Coarctation of Aorta (COA)
Aorta is the large blood tube carrying oxygen rich red blood to the entire body. Coarctation of aorta (COA) is narrowing in this blood tube. This forces the heart to pump harder, until it finally can't do anymore and heart failure sets in.
Some forms of COA are so severe that it causes heart failure as soon as the baby is born. Such babies need emergency surgery to correct the narrowing blood tube as soon as possible. Less severe forms are found out later in infancy, childhood or even as an adult. Heart failure features develop only in the later stages of the disease progression. As the blood flow to the lower body is affected, the pulses in the groin (lower body) are feeble. This is a common way the disease is discovered by the baby’s pediatrician. Sometimes, the blood pressure in the upper half of the body is high. This is another opportunity for suspecting and diagnosing the disease in a timely fashion.
Treatment for COA has different options depending on the situation. In newborn babies with severe coarctation, surgical correction is the treatment of choice. When the baby’s condition is too critical to undergo surgery, a balloon procedure (coarctoplasty) can be done to make the narrow segment bigger. In older babies, balloon procedure (coarctoplasty) is the preferred strategy. Balloon procedure has the risk of the narrowing coming back again after the procedure. Hence in older children and adults with larger blood tubes, stents are used to open up the narrow segment and keep it open for longer compared to balloon angioplasty alone. Balloon angioplasty and stenting for coarctation are done in the catheterization laboratory. This is done without opening the chest, through keyhole procedure through the blood tubes (arteries) of the groin.
COA and its repair
Balloon Coarctoplasty is a procedure to repair the severe coarctation of the aorta. Patients with severe coarctation of the aorta may have symptoms such as excessive sweating, lack of energy or interest in doing things (listlessness), generalized tiredness (lethargy), inability to feed due to lack of energy, decreased amount of urine when compared to the fluid or water intake by the child within short duration of time. All these symptoms are due to the narrowing of the aorta which causes only less amount of blood to pass from the left ventricle to the rest of the body.The reduced amount of blood supply will make it harder for the other organs in the body to keep up with the demands of the body. At the same time extra blood collecting in the left ventricle of the heart can lead to its dysfunction and left sided heart failure.
The exact location of coarctation of the aorta varies from child to child. Sometimes it can be on the transverse, descending thoracic (chest area) or descending abdominal part of the aorta.Doctors diagnose or identify the presence of these defects in the child by observing the symptoms and with the help of a test done for the heart such as echocardiogram, ECG, X ray etc.
Treatment for the Coarctation of aorta depends on the severity of the disease condition and the location of the narrowing of the aorta. Usually the first choice of treatment is Balloon coarctoplasty, done by dilating the narrowest part of the aorta with a balloon. Second choice is stenting, where a mesh covered hollow tube (stent) is placed at the narrowed area to keep the aorta open. Stenting is usually done when the narrowing of the aorta is in the descending thoracic aorta or in the abdominal aorta ( these parts of the aorta have to keep up with the higher level of pressure). Third treatment option is surgery, especially when a child is in his/her first few months of life, when chances of recurrence of coarctation is less. During the surgery, a narrowed part of the aorta is removed, reconstructed or patched to keep that part of the aorta open.