Children and adults with congenital heart disease are increasingly benefiting from non-surgical alternatives to repair their heart defects. The last decade has seen a remarkable advance in the tools and techniques used to treat congenital heart disease in the cardiac catheterization laboratory.This article summarizes a few of the important tools available in 2005 to treat some of these conditions.

Atrial Septal Defect

Secundum atrial septal defects (ASDs) are one of the most common congenital heart defects. The ASD is a hole in the atrial septum that allows a portion of blood returning to the left atrium to pass to the right atrium, right ventricle and pulmonary arteries, thereby placing additional work on these heart structures as well as the lungs. Left untreated, atrial septal defects may lead to right heart failure, atrial arrhythmias, ventricular dysfunction, and pulmonary hypertension.

Elective transcatheter closure of ASDs is currently indicated for patients with ASDs of the secundum type, with a weight of >15kg and evidence of right ventricular dilation. As a lot of ASDs are not diagnosed until adulthood, many are closed in the adult population.

Despite many attempts beginning in the 1970s to invent the ideal transcatheter ASD occluder, the first and only device to date to receive US Food and Drug Administration (FDA) approval for ASD closure is the Amplatzer Septal Occluder (ASO).This device was first approved in the US in 2002.The device is composed of a self-expanding nitinol wire frame composed of two disks and a connecting waist (see Figure 1). Occlusive polyester fabric patches are sewn inside the frame.The device is collapsed into a delivery sheath (7–12 French) that is introduced transvenously and passed across the atrial septum where the device is then placed in position across the defect (see Figure 2).The procedure is assisted by the use of fluoroscopy and either transesophageal or intracardiac echocardiography. The center waist completely ‘fills’ the defect itself and the device is therefore said to be self-centering.This allows the device to close even large defects—up to 38mm in diameter.The ASO is available in connecting waist sizes ranging 4–38mm in diameter. The device can be retrieved and repositioned before release and is therefore very user-friendly. Closure rates are excellent (>98%) and the risk of complications is low.1

Poised on the cusp of FDA approval is the Helex Septal Occluder.The device design is a frame made of a single nitinol wire covered by an expanded polytetrafluorethylene (Gore-Tex®) membrane. In the heart, the device is formed into two round disks that sit on either side of the atrial septum. Because the device is not selfcentering, the device disks must be significantly larger (the manufacturer recommends at least 1.6x) than the diameter of the defect to ensure that the entire defect is covered. The devices are available in disks ranging in size between 15mm and 35mm (in 5mm increments) and are delivered through a 9 French sheath. One advantage of this device is its low-profile; disadvantages include the complexity of the delivery system, and inability to close defects larger than 22mm.