Vascular Disease USMLE Step 1 Practice Question
A 68-year-old woman with a 15-year history of poorly controlled hypertension presents to the emergency department with acute onset of left leg pain and coldness that began 2 hours ago. She reports no preceding trauma or prolonged immobility. Vital signs: BP 168/94 mmHg, HR 102/min, RR 18/min, T 37.2°C. Physical examination reveals pallor of the left foot, absent left femoral and distal pulses, but palpable right femoral pulse. Abdominal examination reveals a pulsatile epigastric mass without tenderness. CT angiography of the abdomen and pelvis shows a 5.5 cm infrarenal abdominal aortic aneurysm with an eccentric mural thrombus and no active extravasation. Laboratory studies: hemoglobin 9.8 g/dL, WBC 8.2 k/µL, creatinine 1.4 mg/dL. Which of the following is the most likely diagnosis explaining her acute presentation?
Answer choices
- AAcute aortic dissection with branch vessel involvement
- BThrombosis of an iliac artery bifurcation secondary to aortic mural thrombus embolizationCorrect answer
- CAcute left femoral artery thrombosis from in-situ thrombosis
- DRuptured abdominal aortic aneurysm with contained hemorrhage
- EAcute mesenteric ischemia from celiac artery compression
- FLeft lower extremity compartment syndrome from rhabdomyolysis
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