Closure of the atrial septal defect is necessary to eliminate the left-to-right shunt and the effects of chronic shunting on the right heart and lungs that eventually produce symptoms. Ideally, an atrial septal defect should be closed before age five to prevent the development of right ventricular dysfunction.
In our patient, closure should not be delayed. This can be accomplished by open heart surgery or percutaneous transcatheter device. Our patient underwent surgery. In experienced medical centers, closure of an uncomplicated secundum atrial septal defect can be accomplished with an extremely low mortality.
Untreated large ASD - complications
An untreated secundum atrial septal defect creates no significant symptoms in the child and survival to adulthood is expected. The major complications that occur in the adult from an untreated large atrial septal defect include right ventricular dysfunction leading to heart failure and atrial dysrhythmias, particularly atrial fibrillation. Paradoxical embolism, a cause of stroke, may occur even with a small atrial septal defect. While not common, pulmonary vascular disease causing pulmonary hypertension is a serious complication of an untreated atrial septal defect.
Older patients - acquired disorders
In older patients with an atrial septal defect, common acquired cardiovascular disorders, such as systemic hypertension and coronary artery disease may decrease left ventricular compliance, thereby increasing the left-to-right shunt. This increases the risk of right ventricular dysfunction and atrial arrhythmias, leading to decreased overall life expectancy for the patient.
Transcather implantation device
Catheterization to implant a device that closes the atrial septal defect can be accomplished in many patients with a secundum defect. The procedure is guided by fluoroscopy with transesophageal or intracardiac echocardiography. It can be accomplished with minimal morbidity and mortality, shortens the hospital stay and leaves no scar. Choice of patients for this technique depends upon location, size and configuration of the defect.
Procedure
The procedure that follows is from another patient. This is a still-frame of a left atrium injection in the left anterior oblique view with angulation that shows an atrial septal defect and the catheter placed through the defect. The right and left atria are well seen. Note a transesophageal echo probe is in place. In the real-time study that follows, note the contrast material filling both the left and the right atria.
This is a still-frame of the right anterior oblique view of the chest showing the heart. A balloon inflated with contrast material is seen straddling the atrial septal defect. The balloon demonstrates the waist that represents the interatrial septal defect. This balloon is used to determine the appropriate size for the closure device.
This is a right anterior oblique view still-frame of the heart demonstrating the procedure to close the atrial septal defect. The left atrial component of the device has been deployed and is seen on the left atrial side of the defect. The right atrial component is being deployed. The waist representing the septal defect is also well seen. In the real-time study that follows, note the catheter delivery device is being withdrawn while assuring the right atrial component remains in place.
In this left anterior oblique view, the device has been released and its two components shown. Note that the left atrial component is larger than the right atrial component. In the real-time study that follows, note that contrast material enters the right atrium and does not flow into the left atrium. Contrast circulates through the lungs and as it returns to the left atrium does not cross into the right atrium. Note also that the transesophageal probe has been removed.
Surgical repair
The following surgical repair of a secundum atrial septal defect is presented through the courtesy of Drs. Michael Greene and Nancy Donahoe and it was carried out at the University of Florida.
The patient has been anesthetized, placed on cardiopulmonary bypass and the right atrium is opened. The suction catheter tip points out the coronary sinus and the tricuspid valve with one leaflet visible. The suction catheter tip point out the boundaries of this very large atrial septal defect.
A portion of pericardium is identified and cleaned of adventitia. This will be trimmed to the correct size and shape and used to patch the interatrial septum. A remnant of the septum primum is present with multiple large holes within it, thus the term Swiss cheese defect. The remnant of septum primum is being excised and the true extent of the atrial septal defect will become even more apparent. The pericardial patch has been lowered into place and suturing initiated.
The defect is now partially closed with the pericardial patch. The patch is then further trimmed to fit before closure is completed. This is the completely repaired defect with the patch in place.
After surgery
Following uneventful recovery from surgery, she was advised regarding bacterial endocarditis prophylaxis for the next six months, the time required for the patch and suture material to become fully endothelialized.