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.

Utility of intraoperative transesophageal echocardiogram in congenital heart disease.

Intraoperative transesophageal echocardiogram (TEE) has improved the perioperative outcome in adult patients. The purpose of the current study was to assess the benefit of intraoperative TEE in patients with congenital heart disease undergoing surgical correction (repair). The results of the patients who had consecutively undergone intraoperative TEE during their congenital heart surgery between January 1998 to June 2000 were reviewed. There were 104 patients (whose ages ranged from one week old to 50 years old (median 5 years old) and their weights from 3 kg to 79 kg (median 15 kg). A significant impact was said to have occurred if these findings prompted a change in surgical procedure following a prebypass study or rebypass for repair of a residual defect. Prebypass TEE had a significant impact in seven patients (6.7%). TEE could be used as a guide to help repair in three patients. The postbypass TEE examination had a significant impact in 15 patients (14.4%). Of these 15 patients, eight were detected primarily by TEE examination. The group of patients in whom TEE had the most significant impact was in patients who had surgery related to the repair of the atrioventricular valve (complete or partial atrioventricular (AV) canal repair, Ebstein's anomaly; 9 out of 22 patients; 41%). A less significant impact was found in surgery for other complex congenital defects (single ventricle or complete transposition of great arteries; eight out of 46 patients; 17.4%). TEE had limited impact in simple congenital lesion. Intraoperative TEE is valuable in the perioperative care of patients with congenital heart defects. We found the most benefit in patients with complete or partial AV canal and Ebstein's anomaly.

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.