J. Kachaner

Percutaneous replacement of pulmonary valve in a right-ventricle to pulmonary-artery prosthetic conduit with valve dysfunction

BACKGROUND Valved conduits from the right ventricle to the pulmonary artery are frequently used in paediatric cardiac surgery. However, stenosis and insufficiency of the conduit usually occur in the follow-up and lead to reoperations. Conduit stenting can delay surgical replacement, but it aggravates pulmonary insufficiency. We developed an innovative system for percutaneous stent implantation combined with valve replacement. METHODS A 12-year-old boy with stenosis and insufficiency of a prosthetic conduit from the right ventricle to the pulmonary artery underwent percutaneous implantation of a bovine jugular valve in the conduit. FINDINGS Angiography, haemodynamic assessment, and echocardiography after the procedure showed no insufficiency of the implanted valve, and partial relief of the conduit stenosis. There were no complications after 1 month of follow-up, and the patient is presently in good physical condition. INTERPRETATION We have shown that percutaneous valve replacement in the pulmonary position is possible. With further technical improvements, this new technique might also be used for valve replacement in other cardiac and non-cardiac positions.

Detection of Transposition of the Great Arteries in Fetuses Reduces Neonatal Morbidity and Mortality

BACKGROUND Transposition of the great arteries (TGA) is a life-threatening malformation in neonates, but it is amenable to complete repair. Prenatal detection, diagnosis, and early management may modify neonatal mortality and mortality. METHODS AND RESULTS Preoperative and postoperative morbidity and mortality were compared in 68 neonates with prenatal diagnosis and in 250 neonates with a postnatal diagnosis of TGA over a period of 10 years. The delay between birth and admission was 2+/-2.8 hours in the prenatal group and 73+/-210 hours in the neonatal group (P<0.01). Clinical condition at arrival, including metabolic acidosis and multiorgan failure, was worse in the neonatal group (P<0.01). Once in the pediatric cardiology unit, the management was identical in the 2 groups (atrioseptostomy, PGE1 infusion, operation date). Preoperative mortality was 15 of 250 (6%; 95% CI, 3% to 9%) in the neonatal group and 0 of 68 in the prenatal group (P<0.05). Postoperative morbidity was not different (25 of 235 versus 6 of 68), but hospital stay was longer in the neonatal group (30+/-17 versus 24+/-11 days, P<0.01). In addition, postoperative mortality was significantly higher in the neonatal group (20 of 235 versus 0 of 68, P<0.01); however, the known risk factors for operative mortality were identical in the 2 groups. CONCLUSIONS Prenatal diagnosis reduces mortality and morbidity in TGA. Prenatal detection of this cardiac defect must be increased to improve early neonatal management. In utero transfer of fetuses with prenatal diagnosis of TGA in an appropriate unit is mandatory.

Transcatheter Implantation of a Bovine Valve in Pulmonary Position A Lamb Study

BACKGROUND Pulmonary regurgitation can lead to severe right ventricular dysfunction, which is a delicate postoperative problem in the long-term follow-up of patients who had surgery for congenital heart diseases. Clinical conditions of patients suffering from pulmonary valve incompetence are improved by valve replacement with a prosthetic valve. To date, the surgical approach is the only option to replace a pulmonary valve. We report the first experience of percutaneous pulmonary valve implantation. METHODS AND RESULTS A fresh bovine jugular vein containing a native valve was sutured into a vascular stent and then cross-linked with a 0.6% glutaraldehyde solution for 36 hours. After being hand-crimped onto a balloon catheter, the device was inserted percutaneously according to standard stent-placing techniques. The valved stent was finally deployed in the position of the native pulmonary valve of the lamb. Hemodynamic evaluation was carried out before and 2 months after implantation. Anatomic evaluation was finally performed. Percutaneous pulmonary valve replacement was successful in 5 lambs. No complications were noted. Early and late angiographic and hemodynamic studies confirmed a good position of the stents with a competent valve at the end of the protocol. One stent was slightly stenotic, with macroscopically visible calcifications. CONCLUSIONS Nonsurgical implantation of pulmonary valves is possible in the lamb. This new technique is similar to standard stent implantation. Thus, it should be feasible in humans, in whom it will lead to a significant reduction of reoperations in patients in need of pulmonary valve replacement.

Coronary Artery Obstruction After the Arterial Switch Operation for Transposition of the Great Arteries in Newborns

OBJECTIVES We sought to describe a large series of coronary artery obstructions after the arterial switch operation for transposition of the great arteries and to discuss their clinical implications. BACKGROUND Aortic root angiography and myocardial perfusion imaging yield ambiguous results regarding the fate of the coronary artery anastomoses after the arterial switch operation. Late death related to coronary artery obstruction and growth of the translocated coronary arteries are of major concern in these patients. METHODS Selective coronary artery angiography was performed prospectively in a total of 165 children. RESULTS A total of 12 coronary occlusions, 8 major stenoses, 6 minor stenoses of the left ostium and 4 stretchings of one coronary artery were identified. Obstructions were more frequent in types D and E (p < 0.001) of the Yacoub and Radley-Smith classification. Coronary obstruction was documented in all patients with electrocardiographic and ultrasound evidence of myocardial ischemia at time of study. Early postoperative ischemia did not predict coronary artery lesion if the patient had fully recovered. Persistent or delayed myocardial ischemia was highly predictive of coronary artery lesions. The incidence of coronary artery obstruction was very high (11 of 35) in patients operated on by a rapidly abandoned technique of single-orifice reimplantation of both coronary artery ostia. CONCLUSIONS Selective coronary angiography is the most accurate means to assess coronary artery obstruction after the arterial switch operation. Precise diagnosis of coronary artery lesions after this operation will help to elucidate the pathogenesis, develop adequate therapeutic strategies and might indicate how to prevent coronary complications after operation.

Long-term fate of the coronary arteries after the arterial switch operation in newborns with transposition of the great arteries.

OBJECTIVE: Concern continues to be expressed about the long-term impact of coronary artery translocation after the arterial switch operation for transposition of the great arteries. This study was conducted to determine the prevalence of obstructions of the translocated coronary arteries by the use of selective coronary artery angiography. METHODS AND RESULTS: 64 children (mean age 7.6 (SD) 1.5 years) who had survived an arterial switch operation underwent evaluation. They had been operated on by one surgeon and they were followed up by a single hospital. Selective coronary artery angiography was possible in 58 patients. Five patients showed occlusion or stenosis of a coronary artery: one occlusion and two stenoses of the left coronary trunk, two occlusions of the circumflex artery. The prevalence of late coronary artery complications was 7.8 (SD) 6.6% (95% CI 1.2 to -14.4%). The three patients with occlusion of one coronary artery had perioperative ischaemic complications, with associated electrocardiogram evidence of ischaemia and left ventricular dysfunction with mitral valve insufficiency. Both patients with stenosis of the left main coronary artery trunk did not have any evidence of an anomaly before catheterisation. CONCLUSIONS: The prevalence of the late coronary artery complications after an arterial switch operation was low in this series. This accords with the view that the arterial switch operation remains the preferred treatment for such patients. Screening for late coronary artery patency should be done by using selective coronary artery angiography, because even patients who remain symptom free can have coronary artery anomalies.

Prevalence of the microdeletion 22q11 in newborn infants with congenital conotruncal cardiac anomalies.

Abstract Conotruncal malformations account for about 50% of congenital heart defects diagnosed in newborns. We studied prospectively 104 patients admitted in our neonatal intensive care unit for conotruncal defects by fluorescence in situ hybridization to estimate the prevalence of the interstitial deletion in this category of congenital heart disease. Cardiac phenotypes were: truncus arteriosus (17), interrupted aortic arch (18), tetralogy of Fallot with or without pulmonary valve atresia (55), tetralogy of Fallot with absent pulmonary valves (5), ventricular septal defect with malalignment of the conal septum (9). We discovered a microdeletion 22q11 at loci D22S39 or D22S398 in 50 newborns (48%). The prevalence of this microdeletion in different groups of conotruncal defects was: truncus arteriosus 7/17, interrupted aortic arch 16/18, tetralogy of Fallot 19/55, absent pulmonary valves 2/5, and ventricular septal defect 6/9 respectively. Only two patients without any clinical or biological feature of the so called CATCH22 syndrome exhibited the deletion. Parental studies confirmed that the deletion occurred de novo in 47/50 cases (three parental microdeletions). On the other hand, recurrence of conotruncal heart defects in families of “undeleted probands” was higher than expected (13%). Conclusion In 50/104 newborns with conotruncal defects, an interstitial deletion 22q11 was found. Fluorescence in Situ Hybridization should be performed in newborn infants with conotruncal defect and at least one additional manifestation of the CATCH22 phenotype.

Quality of life and perceived health status in surviving adults with univentricular heart

OBJECTIVE To evaluate the quality of life in patients with univentricular heart and to determine the impact of sociodemographic and clinical characteristics. DESIGN AND SETTING Retrospective, cross sectional study conducted in a regional paediatric cardiology centre. PATIENTS The health records of 89 survivors with univentricular heart (median age 21 years; range 17–49 years) were reviewed. Sixty seven answered the Duke questionnaire. Sociodemographic and clinical variables were similar in the responders and non-responders. The impact of sociodemographic and clinical variables on individual Dukes measures was assessed. RESULTS The Duke scores of adults with univentricular heart were similar to the normal population. Cyanosis predicted a worse score for physical (p = 0.05) and perceived health measures (p = 0.02). A higher educational level predicted a better score for physical (p = 0.004), mental (p = 0.01), and general health measures (p = 0.02). Orthopaedic problems worsened the social score (p = 0.05). Psychosocial problems worsened the pain score (p = 0.04). In comparison with the other anatomical types, mitral atresia worsened the perceived health score (p = 0.02). Patients younger than 23 years scored better for almost all health and dysfunction measures. CONCLUSIONS Despite repeated interventions and other disease related everyday stresses, a selected group of adults with univentricular heart had a satisfying quality of life.

A mitochondrial cytochrome b mutation but no mutations of nuclearly encoded subunits in ubiquinol cytochrome c reductase (complex III) deficiency.

Abstract Ubiquinol cytochrome c reductase (complex III) deficiency represents a clinically heterogeneous group of mitochondrial respiratory chain disorders that can theoretically be subject to either a nuclear or a mitochondrial mode of inheritance. In an attempt to elucidate the molecular bases of the disease, we first determined the nucleotide sequence of three unknown subunits (9.5 kDa, 7.2 kDa, 6.4 kDa) by cyberscreening of human expressed sequence tag data bases and sequenced the 11 cDNA subunits encoding complex III in five patients with isolated complex III deficiency. No mutation in the nuclearly encoded complex III subunits was observed, but a mutation in the cd2 helix of the mitochondrial (mt) cytochrome b gene was found to alter the conformation of the bc1 complex in one patient with severe hypertrophic cardiomyopathy. The present study is highly relevant to genetic counseling as the absence of mtDNA mutations in all but one patient in our series strongly supports autosomal rather than maternal inheritance in the majority of patients with complex III deficiency.

Balloon valvotomy for critical stenosis or atresia of pulmonary valve in newborns

OBJECTIVES Percutaneous balloon valvotomy was studied retrospectively in newborns with critical pulmonary valve stenosis or atresia to assess its potential role as an alternative therapy to operation. BACKGROUND Severe right ventricular outflow tract obstructions are life-threatening conditions requiring prostaglandin infusion immediately after birth and then relief of the valvular obstruction. To avoid surgical hazards at this age, it would be useful to extend to newborns the balloon valvotomy so effective in older patients. METHODS Ninety-seven newborns (82 with critical pulmonary valve stenosis, 15 with atresia) underwent balloon valvotomy, provided that they had a well developed right ventricle, including an infundibulum close to the pulmonary artery. In patients with atresia, the outflow tract membrane had to be perforated with a wire needle or a radiofrequency probe. RESULTS Balloon valvotomy could be performed in 81 patients and was effective in 77. It caused 3 fatal and 16 nonfatal complications. Ten patients with persistent poor right ventricular compliance despite an effective valvotomy required a surgical shunt. Among the 81 patients in whom the procedure could be performed, right ventricular surgery was avoided in 5 (55%) of the 9 patients with atresia (95% confidence interval [CI] 28% to 80%) and 55 (76%) of the 72 patients with stenosis (95% CI 66% to 86%) at the end of the follow-up period (9.7 years). CONCLUSIONS Balloon pulmonary valvotomy is not always feasible in newborns, but it is relatively safe and effective and should be considered a valid alternative to operation.

Percutaneous balloon valvuloplasty in neonates with critical aortic stenosis

Percutaneous balloon valvuloplasty was attempted in 10 newborn infants with critical aortic valve stenosis and severe congestive heart failure. Three had a very small left ventricle and aortic anulus. In one infant, the aortic valve could not be passed, and in another infant, a technical error resulted in severe valvular damage, aortic insufficiency and death. Among the eight patients who had effective dilation, the stenosis was relieved in seven as assessed by a significant decrease in transvalvular pressure gradient, improvement of left ventricular contraction and eventual inversion of the ductal shunting. The procedure failed in the only patient whose dilation was performed with an undersized balloon. Aortic insufficiency occurred in three infants and was severe (perforated cusp) in one, moderate in one whose valve was dilated with an excessively large balloon and mild and transient in one. None of the three infants with a very small left ventricle recovered (two died and one underwent cardiac transplantation). Among the seven infants with a left ventricle of acceptable size, three underwent subsequent aortic valvotomy; one of these died and two bad good results. The remaining four are doing well 16 +/- 5 months later (mean +/- SD) with mild to moderate residual aortic stenosis and normal left ventricular function. In conclusion, percutaneous balloon valvuloplasty is an acceptable alternative to surgery in neonates with critical aortic valve stenosis. Incidence of complications and good relief of the obstruction depend on a careful technique. Immediate results are similar to those of surgery. Late prognosis depends on the quality of the left heart structures.