Aortic Dissection

Aortic dissection occurs when a tear in the inner wall of the aorta causes blood to flow between the layers of the wall of the aorta, forcing the layers apart. The dissection typically extends anterograde, but can extend retrograde from the site of the intimal tear. Aortic dissection is a medical emergency and can quickly lead to death, even with optimal treatment. If the dissection tears the aorta completely open (through all three layers), massive and rapid blood loss occurs. Aortic dissections resulting in rupture have an 80% mortality rate, and 50% of patients die before they even reach the hospital. All acute ascending aortic dissections require emergency surgery to prevent rupture and death. Chronic enlargement of the ascending aorta from aneurism or previously unrecognized and untreated aortic dissections is repaired electively when it reaches 6 cm (2.4 in) in size and surgery may be recommended between for as little as 4.5 cm (1.8 in) in size if the patient has one of several connective tissue disorders or a family history of ruptured aorta.