An atrial septal defect is a birth defect and consists of an opening in the wall that separates the left atrium from the right atrium. As a result of this pure blood comes into the right atrium from the left atrium and mixes with the impure blood. Thus the right atrium receives more blood than it is supposed to and pushes it into the right ventricle and from there in to the lungs. Due to this increased blood flow in the lungs these patients especially during childhood are prone for recurrent lung infections and they can have a progressive increase in the blood pressure in the lungs. Hence if this defect is causing a significant increase in the blood supply to the lungs (more than twice the blood supply to the body) it needs to be closed. ASD’s may be classified into ostium primum, ostium secundum or sinus venosus.
Traditionally surgery was needed to close all defects, but today a large percentage of ostium secundum can be closed without surgery. The device consists of two discs which are connected together by and waist which fits the size of the defect in the septum and this device is made of nitinol. A catheter ( a thin long tube) is passed along a large vein from the groin and advanced into the heart and guided from the right atrium into the left atrium through the atrial septal defect. The device is then stretched and taken through the catheter and the left atrial disc is released in the left atrium and the the catheter is pulled back into the right atrium and the right atrial disc is released in ti the right atrium. So now we have 2 discs, one in the left atrium and another in the right atrium. These two discs are connected by the waist which exactly fits the defect and closes it. This procedure is done under x-ray and ultrasound guidance. The patients are generally discharged on day two and need to take aspirin for a period of 6 months.
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