Coarctation of the aorta and hypoplasia of the aortic arch
What is coarctation of the aorta?
Coarctation varies in different age groups depending the level of severity and its form. It is also associated with other cardiac alterations such as patent ductus arteriosus, bicuspid aortic valve, ventricular septal defect and anomalies in the mitral valve.
During the neonatal period, some patients’ blood flow may go towards the lower body, which is dependant on the ductus arteriosus. When this begins to close, circulatory collapse occurs due to the excessive load on the heart and insufficient circulation in the abdominal organs. These patients first need to be stabilized and then treated.
Who is affected by coarctation of the aorta?
This is a common type of heart disease representing 5-6% of all heart pathologies. There are between 0.2 and 0.6 cases for every thousand live births.
In the neonatal period, diagnosis is via transthoracic echocardiogram, but after this stage patients do not show symptoms. For this reason, it is diagnosed when high arterial pressure is detected during a routine check up. This is usually done with an echocardiogram, but other tests tend to be carried out such as a CT angiogram or nuclear magnetic resonance imaging to define the characteristics of the coarctation.
Hypoplasia of the aortic arch is also diagnosed prenatally via echocardiogram without the need for further tests.
In the neonatal period, patients usually need surgical treatment. The operation consists of resectioning the narrow segment of the aorta and then joining it to the healthy segments. In older patients, surgery is the preferred option and the procedure is similar to that for new-borns. Techniques to expand the narrowed area such as fitting a patch can also be used,
or in other cases interventional haemodynamics is considered. If this is the case, dilatation with high pressure balloons is performed to correct the narrowing. Following this, a metal stent is implanted in the area of coarctation to keep the vessel at the correct calibre. Hypoplasia of the aortic arch is repaired in the first two weeks of life. This is done by using a patch to enlarge the narrowed section of the aorta. If there is a related ventricular septal defect, this is often closed during the same surgery. Once out of the operating room the mortality rate for this disease is 1%.
6-10% of patients will, however, go on to develop a new narrowing of the aorta (recoarctation). This will require further surgery or another procedure. In 0.5% of cases there are no serious complications associated with this disease, but in older patients there is a chance that arterial hypertension may not improve after the repair. In terms of hypoplasia of the aortic arch, 5 % of those treated require further procedures due to recoarctation.