Transesophageal Echocardiographic Predictor of Significant Right Ventricular Outflow Tract Obstruction After Tetralogy of Fallot Repair.

The optimal method for reconstruction of the right ventricular outflow tract in tetralogy of Fallot repair is yet to be established. Transatrial repair with pulmonary valve preservation avoids the detrimental effects of ventriculotomy and transannular patch; however, because of moderately hypoplastic pulmonary valve, these techniques are associated with undesirable residual right ventricular outflow tract gradients resulting in reoperations. The study sought to define intraoperative echocardiographic predictors of significant right ventricular outflow tract obstruction after tetralogy of Fallot repair. From July 2016 to December 2017, 58 patients with tetralogy of Fallot underwent repair with direct intraoperative pressures measuring and intraoperative transesophageal echocardiography performing after tetralogy of Fallot repair completion. Multivariate analysis was performed using logistic regression analysis to identify independent predictors of right ventricular outflow tract obstruction. One year after tetralogy of Fallot repair, significant right ventricular outflow tract obstruction was present in 12 patients (20.6%): 10 patients (26.2%) after pulmonary valve-sparing procedure and 2 patients (12.5%) after transannular patch (P = 0.35). Right ventricular outflow tract z-score lower than -3.2 had the best predictive value for significant residual right ventricular outflow tract obstruction (area under the curve = 0.979, P < 0.001). Multivariate analysis found that the right ventricular outflow tract z-score reached a statistical significance as a predictor of significant right ventricular outflow tract obstruction (P < 0.0001). Right ventricular outflow tract z-score <-3.2 measured by intraoperative transesophageal echocardiography is an indicator of postoperative right ventricular outflow tract obstruction right after surgery and a predictor of obstruction development following tetralogy of Fallot repair.