The Fontan operation: experience at Siriraj Hospital.

Seventy five patients underwent modified Fontan operation at Siriraj Hospital from October 1987 to December 1998. Cardiology data was analyzed retrospectively. Four patients' data was unavailable. Median age at operation was 9.7 (1.8-34) years old. Tricuspid atresia accounted for 38 per cent of the patients. Ten patients (14.1%) died in the acute post operative period due to consequence of low cardiac output. Another 3 patients (4.2%) expired in the intermediate and late post operative period. Age at operation, pulmonary artery size, pre-operative oxygen saturation, and mean pre-operative pulmonary artery pressure were not different between those who survived and those who died. Abnormal pulmonary vein, atrioventricular valve regurgitation, and underlying ventricular morphology statistically affected the acute survival of modified Fontan operation. Intraoperative aortic cross clamp time, and post operative mean pulmonary artery pressure on day 0, 1 and 2 post operation were found statistically shorter and lower in the survival group. Survival rate at 5 years was 83 per cent. Modified Fontan operation is the final palliative operation of choice for low risk single ventricle physiology in our institution with acceptable outcome. Thorough pre-operative hemodynamic and anatomic studies and staging modified Fontan procedure may include a higher number of candidates and improve the outcome of the operation.

Results of rapid two-stage arterial switch operation in patients with transposition of the great arteries: one-year postoperation.

The rapid two-stage arterial switch operation is an alternative therapy for patients with simple transposition of the great arteries who present beyond the neonatal period and have low left ventricular pressure. It provides normal ventricular function compared to the atrial switch operation. Between July 1994 and February 1997, there were 13 such infants who had rapid two-stage arterial switch operation performed at Siriraj Hospital. There was 1 late death (11 months after the operation). All 12 survivors (mean age 22.4 +/- 5.7 months) were clinically evaluated and had echocardiography performed at 14.8 +/- 4.9 months after the operation. All were asymptomatic. Echocardiogram revealed a residual small atrial septal defect (1 case), small ventricular septal defect (1 case), mild supravalvar neopulmonary stenosis (2 cases), bicuspid neoaortic valve without stenosis (2 cases), dilated neoaortic sinus of Valsalva (6 cases, 50%) and mild neoaortic insufficiency (11 cases, 91.7%). The left ventricular function was hyperdynamic after pulmonary artery banding and significantly decreased to normal level at the time of study (shortening fraction of 43.8 +/- 10.7 vs 29.2 +/- 3.8%, respectively, p = 0.0005). The wall thickness was significantly increased after pulmonary artery banding and decreased overtime (0.48 +/- 0.08 vs 0.32 +/- 0.05 cm, respectively, p < 0.0005). The left ventricular dimension was significantly increased both after pulmonary artery banding and at the time of study (2.06 +/- 0.42 vs 3.32 +/- 0.30 cm, respectively, p < 0.0005). The left ventricular mass was significantly increased after pulmonary artery banding and at the time of study (21.79 +/- 7.79 vs 33.08 +/- 7.40 g/m2, respectively, p = 0.0005). The mortality and morbidity of rapid two-stage arterial switch operation are low. However, long-term follow-up should be monitored.