Aortic Dissection
Diagnosis and Treatment of a Potentially Fatal Condition
Aortic dissection is uncommon but can lead to serious consequences, including death. What exactly is this condition?
Actor John Ritter, star of the television sitcoms Three's Company and 8 Simple Rules For Dating My Teenage Daughter, died in September of 2003 of a condition that is potentially fatal. While filming another episode of 8 Simple Rules, he collapsed unexpectedly. What he had suffered from was an aortic dissection, a tear of the large artery exiting the heart. He died regardless of efforts by surgeons to repair the defect.
This is something that can be scary to hear about for the first time. It is not common, but it can happen.
The Disease Process
The aorta, like all arteries, consists of three layers in its wall. Aortic dissection begins when there is a tear in the innermost layer. Blood gets forced into the space between the inner and middle layers. The inner layer separates from the vessel wall because of pressure from forward blood flow, becoming a loose flap within the artery. This dissection can continue along the length of the artery as more blood is forced in between the layers. From there, a number of things can happen. If the outer layers also tear, massive bleeding can occur. If the flap reaches an artery stemming from the aorta, it can obstruct blood flow into that artery. Organs like the heart, brain, kidneys, and even leg muscles can be affected depending on which arteries are blocked off.
The major symptom is chest pain, particularly one that is severe and feels like something inside is tearing apart. The location of this pain can include the chest plus the back, but it can also involve places like the neck, arms, and abdomen depending on where along the aorta the dissection is occurring. Other symptoms and signs occur with decreased blood flow to certain areas, such as fainting and decreased pulses.
While millions of Americans have high blood pressure and annual cases of aortic dissection are only in the thousands, hypertension is among the most common of risk factors for aortic dissection. Certain inheritable conditions involving weakening of connective tissues, like Marfan's syndrome and Ehlers-Danlos syndrome, are also risk factors. Aortic dissection can happen to anyone, though it is seen more in males and people aged 40 to 70 years.
The Management
After diagnosing aortic dissection with imaging studies, like chest x-ray and chest CT scan, the treatment is typically one of two options: surgical repair or beta-blocker medications to slow the heart and decrease the stress on the aorta. In general, it depends a lot on the location of the dissection. If it is in the descending portion of the aorta away from the heart, beta-blockers are a good start. If it involves the ascending portion just where it exits the heart, surgery is generally the option because the shear forces there are too great to be managed with medication. Of course, other factors determine the best treatment, such as the risk of rupture.
Aortic dissection is rare but the mortality rate increases significantly the longer it goes untreated. There is good news, however. A study conducted by the University of Michigan published in the July 4, 2006, issue of Circulation showed that 90% of patients who had surgery for aortic dissection involving the ascending aorta were still alive three years after diagnosis. With more knowledge about this condition among physicians and patients, aortic dissection may become better managed in the years to come.
References
- eMedicine - Aortic Dissection
- Tsai, Thomas T., et al. "Long-Term Survival in Patients Presenting With Type A Acute Aortic Dissection: Insights From the International Registry of Acute Aortic Dissection (IRAD)." Circulation 114.[Suppl I] (July 4, 2006): I-350 - I-356.
