Atrioventricular valve procedures with repeat fontan operations: influence of valve pathology, ventricular function, and arrhythmias on outcome.

Background: The purpose of this study is to analyze atrioventricular valve procedures when performed in association with repeat Fontan operations and to determine the influence of atrioventricular valvar pathology, ventricular function, and arrhythmias on outcome.

Methods: Between December 1994 and August 2004, 80 patients had repeat Fontan operations that included arrhythmia surgery (78 of 80), venous pathway revision (78 of 80), atrioventricular valve repair-replacement (15 of 80), and other associated procedures. Mean ages were the following: at operation, 20.3 +/- 8.4 years; at prior Fontan, 7.1 +/- 5.8 years. Atrioventricular valve procedures were performed on 8 functionally mitral and 7 functionally tricuspid valves. The average cross-clamp and cardiopulmonary bypass times were 61.9 +/- 42.8 minutes and 218 +/- 82 minutes, respectively.

Results: Ventricular dysfunction (8% vs 54%, p < 0.0001), valvar dysfunction (13% vs 25%, p < 0.05), and atrial arrhythmias (18% vs 86%, p < 0.0001) increased during the preceding 12.0 +/- 4.7 years before the most recent Fontan operation. Multivariate analysis for death, orthotopic cardiac transplantation (OCT), or renal dialysis showed severe ventricular dysfunction, age greater than 25 years, right or ambiguous functional ventricle, and ischemic time greater than 100 minutes to be highly significant. Notably, cardiac index, elevated end diastolic pressure, and atrial fibrillation were not predictors of outcome. Mitral valve repairs were inconsistent due to probable technical misjudgments; most tricuspid valves could not be repaired. Operative and late mortality were 1.2% and 5.0%, respectively. Emergent and late OCT were 1.2% and 3.7%, respectively.

Conclusions: Risk factors for poor outcome are severe ventricular dysfunction, right or ambiguous single ventricle, age greater than 25 years, and ischemic time greater than 100 minutes. Mitral valves are potentially more amenable to repair than are tricuspid valves. Prosthetic valve replacement should be considered when valve repair is questionable.