Acute aortic dissection is life-threatening. The pathophysiology of aortic
dissection usually starts from an intimal tear with subsequent penetration of blood
through the aortic media layer. Sometimes, a spontaneous hemorrhage of the vasa
vasorum within the aortic wall will cause an aortic intramural hematoma to form, which
will initiate aortic dissection. Blood in the aortic wall results in a dissection plane within
the media and creates a false lumen, which may propagate antegradely or retrogradely
along the aorta. Aortic media degeneration and cystic medial necrosis are common
findings in aortic dissection. In addition to aortic medial abnormalities, there are several
risk factors that are associated with acute aortic dissection. Hypertension is the most
common prevalent risk factor. Recent studies have found that several mutations
involving genes encoding for components of extracellular matrix and smooth muscle
cell proteins are responsible for aortic dissection in Marfan syndrome, Loeys-Dietz
syndrome, vascular Ehlers-Danlos syndrome, and familial thoracic aortic aneurysm and
dissection. Congenital aortic diseases, such as coarctation of the aorta or bicuspid aortic
valve are important risk factors for aortic dissection. Other acquired conditions, such as
aortitis, pregnancy, drug abuse, trauma, and some medical and surgical procedures are
also related to aortic dissection. This chapter makes an extensive review of the current
knowledge about the pathophysiology of acute aortic dissection. The known risk factors
that contribute to the occurrence of aortic dissection will be discussed.
Keywords: Acquired disease, Acute aortic dissection, Aortitis, Bicuspid aortic
valve, Coarctation of the aorta, Congenital aortic disease, Congenital connective
tissue disease, Drug abuse, Ehlers–Danlos syndrome, Familial thoracic aortic
aneurysm and dissection, Hypertension, Iatrogenic causes, Loeys–Dietz syndrome,
Marfan syndrome, Pathophysiology, Pregnancy, Risk factors, Trauma, Turner
syndrome, Type A dissection.
