Tissue Surrounding Amplatzer ASO Can Erode The St. Jude Amplatzer Atrial Septal Occluder (ASO) has been associated with rare, but serious, erosion events, according to the U.S. Food and Drug Administration (FDA).
The ASO is a cardiac implant device used in both pediatric and adult patients to treat an abnormal hole between the heart’s upper-left and –right chambers—the atria–known as an atrial septal defect (ASD). The ASO is a metal device that is implanted via a catheter into a vein. The procedure is considered a minimally invasive ASD closure method and is an alternative to open heart surgery.
The FDA is alerting patients and health care providers that tissue surrounding the Amplatzer ASO can erode, leading to life-threatening emergencies that require immediate surgery. Published estimates indicate that these types of serious adverse events take place in about 1-3 out of every 1,000 patients who have been implanted with the Amplatzer ASO. A total of 234,103 Amplatzer ASOs have been implanted worldwide as of March 31, 2013.
Between 2002 and 2011, the agency received more than 100 reports of erosions tied to the St. Jude Amplatzer ASO. In that same period, a number of medical journals published articles in which tissue erosion was reported in patients who had been implanted with the Amplatzer ASO.
Tissue erosion occurs when the Amplatzer ASO rubs against the heart wall
Tissue erosion occurs when the Amplatzer ASO rubs against the heart wall; tissue erosion can create a hole and can also lead to additional scraping or erosion through tissue in the heart’s upper chambers. This typically occurs in the top of the atria, close to the aorta.
The scraping may also lead to separate or simultaneous holes in the heart’s aortic root, which could, in turn, cause blood to build in the cardiac tamponade—the sac surrounding the heart. Should this occur, the heart might not work properly and the patient may need to undergo immediate open-heart surgery to remove the Amplatzer ASO, close the holes in the heart, correct any heart defects caused by the erosion, and close the original defect.
The FDA noted that tissue erosion can also cause fistulas. A fistula is an abnormal scar tissue that connects parts of the heart that had not been connected previously. Although not life threatening, fistulas do require surgery and can lead to congestive heart failure.
Patients implanted with the Amplatzer ASO should seek immediate medical attention, including an ultrasound of the heart (echocardiogram), should they experience chest pain, numbness, sudden weakness, dizziness, fainting, shortness of breath, or rapid heartbeat.
In general, patients implanted with an Amplatzer ASO should follow-up with their cardiologist to receive an echocardiogram at implantation, one day after implantation, before hospital discharge, and one week after implantation. Cardiologist follow-up should take place one month, six months, and one year following implantation and then, once yearly, if no symptoms have occurred, the FDA noted.