Reply to Letter to the Editor Letter to the Editor Reply to

We thank the Editor for giving us the opportunity to reply to the ‘Letter to the Editor’ describing the unguarded tricuspid orifice with pulmonary atresia [1]. We congratulate Kariya et al. for successful surgical treatment using a total right ventricular exclusion and total cavo-pulmonary connection (TCPC). Because of the high mortality of this rare anomaly, there are only a few successful reports on the surgical strategy and procedure for treating this condition. Themain morphological feature of this anomaly is the lack of any guarding valvular tissue at the tricuspid annulus. In addition, this anomaly is associated with a high incidence of pulmonary valvular disease. The morphology of the rightheart system in Kariya’s report would be very similar to that of our case. Haemodynamically, poor right ventricular contractility resulted in the failure of the biventricular repair and caused Fontan circulation in both cases. The clinical course of these two cases is quite different. The most important turning point would be the difference in surgical strategy during childhood. We selected the univentricular repair (extracardiac TCPC) at 6 years of age following a Blalock—Taussig shunt and a bidirectional Glenn’s operation. In contrast, the biventricular repair (right ventricular outflow-tract repair) had been conducted at 5 years of age following a Blalock—Taussig shunt. The biventricular repair for the case with poor right ventricular function such as Kariya’s casewould lead to an enlarged right atrium and ventricle, resulting in congestive right-heart failure with refractory arrhythmia. Then, total right ventricular exclusion and TCPC conversion had been planned at 22 years of age. We had previously reported a total right ventricular exclusion for arrhythmogenic right ventricular cardiomyopathy and Ebstein’s anomaly [2]. This procedure improves cardiac output and reduces supraventricular/ventricular arrhythmia by removing arrhythmogenic tissue from both the right atrium and the right ventricle [3]. Thus, this procedure would be very beneficial for the patient with right ventricular failure and refractory arrhythmia by its action of converting the biventricular heart into a univentricular heart (Fontan circulation). The surgical strategy in Kariya’s report appears to be appropriate for these reasons. Although the surgical strategy for unguarded tricuspid orifice with pulmonary atresia is different in both the cases, Fontan circulation was successfully established in both cases during childhood and adulthood. An accurate diagnosis in the neonatal period, infancy and childhood is important to consider the surgical strategy in the early period of life. Where this anomaly has not been diagnosed until adulthood, total right ventricular exclusion and TCPC conversion would be one of the surgical options for such patients.