Transposition of the great arteries with ventricular septal defect and left ventricular outflow tract obstruction: how to choose in the surgical armamentarium?

Abstract

The surgical treatment of transposition of the great arteries (TGA) with ventricular septal defect (VSD) and left ventricular outflow tract obstruction (LVOTO) is currently a matter of passionate debate. Classical procedures [i.e. Rastelli and reparation a l’Etage ventriculaire (REV) operations] are still favoured by most centres. Introduced in 1984, the Nikaidoh procedure (actually a modification of an operation performed several years earlier by Bex to repair simple TGA) is gaining widespread acceptance. Kramer et al. [1] report their experience with the Nikaidoh procedure and its modification with preservation of the native pulmonary valve (en bloc rotation of the truncus arteriosus). Their results confirm those of other recent series. Despite encouraging mid-term results, the complexity of the procedure, the anatomical contraindications (mainly related to coronary anatomy) and the potential late complications (e.g. aortic regurgitation and coronary obstructions) cannot be underestimated. We, therefore, think that it is too early to endorse the authors’ conclusion that the current results ‘make the aortic translocation the procedure of choice for the treatment of this lesion (TGA/ VSD/LVOTO)’. On the contrary, we believe that all surgical options must be taken into consideration, and that the optimal repair should be chosen on an individual basis. Preoperative evaluation is essential and must be performed in close collaboration between the cardiologist and the cardiac surgeon. Careful echo-Doppler assessment is the key point, although it may be completed using new imaging techniques (particularly 3D reconstruction). Several features of a complex intracardiac anatomy must be fully delineated, including position and size of the VSD, position and size of the conal septum, potential insertions of tricuspid or mitral chordae onto the conal septum and anatomy of the obstructed left ventricular outflow tract. This last element is essential in the decisionmaking. The anatomy of the subvalvar obstruction must be analysed to determine whether it can be relieved surgically or not. Even more important, the evaluation of the valvar area (size of the annulus and anatomy of the leaflets) must ascertain whether the native pulmonary valve is subnormal and able to serve as aortic valve or abnormal but good enough to serve as pulmonary valve or severely dysplastic and not usable. At the end of the evaluation, the best surgical option can be selected, keeping in mind some simple principles: (i) the operative risk should be low, and therefore, the operation kept as simple as possible, (ii) unobstructed left and right ventricular outflow tracts must be reconstructed, (iii) some surgical manoeuvres with potential early and late deleterious consequences (e.g. transfer of the coronary arteries, translocation of the native aortic root, extensive septal resection, mobilization of tricuspid or mitral chordae) should be used with caution and (iv) prosthetic extracardiac conduits (with the inevitable need for multiple reoperations) must be avoided. Our current indications can be summarized as follows: