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Difficulty: Very hardSurgical and Procedural Interventions

A 67-year-old man is evaluated in the emergency department for sudden-onset, severe, tearing pain between his shoulder blades that began two hours ago. He has a history of poorly controlled hypertension, hyperlipidemia, and a 40-pack-year smoking history. On presentation, his blood pressure is 218/114 mmHg in the right arm and 212/110 mmHg in the left arm, and his heart rate is 112/min. Physical examination reveals a distressed, diaphoretic patient. Cardiovascular examination shows a regular rhythm with no murmurs. Abdominal examination reveals diffuse tenderness with voluntary guarding and diminished bowel sounds. The right lower extremity is cool to the touch with absent dorsalis pedis and posterior tibial pulses; left lower extremity pulses are normal. Initial laboratory studies show a serum lactate level of 5.8 mmol/L and a serum creatinine of 2.1 mg/dL (baseline 1.0 mg/dL). Intravenous esmolol and nicardipine infusions are initiated, successfully lowering his blood pressure to 118/74 mmHg and heart rate to 62/min. A computed tomography angiography of the chest, abdomen, and pelvis demonstrates an intimal flap originating just distal to the left subclavian artery and extending into the common iliac arteries. The true lumen is severely compressed by the false lumen. The superior mesenteric and right renal arteries arise from the false lumen, which exhibits delayed and sluggish contrast enhancement. Which of the following is the most appropriate next step in the management of this patient?

  1. Thoracic endovascular aortic repair and branch vessel stentingAnswer
  2. B
    Continued medical management in the intensive care unit
  3. C
    Emergent exploratory laparotomy
  4. D
    Emergent open surgical replacement of the descending aorta
  5. E
    Systemic anticoagulation with intravenous unfractionated heparin

Answer

Thoracic endovascular aortic repair and branch vessel stenting
The correct answer involves performing a thoracic endovascular aortic repair (TEVAR) and branch vessel stenting. This patient has a Stanford Type B aortic dissection (originating distal to the left subclavian artery). While the initial management for Type B dissection is strict anti-impulse therapy (which was appropriately initiated), this patient's presentation is complicated by malperfusion syndrome. Malperfusion is evidenced by his diffuse abdominal pain with elevated lactate (mesenteric ischemia), acute acute kidney injury (renal ischemia), and a cool, pulseless right leg (limb ischemia). The CT scan confirms that the superior mesenteric and right renal arteries originate from the compromised false lumen. In the setting of complicated Type B dissection (malperfusion, rupture, rapid expansion, or refractory pain), emergent procedural intervention is required to open the true lumen and restore flow to the branch vessels. TEVAR has largely replaced open surgical repair in this setting due to significantly lower rates of mortality and perioperative complications, such as spinal cord ischemia.

Step-by-Step Solution

1
Identify the primary diagnosis based on the clinical presentation and imaging.
The patient has an acute Type B aortic dissection, indicated by tearing back pain, severe hypertension, and an intimal flap originating distal to the left subclavian artery on CT angiography.
Accurate anatomical classification (Stanford Type A vs. Type B) dictates the overarching management algorithm.
2
Assess for complications indicating a deviation from standard medical therapy.
The patient exhibits malperfusion syndrome affecting the gut (abdominal pain, elevated lactate), kidneys (elevated creatinine), and right leg (absent pulses, cool extremity), caused by the false lumen compromising branch arteries.
Uncomplicated Type B dissections are managed medically. Complicated Type B dissections (rupture, malperfusion, rapid expansion, intractable pain) require emergent procedural intervention.
3
Select the most appropriate procedural intervention for complicated Type B aortic dissection.
Thoracic endovascular aortic repair (TEVAR) is selected.
Endovascular techniques can fenestrate the flap or stent the true lumen to restore distal perfusion with significantly lower morbidity and mortality compared to open descending aortic surgery.

Key Concept

Management of complicated Type B aortic dissection with malperfusion syndrome requires emergent endovascular intervention (TEVAR/stenting) rather than medical therapy alone.
Estimated Time:2m 0s
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Topics

Surgical and Procedural Interventions

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