Interrupted aortic arch

In this condition, the aorta does not develop completely in the area of the arch. As a result, the aorta is divided into two parts that are not connected to each other. This prevents the flow of blood through the aorta. Because blood flow through the aorta is blocked, the blood supply to the lower body is compromised. At birth, the open ductus arteriosus allows blood to flow from the right ventricle to the lower body. There are often other coexisting heart defects, such as a VSD.

Interrupted aortic arch is usually diagnosed when the ductus arteriosus begins to close. With decreasing circulation to the lower body, serious damage can occur to the liver, kidneys and intestines. Prostaglandin is given to keep the ductus arteriosus open until surgery is performed, usually as soon after birth as possible.

Most often a one-stage repair is undertaken, patching the arch or connecting the two ends of the aortic arch together, closing any VSD, and tying off and dividing the ductus arteriosus into two parts.

Diagram 2.10 Interrupted aortic arch 1 - interruption of aortic arch 2 - descending aorta connected to pulmonary artery by large patent ductus arteriosus 3 - ventricular septal defect Flow patterns are normal to the upper body. However, there is no flow of oxygenated blood to the lower body unless there exist, as in this drawing, shunts such as a ventricular septal defect that allows oxygenated blood into the pulmonary artery, and a patent ductus arteriosus that allows the partially oxygenated blood to travel from the pulmonary artery to the descending aorta (as indicated by the broken white arrow).