Objective: To summarize the experience in arterial switch operation (ASO) for complex congenital heart defect (CHD) with severe pulmonary hypertension (PH) and ventriculoarterial discordant connection in children older than 6 months.
Methods: Twenty-three consecutive pediatric patients suffering from severe CHD, such as transposition of great arteries (TGA), Taussing-Bing anomaly, etc, with moderate to severe PH, 15 male and 8 female, aged 7-84 months, with the body weight of 4.5-20.0 kg, pulmonary pressure of 24.0-80.0 mm Hg, and pulmonary resistance of 49.2-1261.9 dyn.s.cm(-5), and with different complication such as left ventricular outflow tract obstruction (3 cases), subpulmonary membrane (1 case), and subaortic membrane (1 case), underwent ASO under general anesthesia and extracorporeal circulation with low temperature (18 degrees C-22 degrees C) and low volume blood flow (50 ml.kg(-1).min(-1)). The complicated anomalies were corrected simultaneously. Nitric oxide and alpha-blocker were used to the children with PH during the peri-operational period.
Results: Twenty children survived, and were cured and discharged with an obvious improvement of heart function, only one of which had sequel of coma due to cerebral anoxia. After operation the pulmonary pressure decreased to 23 mm Hg +/- 9 mm Hg, significantly lower than that before operation (P = 0.000). Physical activities increased obviously. Three children died post-operatively of the reasons un-related to the pre-operative PH and pulmonary arterial resistance, with a mortality of 13.04%. Follow-up of 14 +/- 8 months showed no death and complication.
Conclusion: ASO can still realize satisfactory early results for the children older than 6 months suffering from complex CHD with moderate to severe PH and ventriculoarterial discordant connection provided they are in a rather good condition without severe cyanosis (SaO(2) > 60%) and with the pulmonary arterial resistance being acceptable (pressure of right atrium < 1000 dyn.s.cm(-5)).