Repair of Atrial Septal Defect (ASD)

An atrial septal defect (ASD) is a hole in the wall between the two upper chambers of the heart. Oxygen-rich blood leaks from the left atrium into the right, so the right side of the heart and the lungs handle too much blood. Many small defects close on their own in the first year of life, but a large defect can over time enlarge the right heart, raise the pressure in the lungs and lead to right heart failure, rhythm problems or stroke. The three main types are ostium secundum (the most common, in the middle of the septum), sinus venosus (high, near the superior vena cava, often with abnormal pulmonary veins) and ostium primum (low, often with a cleft mitral valve). Many secundum defects are now closed with a device in the cardiac catheterization lab. Surgery is used for the other types and for defects that are not suitable for a device. Through a median sternotomy (or occasionally a right anterolateral thoracotomy or another small incision), the child is placed on cardiopulmonary bypass, the right atrium is opened, and the hole is either sewn shut or covered with a patch of Dacron or the child's own pericardium. The setup is the same as an adult open-heart case with smaller instruments. Small patients cool quickly and have little blood to lose, so warming and careful tracking of blood loss and irrigation are part of the scrub's job. Risks include air embolism, rhythm problems or heart block, bleeding, infection and a leftover leak around the patch.