Editorial Comment: Tetralogy of Fallot: a larger infundibular incision in a transatrial repair eliminates the risk of a reoperation for a right ventricular outflow tract obstruction

The surgical repair of tetralogy of Fallot has been offered widely for the last five decades and depending on their geographical location, patients are still offered one of two opposed management strategies and surgical techniques [1]. As comparative studies are unlikely to be undertaken, single-centre reports such as the one published by Sfyridis et al. [2] in this issue are critically important because they will be the only way to delineate the respective benefits of these diverging practices. The first one of these divergence concerns the management of the neonates with tetralogy of Fallot becoming cyanotic. These babies can either be offered an early definitive repair or a palliation with a systemico-pulmonary shunt and later repair. The second divergence relates to the choice of the operative technique favoured, the transventricular or the transatrial-transpulmonary approach. The main difference between these two techniques relies in the approach by which the ventricular septal defect (VSD) is closed. In the transatrial technique, the VSD is closed through the tricuspid valve, while in the transventricular technique, it is closed through the right ventriculotomy. It is therefore claimed that the use of the transatrial technique results in a smaller incision of the outflow tract and a better preservation of the right ventricular function [3, 4]. It is noteworthy that the incidence of transannular incision in both techniques depends on the surgeon's motivation to open widely the outflow tract widely or to leave some degree of obstruction rather than on the technique used. Operations at an earlier age, because of size constraint, have necessitated the use of the transventricular approach, and therefore teams favouring repair in neonates have generally adopted the tranventricular approach [5, 6]. Conversely, teams who are favouring transatrial repair have often, but not always, adopted a strategy of palliation in neonates and delayed repair. It is certain that the comparison between these two approaches and techniques will no longer be subjected to randomization because each centre has adopted one or the other of those strategies and techniques. Each surgeon defends the view that his adopted approach and technique is superior. It seems therefore appropriate to divulgate my own bias. I have previously conducted research establishing the superiority of the transatrial repair and in the last 9 years, I have worked in the team of the Royal Children's Hospital in Melbourne, which has notoriously promoted the transatrial repair since the early 1980s. It is likely that overall mortality is the main outcome that should demarcate a strategy of neonatal repair from a strategy of early palliation and later repair. Before the turn of the century, both strategies were associated with significant mortality in neonates. There are now several reports of minimal mortality with neonatal repair, but still at the cost of a high morbidity, especially in terms of the need for early reintervention [6–8]. The remarkable results of suffering no mortality reported by the team in Athens, if reproduced by other centers, seem to ascertain that both strategies may at least achieve similar survival in neonates. Importantly, this report highlights that all transatrial repairs are not equal and that the way this technique is practiced will considerably impact on its long-term outcomes. The impetus behind the development of transatrial techniques of repair has been the intention to limit the size of the right ventricular incision in order to preserve right ventricular function. It can therefore be easily understood that surgeons practicing this technique have often tended to leave patients with some degree of residual obstruction. This fact is demonstrated by the high rate of reintervention for right ventricular outflow tract obstruction presented in all reports of this technique [9, 10]. The quoted rate of early and late reintervention for right ventricular outflow tract obstruction varies between 10 and 15%. The experience of the Athens team is strikingly different. Undoubtedly, they did open the right ventricular outflow tract more than the other teams who have adopted transatrial repairs. Their immediate postoperative gradient was only 7 mmHg, clearly inferior to the postoperative gradients that we see in our practice in Melbourne. It is extremely interesting to observe that the more liberal opening of the outflow tract by the Athens team resulted in the disappearance of the need for reoperation for right ventricular outflow tract obstruction, a complication that was thought to be inevitably linked to the transatrial technique. One could argue that this policy of opening the outflow tract more widely will result in an unacceptable level of pulmonary regurgitation and in a higher requirement for reintervention for right ventricular dilatation. At this stage of their follow-up, this does not seem to be the case. After a follow-up of 10 years, a relatively short period for the accurate evaluation of the incidence of this complication, but extending up to 25 years, the incidence of reintervention remained remarkably low. It will be essential to report again their results in 10 years to compare their incidence of reintervention with that of the teams who adopted a more restrictive opening of the right ventricular outflow tract. It is my personal biased belief that numerous teams have adopted the transatrial approach in an attempt to preserve the competence of the often severely diseased pulmonary valve. These teams may be subjecting patients to a risk of early reintervention for a residual outflow tract obstruction and of a prolonged hospital stay that is certain, for the uncertain benefit of a slight decrease in the need for a late reintervention for a right ventricular dilatation. It is only by the reporting of single-centre experiences such as that in Athens, that we will be able to determine the best way to perform the transatrial repair, and in particular the ideal extent of the opening of the right ventricular outflow tract. Only then, will we be able to determine whether the transatrial repair of tetralogy of Fallot yields results superior to the transventricular approach in terms of ventricular function and reintervention. Yves d'Udekem is a Career Development Fellow of The National Heart Foundation of Australia (CR 10M 5339).