EGFR and MMP-9 are associated with neointimal hyperplasia in systemic-to-pulmonary shunts in children with complex cyanotic heart disease.

Systemic-to-pulmonary shunt malfunction contributes to morbidity in children with complex congenital heart disease after palliative procedure. Neointimal hyperplasia might play a role in the pathogenesis increasing risk for shunt obstruction. The aim was to evaluate the role of epidermal growth factor receptor (EGFR) and matrix-metalloproteinase 9 (MMP-9) in the formation of neointimal within shunts. Immunohistochemistry was performed with anti-EGFR and anti-MMP-9 on shunts removed at follow-up palliative or corrective procedure. Whole-genome single-nucleotide polymorphisms genotyping was performed on DNA extracted from patients´ blood samples and allele frequencies were compared between the group of patients with shunts displaying severe stenosis (≥ 40% of lumen) and the remaining group. Immunohistochemistry detected EGFR and MMP-9 in 24 of 31 shunts, located mainly in the luminal area. Cross-sectional area of EGFR and MMP-9 measured in median 0.19 mm2 (IQR 0.1-0.3 mm2) and 0.04 mm2 (IQR 0.03-0.09 mm2), respectively, and correlated positively with the area of neointimal measured on histology (r = 0.729, p < 0.001 and r = 0.0479, p = 0.018, respectively). There was a trend of inverse correlation between the dose of acetylsalicylic acid and the degree of EGFR, but not MMP-9, expression within neointima. Certain alleles in epidermal growth factor (EGF) and tissue inhibitor of metalloproteinases 1 (TIMP-1) were associated with increased stenosis and neointimal hyperplasia within shunts. EGFR and MMP-9 contribute to neointimal proliferation in SP shunts of children with complex cyanotic heart disease. SP shunts from patients carrying certain risk alleles in the genes encoding for EGF and TIMP-1 displayed increased neointima.

Continuous inbreeding affects genetic variation, phenology, and reproductive strategy in ex situ cultivated Digitalis lutea.

PREMISE: Ex situ cultivation is important for plant conservation, but cultivation in small populations may result in genetic changes by drift, inbreeding, or unconscious selection. Repeated inbreeding potentially influences not only plant fitness, but also floral traits and interactions with pollinators, which has not yet been studied in an ex situ context. METHODS: We studied the molecular genetic variation of Digitalis lutea from a botanic garden population cultivated for 30 years, a frozen seed bank conserving the original genetic structure, and two current wild populations including the source population. In a common garden, we studied the effects of experimental inbreeding and between-population crosses on performance, reproductive traits, and flower visitation of plants from the garden and a wild population. RESULTS: Significant genetic differentiation was found between the garden population and the wild population from which the seeds had originally been gathered. After experimental selfing, inbreeding depression was only found for germination and leaf size of plants from the wild population, indicating a history of inbreeding in the smaller garden population. Moreover, garden plants flowered earlier and had floral traits related to selfing, whereas wild plants had traits related to attracting pollinators. Bumblebees visited more flowers of outbred than inbred plants and of wild than garden plants. CONCLUSIONS: Our case study suggests that high levels of inbreeding during ex situ cultivation can influence reproductive traits and thus interactions with pollinators. Together with the effects of genetic erosion and unconscious selection, these changes may affect the success of reintroductions into natural habitats.

Low-molecular-weight heparin administered by subcutaneous catheter is a safe and effective anti-coagulation regimen in selected inpatient infants and children with complex congenital heart disease.

BACKGROUND/HYPOTHESIS: Disadvantages of intravenous therapeutic unfractionated heparin, the first-line anti-coagulant agent in children with complex congenital heart disease, include unpredictable pharmacokinetics requiring frequent phlebotomies and the need for continuous intravenous access. OBJECTIVE: To compare efficacy and safety of low-molecular-weight heparin administered by a subcutaneous indwelling catheter with intravenous unfractionated heparin. MATERIALS AND METHODS: Clinical data from 31 inpatients prospectively enrolled to receive subcutaneous low-molecular-weight heparin were compared with those from a historical group of 44 inpatients receiving intravenous unfractionated heparin. Investigation of parents' satisfaction by telephone survey. RESULTS: The percentage of anti-factor Xa levels outside therapeutic range was lower in the subcutaneous low-molecular-weight heparin group compared with the percentage of activated partial thromboplastin times outside therapeutic range in the intravenous unfractionated heparin group (40% versus 90%, p < 0.001). Neither group had a major complication. Transient local reactions occurred in 19% of patients of the subcutaneous low-molecular-weight heparin group. The number of needle punctures and that of placement of indwelling catheters were significantly lower in the subcutaneous low-molecular-weight heparin compared with the intravenous unfractionated heparin group (p < 0.001). In total, 84.2% of parents in the subcutaneous low-molecular-weight heparin group reported a positive experience when asked about comparison with prior intravenous unfractionated heparin treatment. CONCLUSION: Subcutaneous low-molecular-weight heparin offers a safe anti-coagulation regimen for children with complex congenital heart disease providing more efficient therapeutic anti-coagulation and a reduction in needle punctures, thus causing less pain and anxiety in this children.

Changes in pulmonary artery index and its relation to outcome after stage II palliation in patients with hypoplastic left heart syndrome.

OBJECTIVES: This study aimed to prove if pulmonary artery (PA) size influences survival and if an additional aortopulmonary shunt (APS) promotes left PA growth after bidirectional cavopulmonary shunt (BCPS) in patients with hypoplastic left heart syndrome. METHODS: The medical records of patients with hypoplastic left heart syndrome who underwent Norwood procedure and BCPS between 2007 and 2020 were reviewed. Right, left and total (right + left) PA indices were calculated according to Nakata and colleagues. RESULTS: A total of 158 patients were included in this study. The median age at Norwood and BCPS was 8 (7-11) days and 3.6 (3.1-4.6) months, respectively. There were 7 hospital deaths and 12 late deaths. Survival after BCPS was 90.3% at 1 year and 86.2% at 2 years. Total, right and left PA indices were 238 (195-316), 136 (101-185) and 102 (75-130) mm2/m2 at the time of BCPS, and they were 237 (198-284), 151 (123-186) and 86 (69-108) mm2/m2 at the time of Fontan. Left PA index decreased significantly between the time of BCPS and Fontan (P < 0.01). Nine patients needed partial takedown and additional APS due to failing BCPS, but the additional APS did not promote the PA growth significantly. CONCLUSIONS: Preoperative PA index did not affect the mortality after BCPS. The partial takedown and additional APS for failing BCPS were unable to improve left PA size.

Protein-Losing Enteropathy and Plastic Bronchitis Following the Total Cavopulmonary Connections.

BACKGROUND: We aimed to evaluate incidence, outcomes, and predictors of protein-losing enteropathy (PLE) and plastic bronchitis (PB) in a cohort of total cavopulmonary connection (TCPC). METHODS: We included 620 consecutive patients undergoing TCPC between 1994 and 2021. Prevalence and predictors for onset of PLE/PB were evaluated. Death and heart transplantation after onset of PLE/PB were examined. RESULTS: A total of 41 patients presented with PLE/PB (31 with PLE, 15 with PB, and 5 developed both PLE and PB). Their median age at TCPC was 2.2 (interquartile ranges [IQRs], 1.7-3.7) years, and time period to onset for PLE was 2.6 (IQR: 1.0-6.6) years and for PB was 1.1 (IQR: 0.3-4.1) years after TCPC. Independent factors for developing PLE/PB were dominant right ventricle (RV, hazard ratio [HR], 2.243; 95% confidence interval [CI], 1.129-4.458, P = .021) and prolonged pleural effusion after TCPC (HR, 2.101; 95% CI, 1.090-4.049, P = .027). In PLE/PB population, freedom from death or transplantation after PLE/PB diagnosis at 5 and 10 years were 88.7% and 76.4%, respectively. Eleven surgical interventions were performed in 10 patients, comprising atrioventricular valve repairs (n = 4), Fontan pathway revisions (n = 2), pacemaker implantation (n = 2), secondary fenestration (n = 1), diaphragm plication (n = 1), and ventricular assist device implantation (n = 1). In nine patients, a recovery from PLE with the resolution of PLE symptoms and normal protein levels was achieved. Eight patients died and the remaining continued to have challenging protein loss. CONCLUSIONS: Protein-losing enteropathy and PB remain severe complications in the cohort of TCPC. Patients with dominant RV, and prolonged pleural effusions, were at risk for PLE/PB.

Impact of home monitoring program on interstage mortality after the Norwood procedure.

Objective: While early outcome after the Norwood operation for hypoplastic left heart syndrome has improved, interstage mortality until bidirectional cavopulmonary shunt (BCPS) remains a concern. Our aim was to institute a home monitoring program to (HMP) decrease interstage mortality. Methods: Among 264 patients who survived Norwood procedure and were discharged before BCPS, 80 patients were included in the HMP and compared to the remaining 184 patients regarding interstage mortality. In patients with HMP, events during the interstage period were evaluated. Results: Interstage mortality was 8% (n = 21), and was significantly lower in patients with HMP (2.5%, n = 2), compared to those without (10.3%, n = 19, p = 0.031). Patients with interstage mortality had significantly lower birth weight (p < 0.001) compared to those without. Lower birth weight (p < 0.001), extra corporeal membrane oxygenation support (p = 0.002), and lack of HMP (p = 0.048) were risk factors for interstage mortality. Most frequent event during home monitoring was low saturation (<70%) in 14 patients (18%), followed by infection in 6 (7.5%), stagnated weight gain in 5 (6.3%), hypoxic shock in 3 (3.8%) and arrhythmias in 2 (2.5%). An unexpected readmission was needed in 24 patients (30%). In those patients, age (p = 0.001) and weight at BCPS (p = 0.007) were significantly lower compared to those without readmission, but the survival after BCPS was comparable between the groups. Conclusions: Interstage HMP permits timely intervention and led to an important decrease in interstage mortality. One-third of the patients with home monitoring program needed re-admission and demonstrated the need for earlier stage 2 palliation.

Clinical and haemodynamic variables associated with intensive care unit length of stay and early adverse outcomes after the Norwood procedure.

OBJECTIVES: This study was performed to determine the clinical and haemodynamic variables associated with early adverse outcomes after the neonatal Norwood procedure. METHODS: Patients who underwent the neonatal Norwood procedure between 2001 and 2019 were included. The patient diagnosis, morphological characteristics and haemodynamic parameters were analysed to identify factors associated with length of stay (LOS) in the intensive care unit (ICU) and mortality during the stay. RESULTS: A total of 322 patients were depicted. The median age and weight at the Norwood procedure were 9 days and 3.2 kg, respectively. Certain morphological and preoperative parameters, such as birth weight below 2.5 kg, restrictive atrial septal defect, extracardiac anomalies and the diameter of the ascending aorta, were found to be associated with the LOS in the ICU. Analysis using early postoperative haemodynamic variables revealed that systolic arterial pressure, diastolic arterial pressure, serum lactate levels and reduced ventricular function at 2 days postoperatively were associated with the LOS in the ICU. Birth weight <2.5 kg (P = 0.010), a restrictive atrial septal defect (P = 0.001) and smaller ascending aorta (P = 0.039) were associated with death in the ICU. Reduced ventricular function, lower systolic aortic pressure and higher lactate levels at various time points (P < 0.05) were also associated with ICU deaths. The LOS in the ICU was significantly associated with late mortality (P < 0.001, Hazard Ratio (HR) = 1.015). CONCLUSIONS: The LOS in the ICU after the Norwood procedure was predicted by early postoperative haemodynamic variables, suggesting that good early postoperative haemodynamics determine early recovery. A prolonged stay in the ICU after the Norwood procedure was associated with late mortality.

Neointimal hyperplasia in systemic-to-pulmonary shunts of children with complex cyanotic congenital heart disease.

OBJECTIVES: Neointimal hyperplasia might affect systemic-to-pulmonary shunt failure in infants with complex cyanotic congenital heart disease. The aim of this study was to elucidate histopathologic changes in polytetrafluoroethylene shunts and to determine whether increased neointimal formation is associated with early interventions comprising balloon dilatation, stent implantation and shunt revision. Furthermore, we intended to identify clinical factors associated with increased neointimal proliferation. METHODS: Removed shunts were processed for histopathological analysis. Slides were stained with hematoxylin/eosin and Richardson. Immunohistochemistry was performed with anti-alpha-smooth muscle actin and anti-CD68. Non-parametric analysis and univariable regressions were performed to identify clinical factors associated with neointimal hyperplasia and shunt stenosis. RESULTS: Fifty-seven shunts (39 modified Blalock-Taussig anastomosis, 8 right ventricle-to-pulmonary artery anastomosis, 10 central shunts) were analysed. Area of neointimal proliferation within the shunt was in median 0.75 mm2 (interquartile range, 0.3-1.57 mm2) and relative shunt stenosis in median 16.7% (interquartile range, 6.7-30.8%). Neointimal hyperplasia and shunt stenosis correlated with each other and were significantly greater in the group that required early interventions and shunt revision. Univariable linear regression identified smaller shunt size and lower acetylsalicylic acid dosage as factors to be associated with greater neointimal proliferation and shunt stenosis. CONCLUSIONS: In infants with complex cyanotic congenital heart disease, neointimal hyperplasia in systemic-to-pulmonary shunts is associated with early interventions comprising balloon dilatation, stent implantation and shunt revision. Smaller shunt size and lower aspirin dosage are associated with increased neointimal proliferation.

Surgical reintervention on the neo-aorta after the Norwood operation.

OBJECTIVES: We sought to identify the prevalence of surgical reintervention on the neo-aorta after Norwood procedure and its impact on long-term outcomes. METHODS: We reviewed the medical records of all patients who underwent Norwood procedure. The impacts of surgical neoaortic reintervention on outcomes were analysed in each stage of palliation. RESULTS: A total of 335 patients were included in this study. Thirty patients underwent surgical reintervention on the neo-aorta after Norwood procedure. The timing of initial reintervention was before stage II in 13 patients, at stage II in 7, between stage II and stage III in 5, at stage III in 3 and after stage III in 2. A reintervention before stage II was significantly associated with mortality (HR 14.4, 95% confidence interval 6.00-34.6, P < 0.001). In patients who underwent stage II (n = 251), reintervention had no significant impact on mortality. In patients who underwent stage III (n = 188), the previous reintervention was significantly associated with higher mean pulmonary pressure (P = 0.05) and a higher rate of reduced ventricular function (P = 0.002). Greater than mild atrioventricular valve regurgitation was significantly associated with the development of a neoaortic arch stenosis after stage II (P = 0.03). CONCLUSIONS: Surgical reinterventions on the neo-aorta were required in each inter-stage phase. A surgical neoaortic reintervention was not related to increased mortality after stage II but significantly associated with a higher rate of reduced ventricular function and elevated mean pulmonary artery pressure.

Influence of Shunt Type on Survival and Right Heart Function after the Norwood Procedure for Aortic Atresia.

The study objective was to compare the results after Norwood procedure between modified Blalock-Taussig shunt (MBTS) and right ventricle-to-pulmonary artery conduit (RVPAC) according to Sano in patients with hypoplastic left heart syndrome (HLHS) and aortic atresia (AA). A total of 146 neonates with HLHS and AA who underwent the Norwood procedure at our institution between 2001 and 2020 were divided into 2 groups according to shunt type (MBTS or RVPAC). Survival after the Norwood procedure was compared between the groups. Longitudinal right ventricular and tricuspid valve function in each group were evaluated using cubic splines method. RVPAC was performed in 103 patients and MBTS in 43 according to surgeon preference. There were no differences in the 30-day mortality rates (16.5% vs 16.3%, P  = 0.973). Survival at 0.5, 1 and 3 years was 79.6%, 74.6%, and 68.9% in RVPAC and 66.8%, 64.3%, and 58.5% in MBTS (P  =  0.293). Among 23 patients undergoing tricuspid valve procedure, different mechanisms of tricuspid regurgitation were observed between the groups. Longitudinal analysis revealed greater prevalence of late right ventricular dysfunction in RVPAC patients. In 77 patients who completed Fontan procedure, the postoperative N-terminal pro B-type natriuretic peptide value was significantly higher in RVPAC vs MBTS (554 vs 276 ng/L, P  =  0.007). No survival advantage of RVPAC over MBTS was observed in neonates with HLHS and AA undergoing the Norwood procedure. Longitudinal analysis demonstrated a greater prevalence of right ventricular dysfunction and higher N-terminal pro B-type natriuretic peptide values during late follow-up in patients with RVPAC.

Comparison of shunt types in the neonatal Norwood procedure for single ventricle.

OBJECTIVES: The ideal shunt for pulmonary blood flow, modified Blalock-Taussig shunt (MBTS) or right ventricular-pulmonary artery conduit (RVPAC) is yet to be determined. This study aimed to evaluate outcomes after the Norwood procedure according to the type of shunt. METHODS: A total of 322 neonates with hypoplastic left heart syndrome and related anomalies who underwent the Norwood procedure at our institution between 2001 and 2019 were divided into MBTS and RVPAC groups and the outcomes after the Norwood procedure were compared between the groups with respect to mortality after each staged procedure. RESULTS: We identified 322 consequent patients who underwent neonatal Norwood procedure for hypoplastic left heart syndrome (271 patients, 84.2%) and its variant (51 patients, 15.8%). RVPAC was performed in 163 (50.6%) patients and MBTS was performed in 159 (49.4%). There were no differences in the rate of early death (11.0% vs 12.6%, P = 0.69) or late death (7.4% vs 6.9%, P = 0.87) between the 2 groups after the Norwood procedure, and no significant difference in the number of patients who reached bidirectional cavopulmonary shunt (77.9% vs 76.1%, P = 0.69), and there was no difference in mortality after bidirectional cavopulmonary shunt (12.3% vs 7.5%, P = 0.15) or Fontan completion rate (54.0% vs 52.2%, P = 0.42) between the 2 groups. Survival at 0.5, 1, 3 and 6 years after the Norwood procedure was 81.0%, 73.8%, 67.9% and 67.0% in patients with RVPAC and 77.1%, 73.3%, 69.1% and 67.9% in patients with MBTS. There was no significant difference in the survival between the 2 groups during the median follow-up of 2.6 (interquartile ranges: 0.3-8.4, maximal 18.8) years (P = 0.97). CONCLUSIONS: In neonates undergoing the Norwood procedure, our available data of maximal 18.8 years follow-up showed no significant difference in early mortality, inter-stage attritions, or overall survival, between MBTS and RVPAC.

Preoperative risk factors influencing inter-stage mortality after the Norwood procedure.

OBJECTIVES: With improvements in early survival after the stage I palliation (S1P) Norwood procedure for hypoplastic left heart syndrome (HLHS) and its variants, inter-stage death accounts for an increasing proportion of mortality. Our aim was to identify the risk factors for inter-stage mortality. METHODS: The records of 322 neonates with HLHS or a variant who underwent the Norwood procedure at our centre between 2001 and 2019 were retrospectively analysed. RESULTS: The diagnoses included 271 neonates with HLHS (84%) and 51 with variants (16%). Aortic atresia was observed in 138 (43%) patients, mitral atresia in 91 (28%), extracardiac anomalies in 42 (13%) and genetic disorder in 14 (4%). The median age and weight of the patients at the S1P Norwood procedure were 9 (interquartile range: 7-12) days and 3.2 (2.9-3.5) kg, respectively. The median cardiopulmonary bypass time was 137 (107-163) min. Modified Blalock-Taussig shunts were used in 159 (49%) and unvalved right ventricle-to-pulmonary artery shunts in 163 (51%) patients. The number of inter-stage deaths was as follows: between S1P and stage II palliation (S2P), 61 including 38 early (<30 days) and 23 late (>30 days) deaths, and between S2P and stage III palliation, 32 deaths. Low birth weight (<2.5 kg) (odds ratio 4.37, P = 0.020) and restrictive atrial septum (odds ratio 2.97, P = 0.013) were identified as risks for early mortality. Low birth weight [hazard ratio (HR) 0.99/g, P = 0.002] was a risk for inter-stage mortality between S1P and S2P. Extracardiac anomalies (HR 4.75, P = 0.049) and significant pre-S1P atrioventricular valve regurgitation (HR: 7.72, P = 0.016) were risks for inter-stage mortality between S2P and stage III palliation. Other anatomical variables including aortic atresia, anatomical subtypes and the diameter of the ascending aorta nor shunt type were not identified as risk factors for mortality during any inter-stage period. CONCLUSIONS: The risk factors for inter-stage attrition after the Norwood procedure were different between each stage. Preoperative factors, including birth weight, restrictive atrial septum and extracardiac anomalies, adversely affected the inter-stage mortality.

Assessment of interventricular and right-intraventricular dyssynchrony in patients with surgically repaired tetralogy of Fallot by two-dimensional speckle tracking.

AIMS: We aimed to assess interventricular and right-intraventricular dyssynchrony in patients after tetralogy of Fallot (TOF) repair by two-dimensional (2D) speckle tracking and to identify factors associated with dyssynchrony. METHODS AND RESULTS: Forty-two patients after TOF repair with a mean age of 19.8 years and 42 age-matched healthy controls were studied. Longitudinal myocardial deformation (strain) and time-to-peak intervals were assessed by 2D speckle tracking and tissue Doppler imaging (TDI) in an apical four-chamber view. Dyssynchrony was defined as delay above 3 standard deviations of mean values in the control group. Magnetic resonance imaging (MRI) was performed for evaluation of ventricular function. Using 2D speckle tracking, 22 patients (52%) showed interventricular dyssynchrony and 16 (38%) had right-intraventricular dyssynchrony. The interventricular delay correlated significantly with right ventricular (RV) strain (r = 0.687, P < 0.001), RV systolic pressure (r = 0.535, P = 0.001), QRS duration (r = 0.466, P = 0.002), RV end-diastolic (r = 0.377, P = 0.018), and RV end-systolic volumes (r = 0.452, P = 0.004) as well as RV ejection fraction (r = -0.378, P = 0.018). Similarly, the right-intraventricular delay correlated significantly with RV strain (r = 0.534, P < 0.001), QRS duration (r = 0.428, P = 0.005), RV end-systolic volume (r = 0.34, P = 0.038), and RV systolic pressure (r = 0.413, P = 0.015). In multivariate regression analysis, reduced RV strain and prolonged QRS duration remained the main determinant factors predicting dyssynchrony. Moreover, 2D speckle tracking and TDI showed a significant correlation in the assessment of the interventricular (r = 0.738, P < 0.001) and right-intraventricular delay (r = 0.747, P < 0.001). CONCLUSION: Interventricular and right-intraventricular dyssynchrony are detectable in patients after TOF repair by 2D speckle tracking. Reduced RV myocardial deformation and QRS prolongation are the main factors associated with the observed dyssynchrony.

B-type natriuretic peptide to predict ductus intervention in infants <28 weeks.

Patent ductus arteriosus (PDA) is frequent in neonates with gestational age of less than 28 wk. Clinical and echocardiographic signs define hemodynamic significance of PDA, but do not reveal the need for PDA intervention in the first days of life. B-type natriuretic peptide (BNP) has been proposed as a screening tool for PDA in preterm infants. To determine whether BNP can predict the need for PDA intervention, plasma BNP was measured by chemiluminescence immunoassay in 67 preterm infants <28 wk (median 26) on the second day of life in a prospective blinded study. PDA intervention was based on specified clinical and echocardiographic findings. Twenty-four patients (intervention group) received treatment for PDA and 43 patients (controls) remained without intervention. BNP concentrations were higher in the intervention (median 1069 pg/mL) than in the control group (247 pg/mL, p < 0.001). BNP correlated positively with ductal size (R = 0.46, p < 0.001) and atrial/aortic root ratio (R = 0.54, p < 0.001). In conclusion, plasma BNP proved to be a good predictor for ductus intervention (area under the curve: 0.86) with the best cutoff at 550 pg/mL on the second day of life in ventilated infants less than 28 wk gestation (sensitivity: 83%; specificity: 86%).

Mid-term follow-up in patients with diaphragmatic plication after surgery for congenital heart disease.

OBJECTIVE: Diaphragmatic palsy (DP) is a rare but severe complication after surgery for congenital heart disease. Transthoracic diaphragmatic plication is an effective means of treatment for those with respiratory impairment due to DP, but little is known about the mid-term effects of diaphragmatic plication. DESIGN: We performed a study in 24 patients with history of DP. Diaphragm movement was assessed using ultrasound. Patients with DP who were old enough were additionally followed-up with lung function and exercise testing. A group of patients with similar age, diagnoses and operations served as controls. RESULTS: Ultrasound showed that in the majority of cases with history of DP the paralysed diaphragm was static, independently of whether it was plicated or not. Patients with DP had a more restrictive lung function pattern (VC: 54.3 vs. 76.4% predicted, p<0.001; FEV(1): 58.4 vs. 86.2% predicted, p<0.001) and a lower exercise capacity compared with the control group (peak VO2: 24.5 vs. 31.3 ml/kg/min, p=0.03). Comparing patients with and without plication for DP, only a tendency towards lower lung function values in patients after diaphragmatic plication, but no differences regarding exercise capacity, could be found. CONCLUSIONS: Our results provide evidence that DP is a serious surgical complication with a reduction in lung function and exercise capacity, even at mid-term follow-up; however, diaphragmatic plication, a useful tool in treating post-surgical DP in children with respiratory impairment, seems to be without mid-term risk in terms of recovery of phrenic nerve function, lung function values, and exercise capacity.

Postoperative phrenic nerve palsy: early clinical implications and management.

OBJECTIVE: We examined the clinical impact of diaphragmatic palsy (DP) as a result of phrenic nerve injury following cardiothoracic surgery, specifically its effects on morbidity and mortality, early regeneration capacity of the phrenic nerve, and role of surgical diaphragmatic plication. METHODS: A retrospective case control study was performed in 74 children with DP and 74 matched controls after cardiothoracic surgery within the past 14 years. RESULTS: Following 5,128 surgical procedures in children (aged under 18 years) we found an incidence of DP of 1.4%. There were no differences in mortality between the groups, and the cause of death was not related to DP or plication in any of the patients. However, patients with diaphragm impairment had significantly longer duration of mechanical ventilation (median 3 days vs. 1), ICU stay (7 days vs. 3.5), duration of hospital stay (16 days vs. 12), and for antibiotic treatment (16 days vs. 7). Because of prolonged respiratory problems 40 children (54%) underwent surgical diaphragmatic plication to flatten the diaphragm in its inspiratory position. In children with DP younger age was a strong predictor for plication (median 3.8 months vs. 12.1). CONCLUSIONS: Especially in newborns and young infants with DP the length of mechanical ventilation, ICU stay, and hospital stay are prolonged. Early spontaneous recovery of the phrenic nerve is rare. In cases of respiratory impairment early transthoracic diaphragmatic plication is an effective means of treatment.

Management of pediatric patients after implantation of the Berlin Heart EXCOR ventricular assist device.

Within the last 16 years, the Berlin Heart EXCOR systems have been used for circulatory support in 73 infants and children up to 17 years of age (mean, 7 years) with severe circulatory failure resistant to pharmacological therapy at our institution. These were patients with cardiomyopathy, fulminant myocarditis, end-stage congenital cardiac defects, and acute heart failure after congenital heart surgery. Mean EXCOR support time was 36 days (range, 1 to 420 days). Forty-four patients (62%) survived up to transplantation or after weaning and 37 (51%) of them, including 9 infants, were discharged home. These results in patients with very advanced disease have improved significantly during the past few years as the result of technical developments and growing experience in the treatment of patients on the device and in postoperative care. The following article gives answers to five questions frequently asked about intensive care unit treatment while on the device, anticoagulation and additional medical support during left ventricular or biventricular support, the daily treatment of the children, and options for the weaning procedure.

Pneumatic pulsatile ventricular assist devices in children under 1 year of age.

OBJECTIVE: Although considerable progress has been made on ventricular assist devices (VAD) for adults, pneumatic pulsatile circulatory support in young infants is still limited. There is a need for long-term ventricular assist devices to bridge the failing myocardium of young children until recovery or transplantation. Miniaturized devices and innovative modalities need to be optimized. We report on our experience. METHODS: From 1/1992 to 6/2004, 18 infants (6 male/12 female) under 1 year of age were treated with the Berlin Heart Excor VAD. The infants were divided into two groups, depending on the year of treatment. Group A consists of eight infants resuscitated and supported with a pulsatile pneumatic ventricular assist device between 1992 and 1998 and group B consists of 10 infants treated between 1999 and 6/2004. With the pediatric-sized Berlin Heart we used miniaturized extracorporeal pneumatically driven blood pumps, the lowest stroke volume being 10 ml. RESULTS: In 18 children, age 3-345 (median 147) days, artificial replacement of heart function was applied for long-term support (1-64, median 10 days) as a life-saving measure in our hospital. Nine had LVAD and nine BVAD support. All were in cardiogenic shock with multiorgan failure; three had fulminant myocarditis, four cardiomyopathy, and one chronic stage of congenital heart disease. Five children were weaned from the system, three reached heart transplantation, and 10 died on the VAD. There were no differences between groups A and B regarding age, body weight or diagnosis, but the duration of mechanical support differed: Group A, median 2, range 1-16 days; group B, median 12, range 1-100 days. Since 1999 (group B), the survival rate of our small infants has increased to 70% whereas none of the infants in group A survived to be discharged. CONCLUSIONS: The outcome of VAD support in small infants is no longer inferior to that of adult support, now optimized cannulas, modified anticoagulation and optimized surgical and intensive care management have been established.

Paralysis of the phrenic nerve as a risk factor for suboptimal Fontan hemodynamics.

OBJECTIVE: The introduction of the Fontan operation for single ventricle physiology was based on the dual principle of the pulmonary blood flow. It is postulated that normal breathing movements are necessary for passive blood flow into the lungs. We compared patients with and without palsy of the phrenic nerve regarding the sufficiency of Fontan hemodynamics. METHODS: We analyzed 85 consecutive patients, who were available for follow-up after completion of their total cavopulmonary connection (TCPC) between February 1992 and February 2003. The median age at TCPC completion was 4.3 (range 1.3-37) years. Sixty were operated on with an extracardiac conduit and 25 with a lateral tunnel. Fifty patients underwent postoperative heart catheterization with contrast angiography. The diagnosis of diaphragm paralysis was made using echocardiography, fluoroscopy and X-ray examination. Surgical diaphragm plication was performed in 13 patients (Four before and nine after Fontan operation) at a median of 2.2 years after the diagnosis. RESULTS: Twenty-one patients developed fixed palsy of the phrenic nerve during a total of 225 operations before and including completion of TCPC. There were no differences in the incidence of phrenic nerve paralysis between small children (aged <3 years) and older patients or between patients with the extracardiac and intracardiac Fontan procedures. There were no differences in the duration of mechanical ventilation. However, prolonged pleural effusions and a hospital stay of longer than 2 weeks were noted more frequently in patients with palsy (P<0.05). During the median follow-up of 4.6 (range: 0.7-11.4) years significantly more patients with phrenic nerve palsy developed chronic ascites compared to those without palsy (8 of 20 vs. 2 of 65; P<0.001). CONCLUSIONS: Phrenic nerve palsy was recognized as a risk factor for suboptimal Fontan hemodynamics due to the hindrance of passive venous blood flow. Patients with phrenic nerve palsy have a longer hospital stay and a higher incidence of prolonged pleural effusions and of chronic ascites, than those without. Early diaphragm plication may be favorable to optimize the Fontan circuit in these patients. Completion of the TCPC in patients with diaphragm paralysis should be viewed critically.

Regulation of the major isoform of human endothelin-converting enzyme-1 by a strong housekeeping promoter modulated by polymorphic microsatellites.

BACKGROUND: Human endothelin-converting enzyme (ECE)-1, the key enzyme in endothelin biosynthesis, shows broad cell and tissue expression within the cardiovascular system. Expression of ECE-1c, which represents the major ECE-1 isoform, is directed by an alternative promoter, but the mechanisms of ECE-1c promoter regulation are largely unknown. As ECE-1c transcription is initiated from several start sites, we hypothesized that the ECE-1c promoter functions as a housekeeping promoter. OBJECTIVE: To investigate the putative housekeeping function of the ECE-1c promoter in vascular endothelial cells, which represent a main site of its expression. RESULTS: Using promoter reporter assays, gel shift and supershift assays, we have demonstrated, in human endothelial EA.hy926 cells, functionality of cis-acting elements for binding of the CAAT-box binding protein NF-YB, GATA-2) E2F-2, and a GC-box binding factor, which are spatially associated with transcriptional start sites of ECE-1c. In the more upstream promoter region we have identified three highly polymorphic dinucleotide repeats, 5'-(CA)n, (CG)n and 3'-(CA)n, which strongly affected promoter function in endothelial EA.hy926 cells (2.7-fold activation comparing the most active to the least active allele) and, in a similar manner, in human neuronal KELLY cells. Finally, by in-vitro methylation, we were able to achieve strong suppression of the ECE-1c promoter activity in endothelial cells. CONCLUSION: Our results provide a molecular explanation for constitutive expression of ECE-1c mRNA. Modulation by genetic and epigenetic mechanisms as revealed in our study may account for interindividual variation of the constitutive endothelin system activity in humans and thus influence individual predisposition to cardiovascular disease.