Editorial Comment: Corrected transposition of the great arteries: the continuing quest for the optimal surgical management

Hiramatsu et al. [1] have reported their experience with an anatomic repair of congenitally corrected transposition of the great arteries (ccTGA). This included 90 patients operated on between 1983 and 2010. Seventy-two patients with ccTGA, ventricular septal defect (VSD) and pulmonary stenosis underwent atrial switch plus intraventricular rerouting. Eighteen patients without pulmonary stenosis had atrial switch plus arterial switch. The long-term results were carefully evaluated. Differences between the two groups were noted. Patients without pulmonary stenosis (the double-switch group) had a better outcome at 20 years regarding survival (83% vs 76%, NS), freedom from reoperation (94% vs 78%, P < 0.05) or arrhythmia (79% vs 57%, P < 0.05). The total freedom from all cardiac events (death, reintervention or reoperation, arrhythmia) was significantly different (60% in the double-switch group vs 40% in the group with pulmonary stenosis). The functional outcome was similar in both groups and, overall, satisfactory. These results should, however, be taken with caution, because of the small number of patients in the double-switch group. Interestingly, the Birmingham group (another institution with a large experience in this field) has recently reported its own experience between 1991 and 2011 [2]. This included 45 patients with Rastelli-Senning repair and 68 patients with double-switch operation. The results at 10 years were somewhat different. Survival (84% in the double-switch group vs 77% in the Rastelli-Senning group) and freedom from reintervention (50% vs 49%) were similar in both groups. However, freedom from death, transplantation or heart failure was better in the Rastelli-Senning group. These results may seem contradictory. Actually, I think that they show only how difficult it is to draw out firm conclusions when so many factors are involved. ccTGA is a rare malformation; it is therefore difficult (actually impossible for any individual institution) to collect large cohorts of patients who undergo homogeneous surgical approaches. Very different patients are involved; patients with right ventricular dysfunction and severe tricuspid regurgitation because of Ebstein-like malformation are different from patients with a well-functioning right ventricle and a competent tricuspid valve; patients with an intact ventricular septum who need left ventricular retraining before undergoing a double-switch operation are different from patients with a large VSD and a left ventricle ready to sustain the systemic output. Different surgical options are available and may yield different results; regarding atrial switch, the Senning and Mustard operations or hemi-Mustard procedure with cavo-pulmonary anastomosis may influence the incidence of postoperative arrhythmias; reconstructing the right ventricular outflow tract with or without an extracardiac conduit may greatly modify the need for reoperation. Well-designed large multicentre cohort studies are necessary to address all these issues. Before such information is available, some considerations must be kept in mind: