[Outcome of oral bosentan in children with congenital heart disease associated pulmonary arterial hypertension].

OBJECTIVE: To investigate the outcome of dual endothelin receptor antagonist bosentan in children with congenital heart disease (CHD) associated pulmonary arterial hypertension (PAH). METHODS: A total of 32 children were recruited into this prospective and observational study. Among them, there were 18 cases with left-to-right shunt and 14 cases with elevated pulmonary vascular resistance (PVR) in functional single ventricle (FSV). All the cases were treated with oral bosentan, initiated from 90 days before or 8 years after operation, and were followed up periodically to analyze the clinical outcome and monitor its side effects. RESULTS: In the left-to-right shunt group, pulmonary arterial pressure (PAP) was measured at (57 +/- 26), (52 +/- 31) and (46 +/- 22) mm Hg after oral bosentan therapy at 1, 2 and 3 months respectively. The measurements significantly decreased as compared with the pre-dosing level of (74 +/- 15) mm Hg (P < 0.05). After a 3-months therapy of bosentan, World Health Organization functional class (WHO FC) improved significantly (P < 0.01). In the elder cases, the 6-minute walking distance after a 3-month bosentan therapy significantly increased as compared with the pre-dosing level, i. e. (497 +/- 56) vs (424 +/- 31) m (P < 0.05). In the FSV group, as compared with the pre-dosing level, the transcutaneous oxygen saturation increased significantly in the last follow-up during bosentan exposure, i. e. (86 +/- 5)% vs (78 +/- 6)% (P < 0.01). WHO FC improved significantly (P < 0.01) and the incidence of facial edema and pleural effusion was significant lower (P < 0.05) in the last follow-up for the treatment group. Patients tolerated bosentan well and no significant rise in hepatic transaminases was observed. CONCLUSIONS: Bosentan is safe in treating CHD associated PAH in children. In left-to-right shunt cases, oral bosentan can reduce PAP and improve both WHO FC and exercise capacity. And it can also improve WHO FC and transcutaneous oxygen saturation in FSV and reduces the occurrence of elevated PVR-related complications.

Arterial switch operation with coronary arteries from a single sinus in infants.

BACKGROUND: The implantation of a coronary artery (CA) is critical for the arterial switch operation (ASO) done to treat complete transposition of the great arteries (TGA). Coronary artery abnormalities are risk factors for both early and late mortality after surgery. In this study, the methodology and effects of ASO surgery with coronary arteries from a single sinus were evaluated. METHODS AND RESULTS: From March 1999 to June 2006, 31 patients were treated with ASO with coronary arteries from a single sinus in our hospital. They aged 11 hours 16 months (2.8 +/- 3.9 months) and weighted 2.3 7.8 Kg (3.1 +/- 2.5 Kg). 27 cases had TGA and a ventricular septal defect (VSD), and 4 had TGA and an intact ventricular septum (IVS). During surgery, a CA button was implanted in the new proximal aorta with "trapdoor" technique or by inverting 90 degrees dorsally; pericardium or arterial augmentation was implanted at the base of the new major artery. The mortality rate after surgery was 25.8%. After 2-5 years of follow-up, 2 cases with residual shunting recovered spontaneously, 2 cases had residual pulmonary artery obstruction (30-56 mmHg), and none of the patients had any significant changes in myocardial ischemia. CONCLUSION: The implantation of an abnormal coronary artery is practical and feasible; it can reduce both the occurrence of twisting and deforming in the coronary artery after implantation, as well as myocardial ischemia after surgery. Thus, this could improve the surgical success and cure rates.

Use of the lecompte procedure for ventriculoarterial connection abnormalities in infants and children with congenital heart diseases.

BACKGROUND: The Lecompte (REV) procedure is used to correct abnormal ventriculoarterial connections in patients with congenital heart diseases; it avoids the need for an extracardiac conduit for pulmonary outflow tract reconstruction. The present study aimed to investigate effectiveness and criteria of the REV procedure in children with abnormal ventriculoarterial connections. METHODS: Thirty-eight children (mean age, (2.2 +/- 1.7) years; mean weight, (11.5 +/- 3.8) kg) with abnormal ventriculoarterial connections who had an REV procedure in our hospital from January 1998 to May 2006 were studied. Only 10 patients had the usual anteroposterior relationship of the two great arteries. The infundibular septum between the two semilunar valves was aggressively resected to enlarge it and construct a straighter left ventricular outflow tract and a wide tunnel between the ventricular septal defect (VSD) and the aorta. Eighteen cases had the original REV procedure; 20 had a modified REV procedure. RESULTS: All patients are alive; none developed severe complications. The postoperative right ventricular (RV) to left ventricular (LV) pressure ratio was 0.20-0.45. Five patients had RV dysfunction; 2 patients had a pressure gradient in the RV ventricular outlet of 30.0-34.5 mmHg; 3 cases had a 37.5-47.3 mmHg pressure difference in the RPA. All patients had an RV pressure less than half the systemic pressure. These gradients' magnitudes in all patients were consistent with the post-operative RV to LV pressure ratio (P < 0.05). During the follow-up (mean, (4.2 +/- 0.6) years), 2 patients had an RPA pressure gradient of 24.0-29.3 mmHg which abated to less than 10 mmHg after two years. CONCLUSIONS: The REV procedure provides satisfactory short- to medium-term results. It may be superior to the Rastelli procedure for treating ventriculoarterial connection abnormalities; it allows early, complete anatomic repair and reduces the need for late re-operation, since no extracardiac conduit is needed. Longer follow-up is needed to determine long-term outcomes.

[Individualized surgical management of pulmonary atresia with intact ventricular septum].

OBJECTIVE: To delineate individualized surgical management strategy for the optimal management of pulmonary atresia with intact ventricular septum (PA/IVS). METHODS: Between 1997 to 2005, 52 consecutive patients with PA/IVS, 31 male and 21 female, aged 2-9, divided into 2 groups according if right ventricle-dependent coronary circulation (RVDCC) existed, underwent individualized surgical treatment. The patients in Group I (with: RVDCC, n = 6) underwent single ventricle repair. Forty-six patients were in Group II (without RVDCC), 13 of which with severe right ventricular hypoplasia (tricuspid valve Z value < -4)underwent single ventricle repair and 33 of which were with mild to moderate right ventricular hypoplasia (Z value > -4). One critical neonate underwent systemic- pulmonary artery shunt. The other 32 of the 33 patients received right ventricular decompression procedures firstly, and 6 of them presented optimal hemodynamics and oxygenation and achieved biventricular repair. If the patients presented unstable hemodynamics or hypoxemia after right ventricular decompression procedure, an additional shunt was added. 13 young infants (0-2 months) underwent additional systemic-pulmonary artery shunt, and 13 patients (> 3 months-old) underwent additional bidirectional cavopulmonary shunt (1.5 ventricular repair)The patients were followed up for 1-10 years. RESULTS: There were 1 early death in Group I and 7 early deaths in Group II. The total early mortality was 15%. A successful definitive repair was achieved in 26 cases (50%). Follow-up reported 3 late deaths. CONCLUSION: Individualized surgical management based on the presence of RVDCC, right ventricular hypoplasia grading, right ventricular growth potential, hemodynamic situation, and oxygen saturation after the decompression procedure is helpful to improve the surgical results of PA/IVS

[Analysis surgical results of 113 patients with complete transposition of the great arteries].

OBJECTIVE: To review and analysis the surgical results of 113 arteries Switch operations. METHODS: One hundred and thirteen patients had been repaired by arterial Switch operation from January 2001 to December 2005. There were 60 patients with transposition of the great arteries and intact ventricular septum (TGA/IVS), 53 patients with transposition of great arteries and ventricular septal defect (TGA/VSD). The lowest body weight was 2.3 kg, and the youngest operative age was 6 h. The arteries Switch operation was performed underwent deep hypothermic circulation arrest and low-flow perfusion. RESULTS: The total mortality was 9.7%. There were 5 deaths among TGA/IVS (8.3%), 6 deaths among TGA/VSD (11.3%). Following improvement of surgical technique, post-operative management and cardiopulmonary bypass, the operative mortality was decreased from 16.6% to 5.5%. CONCLUSIONS: The main reason for operative mortality was abnormal coronary arteries. The incidence of abnormal coronary arteries was high at TGA/VSD. The surgical results was not infected by the position of great arteries. The low cardiac output was appeared if the ratio of left ventricular pressure and right ventricular pressure less than 0.6.

Seven years' experience of pediatric cardiopulmonary bypass: 8685 cases in Shanghai Children's Medical Center.

Herein we report our 7-year-experience of cardiopulmonary bypass. Between April 1, 1999, and December 31, 2005, 8685 children with congenital heart disease underwent cardiopulmonary bypass in Shanghai Children's Medical Center. The number of cases increased every year, and the number of patients younger than 1 year or weighing <10 kg also increased. Different bypass technology was adapted according to the operation. Roller pumps were used for most of the patients. Crystal cardioplegia (St. Thomas II) was used until blood cardioplegia was introduced in 2003. Ultrafiltrators were set up for infants weighing <10 kg. Mortality rates per year ranged from 1.81% to 3.70%. The most frequent complication was low cardiac output, about 12% in recent years. Arrhythmia, infection, and lung complications were the next three most frequent problems after surgery.

[The role of graded reoxygenation with cardiopulmonary bypass in prevention of reoxygenation injury and its safety].

OBJECTIVE: To investigate the role of graded reoxygenation with cardiopulmonary bypass (CPB) in prevention of reoxygenation injury in children with cyanotic congenital heart defects, and to evaluate its safety. METHODS: Twenty pediatric patients with cyanotic congenital heart defect were randomly divided into 2 equal groups according to CPB methodology: group 1, undergoing routine hyperoxic CPB with CPB primed and initiated at FiO(2) of 1.0, and group 2 undergoing modified CPB with graded reoxygenation (CPB was primed and initiated at FiO(2) of 0.21 and the FiO(2) was increased slowly to 30% to 60% over the next 5 to 10 minutes). Serum troponin 1 (TnI), S100beta protein, and malondialdehyde (MDA) were measured before CPB, and 1 minute, 5 minutes, and 10 minutes after CPB. Near infrared spectroscopy (NIRS) was applied to evaluate the cerebral oxygenated hemoglobin (HbO(2)) and oxidized cytochrome aa3 (CytOx) and jugular venous lactate was measured during the reoxygenation period. Clinical indexes were observed. RESULTS: Before CPB the TnI, S100beta, and MDA levels in these 2 groups were all normal without significant differences between them. After initiation of CPB the TnI, S100beta, and MDA levels in the two groups began to increase. The serum Tn1 levels 1 minute and 5 minutes after the initiation of CPB of the group 1 were significant lower than those of the group 2 (both P < 0.01). The serum S100beta levels 1, 5, and 10 minutes after the initiation of CPB in the group 2 were all lower than those of the group 1 and there were significant differences between these 2 group 5 and 10 minutes after (both P < 0.05). The serum MDA levels 1, 5, and 10 minutes of the group 1 were significantly higher than those of the group 2 (all P < 0.05). NIRS showed that HbO(2) decreased slightly because of hemodilution when CPB was begun, and then increased rapidly 2 minutes after the initiation of CPB; and CytOx decreased progressively during the reoxygenation period, however, without significant difference between these 2 groups. The serum lactate level was markedly increased 1 minute after the initiation of CPB and then gradually decreased through the reoxygenation period, however, without significant differences between these 2 groups. There was no significant difference between the two groups in clinical observation. CONCLUSION: Not damaging the cerebral aerobic metabolism, graded reoxygenation with CPB can reduce the extent of reoxygenation injury of routine hyperoxic CPB and is an easy, effective, and safe CPB strategy.

[Single-stage arterial switch operation for transposition of the great arteries and Taussig-Bing with aortic arch obstruction].

OBJECTIVE: To evaluate one-stage arterial Switch operation for transposition of the great arteries (TGA) and Taussig-Bing with aortic arch obstruction. METHODS: From January 2001 to June 2004, 8 patients had aortic arch obstruction, 3 with TGA and 5 with Taussig-Bing. Except one patient was 8 months old, all of others were 5 days to 3 months old, the mean operation age was (40 +/- 36) d and the mean weight was (4.3 +/- 0.5) kg. All patients were repaired by one-stage operation. The aortic arch obstruction was repaired in deep hypothermia circulatory arrest, and arterial switch procedure was performed in deep hypothermia and low flow perfusion. RESULTS: There had 1 death who was 8 months old and had low cardiac output, complete artrioventricular block (AVB) and severe pulmonary hypertension postoperation. One patient was 3 months old who had asphyxia at 5 days postoperatively. Six patients followed up from 5 months to 2 years. One Taussig-Bing with interrupted aortic arch had residual obstruction at the anastomosis of aorta. Two had trivial aortic valve regurgitation, and one had mild pulmonary valve regurgitation. CONCLUSIONS: One-stage repair for TGA and Taussig-Bing with aortic obstruction achieves excellent results. The reasons for the death were pulmonary hypertension and abnormal coronary artery. The operative procedure should be performed as early as possible for the better result.

Lung function after deep hypothermic cardiopulmonary bypass in infants.

There is increasing concern about neurologic injury due to deep hypothermia with low flow during repair of complex congenital heart defects in neonates and infants. Twenty infants with ventricular septal defect and pulmonary hypertension were randomly assigned to cardiac repair under deep hypothermia with circulatory arrest or deep hypothermia with low flow. Measurements of static pulmonary compliance, airway resistance, and respiratory index were performed before institution of cardiopulmonary bypass and at 5 minutes and 2 hours after cessation of cardiopulmonary bypass. Both groups had significant pulmonary dysfunction in terms of static pulmonary compliance, airway resistance, and respiratory index. There was greater impairment of pulmonary compliance and respiratory index after deep hypothermia with low flow, and this group required longer intensive care unit stay.

Lung perfusion with oxygenated blood during aortic clamping prevents lung injury.

To evaluate the protective effect of continuous pulmonary perfusion with oxygenated blood during aortic crossclamping, 12 mixed-breed piglets (7-12 kg) were placed on cardiopulmonary bypass for 130 minutes. An experiment group of 6 (group E) had continuous pulmonary perfusion with oxygenated blood during cardiopulmonary bypass, while the other 6 served as controls (group C). Pulmonary function was measured at the beginning and end of cardiopulmonary bypass and one hour later. Histology was compared before and after cardiopulmonary bypass. Pulmonary function after cardiopulmonary bypass was significantly better in group E than group C. There was preservation of the normal pulmonary parenchyma in group E, whereas group C had marked intra-alveolar edema and abundant intra-alveolar neutrophils. Anoxia of lung tissue during aortic crossclamping on cardiopulmonary bypass is probably the major factor in lung injury. Continuous pulmonary perfusion was effective in preventing lung injury during aortic crossclamping.

[Arterial switch operation for transposition of the great arteries and double outlet of right ventricle with subpulmonary ventricular septum defect].

OBJECTIVE: To summarize the clinical experience on the arterial switch operation for complex congenital heart disease in recent 3 years in our hospital. METHODS: Sixty-one patients with complex congenital heart disease received by arterial switch operation from Jan 2000 to May 2003. There were 26 patients with transposition of the great arteries and intact ventricular septum (TGA-IVS), 19 patients with transposition of the great arteries and ventricular septal defect (TGA-VSD) and 16 patients with double outlet of right ventricle with subpulmonary ventricular septum defect (Taussig-Bing). RESULTS: There were 2 death among TGA-IVS cases, 4 deaths among TGA-VSD cases and 4 deaths among Taussig-Bing cases. The total operative mortality was 16%. All patients were followed up 3 months to 3 years. In all patients, the cyanosis disappeared and the physical activities increased obviously. One patients with Taussig-Bing keep moderate mitral valve reflux unchanged, 2 patients with TGA had pulmonary and aortic supra-valve stenosis with 40 mmHg pressure gradient. One patient with subpulmonary stenosis and residual VSD was re-operated 3 months later. All survivor had good heart function. CONCLUSIONS: The effect of arterial switch operation on the treatment of TGA was well accepted in this study. The procedure used in treatment on Taussig-Bing can prevent pulmonary obstruction and avoid the complication of left ventricular outflow tract obstruction caused by intraventricular repair.

Near-infrared spectroscopy monitoring of brain oxygen in infant cardiac surgery.

The use of near-infrared spectroscopy for monitoring cerebral oxygenation during different types of cardiopulmonary bypass was evaluated in 24 patients aged 5 to 13 months. They underwent open-heart surgery under cardiopulmonary bypass with moderate hypothermia, deep hypothermia with low flow, or deep hypothermia with circulatory arrest. Near-infrared spectroscopy data were compared with electroencephalography and biochemical indicators (neuron-specific enolase, lactate). Near-infrared spectroscopy data showed no correlation with biochemical indicators in patients undergoing cardiopulmonary bypass with moderate hypothermia or deep hypothermia with low flow. In the deep hypothermia with circulatory arrest group, the oxygenated hemoglobin signal declined to a nadir during circulatory arrest. The period from reaching the nadir until reperfusion and the minimum values of oxygenated hemoglobin correlated closely with increases in neuron-specific enolase and lactate. All patients with an oxygenated hemoglobin-signal nadir time < 35 min were free from behavioral evidence of brain injury. The oxygenated hemoglobin-signal nadir time may be useful in predicting the safe duration of circulatory arrest.

Surgical experience of coarctation of the aorta in infants and young children.

We evaluated the effectiveness of surgical treatment for coarctation of the aorta in infants and young children, based on our experience over 7 years. From March 1999 to December 2005, 168 cases of coarctation of the aorta in patients aged 21 days to 3 years were treated by end-to-end, extended end-to-end, or extended end-to-side ascending aorta and aortic arch anastomosis. The mortality rate was 0.6%. In 138 (82%) patients, the pressure in the lower extremity was higher than in the upper extremity. During 6-24 months of follow-up, hoarseness appeared in 6 patients. Echocardiography revealed stenosis of the end-to-end anastomosis in only 2 patients. We suggest that the best option for surgical treatment of coarctation of the aorta with associated cardiac malformations is a one-stage procedure using a median sternotomy approach. It is better to perform extended end-to-end anastomosis or anastomosis between the distal descending aorta and the left wall of the ascending aorta, or to extend this anastomosis to the transverse arch.

Surgical treatment of persistent fifth aortic arch associated with interrupted aortic arch.

This study describes two cases of the rare congenital anomaly, persistent fifth aortic arch. Both cases involve boys (1 at 9 years of age and another at 7 months of age). To detect persistent fifth aortic arch with interrupted aortic arch, the following methods were used: echocardiogram, angiocardiography, and magnetic resonance imaging. In both cases the blood pressure between the upper and lower limbs differed. To relieve the obstruction of blood flow, each case was surgically repaired using patching or conduit interposition. Postoperative courses were uneventful. Two-year to 5-year follow-up examinations were positive showing that the anastomosis was unobstructed and the velocity of blood flow to the descending aorta was normal.