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Aortic Dissection

David A. Wa ld, DO

Key Points

• Always consider aortic dissection in patients presenting

with the acute onset of chest or thoracic back pain.

• Initiate a rapid reduction in heart rate and blood pressure in all patients with a high clinical suspicion for aortic dissection before obtaining confirmatory diagnostic

imaging.

INTRODUCTION

Acute aortic dissection is a rare but potentially life-threatening

condition. Although the true incidence is unknown, it is

estimated that there are between 6,000 and 10,000 new

cases annually in the United States. Aortic dissection is

more prevalent in men and in patients with advanced age,

with approximately 75% occurring in patients between

40 and 70 years of age. Younger patients with aortic dissection usually have a history of an underlying connective

tissue disease. Of note, about half of all aortic dissections

in women under the age of 40 years occur in the third trimester or early postpartum period.

Risk factors for acute aortic dissection include chronic

hypertension, a bicuspid aortic value, coarctation of the

aorta, or inherited connective tissue disorders such as

Ehlers-Danlos and Marfan syndromes. Vascular inflammatory disorders such as giant cell arteritis or Takayasu arte ­

ritis are additional risk factors for dissection.

Aortic dissection results from a tear in the intimal layer

of the vessel wall. Common inciting factors include the

chronic conditions listed previously, as well as illicit drug

use or blunt thoracic trauma. High-pressure pulsatile

blood will travel through this tear into the media layer of

the aorta, thereby separating the intima from the adventitia. This creates a false lumen for aortic blood flow that can

70

• Stanford type A (proximal) dissections typically require

surgical intervention, whereas Stanford type B (dista l)