THE ARTERIAL SWITCH-OPERATION - EARLY AND MIDTERM (6 YEARS) RESULTS WITH PARTICULAR REFERENCE TO TECHNICAL PROBLEMS

Since February 1985 the arterial switch operation (ASO) has become the surgical treatment of choice for newborns with simple TGA, appropiate forms of complex TGA and double outlet right ventricle (DORV) as well at our institution. Between 1985 and 1990 a total of 87 patients underwent surgery. In 60 patients with simple TGA and 8 patients with complex TGA or DORV, respectively, an arterial switch-operation was performed. Because of coronary artery anomalies (n = 13), dysplastic pulmonary valves (n = 3) or pressure drop in the left ventricle (n = 1), the initially planned arterial switch operation was discarded and a Mustard type procedure was in 17 patient. Finally there were two primarily performed Mustard operations. The hospital mortality after arterial switch for simple TGA was 15% (9/60), 0/8 in patients with complex TGA. Late mortality was calculated to be 12% (1/8) in patients with complex TGA and 3/60 in patients with simple TGA. Within the Mustard group there were 2/19 hospital deaths and one late death. Causes of early death after arterial switch were: intraoperative myocardial infarct (n = 3) low cardiac output syndrome (n = 2), intractable bleeding (n = 2), metabolic acidosis (n = 1), and septicemia (n = 1). Late after surgery there was one death due to chylothorax after thrombotic obstruction of the SVC, and 3 more deaths secondary to intraoperative infarct, progressive LV dysfunction and meningitis, respectively. Among the long-term survivors 2 patients developed a severe supravalvulary pulmonar stenosis. There were no significant arrhythmias, supravalvulary pulmonar aortic stenoses, aortic insufficiency or myocardial perfusion disturbances. Inferences: There is no significant difference in hospital mortality when comparing patients who underwent an arterial switch or a Mustard type operation. The functional results after follow up times of 5-10 years are superior after an arterial switch operation.