• Persistent Ductus Arteriosus
• Aortopulmonary Collaterals and Other Vessels
Sometimes treatment for congenital heart disease (heart defects that are present at birth) will involve stopping blood flow through an unwanted blood vessel. The process of blocking the vessel is called occlusion. During the procedure to occlude the vessel(s), a catheter (a thin flexible tube) is inserted through a small incision site in the skin and threaded through a blood vessel to the point where the treatment will be administered. Devices such as a coil or small particles are placed to prevent blood from continuing past that point through the vessel.
Persistent Ductus Arteriosus (PDA)
The ductus arteriosus is a normal vessel that is open between the main lung artery (pulmonary artery) and main body artery (aorta) while a baby is in the womb. It allows oxygenated blood from the placenta to pass through to the body since the lungs are not being used. After a baby is born, the ductus arteriosus is “programmed” to close up by itself within the first few days after birth. Occasionally, this vessel doesn’t completely close by itself. In this case, blood will then pass in the opposite direction – red oxygenated blood can pass to the lungs where the blue blood from the veins is carried. This results in inefficiency in circulation and may result in heart chamber enlargement, excessive blood pressure that is transmitted to the lung arteries, and possibly symptoms of congestive heart failure (CHF). In many situations, the PDA can be occluded (closed off) using special coils or devices that are delivered by a catheter rather than requiring surgery.
For more information about this heart defect, visit Persistent Ductus Arteriosus.
Aortopulmonary Collaterals and Other Vessels
Aortopulmonary Collaterals: Occasionally, extra blood vessels may arise from the aorta and then travel to the lungs. These are called aortopulmonary (AP) collaterals. They may be present in the setting of other congenital heart disease, particularly pulmonary atresia with ventricular septal defect. If these vessels supply blood to a segment of lung that has blood flow from another source, it may be advantageous to occlude (close off) these extra vessels if these vessels will not be used during surgery.
Similarly, small vessels may arise from normal arteries, which then allow extra blood to go to the lungs in the presence of long-standing cyanotic (causing bluish-skin) congenital heart disease. Some doctors believe that the presence of these vessels may be disadvantageous by allowing extra blood to enter the lung vessels, and the presence of these vessels may prolong the hospital stay after heart operations. These vessels can also be occluded using metal coils or small polyvinyl alcohol particles.
Venovenous Collaterals: At some stages of palliative (symptom-reducing) surgery for cyanotic single ventricle congenital heart disease, small veins may open up and become larger. They allow blue blood to bypass the lungs and go directly back to the heart. This may result in an excessive blueness (cyanosis) of the child’s skin. Coils and devices can be used to stop blood flow from bypassing the lungs. When the blood is able to enter the lungs, it can pick up oxygen that is necessary to support healthy functioning and the child’s skin will return to a normal color.