The distance from the Amplatzer septal occluder to the mitral valve in patients undergoing interventional closure of defects in the oval fossa increases with growth of the patient

Abstract

The Amplatzer septal occluder is an alternative to operative closure of atrial septal defects within the oval fossa. An issue when deploying the device is its distance from the mitral valve. The purpose of this study is to determine how this distance changes with growth of the patient. We identified, through a review of charts, all patients undergoing closure of defects within the oval fossa by insertion of an Amplatzer septal occluder. Data were obtained from the echocardiogram 24 hours after closure, and at most recent follow-up, including left ventricular end-diastolic diameter, left atrial diameter, degree of mitral valvar regurgitation, body surface area, and distance from the device to the mitral valve. We divided the patients into 2 groups based upon change in body surface area. The first group had an increase in body surface area of at least 10%. All others were in the second group. We inserted 55 Amplatzer septal occluders in 54 patients. Of these we excluded 17 patients, 1 because quality of images was inadequate, 1 who underwent placement of 2 devices, 1 in whom the device embolised to the left ventricle the day after deployment, and 14 who have not yet had a follow-up echocardiogram. The group which exhibited an increase in body surface area of greater than 10% demonstrated an increase in distance from the device to the mitral valve, left ventricular end-diastolic, and left atrial diameters. Those who did not undergo significant growth had no increase in distance from the device to the mitral valve, but did have an increase in left atrial and left ventricular end-diastolic diameters. No patient developed mitral regurgitation. We conclude that, when deploying an Amplatzer septal occluder close to the mitral valve in children, the distance from the device to the mitral valve can be expected to increase with growth of the patient.