Surgical Closure
ASDs may be closed by patching or suturing during open heart surgery. Minimally invasive surgical repair, involving special instruments that are inserted into 3 or 4 holes in the chest, may also be possible.

In open heart surgery, small defects may be closed with simple sutures using a monofilament thread made of Prolene or Polypropylene.

Larger holes may be covered with patches made of pieces of pericardium (the membrane that covers the heart) or of silk or a synthetic material such as Dacron or Teflon (see animation at left).

Transcatheter Closure
An alternative to open heart surgery in the treatment of ASDs is the use of devices that are introduced into the heart with the use of a catheter during a catheterization procedure.

Before closing an ASD with a transcatheter device, the size of the hole or holes must be determined. One way to accomplish this is to use the Amplatzer® Sizing Balloon. A catheter containing a balloon is introduced into the heart and the balloon is inflated to measure the diameter of the ASD. There are radiopaque markers at regular intervals on the balloon which may be read radiometrically, with ultrasound, or with a sizing plate.

When the ASD has been accurately measured, an appropriately sized septal occluder is introduced in a separate catheterization to close the hole. The catheter enters from the groin or forearm, and continues into the heart via the Vena Cava.  An ASD with insufficient rims of atrial muscle to hold the device in place are referred for surgery.