Medium term outcome for infant repair in tetralogy of Fallot: Indicators for timing of surgery

Pulmonary Valve Endocarditis With Tetralogy of Fallot: A Comprehensive Exploration

Infective endocarditis, a fatal infection with rising morbidity and mortality rates among infants and children, is characterized by microbial infection within the endocardium, the inner lining of the heart including heart valves. The heightened susceptibility to infection in children is attributed to pre-existing pathologies, structural defects, and comorbidities. This report details a case of a one-year-old child with tetralogy of Fallot, showcasing isolated pulmonary valve vegetations as a distinctive manifestation of infective endocarditis.

Considerations in Timing of Surgical Repair in Tetralogy of Fallot

Certain aspects of the treatment of tetralogy of Fallot (TOF) repair remain controversial. The optimal timing of the elective repair of asymptomatic patients and the ideal strategy for managing symptomatic neonates and infants with TOF are still debated despite years of experience in TOF treatment. In this article, we discuss why a surgical correction at 3-6 months of age is likely the ideal time frame for the elective repair of TOF. We also elaborate on our strategy for managing symptomatic neonates and infants with TOF and why we prefer an early single-stage primary repair.

Outcomes of Transannular Repair of Tetralogy of Fallot With a Contegra® Monocuspid Patch

BACKGROUND

Surgical repair of tetralogy of Fallot (ToF) depends on the anatomical variations of the heart defect. A group of patients with a hypoplastic pulmonary valve annulus required a transannular patch. This study aimed to evaluate the early and late outcomes of ToF repair with a transannular Contegra® monocuspid patch in a single center.

METHODS

A retrospective review of medical records was conducted. This study included 224 children with a median age of 13 months who underwent ToF repair with a Contegra® transannular patch in over 20 years of observation. The primary outcomes were hospital mortality and need for early reoperations. The secondary outcomes were late death and event-free survival.

RESULTS

The hospital mortality in our group was 3.1%, whereas two patients required early reoperation. Three patients were excluded from the study because follow-up data were not available. In the remaining group of patients (212 patients), the median follow-up was 116 (range, 1-206) months. One patient died because of sudden cardiac arrest at home six months after surgery. Event-free survival was observed in 181 patients (85.4%), whereas the remaining 30 patients (14.1%) required graft replacement. The median time to reoperation was 99 (range, 4-183) months.

CONCLUSIONS

Although surgical treatment of ToF has been performed for more than 60 years worldwide, the optimal approach in children with a hypoplastic pulmonary valve annulus remains debatable. Among options, the Contegra® monocuspid patch can be effectively used in transannular repair of ToF with good long-term results.

The American Association for Thoracic Surgery (AATS) 2022 Expert Consensus Document: Management of infants and neonates with tetralogy of Fallot

OBJECTIVE

Despite decades of experience, aspects of the management of tetralogy of Fallot with pulmonary stenosis (TOF) remain controversial. Practitioners must consider newer, evolving treatment strategies with limited data to guide decision making. Therefore, the TOF Clinical Practice Standards Committee was commissioned by the American Association for Thoracic Surgery to provide a framework on this topic, focused on timing and types of interventions, management of high-risk patients, technical considerations during interventions, and best practices for assessment of outcomes of the interventions. In addition, the group was tasked with identifying pertinent research questions for future investigations. It is recognized that variability in institutional experience could influence the application of this framework to clinical practice.

METHODS

The TOF Clinical Practice Standards Committee is a multinational, multidisciplinary group of cardiologists and surgeons with expertise in TOF. With the assistance of a medical librarian, a citation search in PubMed, Embase, Scopus, and Web of Science was performed using key words related to TOF and its management; the search was restricted to the English language and the year 2000 or later. Articles pertaining to pulmonary atresia, absent pulmonary valve, atrioventricular septal defects, and adult patients with TOF were excluded, as well as nonprimary sources such as review articles. This yielded nearly 20,000 results, of which 163 were included. Greater consideration was given to more recent studies, larger studies, and those using comparison groups with randomization or propensity score matching. Expert consensus statements with class of recommendation and level of evidence were developed using a modified Delphi method, requiring 80% of the member votes with 75% agreement on each statement.

RESULTS

In asymptomatic infants, complete surgical correction between age 3 and 6 months is reasonable to reduce the length of stay, rate of adverse events, and need for a transannular patch. In the majority of symptomatic neonates, both palliation and primary complete surgical correction are useful treatment options. It is reasonable to consider those with low birth weight or prematurity, small or discontinuous pulmonary arteries, chromosomal anomalies, other congenital anomalies, or other comorbidities such as intracranial hemorrhage, sepsis, or other end-organ compromise as high-risk patients. In these high-risk patients, palliation may be preferred; and, in patients with amenable anatomy, catheter-based procedures may prove favorable over surgical palliation.

CONCLUSIONS

Ongoing research will provide further insight into the role of catheter-based interventions. For complete surgical correction, both transatrial and transventricular approaches are effective; however, the smallest possible ventriculotomy should be utilized. When possible, the pulmonary valve should be spared; and if unsalvageable, reconstruction can be considered. At the conclusion of the operation, adequate relief of the right ventricular outflow obstruction should be confirmed, and identification of a significant fixed anatomical obstruction should prompt further intervention. Given our current knowledge and the gaps identified, we propose several key questions to be answered by future research and potentially by a TOF registry: When to palliate or proceed with complete surgical correction, as well as the ideal type of palliation; the optimal surgical approach for complete repair for the best long-term preservation of right ventricular function; and the utility, efficacy, and durability of various pulmonary valve preservation and reconstruction techniques.

Fetal cardiac parameters for predicting postnatal operation type of fetuses with tetralogy of Fallot

Background

To assess fetal cardiac parameters predictive of postnatal operation type in fetuses with tetralogy of Fallot (TOF).

Methods

Echocardiographic data obtained in the second and third trimesters were retrospectively reviewed for fetuses diagnosed with TOF between 2014 and 2018 at Asan Medical Center. The following fetal cardiac parameters were analyzed: 1) pulmonary valve annulus (PVA) z-score, 2) right pulmonary artery (RPA) z-score, 3) aortic valve annulus (AVA) z-score, 4) pulmonary valve peak systolic velocity (PV-PSV), 5) PVA/AVA ratio, and 6) RPA/descending aorta (DAo) ratio. These cardiac parameters were compared between a primary corrective surgery group and a palliative shunt operation followed by complete repair group.

Results

A total of 100 fetuses with TOF were included. Only one neonatal death occurred. Ninety patients underwent primary corrective surgery and 10 neonates underwent a multistage surgery. The PVA z-score, RPA z-score, and RPA/DAo ratio measured in the second trimester and the PVA z-score, RPA z-score, and PVA/AVA raio measured in the third trimester were significantly lower in the multistage surgery group, while the PV-PSV as measured in both trimesters were significantly higher in the multistage surgery group.

Conclusion

Fetal cardiac parameters are useful for predicting the operation type necessary for neonates with TOF.

Heart failure biomarker levels correlate with invasive haemodynamics in pulmonary valve replacement

BACKGROUND

Although widely used in cardiology, relation of heart failure biomarkers to cardiac haemodynamics in patients with CHD (and in particular with pulmonary insufficiency undergoing pulmonary valve replacement) remains unclear. We hypothesised that the cardiac function biomarkers N-terminal pro-brain natriuretic peptide (NT-proBNP), soluble suppressor of tumorigenicity 2, and galectin-3 would have significant associations to right ventricular haemodynamic derangements.

METHODS

Consecutive patients ( n = 16) undergoing cardiac catheterisation for transcatheter pulmonary valve replacement were studied. NT-proBNP, soluble suppressor of tumorigenicity 2, and galectin-3 levels were measured using a multiplex enzyme-linked immunosorbent assay from a pre-intervention blood sample obtained after sheath placement. Spearman correlation was used to identify significant correlations (p ≤ 0.05) of biomarkers with baseline cardiac haemodynamics. Cardiac MRI data (indexed right ventricular and left ventricular end-diastolic volumes and ejection fraction) prior to device placement were also compared to biomarker levels.

RESULTS

NT-proBNP and soluble suppressor of tumorigenicity 2 were significantly correlated (p < 0.01) with baseline mean right atrial pressure and right ventricular end-diastolic pressure. Only NT-proBNP was significantly correlated with age. Galectin-3 did not have significant associations in this cohort. Cardiac MRI measures of right ventricular function and volume were not correlated to biomarker levels or right heart haemodynamics.

CONCLUSIONS

NT-proBNP and soluble suppressor of tumorigenicity 2, biomarkers of myocardial strain, significantly correlated to invasive pressure haemodynamics in transcatheter pulmonary valve replacement patients. Serial determination of soluble suppressor of tumorigenicity 2, as it was not associated with age, may be superior to serial measurement of NT-proBNP as an indicator for timing of pulmonary valve replacement.

Staged Versus Complete Repair in the Symptomatic Neonate With Tetralogy of Fallot

BACKGROUND

The optimal management of tetralogy of Fallot (TOF) in symptomatic neonates remains unknown. We compared outcomes for those undergoing palliation vs complete repair in the neonatal period.

METHODS

In a retrospective cohort study of symptomatic neonates with TOF who had a neonatal complete repair (group 1, n = 112) or staged repair (group 2, n = 26) from 2000 to 2013, we compared outcomes at 4 time points: neonatal complete repair vs palliation (group 1 vs 2A), neonatal vs later complete repair (group 1 vs 2B), the single vs combined admissions to achieve a complete repair (group 1 vs group 2A + 2B), and cumulative events 2 years after complete repair for both groups.

RESULTS

Demographics, anatomy, comorbidities, surgical approach, and mortality were similar between groups 1 and 2. Group 1 had a longer duration of cardiopulmonary bypass and deep hypothermic circulatory arrest and more postprocedure cardiac events compared with group 2A; a longer duration of intubation, intensive care, and postprocedure hospital stay compared with groups 2A and 2B; and a longer total hospital stay compared with group 2B. With combined admissions for group 2, there was no difference in the total duration of intensive care, total hospital stay, or reinterventions compared with group 1.

CONCLUSIONS

Both management options result in similar survival; however, early morbidity was greater with neonatal complete repair. The impact of increased neonatal exposures, such as cardiopulmonary bypass, deep hypothermic circulatory arrest, and intensive care, on neurocognitive development requires further study but should be considered when choosing an optimal strategy.

Complete Versus Staged Repair for Neonates With Tetralogy of Fallot: Establishment and Validation of a Cohort of 2235 Patients Using Detailed Surgery Sequence Review of Health Care Administrative Data

BACKGROUND

The surgical strategy for neonates with tetralogy of Fallot (TOF) consists of complete or staged repair. Assessing the comparative effectiveness of these approaches is facilitated by a large multicenter cohort. We propose a novel process for cohort assembly using the Pediatric Health Information System (PHIS), an administrative database that contains clinical and billing data for inpatient and emergency department stays from tertiary children's hospitals.

METHODS

A 4-step process was used to identify neonates with TOF: (1) screen neonates in PHIS with International Classification of Diseases-9 (ICD-9) diagnosis or procedure codes for TOF; (2) include patients with TOF procedures before 30 days of age; (3) exclude patients with missing 2-year follow-up data; (4) analyze patients' 2-year surgery sequence patterns, exclude patients inconsistent with a treatment strategy for TOF, and designate patients as complete or staged repair. Manual chart review at 1 PHIS center was performed to validate this process.

RESULTS

Between January 2004 and March 2015, 5862 patients were identified in step 1. Step 2 of cohort assembly excluded 3425 patients (58%); step 3 excluded 148 patients (3%); and step 4 excluded 54 patients (1%). The final cohort consisted of 2235 neonates with TOF from 45 hospitals. Manual chart review of 336 patients showed a positive predictive value for accurate PHIS identification of 44% after step 1 and 97% after step 4.

CONCLUSIONS

This systematic cohort identification algorithm resulted in a high positive predictive value to appropriately categorize patients. This carefully assembled cohort offers a unique opportunity for future studies in neonatal TOF outcomes.

When is the Best Time for Corrective Surgery in Patients with Tetralogy of Fallot between 0 and 12 Months of Age?

Objective

To identify the best time for corrective surgery of tetralogy of Fallot (TF) in children aged 0-12 months and to report the most frequent complications during the first 3 years postoperatively.

Methods

Systematic review of studies published between 2000 and 2017 on corrective surgery for TF. Articles were selected through search of electronic databases (PubMed, SciELO, Scopus, Lilacs, Google Scholar, and Cochrane). Length of stay in intensive care unit, duration of mechanical ventilation, and peri/postoperative complications were analyzed for data discussion and research interpretation.

Conclusion

Definitive corrective surgery is the best alternative, and the earlier it is performed, the lower the occurrence of harmful effects and the greater the chances of cardiorespiratory recovery. This systematic review suggests that the best time to perform definitive corrective surgery for TF in the first year of life is during 3-6 months of age in children with no or mild symptoms. Children with severe symptoms should undergo surgery immediately.

Impact of timing on in-patient outcomes of complete repair of tetralogy of Fallot in infancy: an analysis of the United States National Inpatient 2005-2011 database

Background

This study aimed to investigate whether age at complete repair of tetralogy of Fallot (TOF) impacts postoperative morbidity and length of hospital stay in infants less than 365 days of age.

Methods

The United States Nationwide Inpatient Sample was searched for infants 0–365 days of age that underwent complete repair of TOF between 2005 and 2011. Patients were categorized based on age at time of repair: 0–30 days; 31–90 days; 91–180 days; > 180 days.

Results

A total of 1112 infants were included in the study. Multivariate analysis showed the risk of postoperative complications was 40% lower in infants ≥91 days old at the time of repair as compared to those ≤30 days old. In addition, children > 30 days old at the time of repair had a significantly shorter length of hospital stay than those aged ≤30 days. In the subgroup with elective repair, older age was associated with a shorter length of hospital stay as compared to those ≤30 days old at repair, while association between age at complete repair of TOF and postoperative complication was not significant among the groups after adjusting for confounders.

Conclusions

In children < 1 year old, postoperative complications and length of hospital stay are affected by the timing of complete repair of TOF.

Primary surgical repair of tetralogy of Fallot at under three months of age

Background Classical management of small infants with tetralogy of Fallot has involved placement of a Blalock-Taussig shunt followed later by complete repair, rather than primary complete repair which is the strategy adopted in larger infants. Some advantages of early complete repair compared to a staged strategy have been shown. We sought to review our institutional outcomes. Methods Patients under 3-months old undergoing complete surgical repair of tetralogy of Fallot in our institution between 2005 and 2015 were retrospectively reviewed and compared with an older control group matched by anatomical diagnosis and outflow tract intervention. Results Fourteen index cases (group A) and 14 controls (group B) were identified. At surgery, the median age was 43 days and weight 4.2 kg in group A, and 130 days and 6.1 kg in group B. Nine of 14 in group A were admitted for surgery as emergencies compared to none in group B. Peak inotrope score (22.3 vs. 12.8, p = 0.02) and intensive care unit stay (4.4 vs. 2.6 days, p = 0.02) were higher in group A. Bypass and crossclamp times, duration of intubation, and total length of stay did not differ. Conclusions We conclude that although babies undergoing early repair of tetralogy of Fallot have an increased need for intensive care support in the early postoperative period, the total length of stay is not prolonged despite more emergency admissions. As it is known that early repair may reduce long-term morbidity, we propose consideration of earlier complete repair of tetralogy of Fallot.

Optimal Timing for Elective Early Primary Repair of Tetralogy of Fallot: Analysis of Intermediate Term Outcomes

BACKGROUND

We have previously demonstrated that early primary repair of tetralogy of Fallot with pulmonary stenosis (TOF) can be safely performed without increase in hospital resource utilization or compromise to surgical technical performance scores (TPS). We sought to identify the optimal timing for elective early primary repair of TOF with respect to intermediate-term reintervention.

METHODS

Retrospective review of all patients with TOF undergoing elective primary repair between September 2004 and December 2013 was performed. Patients were stratified into reintervention group or no reintervention group. Multivariable Cox regression analysis identified independent predictors of reintervention. Youden's J-index in receiver operating characteristic analysis identified optimal age cutoff predictive of reintervention. Kaplan-Meier analysis with the log-rank test compared reintervention rates stratified by age and TPS.

RESULTS

A total of 129 patients with median (interquartile range) age and weight of 78 days (56 to 111) and 5 kg (4.1 to 5.7), respectively, underwent primary repair. After a median (interquartile range) follow-up of 2.3 years (0.1 to 4.6), 18 patients (14%) required a total of 22 reinterventions. Youden's J-index revealed significantly lower risk of intermediate-term reintervention when repaired after 55 days of age (8% for >55 days old versus 31% for ≤55 days of age). Multivariable Cox regression identified age 55 days and younger (hazard ratio [HR] 4.5, 95% confidence interval [CI] 1.6 to 12.8, p = 0.004), valve sparing repair (HR 15.3, 95% CI 1.8 to 128.5, p < 0.001), residual right ventricular outflow tract (RVOT) gradient (HR 1.11, 95% CI 1.1 to 1.2, p < 0.001), and inadequate TPS (HR 21.5, 95% CI 7.4 to 63, p < 0.001) as independent predictors of overall intermediate-term reintervention.

CONCLUSIONS

Elective repair in patients greater than 55 days of age, irrespective of size of the patient, can be safely performed without any increase in reintervention rates. Both residual peak RVOT gradient and TPS are effective in identifying patients at increased risk of reintervention.

Patient-Specific MRI-Based Right Ventricle Models Using Different Zero-Load Diastole and Systole Geometries for Better Cardiac Stress and Strain Calculations and Pulmonary Valve Replacement Surgical Outcome Predictions

Background

Accurate calculation of ventricular stress and strain is critical for cardiovascular investigations. Sarcomere shortening in active contraction leads to change of ventricular zero-stress configurations during the cardiac cycle. A new model using different zero-load diastole and systole geometries was introduced to provide more accurate cardiac stress/strain calculations with potential to predict post pulmonary valve replacement (PVR) surgical outcome.

Methods

Cardiac magnetic resonance (CMR) data were obtained from 16 patients with repaired tetralogy of Fallot prior to and 6 months after pulmonary valve replacement (8 male, 8 female, mean age 34.5 years). Patients were divided into Group 1 (n = 8) with better post PVR outcome and Group 2 (n = 8) with worse post PVR outcome based on their change in RV ejection fraction (EF). CMR-based patient-specific computational RV/LV models using one zero-load geometry (1G model) and two zero-load geometries (diastole and systole, 2G model) were constructed and RV wall thickness, volume, circumferential and longitudinal curvatures, mechanical stress and strain were obtained for analysis. Pairwise T-test and Linear Mixed Effect (LME) model were used to determine if the differences from the 1G and 2G models were statistically significant, with the dependence of the pair-wise observations and the patient-slice clustering effects being taken into consideration. For group comparisons, continuous variables (RV volumes, WT, C- and L- curvatures, and stress and strain values) were summarized as mean ± SD and compared between the outcome groups by using an unpaired Student t-test. Logistic regression analysis was used to identify potential morphological and mechanical predictors for post PVR surgical outcome.

Results

Based on results from the 16 patients, mean begin-ejection stress and strain from the 2G model were 28% and 40% higher than that from the 1G model, respectively. Using the 2G model results, RV EF changes correlated negatively with stress (r = -0.609, P = 0.012) and with pre-PVR RV end-diastole volume (r = -0.60, P = 0.015), but did not correlate with WT, C-curvature, L-curvature, or strain. At begin-ejection, mean RV stress of Group 2 was 57.4% higher than that of Group 1 (130.1±60.7 vs. 82.7±38.8 kPa, P = 0.0042). Stress was the only parameter that showed significant differences between the two groups. The combination of circumferential curvature, RV volume and the difference between begin-ejection stress and end-ejection stress was the best predictor for post PVR outcome with an area under the ROC curve of 0.855. The begin-ejection stress was the best single predictor among the 8 individual parameters with an area under the ROC curve of 0.782.

Conclusion

The new 2G model may be able to provide more accurate ventricular stress and strain calculations for potential clinical applications. Combining morphological and mechanical parameters may provide better predictions for post PVR outcome.

Influence of Age and Weight on Technical Repair of Tetralogy of Fallot

BACKGROUND

We have previously shown that early primary repair of tetralogy of Fallot can be performed without increased morbidity or resource utilization. The technical performance score (TPS) is a self-assessment tool used to identify patients at risk of poor postoperative outcomes. We hypothesized that adequate technical repair can be obtained regardless of the patient's preoperative age or size.

METHODS

A retrospective review of all tetralogy of Fallot patients repaired between September 2004 and December 2013 was performed. The postoperative predischarge echocardiogram was reviewed to assign a TPS rating of optimal, adequate, or inadequate. The TPS groups were compared by univariate analysis using the Kruskal-Wallis test for continuous variables and χ(2) analysis for categoric variables. Multivariable logistic regression analysis was performed to identify independent predictors of inadequate TPS.

RESULTS

Among 167 patients (1 operative mortality), TPS was optimal in 88, adequate in 62, and inadequate in 17. Patients with worse TPS had longer ventilation time (p = 0.031), hospital length of stay (p = 0.036), and higher hospital charges (p = 0.005). Multivariable regression analysis revealed discontinuous branch pulmonary arteries (odds ratio 18.24, 95% confidence interval: 1.42 to 234, p = 0.015) as the only independent predictor of inadequate TPS. Younger age at repair (p = 0.245) and smaller weight (p = 0.260) were not associated with inadequate TPS.

CONCLUSIONS

Technical adequacy of tetralogy of Fallot repair is affected by anatomic subsets (discontinuous branch pulmonary arteries) and not by the patient's age or size. Worse TPS is associated with higher postoperative morbidity and hospital charges. Younger age and size should not be a deterrent for early primary repair.

Mechanical stress is associated with right ventricular response to pulmonary valve replacement in patients with repaired tetralogy of Fallot

OBJECTIVE

Patients with repaired tetralogy of Fallot account for a substantial proportion of cases with late-onset right ventricular failure. The current surgical approach, which includes pulmonary valve replacement/insertion, has yielded mixed results. Therefore, it may be clinically useful to identify parameters that can be used to predict right ventricular function response to pulmonary valve replacement.

METHODS

Cardiac magnetic resonance data before and 6 months after pulmonary valve replacement were obtained from 16 patients with repaired tetralogy of Fallot (8 male, 8 female; median age, 42.75 years). Right ventricular ejection fraction change from pre- to postpulmonary valve replacement was used as the outcome. The patients were divided into group 1 (n = 8, better outcome) and group 2 (n = 8, worst outcome). Cardiac magnetic resonance-based patient-specific computational right ventricular/left ventricular models were constructed, and right ventricular mechanical stress and strain, wall thickness, curvature, and volumes were obtained for analysis.

RESULTS

Our results indicated that right ventricular wall stress was the best single predictor for postpulmonary valve replacement outcome with an area under the receiver operating characteristic curve of 0.819. Mean values of stress, strain, wall thickness, and longitudinal curvature differed significantly between the 2 groups with right ventricular wall stress showing the largest difference. Mean right ventricular stress in group 2 was 103% higher than in group 1.

CONCLUSIONS

Computational modeling and right ventricular stress may be used as tools to identify right ventricular function response to pulmonary valve replacement. Large-scale clinical studies are needed to validate these preliminary findings.

Clinical utility of the plasma brain natriuretic peptide level in monitoring tetralogy of fallot patients over the long term after initial intracardiac repair: considerations for pulmonary valve replacement

Clinicians are currently encountering an increasing number of patients in the long-term period after tetralogy of Fallot (TOF) repair presenting with pulmonary valve regurgitation (PR) or right ventricular (RV) dysfunction. The purpose of this study was to evaluate the clinical utility of the plasma brain natriuretic peptide (BNP) level and consider surgical indications and timing of pulmonary valve replacement (PVR). We examined 33 patients (21 males, 12 females, mean age 14.5 ± 2.8 years) who underwent TOF repair at Kitasato University Hospital. All patients were evaluated using echocardiography and blood sampling. The mean age at the time of initial repair was 1.3 ± 0.7 years. The patients with moderate-severe PR exhibited significantly higher plasma BNP levels than the patients with trivial-mild PR (mean 37.5 ± 33.1 vs. 17.3 ± 6.6 pg/ml, p = 0.013). The mean plasma BNP level with cardiac symptoms was higher than that observed in the patients without any symptoms (71.4 ± 46.1 vs. 25.0 ± 14.0 pg/ml, p = 0.005). The mean BNP level was significantly decreased after PVR (71.3 ± 46.1-26.1 ± 13.2 pg/ml, p = 0.009), and the plasma BNP level was found to be positively correlated with the RV end-diastolic pressure (r = 0.851; p = 0.008). The optimal BNP cut-off value for considering PVR was 32.15 pg/ml (sensitivity, 85.7 %; specificity, 83.3 %). The plasma BNP level may become a useful diagnostic tool for considering the indications and optimal timing of PVR over the long term after TOF repair.

Right ventricle-pulmonary circulation dysfunction: a review of energy-based approach

Patients with repaired or palliated right heart congenital heart disease (CHD) are often left with residual lesions that progress and can result in significant morbidity. However, right ventricular-pulmonary arterial evaluation and the timing of reintvervention is still subjective. Currently, it relies on symptomology, or RV imaging-based metrics from echocardiography or MR derived parameters including right ventricular (RV) ejection fraction (EF), end-systolic pressure (ESP), and end-diastolic volume (EDV). However, the RV is coupled to the pulmonary vasculature, and they are not typically evaluated together. For example, the dysfunctional right ventricular-pulmonary circulation (RV-PC) adversely affects the RV myocardial performance resulting in decreased efficiency. Therefore, comprehensive hemodynamic assessment should incorporate changes in RV-PC and energy efficiency for CHD patients. The ventricular pressure-volume relationship (PVR) and other energy-based endpoints derived from PVR, such as stroke work (SW) and ventricular elastance (Ees), can provide a measure of RV performance. However, a detailed explanation of the relationship between RV performance and pulmonary arterial hemodynamics is lacking. More importantly, PVR is impractical for routine longitudinal evaluation in a clinical setting, because it requires invasive catheterization. As an alternative, analytical methods and computational fluid dynamics (CFD) have been used to compute energy endpoints, such as power loss or energy dissipation, in abnormal physiologies. In this review, we review the causes of RV-PA failure and the limitation of current clinical parameters to quantify RV-PC dysfunction. Then, we describe the advantage of currently available energy-based endpoints and emerging energy endpoints, such as energy loss in the Pas or kinetic energy, obtained from a new non-invasive imaging technique, i.e. 4D phase contrast MRI.

"Baby Heart Project": the Italian project for accreditation and quality management in pediatric cardiology and cardiac surgery

Optimization of the relationship between the supply and the demand for medical services should ideally be taken into consideration for the planning within each national Health System. Although government national health organizations embrace this policy specifically, the contribution of expert committees (under the scientific societies' guarantee in any specific medical field) should be advocated for their capability to collect and analyze the data reported by the various national institutions. In addition, these committees have the competence to analyze the need for the resources necessary to the operation of these centers. The field of pediatric cardiology and cardiac surgery may represent a model of clinical governance of particular interest with regard to programming and to a definition of the quality standards that may be extended to highly specialized institutions and ideally to the entire Health System. The "Baby Heart Project," which represents a model of governance and clinical quality in the field of pediatric cardiology and cardiac surgery, was born from the spontaneous aggregation of a committee of experts, supported by duly appointed Italian Scientific Societies and guided by a national agency for accreditation. The ultimate aim is to standardize both procedures and results for future planning within the national Health System.

Non-invasive evaluation of energy loss in the pulmonary arteries using 4D phase contrast MR measurement: a proof of concept

Background

The repair surgery of congenital heart disease (CHD) associated with the right ventricular (RV)-pulmonary artery (PA) pathophysiology often left patients with critical post-operative lesions, leading to regurgitation and obstruction in the PAs. These lesions need longitudinal (with time) assessment for monitoring the RV function, in order for patients to have appropriate treatment before irreversible RV dysfunction occurs. In this research, we computed energy loss in the branch PAs using blood flow and pressure drop data obtained from 4D phase contrast (PC) MRI, to non-invasively quantify the RV-PA pathophysiology.

Methods

4D PC MRI was acquired for a CHD patient with abnormal RV-PA physiology, including pulmonary regurgitation and PA stenosis, and a subject with normal RV-PA physiology. The blood velocity, flow rate, and pressure drop data, obtained from 4D PC MRI, were used to compute and compare the energy loss values between the patient and normal subjects.

Results

The pressure drop in the branch PAs for the patient was −1.3 mmHg/s and −0.2 mmHg/s for the RPA and LPA, respectively, and was larger (one order of magnitude) than that for the control. Similarly, the total energy loss in the branch PAs for the patient, -96.9 mJ/s and −16.4 mJ/s, for the RPA and LPA, respectively, was larger than that for the control.

Conclusions

The amount of energy loss in the pulmonary blood flow for the patient was considerably larger than the normal subject due to PA regurgitation and PA stenosis. Thus, we believe that the status of RV-PA pathophysiology for CHD patients can be evaluated non-invasively using energy loss endpoint.

Timing of complete repair of non-ductal-dependent tetralogy of Fallot and short-term postoperative outcomes, a multicenter analysis

OBJECTIVE

There is cross-center variability with regard to timing repair of non-ductal-dependent tetralogy of Fallot (TOF). We hypothesized that earlier repair in the neonatal period is associated with increased mortality and morbidity.

METHODS

This was a retrospective analysis of the Pediatric Health Information System of tetralogy of Fallot patients undergoing complete repair from 2004 through 2010 between the ages of 1 day to younger than 19 years. Patients with pulmonary valve atresia, those who received prostaglandin during hospital admission, and those who underwent prior shunt palliation were excluded.

RESULTS

A total of 4698 patients met our inclusion criteria, of whom 202 were younger than 30 days old (group A), 861 were 31 to 90 days old (group B), 1796 were 91 to 180 days old (group C), and 1839 were older than 180 days (group D). In-hospital mortality, intensive care unit length of stay, and total hospital length of stay were significantly higher in group A. Patients in group A had a significantly increased postoperative requirement for mechanical ventilation, intravenous blood pressure support, medical diuresis, extracorporeal membrane oxygenation, gastrostomy tube insertion, heart catheterization, and surgical revision. Significant institutional variability was noted for timing of TOF complete repair, with one third of the centers performing 75% of the repairs at younger than 30 days old. The institutional approach to timing TOF complete repair showed no relation to surgical volume.

CONCLUSIONS

Across all centers analyzed, primary neonatal elective TOF repair (<30 days of age) is associated with significantly higher postoperative in-hospital morbidity and mortality, although a few centers have shown an ability to use this strategy with excellent survivability.

Results of elective repair at 6 months or younger in 277 patients with tetralogy of Fallot: a 14-year experience at a single center

OBJECTIVE

To report practice and outcomes in infants undergoing elective repair of tetralogy of Fallot.

METHODS

A review of a retrospective cohort of elective complete repair of infants age 6 months or younger from 1995 to 2009 was performed. Patients were excluded because of previous interventions, hypercyanotic episodes, intensive care admissions, additional major cardiac defects, or if they were not discharged after birth. Length of stay, mortality, and complications were recorded. Association was determined using logistic or linear regression models and univariate testing determined the multivariate model.

RESULTS

There were 277 patients included. The hospital mortality rate was zero. A total of 87.4% of patients were discharged home within 7 days of repair, and 21.6% of patients were discharged on or before the third postoperative day. The postoperative course was uncomplicated in 245 patients (88.4%). Longer support time was associated independently with increased odds of complications (P < .001). Longer support time, younger age, chromosomal abnormality, and presence of a complication were associated independently with a longer hospital stay (all P < .001). Patients younger than 3 months (n = 110) had a longer median hospital stay (4 vs 3 days; P < .001) and longer support times (77.3 ± 35.1 min vs 66.4 ± 34 min; P < .01).

CONCLUSIONS

Elective tetralogy of Fallot repair was performed at 6 months or younger with low morbidity, no hospital mortality, and an 11.6% complication rate. Longer support times, lower weight, chromosomal abnormalities, and complications were associated with a significantly increased duration of hospital stay.

Is there any need for a shunt in the treatment of tetralogy of Fallot with one source of pulmonary blood flow?

OBJECTIVES

In symptomatic patients, performing a primary repair of tetralogy of Fallot (TOF), irrespective of age or placing a shunt, remains controversial. The aim of the study was to analyse the policy of primary correction.

METHODS

Between May 2005 and May 2012, a total of 87 consecutive patients with TOF, younger than 6 months of age, underwent primary correction. All patients had one source of pulmonary blood flow, with or without a patent ductus arteriosus. The median age at surgery was 106 ± 52.3 days (8-180 days). Twelve patients (13.8%) were newborns. Two groups were analysed: group I, patients <1 month of age; group II, patients between 2-6 months of age.

RESULTS

There was no early or late death at 7 years of follow-up. There was no difference in bypass time or hospital stay between the two groups, but the Aristotle comprehensive score (P < 0.0001), ICU stay (P = 0.030) and the length of ventilation (P = 0.014) were significantly different. Freedom from reoperation was 87.3 ± 4.3% and freedom from reintervention was 85.9 ± 4.2% at 7 years, with no difference between the two groups. Neurological development was normal in all patients, but 1 patient in Group II had cerebral seizures and showed developmental delay. Growth was adequate in all patients, except those with additional severe non-cardiac malformations that caused developmental delay. Eighty-five per cent of the patients were without cardiac medication.

CONCLUSIONS

Even in symptomatic neonates and infants <6 months of age, primary repair of TOF can be performed safely and effectively. One hundred per cent survival at 7 years suggests that early primary repair causes no increase in mortality in the modern era. Shunting is not necessary, even in symptomatic newborns, thus avoiding the risk of shunt-related complications and repeated hospital stays associated with a staged approach.

Acute gastric volvulus: an unreported long-term complication of pericardial drainage

We report the case of a girl who had tetralogy of fallot (TOF) repaired at birth without any associated diaphragmatic hernia. At the age of 2½ years, she experienced an upper gastrointestinal occlusion. At laparoscopy an organoaxial gastric volvulus was observed related to a peritoneal adhesion secondary to pericardial drainage that had been performed at the time of the TOF repair. After reduction of the volvulus, a phrenofundopexy was done. Postoperatively, the child has remained asymptomatic with a follow-up of 24 months. There are few cases of pericardial drainage complications documented in the literature but none in the pediatric population. Based on this observation, we advise that during pericardial drainage tube placement, the peritoneal cavity be carefully avoided to prevent formation of intra-peritoneal adhesions and the risk of gastric volvulus.

Late surgical treatment of tetralogy of Fallot

Aim

To study early post-operative results and follow up of patients over a year old, operated on for tetralogy of Fallot (ToF).

Methods

This retrospective analysis included 22 patients (14 male and eight female) with a mean age of 9.18 ± 6.5 years (range 13.5 months to 26 years), who underwent complete repair of ToF between April 2003 and June 2009. Data from patients’ records, pre-operative cardiac catheterisation studies, operative intervention, and pre-operative and postoperative two-dimensional echocardiographic studies were reviewed. All patients underwent complete repair including closure of ventricular septal defect (VSD). A trans-annular patch was used in 12 patients while an infundibular patch was used in 10 others. Patients were evaluated one, three, six and 12 months after surgery, and annually thereafter. The duration of follow up was from eight months to six years post surgery.

Results

Classical ToF was found in 10 patients. Twelve cases had associated anomalies: two patients with hypoplastic pulmonary artery branches, two with arterial duct malformations, and eight had proximal stenosis of the left branch of the pulmonary artery. NHYA class distribution was as follows: class I: two patients; class II: five subjects; class III: 10 patients; class IV: five subjects. The mean stay in hospital was 15 ± 7 days. Two patients (9%) died during the early post-surgical period. At a mean follow-up interval of 32 ± 9 months, all patients were asymptomatic and in NYHA class I. No late deaths occurred. In three patients, we registered isolated monomorphic ventricular extrasystoles. The right ventricle outflow tract (RVOT) pressure gradient was 29 ± 1.5 mmHg in the acute post-surgical period and it did not change significantly during follow up. The right ventricular function was defined as normal in 95% of the patients in the study and was mildly depressed in 5%.

Conclusion

Even if treated later in life, our study showed very good surgical results of patients with ToF.

Repaired tetralogy of Fallot: the roles of cardiovascular magnetic resonance in evaluating pathophysiology and for pulmonary valve replacement decision support

Surgical management of tetralogy of Fallot (TOF) results in anatomic and functional abnormalities in the majority of patients. Although right ventricular volume load due to severe pulmonary regurgitation can be tolerated for many years, there is now evidence that the compensatory mechanisms of the right ventricular myocardium ultimately fail and that if the volume load is not eliminated or reduced by pulmonary valve replacement the dysfunction might be irreversible. Cardiovascular magnetic resonance (CMR) has evolved during the last 2 decades as the reference standard imaging modality to assess the anatomic and functional sequelae in patients with repaired TOF. This article reviews the pathophysiology of chronic right ventricular volume load after TOF repair and the risks and benefits of pulmonary valve replacement. The CMR techniques used to comprehensively evaluate the patient with repaired TOF are reviewed and the role of CMR in supporting clinical decisions regarding pulmonary valve replacement is discussed.

Tetralogy of Fallot repair: the Right Ventricle Infundibulum Sparing (RVIS) strategy

Despite the excellent operative survival for tetralogy of Fallot (TOF) repair, well-documented long-term complications and reduced life expectancy remain challenges for these patients and their clinicians. In an attempt to change the natural history of repaired TOF, we at Texas Children's Hospital (Houston, TX) have developed a management strategy not focused on age, but rather focused on preserving the right ventricular (RV) infundibulum. The RV infundibulum sparing (RVIS) repair of TOF consists of a transatrial and transpulmonary approach to close the ventricular septal defect and resect RV infundibular muscle coupled with a mini (< 5 mm) transannular patch or no ventricular incision. This strategy is applied with the ambition of decreasing the well-documented, long-term complications of TOF repair with large right ventriculotomies such as RV dilation, arrhythmias, need for pulmonary valve replacement, and RV failure. The RVIS strategy is an attempt based on our current knowledge and experience to optimize the time of repair so that we can not only maximize the early operative results but the long-term effects of this approach as these children mature into adolescents and adults. We have uniformly applied the RVIS strategy since 1995, which includes over 320 isolated TOF patients. We are currently reviewing this cohort in hopes that it will strengthen our beliefs and known results as well as give us more insight into whether the RVIS strategy can change the natural history of repaired TOF.

Primary early correction of tetralogy of Fallot irrespective of age

OBJECTIVE

The policy of early repair of patients with tetralogy of Fallot, irrespective of age, as opposed to initial palliation with a shunt, remains controversial. The aim of our study was to analyze the midterm outcome of primary early correction of tetralogy of Fallot.

METHODS

Between 1996 and 2005, a total of 61 consecutive patients less than 6 months of age underwent primary correction of tetralogy of Fallot in two institutions. The median age at surgery was 3.3 months, and 27 patients (44%) were younger than 3 months of age, including 12 (20%) newborns. We analyzed the patients in 2 groups: those younger than 3 months of age, and those aged between 3 and 6 months.

RESULTS

There was one early (1.6%), and one late death. Actuarial survival was 98.4%, 96.7%, 96.7% at 1, 5, and 10 years respectively, with a median follow up of 4.5 years. There was no difference in survival, bypass time, lengths of ventilation, and hospital stay between the groups. A transjunctional patch was placed significantly more often in the patients younger than 3 months (p = 0.039), with no adverse effect on survival and morbidity during the follow-up. Freedom from reoperation was 98.2%, 92.2%, and 83% at 1, 5, and 10 years respectively, with no difference between the groups.

CONCLUSION

Elective primary repair of tetralogy of Fallot in asymptomatic patients is delayed beyond 3 months of age. In symptomatic patients, primary repair of tetralogy of Fallot is performed irrespective of age, weight and preoperative state. This approach is safe, and provides an excellent midterm outcome with acceptable morbidity and rates of reintervention. The long-term benefits of this approach must be established by careful follow-up, with particular emphasis on arrhythmias, right ventricular function, and exercise performance.