DORV with non-committed VSD and Taussig-Bing hearts. Controversial anatomic entities

We read, with interest, the excellent paper by Lacour-Gayet et al. [1], regarding the biventricular repair of double outlet right ventricle (DORV) with non-committed ventricular septal defect (VSD) using the arterial switch operation. Congratulations for such excellent results.

We have a very different point of view regarding the type of hearts the authors are describing in their paper and about the concept of Taussig-Bing hearts.

The true Taussig-Bing hearts are a type of DORV, with double subarterial conus and mitro-pulmonar discontinuity. The pulmonary artery always arises entirely from the right ventricle, independently of the size and location of the VSD, near or far from the subpulmonary conus. When the pulmonary artery does not arise entirely from the right ventricle, the subpulmonary conus never exists and this malformation is always a D-TGA, independently of the grade of pulmonary overriding.

We think, that because the anatomical characteristic of the hearts operated; location of the VSD, double subarterial conus and presence of typical subaortic obstruction, the authors are operating true Taussig-Bing hearts, with a perimembranous ventricular septal defect of variable size [2]. The sagitally malpositioned infundibular septum is the cause of the subaortic obstruction and also determines the location of the VSD, always related to the trabecula septomarginalis, above, below or between the arms of the trabecula. These hearts are very different from the D-TGA hearts with pulmonary overriding, very frequently mixed and confused in literature.

It is our perception, that these types of hearts are also different from non-committed DORV hearts, as named in the manuscript.

In the true non-committed DORV heart, the VSD is not directly related to the membranous septum, being an atrioventricular canal type defect or a muscular defect, located in the inlet, mid or trabecular septum [3]. Subaortic stenosis is not necessarily present in these types of hearts. When a biventricular repair is planned, if the rerouting of the left ventricle to the pulmonary artery is possible, the direct rerouting without obstruction to the aorta (type of Kawashima repair) is also usually possible.

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