The heart is divided into four chambers. The upper chambers are the atria and the lower chambers are the ventricles. The right side of the heart—right atrium and right ventricle—pumps blood to the lungs to pick up oxygen and the left side of the heart takes this oxygen-rich blood and sends it throughout the body. The system works very well when the right and left sides of the heart are separated by heart muscle in the middle, a muscle known as a septum. When there is a hole in the wall between the two ventricles, it is known as a ventricular septal defect. By extension, the surgery to repair this congenital heart abnormality is called ventricular septal defect closure.
Unlike an atrial septal defect which can go unnoticed for some time, ventricular septal defect usually causes serious symptoms. VSDs are fairly common, occurring in about three out of every 1,000 babies born. In fact about 25% of all structural heart defects present at birth are ventricular septal defects. There are two main types of ventricular septal defect, peri-membranous and muscular ventricular septal defect. The former tend to close on their own while the latter type needs some sort of treatment.
The traditional way to perform VSD closure surgery is to have major, “open heart” surgery. In this approach the sternum (breastbone) is cut top to bottom and the rib cage is opened. A heart-lung bypass machine or pump is then used to divert the blood while the heart is operated on directly. The VSD closure surgery usually requires a graft of tissue or wire mesh placed across the hole in the ventricular septum.
Alternatively, VSD closure surgery is done by interventional cardiologists or interventional radiologists using a device that is inserted from inside the blood vessels. The VSD closure device is placed in the same way that an angiogram is performed in that a catheter is placed in the femoral (leg) vein and snaked up to the heart. Then a metal, mesh plug (reminiscent of an empty spool of thread) is expanded to fill in the ventricular septal defect. Over time new heart cells will grow over the VSD closure device.
The biggest advantage of a percutaneous VSD closure device (like Amplatzer VSD closure system) is that it allows the patient to forego open heart surgery. Therefore ventricular septal defect closure performed in this way is associated with much shorter recovery times both in and out of the hospital.
With any ventricular septal defect closure, there are risks involved. In the “open heart” approach, complications can arise from the heart-lung bypass machine. The risk increases the longer that the patient is on the bypass machine. Some of the more serious complications of percutaneous VSD closure (with a VSD closure device) are infection (including endocarditis), stroke, and damage to the blood vessels. The size of the ventricular septal defect must be small enough in order to use a VSD closure device. Also since the VSD closure device is made of a nickel alloy, patients may need to be screened for nickel allergy prior to placement.
In select patients, a percutaneous VSD closure device can restore a functioning heart and spare the process of open heart surgery.