Impact of Characteristics at Stage-2-Palliation on Outcome Following Fontan Completion

The optimal timing of stage-2-palliation (S2P) in single left ventricle is not clear. The aim of this study was to identify S2P related factors associated with outcomes after total cavopulmonary connection (TCPC), particularly relative to the dominant systemic ventricle. A total of 405 patients who underwent both S2P and TCPC at our institute between 1997 and 2017 was included. Patients were divided into two groups, dominant right ventricle (RV type, n = 235) and dominant left ventricle (LV type, n = 170). S2P related factors associated with mortality, postoperative ventricular function, and late exercise capacity following TCPC, were analyzed. The median age at S2P was 4 [3-7] and 6 [3-11] months in RV and LV type patients, respectively (p = 0.092). Survival after TCPC was similar in RV and LV type patients (p = 0.280). In those with RV type, risk factors for mortality following TCPC were older age (p < 0.001), heavier weight (p = 0.001), higher PAP (p < 0.001), higher TPG (p = 0.010), and lower SO2 (p = 0.008) at S2P. In those with LV type, no risk factor was identified. Risk factors for postoperative impaired ventricular function were older age and higher weight at S2P in both RV and LV type patients. Older age at S2P was also identified as a risk for inferior peak oxygen uptake (VO2) years after TCPC both in RV and LV type patients. Older age at S2P was associated with higher mortality after Fontan completion only in RV type patients. However, it was associated with postoperative ventricular dysfunction and lower exercise capacity after TCPC in both RV and LV type patients.