Ascending Aortic dissection
Descending Aortic dissection
Answer B. Descending Aortic dissection
Aortic dissection is a devastating disease that occurs as a result of the degeneration of the thoracic aorta.
Middle-aged men are the most often affected with only 5% of dissections occurring in the under 40 age group.
The classical presentation is the sudden onset of a razor-sharp pain between shoulder blades.
There are two major types of classification, the De Bakey and the Stanford.
The Stanford classification is simpler with two types of dissection described, Type A and Type B. Type A is equivalent to a De Bakey Type I or Type 11 dissection, involving the ascending arch, whereas Type B just involves the descending aorta. Type A is generally treated with urgent surgery with Type B generally being treated conservatively.
Sign on chest radiograph-
The most common abnormality is the widening of the mediastinum which is often associated with an indistinct outline of the aorta or an irregular wavy contour.
More characteristic but a less frequent radiological finding is localized dilatation of the aortic knuckle and upper descending aorta, giving rise to a prominent hump sign which will indicate aneurysmal dilatation or unfolding
of the arch.
The CT scan will show the true and false lumens associated with dissection.