Hans De Wilde

Transthoracic Echocardiography Guidance of Transcatheter Atrial Septal Defect Closure in Children

Transesophageal echocardiography (TEE) guidance is part of interventional closure of secundum atrial septal defect (ASD) in children and adults. However, sometimes TEE is impossible for technical or anatomical reasons. If available, intracardiac echocardiography can be used, but especially in children, transthoracic echocardiography (TTE) can be an easy, safe, and cheap alternative. We report two cases in which TEE was replaced by TTE during percutaneous ASD closure. In the first case VACTERL association with a surgically repaired tracheoesophageal fistula was a relative contraindication to TEE. In the second case, technical failure of the transesophageal probe occurred during the procedure. In both cases the ASD was successfully closed with an atrial septal occluder device under TTE guidance. Using TTE can be sufficient and safe in children with good imaging windows, especially from subcostal views.

Univentricular heart and Fontan staging: analysis of factors impacting on body growth

OBJECTIVES The optimal timing of the Fontan staging for a univentricular heart and its impact on growth remains debateable. In a Fontan cohort, the influence of staged interventions and patient factors on somatic development was explored. METHODS We reviewed 64 total cavopulmonary connection (TCPC) patients treated since 1992. Serial anthropometric parameters recorded from birth to the latest follow-up (mean 12.5 ± 6.1 years) and at each intervention [neonatal surgery, bidirectional cavopulmonary anastomosis (BCPA), TCPC, catheter treatment] were converted to z-scores. The influence of saturation, heart failure treatment and surgery intervals on growth was determined. RESULTS The mean z-scores for weight and height changed significantly at each surgery up to the TCPC (-0.3 ± 1.2 and 0 ± 1 at birth, -1.3 ± 1.9 and -0.9 ± 1.7 at neonatal surgery, -2.1 ± 1.2 and -1.6 ± 1.3 at the BCPA, -1.2 ± 1.3 and -0.7 ± 1.4 at the TCPC for weight and height, respectively; P < 0.05 for each interval), with the largest decline before the BCPA, and the most marked improvement before the TCPC. Z-scores did not change significantly after the TCPC. Younger age at the BCPA had a positive influence on the weight z-score at the TCPC (P < 0.05); somatic growth at the latest follow-up (FU) was negatively influenced by heart failure treatment (P < 0.05). CONCLUSIONS Body growth is severely impaired in Fontan patients. A close interstage follow-up between the first surgery and the BCPA must be targeted at optimizing nutritional support to counter the important growth retardation occurring before the BCPA. The better catch-up growth at the TCPC when the BCPA is performed earlier in life supports the current trend to perform the BCPA at a younger age. Heart failure treatment after a Fontan completion is independently associated with decreased late somatic development.

Functional analysis of the anatomical right ventricular components: should assessment of right ventricular function after repair of tetralogy of Fallot be refined?

OBJECTIVE Follow-up after tetralogy of Fallot (ToF) repair is directed to detect timely right ventricular (RV) dysfunction by following pulmonary regurgitation and global RV size, with little attention for the effective contribution of regional RV dysfunction. This study investigates the contribution of regional RV dysfunction on exercise capacity after ToF repair. METHODS Forty-two patients were investigated with cardiac magnetic resonance imaging for regional RV dysfunction in relation to global RV function by functional quantification of the sinus and outflow part of the RV. The impact of regional and global RV dysfunction on clinical status was studied by exercise testing. RESULTS Global RV function was lower than sinus function (ejection fraction (EF) 52±12% vs 58±10%, P<0.001), attributable to the adverse influence of right ventricular outflow tract (RVOT) dysfunction (EF 34±17%). Percent predicted peak VO2 correlated better with the RV sinus ejection fraction compared with the global RV ejection fraction (r=0.51, P=0.001 vs r=0.44, P=0.004). Multivariate analysis revealed the EF of RV sinus (β=0.34, 95% CI 0.07-0.61, P=0.013) and the extent of RVOT akinesia (β=-0.28, 95% CI -0.50; -0.06, P=0.015) as significant determinants of exercise capacity. Impaired exercise performance occurred in 43% of the patients, and was independently determined by the type of repair (transventricular vs transatrial: OR 6.0, 95% CI 1.31-17.3, P=0.02) by associating greater sinus and RVOT dysfunction. CONCLUSION Functional analysis of the RV components shows that exercise capacity after repair of ToF is better predicted by systolic function of the RV sinus as the extent of RVOT dysfunction commonly leads to underestimation of global RV function. This method of differential quantification of regional RV function might be more appropriate than assessment of global RV function during the long-term follow-up of repaired ToF patients.

The fate of the aortic root after early repair of tetralogy of Fallot

OBJECTIVE Late aortic root dilatation is a growing concern in patients operated on for tetralogy of Fallot (ToF). This longitudinal follow-up study sought to evaluate the changes in the aortic root dimensions in relation to body growth, assuming that early repair of tetralogy of Fallot might prevent late aortic dilatation. METHODS A retrospective analysis of the aortic root dimensions was performed in 88 patients repaired early for tetralogy of Fallot by echocardiographic measurement of aortic annulus, sinus of Valsalva and sinotubular junction, adjusted for body surface area and expressed as z-scores. Mean age at repair was 9.7 + or - 7.4 months. Median age was 7.3 months (range 45 days-29 months). RESULTS At the time of repair, all root dimensions were enlarged: z-score of the annulus 3.32 + or - 1.66; sinus 3.54 + or - 1.49; sinotubular junction 2.74 + or - 1.19. Within a mean follow-up of 6.9 + or - 4.4 years, the mean z-scores of both annulus and sinotubular junction significantly decreased to normal size at 7 years postoperatively: z-score of annulus 0.95 + or - 0.7 (p=0.006), z-score of sinotubular junction 0.99 + or - 1.47 (p=0.006). The z-score of the aortic sinuses appeared to regress slower to 2.78 + or - 1.26 (p=0.262). The indexed sinus diameter however regressed significantly from a mean of 51.4 + or - 13.4 mmm(-2) at correction to 28.9 + or - 7.2 mmm(-2) (p=0.0001) at latest follow-up. Evolution of aortic root size after repair was independent of aortic arch side, sex, age at repair or previous shunt palliation. CONCLUSIONS The initially dilated aortic root in tetralogy of Fallot normalises in size at the level of the annulus and sinotubular junction within 7 years after early repair. This process seems delayed at the level of the aortic sinuses, although the indexed root diameter shows significant regression over time. These results suggest that early repair of ToF abrogates the enlargement of the aortic root, validating one aspect of the need for tetralogy correction at a young age.

Increased aortic stiffness in prepubertal girls with Turner syndrome

BACKGROUND Aortic dilation and dissection contribute highly to the increased mortality of Turner syndrome (TS) but the exact pathophysiology is not completely understood. DESIGN Prospective case - control study. METHODS 15 prepubertal TS girls (median age 10.64, IQ 8.31-11.04) with a tricuspid (TAV, n=9) or a bicuspid (BAV, n=6) aortic valve, and 31 sex-, age-, and height-matched healthy controls underwent a cardiac and vascular ultrasound to evaluate aortic dimensions and elastic properties of the aortic wall. RESULTS TS BAV had significantly larger ascending aortic diameters than controls for absolute diameter, 22.2±5.1mm vs. 18.6±1.9mm (p=0.014) and z-score 1.7±2.1 vs. 0.1±0.7 (p=0.008). Distensibility of the ascending aorta was lower in the TS than in controls (40.2×10-3kPa-1, IQ 31.3-56.2 vs. 62.9×10-3kPa-1, IQ 55.5-76.5, p=0.003), both for TS TAV (p=0.014) and BAV (p=0.005). Stiffness index was higher in TS than in controls (5.26, IQ 3.34-5.26 vs. 3.23, IQ 2.55-3.24, p=0.005), both for TS TAV (p=0.028) and TS BAV (p=0.006). Pulse wave velocity was not different between groups. There was no correlation between stiffness and z-score of the ascending aortic diameter. CONCLUSIONS In prepubertal TS girls, stiffness of the ascending aorta is increased in patients with a BAV and TAV while dilation of the ascending aorta is more frequent in BAV. This suggests an intrinsic aortic wall abnormality making all TS patients at increased risk for severe aortic complications although the risk is the highest for TS with BAV.

Current outcomes of the bi-directional cavopulmonary anastomosis in single ventricle patients: analysis of risk factors for morbidity and mortality, and suitability for Fontan completion

OBJECTIVES The bi-directional cavopulmonary anastomosis forms an essential staging procedure for univentricular hearts. This review aims to identify risk factors for morbidity, mortality, and suitability for Fontan completion. METHODS A total of 114 patients undergoing cavopulmonary anastomosis between 1992 and 2012 were reviewed to assess primary - mortality and survival to Fontan completion - and secondary outcome endpoints - re-intubation, new drain, and ICU stay. Median age and weight were 8 months and 6.9 kg, respectively. In 83% of patients, 1-3 interventions had preceded. Norwood-type procedures became more prevalent over time. RESULTS Extubation occurred after a median of 4 hours, median ICU stay was 2 days; 10 patients (8.8%) needed re-intubation and 18 received a new drain. Higher central venous pressure and transpulmonary gradient were risk factors for new drain insertion (p<0.01). Higher pre-operative pulmonary pressure correlated with increased inotropic support and prolonged intubation (p=0.01). Need for re-intubation was significantly affected by younger age at operation (p=0.01). Hospital and pre-Fontan mortality were 11.4 and 5.3%, respectively. Operative mortality was independently affected by younger age (p=0.013), lower weight (p=0.02), longer bypass time (p=0.04), and re-intubation (p=0.004). Interstage mortality was mainly influenced by moderate ventricular function (p=0.03); 82% of survivors underwent or are candidates for Fontan completion. CONCLUSION The cavopulmonary anastomosis remains associated with adverse outcomes. Age at operation decreases with rising prevalence of complex univentricular hearts. Considering the important impact of re-intubation on hospital mortality, peri-operative management should focus on optimising cardio-respiratory status. Once this selection step is taken, successful Fontan completion can be expected, provided that ventricular function is maintained.

Early-onset primary antibody deficiency resembling common variable immunodeficiency challenges the diagnosis of Wiedeman-Steiner and Roifman syndromes

Syndromic primary immunodeficiencies are rare genetic disorders that affect both the immune system and other organ systems. More often, the immune defect is not the major clinical problem and is sometimes only recognized after a diagnosis has been made based on extra-immunological abnormalities. Here, we report two sibling pairs with syndromic primary immunodeficiencies that exceptionally presented with a phenotype resembling early-onset common variable immunodeficiency, while extra-immunological characteristics were not apparent at that time. Additional features not typically associated with common variable immunodeficiency were diagnosed only later, including skeletal and organ anomalies and mild facial dysmorphism. Whole exome sequencing revealed KMT2A-associated Wiedemann-Steiner syndrome in one sibling pair and their mother. In the other sibling pair, targeted testing of the known disease gene for Roifman syndrome (RNU4ATAC) provided a definite diagnosis. With this study, we underline the importance of an early-stage and thorough genetic assessment in paediatric patients with a common variable immunodeficiency phenotype, to establish a conclusive diagnosis and guide patient management. In addition, this study extends the mutational and immunophenotypical spectrum of Wiedemann-Steiner and Roifman syndromes and highlights potential directions for future pathophysiological research.

Outcome after prenatal and postnatal diagnosis of complex congenital heart defects and the influence of genetic anomalies

Determine prenatal detection rate, mortality and association with genetic abnormalities in patients with severe CHD.

Small-sized conduits in the right ventricular outflow tract in young children : bicuspidalized homografts are a good alternative to standard conduits

OBJECTIVES Downsizing a homograft (HG) through bicuspidalization has been used for more than 2 decades to overcome the shortage of small-sized conduits for reconstruction of the right ventricular outflow tract (RVOT) in young children. Our goal was to investigate the durability of bicuspidalized HGs compared with other small HGs. METHODS A retrospective analysis of 93 conduits ≤20 mm, implanted over 23 years, was performed. The end-points were survival, structural valve degeneration and conduit replacement. The conduits comprised 40 pulmonary HGs, 12 aortic HGs, 17 bicuspidalized HGs and 24 xenografts. RESULTS The median age, mean conduit diameter and z-value at implantation were 1.4 (interquartile range 0.3-3) years, 16.5 ± 2.7 mm and 2.8 ± 1.3, respectively. Valve position was heterotopic in 59 patients and orthotopic in 34 patients. At a mean follow-up period of 7.6 ± 5.9 years, the hospital survival rate was 89%. Freedom from explant at 5 and 10 years was 83 ± 5% and 52 ± 6%, respectively. Freedom from structural valve degeneration was 79 ± 5% at 5 years and 47 ± 6% at 10 years [68 ± 8% for pulmonary HG, 42 ± 16% for bicuspidalized HG, 31 ± 15% for aortic HG and 20 ± 9% for xenografts (log rank P < 0.001)]. Multivariable analysis indicated an increased risk for structural valve degeneration with smaller conduit size (hazard ratio 0.79, 95% confidence interval 0.67-0.94; P < 0.008), extra-anatomic position (hazard ratio 2.71, 95% confidence interval 1.33-5.50; P = 0.006) and the use of xenografts compared with non-downsized pulmonary HGs (hazard ratio 4.90, 95% confidence interval 2.23-10.76; P < 0.001). CONCLUSIONS Appropriately sized pulmonary HGs remain the most durable option for a right ventricular outflow tract conduit in young children. However, when a small pulmonary HG is unavailable, bicuspidalization offers a valid alternative, preferable to xenograft conduits, at mid-term follow-up.

Single-center experience with mechanical valve replacement in children and adolescents : a lifelong challenge

BACKGROUND RESULTS Valve repair is the preferred treatment in paediatric patients with valvular heart disease. However, replacement is sometimes unavoidable. In young patients, the use of a mechanical prosthesis is favoured to avoid reoperations for premature structural degeneration of the valve. However, mechanical valve replacement in a paediatric population is limited by small cardiac dimensions and the need for lifelong oral anticoagulation. Limited long-term data is available, especially regarding INR management and valve-related events. •