Avantages et risques de la chirurgie cardiaque dans la trisomie 21

Down's syndrome is the most frequent chromosomic anomaly. Fifty percent are associated with a congenital heart disease. Life expectancy and quality of life are increasing since 15 years with improving surgical techniques.

PATIENTS AND METHODS

This study presents 73 patients with Down's syndrome who underwent a surgical repair of congenital heart disease between 1992 and 2002. Among them, 37 (50.6%) had a complete atrio-ventricular septal defect (AVSD) and 36 an other anomaly.

RESULTS

Five children died in the post operative period: all had an AVSD. Two late deaths occurred due to extra cardiac causes during the follow up. Two children who underwent a repair of AVSD had to be reoperated. The majority of the children are doing well, without any cardiac symptom. Thirty-eight percent of patients with AVSD repair have a middle mitral or tricuspid regurgitation and three had a massive mitral or tricuspid regurgitation. One child presents neurological sequelae related to surgery.

CONCLUSION

Congenital heart diseases in Down's syndrome can be repaired with a limited risk of death. Final results are good for many children with significant improvement of the quality of life and life expectancy.

Early balloon dilatation of the pulmonary valve in infants with tetralogy of Fallot. Risks and benefits

BACKGROUND

Balloon dilatation, an established treatment for pulmonary valve stenosis, remains a controversial procedure in tetralogy of Fallot.

METHODS AND RESULTS

Balloon dilatation of the pulmonary valve was performed in 19 infants with tetralogy of Fallot. Its effects on the severity of cyanosis, the growth of the pulmonary valve and pulmonary arteries, and the need for transannular patching were evaluated. Clinical, echographic, angiographic, hemodynamic, and operative data were analyzed. The procedure was safe in all, without significant complications. After balloon dilatation, systemic oxygen saturation increased from a mean value of 79% to 90%. This increase proved to be short-lasting in 4 patients, who required surgery before the age of 6 months. Balloon dilatation increased pulmonary annulus size in each case, from a mean value of 4.9 to 6.9 mm (P < .001). This gain in size remained stable over time, with a mean Z score of -4.8 SD before dilatation, -3.1 SD immediately after the procedure, and -2.7 SD at preoperative catheterization (P < .001). Pulmonary artery dimensions remained unchanged immediately after balloon dilatation but increased at follow-up from a Z score mean value of -2.5 to -0.06 SD and from -2.2 to 0.04 SD for right and left pulmonary arteries, respectively (P < .001). At the time of corrective surgery, the pulmonary annulus was considered large enough to avoid a transannular patch in 69% of the infants. This represented a 30% to 40% reduction in the need for a transannular patch compared with the incidence of transannular patch expected before balloon dilatation.

CONCLUSIONS

Pulmonary valve dilatation in infants with tetralogy of Fallot is a relatively safe procedure and appears to produce adequate palliation in most patients. It allowed the growth of the pulmonary annulus and of the pulmonary arteries, resulting in a mean gain of 2 SD for those structures.

[Percutaneous embolization of a pulmonary arteriovenous fistula in a child]

BACKGROUND

Pulmonary arteriovenous fistula is a rare vascular abnormality in children that is usually treated by lobectomy. This report describes a case that was improved by coil embolization.

CASE REPORT

A thoracic X-ray was routinely taken before amygdalectomy in a 6 year-old girl. It showed a consolidation area in the left superior lobe that persisted despite treatment with erythromycin for 3 weeks. Bronchoscopy was normal, but study of blood gases showed a refractory hypoxemia with moderate cyanosis and hemoglobin at 16.2 g/dl. Right-heart catheterization and angiography showed a pulmonary arteriovenous fistula that was treated by coil embolization. A control investigation 3 months later showed normal arterial oxygen saturation, hemoglobin at 14.5 g/dl and reduced pulmonary condensation.

CONCLUSION

Pulmonary arteriovenous fistula may show few symptoms. Coil embolization appears to be a useful initial non-aggressive treatment.

Pulse oximetry versus measured arterial oxygen saturation: a comparison of the Nellcor N100 and the Biox III

Pulse oximetry is noninvasive, fast, and simple, making it a very popular way of assessing oxygenation in pediatric patients. However, there are few studies that establish the accuracy of this technology over a wide range of oxygen saturations in children. This study, done in 47 children aged from 1 day to 16 years with congenital heart disease and undergoing cardiac catheterization, compared the direct measurement of arterial oxygen saturation to values from pulse oximetry. Oxygen saturation was measured by an IL-282 Co-oximeter, which also measured carboxyhemoglobin and methemoglobin, and was compared to values obtained from both a Biox III and Nellcor N100. Both pusle oximeters gave values that closely correlated with the actual saturation (r = 0.91 and 0.93, respectively) with standard errors of the estimate of 4.1 and 3.2%, respectively. For both devices, the error increased with decreasing saturations, being progressively larger below a saturation of 80%. The difference between the actual saturation and that measured by pulse oximetry bore no relationship to the presence of carboxyhemoglobin, methemoglobin, fetal hemoglobin, bilirubin, cardiac index, or age of the patient. In conclusion, pulse oximetry, while a very useful technology in pediatrics, must be interpreted with some caution in children with severe cyanosis.

Total anomalous pulmonary venous connection. Long-term results following repair under 3 months of age

The surgical experience with total anomalous pulmonary venous connection (TAPVC) at the University of Louvain (Brussels) between the years 1975 and 1986 is reviewed. Nineteen patients aged two days to three months with TAPVC were studied. The types of TAPVC were supracardiac in 9 patients, cardiac in 4, infracardiac in 4 and mixed in 2. Profound hypothermia induced by surface cooling, limited cardiopulmonary by-pass and total circulatory arrest were used in all cases. The 4 early deaths concerned the first four neonates who were critically ill. All operative survivors are followed for a mean of 3.5 years (12 months to 8 years). There are two late deaths due to reoperation for pulmonary venous obstruction. All 13 survivors are well at last review. Eleven of them have been recatheterized 4 to 33 months after repair (19 months in average). The pulmonary artery and capillary pressures fell to a normal level after a few months. Ventricular function which was markedly depressed preoperatively, was evaluated by quantitative angiocardiography and echocardiography. It returned to normal late postoperatively. The hospital mortality for the repair of TAPVC in the neonates remains appreciable. Total correction at one operation is advisable. The incidence of postoperative pulmonary venous obstruction is of particular concern. The late postoperative functional and hemodynamic results are excellent. The repair of TAPVC can be considered curative.

Long-term follow-up of the Senning operation for transposition of the great arteries in children under 3 months of age

Twenty-six patients aged 6 days to 3 months (mean 57 days) underwent a Senning procedure for transposition of the great arteries. Twenty-two had intact ventricular septum and four had a small ventricular septal defect. They were followed up for 1 month to 8 years (mean 4 years). There were no late deaths. At late examination, 25 patients were asymptomatic and there was no clinical or echographic evidence of caval or pulmonary venous obstruction. Growth was normal in all but two patients. Neurologic assessment was abnormal in eight patients. The electrocardiogram showed sinus rhythm in 22 patients and asymptomatic arrhythmias in four. Twenty-three patients underwent cardiac catheterization and angiographic studies 2 to 72 months postoperatively (mean 15 months), which demonstrated effective left and right atrial contraction. An atrial shunt was noted in one patient and a ventricular shunt in one. Two infants (8%) had a residual left ventricular outflow tract obstruction (gradients of 26 and 37 mm Hg). Two had mild superior vena caval obstruction (gradients of 4 and 5 mm Hg). We conclude that the Senning procedure can be performed in early infancy with good results and a low incidence of late complications.

[Median- and long-term results of Mustard and Senning operations in isolated transposition of great vessels]

This study concerns 89 cases of isolated transposition with early surgical repair by auricular transposition of the venous returns. Fairly good results were obtained with an operative mortality rate less than 10%, few postoperative complications, and long-term follow-up without significant worsening of the functional capacities of these patients. From this study, the authors state precisely the present indications for treatment of isolated transposition.

Computer interpretation of pediatric orthogonal electrocardiograms: statistical and deterministic classification methods

Statistical multivariate and conventional deterministic methods of computerized interpretation of the electrocardiogram (ECG) were compared in the analysis of 1711 pediatric orthogonal ECGs validated by nonelectrocardiographic criteria on the basis of clinical and anatomic diagnoses. Among 642 children catheterized for the evaluation of congenital heart disease, there were 140 patients with left ventricular hypertrophy, 299 with right ventricular hypertrophy, and 203 with biventricular hypertrophy. A group of 1069 obviously healthy school children was studied as a control. The overall accuracy of multigroup ECG diagnosis was 85% and 79% for the statistical and deterministic methods, respectively. The diagnostic performances of both methods expressed in terms of sensitivity and predictive value were the highest for normal children and those with right ventricular hypertrophy and lowest for children with biventricular hypertrophy. The statistical method was more sensitive in the diagnosis of left ventricular hypertrophy (74% vs 64%), right ventricular hypertrophy (86% vs 83%), and biventricular hypertrophy (62% vs 50%). Mutual agreement for a correct diagnosis by the two methods was 83% for normal children and 82% for those with right ventricular hypertrophy but only 61% for children with left ventricular hypertrophy and 39% for those with biventricular hypertrophy. In conclusion, better classification results are obtained with statistical multivariate techniques as compared with conventional deterministic analysis, but both methods of ECG interpretation are complementary and their combination in the same electrocardiographic computer program can improve diagnostic accuracy.

Myxomatous degeneration of the mitral valve in a child with Turner syndrome and partial anomalous pulmonary venous return

This a report of myxomatous mitral valve degeneration in a child with Turner syndrome. The diagnosis was first suspected at 7 months of age. At 5 years of age, ultrasonic and angio-cardiographic confirmation prompted a successful mitral valve replacement with a Starr prosthesis. The child also had partial anomalous pulmonary venous return and a dysplastic right kidney. The child has remained well for 4 years after surgery.

[Mitral valve replacement in an infant with disseminated lupus erythematosus and Libman-Sacks endocarditis]

The authors report a case of Libman-Sacks endocarditis of the posterior mitral leaflet in a child treated for disseminated lupus erythematosus for 8 years. Mitral valve replacement was performed. Libman-Sacks vegetations are hardly ever recognised in vivo and have never been previously reported in a child. The incidence of this cardiac complication of lupus erythematosus is probably higher than indicated in the literature. Attentive cardiac examination and systematic echocardiography should be part of routine follow-up of patients with disseminated lupus erythematosus.

Influence of age on atrioventricular conduction intervals in children with and without atrial septal defect

His bundle electrograms were recorded in 42 patients with secundum atrial septal defects (ASD) and in 50 controls, aged 1 month to 16 years, in normal sinus rhythm and with normal PR intervals. Intervals PA (P less than 0.01) and PR (P less than 0.02) were found to be significantly prolonged in ASD patients. Analyzing the results according to age, a significant increase for intervals AH (P less than 0.05), HV (P less than 0.001) and PR (P less than 0.001) was noted in the oldest ASD children as compared to the younger ASD children, whereas in controls only the PR interval was found to be significantly prolonged (P less than 0.05) in the oldest subgroup. Under the age of three years, atrioventricular conduction intervals were not significantly different whether or not an ASD was present. However, in older children with ASD as compared to controls, a significant increase was noted for interval PA (P less than 0.03) in children four to eight years old and for intervals HV (P less than 0.01) and PR (P less than 0.001) in children 9 to 16 years old. ASD patients showed a more significant correlation with age for interval PR with a significantly steeper slope of the regression line. Results show the impact of ASD on AV conduction to be age-related, with involvement not only of the PA interval but also of the HV interval.

Atrioventricular conduction and right atrial volume in children with and without secundum atrial septal defects

Images

[Prostaglandins E1 in the treatment of neonatal cardiopathies related to ductus arteriosus. 19 cases]

A series of 19 neonates with persistent ductus arteriosus associated with right heart pathology such as pulmonary or tricuspid atresia (13 cases), left heart and aortic arch pathology (3 cases) and simple transposition of the great arteries (3 cases) is presented. The efficacity of an infusion of prostaglandins (PG E1, 0,05 /kg/min) in improving the clinical condition of the patients before surgery was confirmed. A rapid improvement in the blood gases (02 saturation) was obtained in right heart pathology. In children with the second group, the efficacity of PG depended mainly on the clinical state and degree of peripheral hypoperfusion before therapy. For this reason, the infusion should be instituted as soon as possible, even before confirmation of the diagnosis. PG were used in a newborn with simple transposition of the great arteries in association with balloon septostomy in order to obtain an earlier result with the latter procedure. The incidence of side effects was higher in this than in other reported series. The protocol of infusion and its surveillance are discussed. Prolonged infusion of PG is not advised as it was probably responsible for oedematous infiltration of the vessel wall in one child.

[Circulatory arrest under deep hypothermia in the correction of the interventricular communication in the newborn (author's transl)]

The technique of circulatory arrest under deep hypothermia has completely changed the therapeutic outlook of some congenital heart malformations in the newborn. The authors have tried this method particularly in neonate cases of the interventricular communication. This experience bears on ten newborn cases aged 3 to 11 months. Surgical indication was mandatory because of global heart failure, unresponsive to conservative treatment. Intracardiac correction is realized under optimal conditions of operative technique by means of the circulatory arrest. In six cases, the interventricular communication is large and isolated; in four cases there were multiple interventricular communications. The immediate postoperative is favourable in all cases. One was reoperated for a residual shunt. Evolution is satisfactory in nine cases. There was one late death. Hemodynamic controls prove the soundness of this method of treatment. Favourable results up to 2 1/2 years after the procedure encouraged the authors to extend the indications for deep hypothermia and circulatory arrest to other congenital anomalies of the newborn.

[Intralobar sequestration causing heart failure in a new born infant. Surgical correction]

The authors report the occurrence of an intralobar pulmonary sequestration in a neonate with symptoms of congestive heart failure, due to a fistula effect in the sequestrated area. The venous drainage was directed mainly to the superior caval vein via azygos vein and accessorily to the left atrium. The patient became asymptomatic after lobectomy performed at the age of 11 days.

Precocity of pulmonary vascular obstruction of Down's syndrome

Studying the pulmonary vascular resistance in children with ventricular septal and endocardial cushion defects, the authors found a statistically significant earlier and more severe reaction in children with Down's syndrome as compared to normals. Cardiac investigations with regard to surgical intervention should be made early in life, if the parents wish their child with Down's syndrome to undergo surgery.