Among dissecting aneurysm types, which has the lowest mortality rate?

Among dissecting aneurysm types, which has the lowest mortality rate?

• A. Type I
• B. Type III
• C. Type II
• D. Type IV

Answer: (B)

The longest survival odds come from a dissection that starts in the descending thoracic aorta. When the tear is confined to the descending aorta, the immediate life-threatening involvement of the heart and major arch vessels is less likely, so early mortality tends to be lower. In contrast, dissections that involve the ascending aorta carry higher risk of fatal complications like coronary or aortic arch vessel compromise and rupture into the pericardial sac. Rupture into the pericardial space, often considered the most catastrophic scenario, has the worst prognosis. Therefore, the dissection beginning in the descending aorta has the lowest mortality among these types.

The longest survival odds come from a dissection that starts in the descending thoracic aorta. When the tear is confined to the descending aorta, the immediate life-threatening involvement of the heart and major arch vessels is less likely, so early mortality tends to be lower. In contrast, dissections that involve the ascending aorta carry higher risk of fatal complications like coronary or aortic arch vessel compromise and rupture into the pericardial sac. Rupture into the pericardial space, often considered the most catastrophic scenario, has the worst prognosis. Therefore, the dissection beginning in the descending aorta has the lowest mortality among these types.