A hole in the heart is not just a line from a sentimental romantic movie, it is a real medical condition affecting thousands of newborns each year. Two of the more common holes in the heart are between two of the four chambers in the heart. When a hole exists between the upper chambers, it is called an atrial septal defect or ASD. When the defect is between the lower, bigger chambers, it is a ventricular septal defect or VSD. When an ASD or VSD causes symptoms, it must be fixed, usually surgically. This article describes ASD/VSD closures.
The traditional approach to ASD/VSD closures is through open heart surgery. The chest is opened completely, the sternum is cut through from top to bottom, and the ribs are spread so that the heart can be accessed directly. The blood must be diverted to a heart-lung bypass machine so that the interior of the heart can accessed without excessive bleeding. In the case of small atrial septal defects, the wall between the heart chambers is closed with sutures. ASD surgery to repair larger defects may require the use of a mesh or a membrane that is sewn into the heart muscle to close off the blood flow between the two chambers. In VSD closure surgery, the defect usually requires a patch of some sort.
The patches used in ASD/VSD closures are a synthetic material that is designed to be hypoallergenic or non-allergenic. This means that the immune system should not react to the material. Often this material is either Dacron or PTFE. Heart cells may eventually grow over the synthetic patch.
Obviously open heart surgery is a major ordeal, especially in infants and children who have symptomatic ASDs and VSDs. An exciting innovation that has greatly shortened the recovery time in ASD/VSD closures is the use of a percutaneous ASD or VSD closure device.
Just like angioplasty or an angiogram, a thin catheter is introduced in a blood vessel in the leg and snaked up to the heart. Once the tip of the catheter has reached the atrium or ventricle, a small bit of dye that shows up on X-ray is injected. Once the ASD or VSD has been visualized, the catheter deploys a metal device that is shaped like a spool of thread. One edge of the “spool” is in one heart chamber and the spool spans the atrial or ventricular septal defect. Once in place across the two chambers, the edges of the spool are closed together and the hole is closed.
The advantages of the percutaneous ASD closure or VSD closure are several. In contrast to ASD or VSD closure surgery, the percutaneous approach completely avoids open heart surgery. Also, the procedure can be done under local anesthesia with intravenous sedative, although young children may require general anesthesia if they cannot remain still during the ASD/VSD closure. This device has been used most extensively for ASD closure but is being studied for its widespread use in VSD closure because of its many important advantages.