Levels of exhaled nitric oxide before and after surgical and transcatheter device closure of atrial septal defects in children

Objectives: We have shown that exhaled nitric oxide levels decrease after surgical closure of congenital left-to-right cardiac shunts. It remains unclear whether the change in exhaled nitric oxide levels reflects endothelial injury caused by the use of cardiopulmonary bypass or the decrease in pulmonary blood flow attendant on shunt closure. Transcatheter atrial septal defect closure permits shunt closure without the use of cardiopulmonary bypass. Therefore we compared changes in exhaled nitric oxide levels after surgical and transcatheter device closure of atrial septal defects. Methods: We enrolled sequentially 30 children undergoing atrial septal defect closure. Fifteen patients (age range, 0.4-16 years; median age, 6.5 years) underwent surgical atrial septal defect closure with cardiopulmonary bypass, and 15 patients (age range, 4-17 years; median age, 8.4 years) had device closure of the atrial septal defect in the catheterization laboratory. We measured nitric oxide levels in end-tidal expiratory gas with a rapid-response chemiluminescent analyzer before and after atrial septal defect closure. Results: After surgical repair of the atrial septal defect, exhaled nitric oxide decreased by 21%, from 10.9 ± 4.4 to 8.4 ± 3.3 ppb (P