Diminution and Closure of Large Ventricular Septal Defects After Pulmonary Artery Banding

Abstract

In a period of 15 years (1957-1972), 114 infants (51 males, 63 females) with the diagnosis of ventricular septal defect and congestive heart failure underwent pulmonary artery banding at The Children's Hospital Medical Center in Boston. A second study performed in 55 of these revealed the left-to-right shunt through the ventricular septal defect to be greatly diminished in seven and completely closed in three. Pulmonary artery banding proved clinically beneficial to all patients restudied. Important hemodynamic changes, documented at the second study in all ten patients, included a significant decrease in left-to-right shunt and a drop in pulmonary arteriolar resistance to normal range. The right ventricular pressure, post banding, ranged from suprasystemic levels in those with muscular defects to half systemic levels in the majority of those with membranous defect. The muscular ventricular septal defects closed by muscular tissue, the membranous defects by aneurysm formation at the "exit" of the left-to-right shunt on the right ventricular septal surface. There is a surprisingly high closure rate (19%) in these large ventricular septal defects after pulmonary artery banding noted. Hemodynamic mechanisms to account for closure are proposed.