artery
The patient has popliteal aneurysm, a dilation of part of the popliteal artery due to genetic and/or inflammatory processes. Most often this is asymptomatic, but it can cause mass effect to surrounding structures such as the tibial nerve as in this patient.
Answer choice A: External iliac artery, common femoral artery, obturator artery, popliteal artery, is incorrect. The obturator artery does not come from the common femoral artery but rather from the internal iliac artery.
Answer choice C: Internal iliac artery, common femoral artery, deep femoral artery, popliteal artery, is incorrect. The internal iliac artery does not branch into the common femoral artery, and the popliteal artery comes from the superficial femoral artery.
Answer choice D: Internal iliac artery, common femoral artery, popliteal artery, is incorrect. The internal iliac artery does not branch into the common femoral artery.
Answer choice E: Superior mesenteric artery, external iliac artery, femoral artery, popliteal artery, is incorrect. The superior mesenteric artery does not branch into the external iliac artery.
Key Learning Point
The external iliac artery branches into the common femoral artery and then the superficial femoral artery which supplies the popliteal artery.
