Coarctation of the aorta in children at Siriraj Hospital.

A retrospective analysis of 33 children who were diagnosed to have coarctation of aorta at Siriraj Hospital between January 1989 and December 1998 was undertaken. There were 21 males (64%) and 12 females (36%). Their ages ranged from one day to 11 years (median 2 months). The majority of the patients (78.8%) were presented early within the first year of life. The predominant clinical manifestations were congestive heart failure (69.6%), systemic hypertension of the upper extremities (36.3%) and decreased femoral pulses. Chest roentgenogram revealed cardiomegaly (70%) and increased pulmonary blood flow (84%), reflecting congestive heart failure and associated left-to-right shunting. Electrocardiogram showed normal pattern (33.3%), right ventricular hypertrophy (33.3%), left ventricular hypertrophy (22.2%) and biventricular hypertrophy (11.2%). The younger the patient is, the more right ventricular predominance is demonstrated. According to the echocardiogram and/or aortogram, juxtaductal type was found in 51.5 per cent, postductal type in 27.3 per cent and preductal type in 21.2 per cent. Medical management included prostaglandin E1 infusion in a newborn baby presented with low-cardiac output state, anticongestion and antihypertension, if indicated, followed by surgical correction. The result of coarctectomy with end-to-end anastomosis with or without arch augmentation was good. The operative mortality rate was 5 per cent. The overall mortality in the present study was 9 per cent. The most common causes of death were multiorgan failure and pulmonary infection. Residual coarctation was found in 5 per cent.

Limitation of transthoracic echocardiography in the diagnosis of congenital heart diseases.

Nowadays, it has been widely accepted that echocardiography is the most efficient, non invasive diagnostic tool to diagnose congenital heart diseases. However, cardiac catheterization remains the gold standard to diagnose and obtain hemodynamic data prior to cardiovascular surgery. In order to find out the accuracy of transthoracic echocardiography in relation to the anatomical diagnosis of congenital heart diseases, 175 consecutive patients who underwent diagnostic cardiac catheterization during January 1999 to December 1999 were reviewed. All of them had complete echocardiographic studies prior to the procedure. The male to female ratio was 1.06:1. The median age at the time of echocardiography was 3.36 (0.01-28.8) years old. The indications of the cardiac catheterization were to demonstrate cardiovascular anatomy 64 per cent, to obtain pulmonary artery pressure and pulmonary vascular resistance 13.7 per cent, and to get both information 22.3 per cent. Tetralogy of Fallot (23.4%) was the most frequent cardiac malformation, followed by complex congenital heart diseases (22.3%), simple left to right shunt (12%), pulmonary atresia with ventricular septal defect (8.6%), tricuspid atresia (5.7%), simple d-transposition of great arteries (4%), etc. From cardiac catheterization; 49 cases (28%) revealed additional data which were surgically important, 3 cases (1.7%) resulted in different diagnoses, and 3 cases (1.7%) revealed additional information which was not surgically important. Inadequate imaging technique (36 cases, 65.5%) and limitation of technique (19 cases, 34.5%) were the reasons for missing anatomical findings of transthoracic echocardiography. Age at the time of echocardiography was not a significant factor affecting the accuracy. Persistent left superior vena cava, multiple aorto-pulmonary collateral arteries, pulmonary artery anatomy, and coronary artery anatomy were the most frequent cardiac lesions misdiagnosed by transthoracic echocardiography that were somewhat surgically important. The incorrect echocardiographic diagnoses were aorto-pulmonary window, patent ductus arteriosus, and vascular ring. Thorough and extensive echocardiographic scanning coupled with cooperative or adequately sedated patients by an experienced operator using an efficient echocardiographic machine might improve the accuracy of transthoracic echocardiography in the diagnosis of congenital heart diseases.

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.

Intermediate term follow-up on transcatheter closure of atrial septal defects by Amplatzer septal occluder.

BACKGROUND: Surgical repair of secundum atrial septal defect (ASD) is a safe, widely accepted procedure with negligible mortality. However, it is associated with morbidity, discomfort and a thoracotomy scar. As an alternative to surgery, a variety of devices for transcatheter closure of ASD have been developed. OBJECTIVES: We report our clinical experience with transcatheter closure of ASD using the Amplatzer Septal Occluder, a new occlusion device with intermediate term follow-up. PATIENTS & METHOD: Patients having ASD met established two-dimensional echocardiographic criteria for transcatheter closure were selected. ASD size was measured by transesophageal echocardiogram (TEE) and balloon occlusion catheter (stretched diameter). The Amplatzer's size was chosen to be equal to or 1 mm less than the stretched diameter. The device was advanced transvenously into a guiding sheath and deployed under fluoroscopic and TEE guidance. Once its position was optimal, it was released. TEE was undertaken to demonstrate the residual shunt. RESULTS: There were 26 patients with a mean age of 17.2 +/- 15.9 years old (2 to 60) and a mean weight of 22 +/- 37.5 kg. (10.7 to 62.5). The mean ASD diameter measured by TEE was 18.3 +/- 5.2 mm. and by stretched diameter was 22 +/- 7.5 mm. Four patients who had ASD stretched diameter over 32 mm were excluded because a larger device was not available. Devices were deployed in 22 patients with sizes from 9 to 30 mm (median = 22mm). Immediately after closure a tiny residual shunt was observed at the core of the device in each case. At 24 hours only two patients had a small (< 2 mm) shunt. One patient with fenestrated ASD had a device embolized into the right ventricle with successful removal and surgical closure. Patients were followed-up for a mean duration of 8 +/- 3.5 months (from 3 to 12 months). Complete occlusion was found in 20 out of 21 patients (95%). CONCLUSION: The Amplatzer Septal Occluder is a new device designed for closure of different sizes of ASD and can be easily and safely deployed. Our experience showed that this device could be used to close an ASD as large as 30 mm. The intermediate term follow-up also demonstrated an excellent closure result. Caution should be undertaken with patients who have a fenestrated atrial septal defect particularly at the septal rim.

Transcatheter laser-assisted balloon valvulotomy as primary treatment in newborn with pulmonary atresia and intact ventricular septum.

We report our initial experience and the first case in Thailand in successfully performing transcatheter laser perforation of membranous pulmonary valve and subsequent balloon dilations of the valve in a 14-day-old baby with pulmonary atresia and intact ventricular septum. After the procedure, right ventricular angiograms revealed anterograde flow across the pulmonary valve. There was no major complication. Doppler echocardiography one week later demonstrated a pressure gradient across the pulmonary valve of 30 mmHg and right ventricular systolic pressure of 60 mmHg. Her peripheral oxygen saturation improved from 70's immediately after the procedure to 92-97 per cent at one-month after the procedure.

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.

Percutaneous balloon pulmonary valvuloplasty in children: experience at Siriraj Hospital.

Twenty-seven children with pulmonary valvar stenosis with pressure gradient (PG) > or = 40 mmHg underwent percutaneous balloon pulmonary valvuloplasty (PBPV) at Siriraj Hospital between February 1993 and August 1996. There were 13 males and 14 females, with an age range from 2 months to 14 years, and body weight from 4.7 to 42.1 kg. The majority (92.6%) were asymptomatic. Before the PBPV, the pulmonary valve annulus (PVA) measured by echocardiography was significantly greater than that measured by cardiac catheterization (15.2 +/- 3.7 vs 14.5 +/- 3.9 mm, P = 0.006). However, there was linear association (r = 0.972) between the two methods. The PG obtained by the two methods showed no significant difference (90.8 +/- 35.3 by echocardiography vs 97.3 +/- 47.2 mmHg by catheterization, P = 0.266). Immediately after PBPV, the right ventricular systolic pressure (113.7 +/- 41.1 pre vs 62.3 +/- 28.1 mmHg post) and the PG 103.4 +/- 43.4 pre vs 49.0 +/- 31.1 mmHg post) were significantly reduced (p < or = 0.0005). At 6-mo follow-up echocardiography, the PG was 28.6 +/- 17.6 mmHg and was significantly reduced (P = 0.0005). The PVA significantly increased at the 12 mo follow-up (15.2 +/- 3.6 pre vs 17.6 +/- 3.8 mm post, P = 0.001). Only minor complications were reported in the present study; bleeding (3.7%), transient bradycardia (7.4%) and pulmonary regurgitation not more than moderate severity (79%). The immediate and intermediate results of PBPV are excellent with a success rate of 85 per cent.

Successful transcatheter coil embolizations of complex pulmonary arteriovenous fistulas: the first case in Thailand.

Successful transcatheter coil embolizations of the left lower lobe pulmonary arteriovenous fistulas, the first case in Thailand, in a 6-year-old boy presenting with increased cyanosis was reported. Transcatheter management of unusual sites of right-to-left intrapulmonary shunting can provide gratifying clinical improvement in some children.