Role of Echocardiography during Transcatheter Closure of an Atrial Septal Defect:
A Case Report

Nicole Dobija, DDS MD, Monica Botero, MD,
Department of Anesthesiology, University of Florida, Gainesville, Florida

Background: Echocardiography, has been used for reliable imaging during cardiac surgery and for guidance of catheter placement during transcatheter closure of atrial septal defects, (ASD). We describe a case of embolization of the occluder device to the mitral annulus, requiring emergent surgical intervention. Intraoperative transesophageal echocardiography (TEE) was instrumental in guiding the surgical intervention.

Case Report: A 35-year-old man was admitted to the hospital for elective transcatheter closure of his medium size atrial septal defect in the cardiac catheterization laboratory.. His medical history was significant for hypertension, intermittent atrial fibrillation, and worsening shortness of breath and chest pain. He has had no evidence of stroke or transient ischemic attacks. Cardiac catheterization was initiated with continuous conscious sedation utilizing intracardiac echocardiography. The cardiac catheterization demonstrated normal cardiac anatomy except for a 16 mm secundum-type ASD and slightly elevated right ventricular pressures. A 32 mm Amplatzer septal occluder device (AGA Medical, Golden Valley, MN) was prepared. It consists of two self-expanding discs made of nitinol wire mesh and covered with polyester that are connected by a thin waist. During deployment of the device, it failed to align parallel to the right and left atrial septums and dislocated to the left atrium. Several attempts to dislodge the device were unsuccessful. The patient was transferred emergently to the operating room for surgical intervention. General anesthesia was induced emergently with oxygen, fentanyl, pancuronium, and isoflurane.
Intraoperative TEE showed that the occluder device had migrated through the mitral annulus and had positioned itself to occupy the entire mitral valve opening. Any manipulation of the heart worsened the mitral valve inflow obstruction and resulted in severe hypotension. Therefore, cardiopulmonary bypass was instituted rapidly. The device was removed and the ASD was surgically repaired. The patient was separated from cardiopulmonary bypass without difficulty and transferred to the cardiothoracic intensive care unit for postoperative management.

Conclusion: A septal occluder has become an alternative to surgery, for closure of small to medium-sized ASDs. Large ASDs, greater than 36 mm, can be closed with this method but are prone to complication such as pericardial effusions, indentations and wear on the aortic root, as well as pericardial tamponade. This is the first reported case of an Amplatzer device with transmitral embolization requiring emergent surgical intervention. There has been one other case of device migration into the aortic root thirty days post placement requiring surgical removal. In both cases TEE was instrumental for locating the device and evaluating the hemodynamic effects caused by the migrated occluder.