EXTRACARDIAC VERSUS LATERAL TUNNEL FONTAN: A META-ANALYSIS OF LONG-TERM RESULTS WITH SPECIAL FOCUS ON ARRHYTHMIAS

Abstract

Many modified Fontan operations were described to improve the surgical outcome, such as lateral tunnel (LT) and lastly extracardiac conduit (EC). As survival increases, there is growing awareness of the long-term consequences of a Fontan circulation and the associated morbidity and mortality. Comparative data on the incidence of supraventricular arrhythmias and sinus node dysfunction post-EC and post-LT Fontans are controversial. Because the only available contemporary data on this topic are limited to small single-center series compromised by small numbers and referral bias, we performed a meta-analysis to pool all available long-term results data of EC and LT Fontans with a special focus on arrhythmias. Keywords for PubMed and EMBASE search were: «Fontan », « long-term results » , « cardiac replacement therapy » and « arrhythmia» limited to publications from 2000 until 2016 in humans. Inclusion criteria were: Studies reporting on long-term results of Fontan comparig EC and LT and completeness of follow-up of 90%. Kaplan Meier curves in each of the selected studies were digitized. Time-to-event (TTE) data from different studies were stored together and Statistical METHODS for TTE data were employed to analyze outcomes. 12 studies were selected with 3330 patients (1729 EC, 1601 LT). Studies were symmetrically distributed on Funnel plot. Survival at 20 years was 93% [87,99] and 89% [83,95] respectively in the EC and LT groups (log-rank p value = 0.007). Freedom from tacharrhythmia was significantly higher in the EC group (92% [91,93] and 83% [81,55] at 15 years; log-rank p value = < 0.0001) whereas there was no significative difference between the 2 groups in term of bradyarrhythmia (log-rank p value = 0.7). Risk of thromboembolic events was 2.87%/ year in the EC group Vs 0.9%/ year in the LT group (OR= 2,15 [0.95; 4.85]; p=0.07). A meta-regression was performed including as confounding vaiables : age, sex, ventricle morphology, heterotaxy, tricuspid atresia and pre-Fontan collaterals. All these variables didn’t influence neither survival nor freedom from tachyarrhythmia. The long-term survival of Fontan population is excellent. EC confers long-term survival advantage over the LT without higher rate of re-operations. The incidence of arrhythmias increases with time since surgery. EC, even though it makes it more challenging for the electrophysiologist, preserves sinus node function and reduces significantly the incidence of long-term postoperative arrhythmias as compared with LT. A trend to greater embolic events was observed in the extracardiac conduit patients.View Large Image Figure ViewerDownload Hi-res image Download (PPT)