ANN ARBOR, Mich. -- Each year, 10,000 Americans suffer a sudden tear in the lining of their bodys largest blood vessel, the aorta. Its often misdiagnosed, and it can kill if not treated immediately. Actor John Ritter died of such a tear in 2003.
Better medical imaging and treatments such as medication, surgery and catheter-based procedures are now giving more patients a chance to survive this crisis, called aortic dissection. But once they leave the hospital, patients face a one-in-four chance of dying within a few years. And doctors dont have a reliable way of predicting who is most at risk of dying, and who might benefit most from surgery or other treatment.
Now, a study published in the July 26 New England Journal of Medicine by an international team of researchers may offer hope for aortic dissection survivors, and give guidance for their physicians. The researchers, led by University of Michigan Cardiovascular Center experts, propose a new way to predict post-hospital death risk for aortic dissection patients, and a new model for the mechanism behind that risk.
Their model focuses on a phenomenon that can easily be seen on modern medical-imaging scans: the presence of blood clots in the channel created when the layers of the aorta separate like two layers of an onion. This channel, called the false lumen, runs alongside the true lumen, which is the hollow middle area of the aorta that acts as the pipeline for blood to flow out of the heart and down through the abdomen.
As blood enters the false lumen from the top of the tear in the aorta, it gets trapped inside the new channel. Often, small openings at the bottom of the newly formed channel will allow the blood to flow out. But if the openings arent large, blood flow inside the false lumen is slowed down, pressure increases, and clots begin to form.
The study shows that the risk of post-hospital death is more than two-and-a-half times greater for patient
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Contact: Kara Gavin
kegavin@umich.edu
734-764-2220
University of Michigan Health System
25-Jul-2007