Closure of ASD and PFO
Once the diagnosis of an ASD suitable for interventional closure, or a PFO responsible for paradoxical embolism is made, it is time to close it. Today, in most cases of patients with an ASD and in nearly all patients with a PFO, closure can be achieved without open-heart surgery but by using interventional catheterization.
Interventional closure: The closure is performed in a cardiac catheterization laboratory, a so-called cath lab. Techniques vary between clinics and physicians active in catheter intervention. The procedure can be done under local anesthesia, with the support of sleeping medication (sedation) or by general anesthesia and will be performed by a (pediatric) cardiologist. A thin tube - a catheter - is inserted into a blood vessel in the groin and guided to the heart. The exact size of the PFO or ASD is measured by ultrasound transesophageal echography(TEE), intracardiac echography(ICE) and the surrounding tissue is assessed. In many cases of PFO and in most patients with an ASD, the size of the defect is measured exactly by inserting a soft balloon, known as balloon sizing. Everything is constantly controlled by X-ray. Then the catheter is exchanged for a larger catheter, the delivery sheath.
The appropriate device, an ASD occluder or a PFO occluder is pushed through to be placed across the hole, through the delivery sheath. The occluders consist of a left-sided disk and a right-sided disk. The left-sided disk is deployed first and then retracted directly to the septum. Then the right-sided disk is deployed and thus the occluder will seal the defect between the two disks. Once the device is in the correct position, the physician will release the device and withdraw the delivery sheath. The defect is now closed and the tissue will grow around the device and be a permanent part of the septum. Typically the procedure takes approximately 60 minutes.