Tissue erosion is a rare but life-threatening side effect of St. Jude Medical’s Amplatzer Atrial Septal Occluder (ASO), a cardiac implant used to close holes in the heart. Patients who develop tissue erosion may need emergency open-heart surgery. In some cases, complications can lead to heart failure and death.
What is the St. Jude Amplatzer ASO?
St. Jude Medical manufactures the Amplatzer Atrial Septal Occluder (ASO). It is used to close atrial septal defects (ASD), also known as “hole in the heart” defects, in children and adults. People with this defect have a hole between the upper left and right chambers of the heart (“atria”), which usually causes too much blood to flow into the lungs.
The Amplatzer ASO is a minimally-invasive, non-surgical treatment for ASD. It is implanted through a vein in the groin, guided into the patient’s heart with a catheter, and designed to close the hole in the heart by “sandwiching” it between two metal discs. Tissue grows around the Amplatzer and closes the hole.
What is the problem?
In rare cases, the Amplatzer ASO can erode into the heart, create a hole, and cause a life-threatening emergency that must be treated with open-heart surgery. The U.S. Food and Drug Administration (FDA) published the following Safety Communication on October 17, 2013:
“The device rubbing against the wall of the heart can erode the tissue and create a hole. It can also lead to further scraping or erosion through tissue in the upper chambers (atria) of the heart, primarily in the top of the atria near the aorta. This scraping may also cause separate or simultaneous holes in the aortic root, potentially leading to blood building up in the sac surrounding the heart (cardiac tamponade). If too much blood builds up in this sac, the heart will not be able to work properly.”
How Common is Tissue Erosion from the Amplatzer ASO?
St. Jude received FDA approval for the Amplatzer ASO in 2001. Between 2002 and 2011, over 100 cases of tissue erosion were reported to the FDA. The estimated incidence is 1-3 cases of tissue erosion per 1,000 patients. Several medical journals have documented case repots, although risk-factors have not been identified, and some patients may have higher risks than others.
The FDA is specifically concerned about St. Jude’s Amplatzer ASO because “This type of device failure has not been seen in similar devices used to treat this condition.” They have also required new safety studies for patients who were recently implanted with the device.
Class 1 Recall of St. Jude Amplatzer TorqVue Delivery System
In January 2013, St. Jude recalled the Amplatzer TorqVue Delivery System because the core wires could fracture. The device is used to assist the attachment, loading, delivery, and deployment of Amplatzer Occluder devices.
Studies of Tissue Erosion from St. Jude Amplatzer ASO
- December 2004, Catheter Cardiovascular Intervention: Amplatzer ASO linked to 28 cases of tissue erosion, including 14 in the United States, with an estimated incidence of 0.1%.
- May 2011, Annals of Thoracic Surgery: The Amplatzer ASO eroded into a patient’s aortic root, causing congestive heart failure.
- October 2013, Catheter Cardiovascular Intervention: Case report of Amplatzer ASO that eroded 8 years after implantation.
Side Effects of Tissue Erosion
- Cardiac perforation
- Fistula formation
- Scar tissue
- Migration of the Amplatzer
- Congestive heart failure
- Cerebral embolism
- Emergency open-heart surgery