Early and mid-term outcome of the arterial switch operation in 114 consecutive patients : A single centre experience

The arterial switch operation (ASO) has become the treatment of choice in patients with simple or complex transposition of the great arteries (TGA). The purpose of this study was to assess early and mid-term outcome after ASO in a single centre.

Between 1995 and December 2005, 114 consecutive patients underwent an ASO at our institution, performed by one single surgeon. Patients charts, surgical reports and echocardiograms were retrospectively reviewed. Patients were analyzed in 3 different groups: Group I consisted of 77 neonates with TGA and intact ventricular septum, group II of 13 patients with TGA and ventricular septal defect which had to be closed surgically and group III of 24 patients with various forms of TGA in a complex setting. The patient's median weight was 3.23 kg (1.65-8.30). Twenty-five neonates were born preterm, 18 were diagnosed prenatally. Median follow-up time was 20.7 months (0.3-128.6).

The thirty day mortality was 1.75% (2/114), late mortality 0.88% (1/112) accounting for an overall mortality of 2.63%. There was only one early coronary event and so far no late events. Ten of 111 survivors required reoperation, all but 1 from group III. Prevalence of supravalvular pulmonary stenosis was 4.7%. Freedom from reoperation at 5 years of follow-up time was 87.5%. One patient required permanent pacing, no other late arrhythmias occurred. In our series the only risk factor for increased mortality and morbidity was a body weight of less than 2500 g at the time of operation. No better outcome could be demonstrated in the prenatally diagnosed patients.

The ASO can be performed safely and with low mortality and morbidity even in patients with complex TGA. Follow-up of these patients is required to detect residual problems like supravalvular pulmonary stenosis, coronary problems, arrhythmias and aortic valve dysfunction.