Coarctation of the Aorta

Overview

Coarctation of the aorta (CoA) is a congenital (present at birth) condition where there's narrowing of the main blood vessel that carries oxygen-rich blood from the heart to the body (aorta). The narrowed segment (coarctation) is typically short, with the aorta opening up to normal size past the coarctation. However, the coarctation can cause problems with increased work of the heart and high blood pressure.

Typically, the narrowed segment occurs where the ductus arteriosus, a blood vessel in all newborns, connects to the aorta. It should shrink and eventually close within the first few days of life. Still, in some cases, the narrowing of the ductus causes the main aorta to narrow, where some of this ductal tissue has extended to the aorta, creating a coarctation. If this occurs, newborn babies can become sick. They have feeding problems, fussiness, sweating, paleness, and difficulty breathing. Also, it becomes difficult to feel pulses in the baby.

Symptoms

The classic findings on a physical exam for CoA are high blood pressure in the arms compared to the legs, and weak pulses felt in the legs. CoA can be confirmed with tests such as an echocardiogram or a cardiac magnetic resonance imaging (MRI) scan. If severe, CoA can cause heart failure in infancy, as the heart must work too hard to get blood to pass through the area of narrowing. The baby may become rapidly sick, breathing heavily and feeding poorly. However, if heart failure does not occur, some people may not have coarctation diagnosed until later in life, perhaps as adults. The body tries to get blood around the coarctation by rerouting blood through other vessels, such as the intercostal (under the ribs) arteries or other collateral vessels. This allows more blood to reach the lower body than would otherwise pass through the narrowed aorta.

Progression and possible complications

Without treatment to correct CoA, the average life expectancy is 34 years. Even when the narrowed artery is corrected, adults born with CoA may face ongoing health problems, including hypertension (high blood pressure), weakening of the aorta wall, and aneurysm. With an aneurysm, the vessel wall weakens and “balloons” or forms a “sack,” making it vulnerable to rupture. Some people with CoA may also have cerebral (in the head) aneurysms.

Treatment

If a coarctation is detected in a newborn, a medicine that is used to keep the ductus open, called prostaglandin E1, is given through an IV. As the ductus remains open, it keeps the surrounding aorta from narrowing. Once the baby is stabilized, the coarctation is treated with surgery. This usually involves cutting out the narrowed segment of the aorta and reconnecting the normal aortic tissue. Opening of the coarctation area in a hospital’s catheterization lab using angioplasty is generally not performed due to a high incidence of recurrent narrowing. Placement of a small, wire cage (stent) to hold the aorta open is also generally not performed in babies since these stents generally can’t be expanded to full adult size over time. However, there are some instances where these procedures may be considered.

When cases of coarctation are not diagnosed in the newborn period, but rather when the child is older, surgery or angioplasty and stenting may be options. Angioplasty and stenting for CoA are similar to the procedures performed on the heart arteries in adults, except on a larger scale. The narrowed area can be dilated in a hospital’s catheterization lab with a special type of angioplasty flexible tube (catheter) with a balloon on the end. The balloon is inflated within the narrowed segment to dilate and disrupt the surrounding tissue. When the balloon is deflated, the aorta should stay enlarged. It’s hoped that remodeling of the tissue will occur that will allow future continuing growth of the blood vessel in this area. When a stent is used, it’s placed over the balloon and inflated within the narrowed area. When the balloon is deflated, the stent remains open inside the vessel and keeps it from narrowing down.