High-Performing Fontan Patients: A Fontan Outcome Registry by Cardiac Magnetic Resonance Imaging Study.

Background: Fontan patients exhibit decreased exercise capacity. However, there is a subset of high-performing Fontan (HPF) patients with excellent exercise capacity. Objectives: This study aims to: 1) create a Fontan-specific percent predicted peak VO2 tool using exercise data; 2) examine clinical factors associated with HPF patients; and 3) examine late outcomes in HPF patients. Methods: Patients in the multi-institutional Fontan Outcomes Registry Using CMR Examination above the age of 8 years who had a maximal exercise test were included. An HPF patient was defined as a patient in the upper Fontan-specific percent predicted peak VO2 quartile. Multivariable logistic regression was employed to investigate factors associated with the HPF and Cox regression was used to examine the association between HPF patients and late outcomes (composite of death or listing for cardiac transplant). Results: The study included 813 patients (mean age: 20.2 ± 8.7 years). An HPF patient was associated with left ventricular morphology (OR: 1.50, P = 0.04), mixed morphology (OR: 2.23, P < 0.001), and a higher ejection fraction (OR: 1.31 for 10% increase, P = 0.01). Patients with at least moderate atrioventricular valve regurgitation, protein-losing enteropathy, or who were using psychiatric medications, were less likely to be an HPF patient. After a mean follow-up of 3.7 years, 46 (5.7%) patients developed a composite endpoint. HPF had a lower risk of death or listing for cardiac transplant (HR: 0.06 [95% CI: 0.01-0.25]). Conclusions: Patients with HPF have more favorable outcomes when compared to patients with lower exercise capacity. This large registry data highlights the role of exercise testing in providing personalized care and surveillance post-Fontan.

Optimal shunt type for Norwood procedure: Predicted adverse impact of discordant surgical approach.

BACKGROUND: The Single Ventricle Reconstruction (SVR) trial compared survival after Norwood procedure with either modified Blalock Taussig shunt (MBTS) or right ventricle pulmonary artery shunt (RVPAS). METHODS: Data from all 549 participants in the SVR trial were used to develop the MBTS TFSA algorithms, which predicted the transplantation free survival advantage (TFSA) following MBTS versus RVPAS at 1 and 6 years after Norwood procedure. Linear regression analysis of the MBTS TFSA values was performed to identify factors related to more optimal outcomes with MBTS at each timepoint. The impact of discordant management (ie. predicted shunt type did not equal the one actually received) on outcomes and the extent of inconsistencies between predictions were evaluated. RESULTS: The MBTS TFSA algorithm favored MBTS over RVPAS for only 6.2% of participants at 1 year and for 27.0% at 6 years. In terms of both 1- and 6-year outcomes, MBTS was favored with younger age at Norwood procedure and pre-Norwood intubation, while RVPAS was favored with younger gestational age and metrics indicating larger RV size in the parasternal echocardiographic views. Other predictors were timepoint specific. MBTS TFSA based allocation could have led to an absolute risk reduction in heart transplantation and mortality of 8.0% at 1 year and 16.8% at 6 years, mostly by preventing discordant MBTS management. Notably, separate predictions from the 1 year and 6-year algorithms produced discordant predictions for 136 participants (24.8%). CONCLUSIONS: The incorporation of data derived patient specific factors for selection of shunt type for the Norwood procedure may produce more optimal transplantation free survival. These precision medicine algorithms require prospective validation.

Postoperative Outcomes of Fontan Operation in a Multicenter Italian Study. How Far Have We Gone? Early Outcomes After Fontan Operation.

Despite the clinical results of the Fontan operation have certainly improved, it still presents with an inherent surgical risk of death and early morbidities. This is a retrospective clinical study of children undergoing Fontan operation in 9 congenital cardiac centers in Italy between 1990 and 2023. Clinical and surgical data were collected via a dedicated RedCap database. Primary outcome was cohort's mortality, also considering different decades, while secondary outcomes were postoperative complications and reintervention. In the last 3 decades, there were 897 patients undergoing Fontan operation, M/F 512/384, median age: 4.5 years (IQR 3.3-6.4), median weight 16 kg (IQR 14-22). A first palliation was deemed necessary in 710 patients (80%), and most patients underwent a staged Fontan (93%); an extracardiac conduit was used in 790 patients (88%). Postoperative complications (mild to severe) occurred in 410 patients (46%), and early reinterventions were required in 66 patients (7.5%). Overall operative mortality was 1.7% (15 patients). Age at Fontan greater than 4 years was associated with an early need for transcatheter reintervention (adj p value = 0.037) and a higher incidence of postoperative complications (adj p value = 0.017). The Fontan operation has seen significant improvements in immediate outcomes, notably a remarkable reduction in overall mortality to just 1.35% in the last decade. While minor complications have remained steady, there has been a substantial decrease in major early complications, deaths, and the need for reinterventions. Notably, patients aged over 4 years seem to face a higher risk of postoperative morbidity, underscoring the critical role of age in preoperative assessment and management strategies for Fontan patients.

Impact of Atrioventricular Valve Intervention at Each Stage of Single Ventricle Palliation.

Background: Significant atrioventricular valve dysfunction can be associated with mortality or need for transplant in functionally univentricular heart patients undergoing staged palliation. The purposes of this study are to characterize the impact of concomitant atrioventricular valve intervention on outcomes at each stage of single ventricle palliation and to identify risk factors associated with poor outcomes in these patients. Methods: The Society of Thoracic Surgeons Congenital Heart Surgery Database was queried for functionally univentricular heart patients undergoing single ventricle palliation from 2013 through 2022. Separate analyses were performed on cohorts corresponding to each stage of palliation (1: initial palliation; 2: superior cavopulmonary anastomosis; 3: Fontan procedure). Bivariate analysis of demographics, diagnoses, comorbidities, preoperative risk factors, operative characteristics, and outcomes with and without concomitant atrioventricular valve intervention was performed. Multiple logistic regression was used to identify predictors associated with operative mortality or major morbidity. Results: Concomitant atrioventricular valve intervention was associated with an increased risk of operative mortality or major morbidity for each cohort (cohort 1: 62% vs 46%, P < .001; cohort 2: 37% vs 19%, P < .001; cohort 3: 22% vs 14%, P < .001). Black race in cohort 1 (odds ratio [OR] 3.151, 95% CI 1.181-9.649, P = .03) and preterm birth in cohort 2 (OR 1.776, 95% CI 1.049-3.005, P = .032) were notable predictors of worse morbidity or mortality. Conclusions: Concomitant atrioventricular valve intervention is a risk factor for operative mortality or major morbidity at each stage of single ventricle palliation. Several risk factors are associated with these outcomes and may be useful in guiding decision-making.

Deferred Norwood in the setting of airway compression in double-inlet left ventricle with dextro-transposition of the great arteries.

A 4.1 kg male neonate with a diagnosis of double-inlet left ventricle with dextro-transposition of the great arteries was intubated shortly after birth due to respiratory insufficiency. The initial management consisted of a successful Stage I hybrid procedure. Persistent respiratory insufficiency led to cross-sectional imaging and bronchoscopy that demonstrated severe airway compression from a dilated main pulmonary artery. A Norwood procedure with Blalock-Thomas-Taussig shunt was performed at 1 month of age to relieve the airway obstruction. The patient was discharged home on room air at 2 months of age. This case highlights a unique single-ventricle anatomic variant with airway compression, which was successfully managed with deferred Norwood palliation.

Outcomes of Patients Undergoing the Kawashima Procedure at an Early Age: A Single Center Experience.

BACKGROUND: Previous reports have demonstrated the safety and efficacy of performing early Kawashima procedure (KP). Despite this, more recent studies have shown that the average age at the time of operation remains greater than one year of age. We report our experience with performing KP at an earlier age than previously reported. METHODS: A retrospective review was completed of patients undergoing KP at a single center (January 2000 to June 2020). Clinical outcomes were examined. RESULTS: Initial palliation was performed in 11 out of 12 patients. Age and weight at time of KP were 8.25 months (6.4-9.7) and 7.7 kg (6.5-8.6). Intensive care unit stay was 3.16 days (1-12), overall length of stay was 9.5 days (3-22). There was one unplanned reoperation, and no mortality in the cohort. Discharge oxygen saturation was 88% (80%-98%). Seven patients developed pulmonary arteriovenous malformations (PAVMs) with six proceeding to hepatic vein incorporation (HVI). Interval time to development of PAVMs was 42.3 months (16-121). Four of the 12 patients were left with antegrade pulmonary blood flow (PBF) and three (75%) remain without PAVMs. Median follow-up was 10 years (1.5-22) with 11 of 12 (91.67%) survival for the cohort. CONCLUSIONS: The KP can be done at a younger age than previously reported with adequate early and late results. Most patients will go on to develop PAVMs and require HVI but leaving patients with some antegrade PBF is likely protective but will need further investigation to show definitive benefit.

Breast Milk and Necrotizing Enterocolitis in Congenital Heart Disease: A Case-Control Study.

Background: Necrotizing enterocolitis (NEC) is a complication that can affect infants with congenital heart disease (CHD). The objective of this study is to determine whether breast milk, which is associated with decreased incidence of NEC in preterm infants, is protective in infants with CHD. Methods: Retrospective case-control study of infants ≥ 33 weeks gestational age with CHD who underwent cardiac surgery during their admission to the Infant Cardiac Unit from 2008 to 2017. Cases were defined as infants with modified Bell's stage ≥ II NEC. Controls were matched by date of birth, gestational age, and pre- or postcardiac surgery feed initiation. Results: A total of 926 infants with gestational age ≥ 33 weeks and CHD were admitted; 18 cases of NEC were identified and compared with 84 controls. Breast milk intake was higher in controls, but this difference was not statistically significant. Single ventricle (SV) physiology was identified as an independent risk factor for NEC by multivariable analysis. Analysis of infants with SV physiology demonstrated that median age at time of surgery was 9 days (interquartile range [IQR], 7-12) in NEC cases and 5 days (IQR, 4-9) in controls (P = .02). Conclusions: While this study is inconclusive with regard to feeding composition and risk of NEC in infants with CHD, the trend toward greater intake of breast milk in the control group suggests that breast milk may be protective for these infants. Infants with SV physiology are at high risk for NEC. Earlier time to stage I palliation may be a modifiable risk factor for NEC.

Retrospective Cohort Study of Additional Procedures and Transplant-Free Survival for Patients With Functionally Single Ventricle Disease Undergoing Staged Palliation in England and Wales.

BACKGROUND: Reinterventions may influence the outcomes of children with functionally single-ventricle (f-SV) congenital heart disease. METHODS AND RESULTS: We undertook a retrospective cohort study of children starting treatment for f-SV between 2000 and 2018 in England, using the national procedure registry. Patients were categorized based on whether they survived free of transplant beyond 1 year of age. Among patients who had transplant-free survival beyond 1 year of age, we explored the relationship between reinterventions in infancy and the outcomes of survival and Fontan completion, adjusting for complexity. Of 3307 patients with f-SV, 909 (27.5%), had no follow-up beyond 1 year of age, among whom 323 (35.3%) had ≥1 reinterventions in infancy. A total of 2398 (72.5%) patients with f-SV had transplant-free survival beyond 1 year of age, among whom 756 (31.5%) had ≥1 reinterventions in infancy. The 5-year transplant-free survival and cumulative incidence of Fontan, among those who survived infancy, were 93.4% (95% CI, 92.4%-94.4%) and 79.3% (95% CI, 77.4%-81.2%), respectively. Both survival and Fontan completion were similar for those with a single reintervention and those who had no reinterventions. Patients who had >1 additional surgery (adjusted hazard ratio, 3.93 [95% CI, 1.87-8.27] P<0.001) had higher adjusted risk of mortality. Patients who had >1 additional interventional catheter (adjusted subdistribution hazard ratio, 0.71 [95% CI, 0.52-0.96] P=0.03) had a lower likelihood of achieving Fontan. CONCLUSIONS: Among children with f-SV, the occurrence of >1 reintervention in the first year of life, especially surgical reinterventions, was associated with poorer prognosis later in childhood.

Human Genetics of Tricuspid Atresia and Univentricular Heart.

Tricuspid atresia (TA) is a rare congenital heart condition that presents with a complete absence of the right atrioventricular valve. Because of the rarity of familial and/or isolated cases of TA, little is known about the potential genetic abnormalities contributing to this condition. Potential responsible chromosomal abnormalities were identified in exploratory studies and include deletions in 22q11, 4q31, 8p23, and 3p as well as trisomies 13 and 18. In parallel, potential culprit genes include the ZFPM2, HEY2, NFATC1, NKX2-5, MYH6, and KLF13 genes. The aim of this chapter is to expose the genetic components that are potentially involved in the pathogenesis of TA in humans. The large variability in phenotypes and genotypes among cases of TA suggests a genetic network that involves many components yet to be unraveled.

Molecular Pathways and Animal Models of Tricuspid Atresia and Univentricular Heart.

The process of valve formation is a complex process that involves intricate interplay between various pathways at precise times. Although we have not completely elucidated the molecular pathways that lead to normal valve formation, we have identified a few major players in this process. We are now able to implicate TGF-ß, BMP, and NOTCH as suspects in tricuspid atresia (TA), as well as their downstream targets: NKX2-5, TBX5, NFATC1, GATA4, and SOX9. We know that the TGF-ß and the BMP pathways converge on the SMAD4 molecule, and we believe that this molecule plays a very important role to tie both pathways to TA. Similarly, we look at the NOTCH pathway and identify the HEY2 as a potential link between this pathway and TA. Another transcription factor that has been implicated in TA is NFATC1. While several mouse models exist that include part of the TA abnormality as their phenotype, no true mouse model can be said to represent TA. Bridging this gap will surely shed light on this complex molecular pathway and allow for better understanding of the disease process.

The utility of novel STE parameters in echocardiographic assessment of single ventricle after Fontan palliation.

Background and aims of the study A functionally single ventricle (FSV) refers to a group of congenital heart defects that are not amenable for biventricular correction. The Fontan operation is utilized as surgical treatment for most of FSV patients. The evaluation of FSV function is extremely difficult due to its unique pathophysiology. This study aimed to explore the efficacy of speckle tracking echocardiography (STE) parameters measured at rest and during exercise for comprehensive assessment of univentricular heart. METHODS: We enrolled 37 patients with a functionally single ventricle after the Fontan operation, hospitalized in the Department of Congenital Heart Defects between years 2019 and 2021.The echocardiographic stress tests were performed in the Echocardiography Laboratory of the Congenital Heart Defects Department. The study was conducted on a bicycle ergometer in a semi-recumbent position. The parameters obtained by speckle tracking echocardiography (STE): the longitudinal strain of the FSV free wall (Ɛ) and the longitudinal strain of myocardial layers: subendocardial, medial and subepicardial were analyzed. A transmural longitudinal strain gradient (TG) was calculated as the difference between longitudinal deformation of the subendocardial and subepicardial layers. Current results of cardiac magnetic resonance imaging (CMR) and cardio-pulmonary test (CPET) were also incorporated. Demographic data, past interventions, pharmacological treatment and comorbidities were extracted from medical records. RESULTS: Ɛ at rest and during exercise were not related to the parameters of physical capacity obtained on CPET nor to the CMR results. The transmural strain gradient was dependent on physical performance parameter- peak oxygen uptake- and related to the FSV ejection fraction calculated by magnetic resonance imaging. CONCLUSIONS: The transmural strain gradient and FSV free wall strain are readily measurable and suitable for evaluating single ventricle function. The TG is positively correlated with peak oxygen uptake during the cardiopulmonary test and with the ejection fraction derived from cardiac magnetic resonance imaging. The applicability of these findings in patients undergoing the Fontan procedure warrants further exploration.

Cardiovascular Outcomes in Fontan Patients With Right vs Left Univentricular Morphology: A Multicenter Study.

Background: There is a paucity of data on long-term outcomes after Fontan palliation in patients with a dominant morphological univentricular right (uRV) vs left (uLV) ventricle. Objectives: The purpose of this study was to compare the incidence of atrial arrhythmias, thromboembolic events, cardiac transplantation, and death following Fontan palliation in patients with uRV vs uLV. Methods: The Alliance for Adult Research in Congenital Cardiology conducted a multicenter retrospective cohort study on patients with total cavopulmonary connection Fontan palliation across 12 centers in North America. All components of the composite outcome, that is, atrial arrhythmias, thromboembolic events, cardiac transplantation, and death, were reviewed and classified by a blinded adjudicating committee. Time-to-event analyses were performed that accounted for competing risks. Results: A total of 384 patients were followed for 10.5 ± 5.9 years. The composite outcome occurred in 3.7 vs 1.7 cases per 100 person-years for uRV (N = 171) vs uLV (N = 213), respectively (P < 0.001). In multivariable analyses, uRV conferred a >2-fold higher risk of the composite outcome (HR: 2.17, 95% CI: 1.45-3.45, P < 0.001). In secondary analyses of components of the primary outcome, uRV was significantly associated with a greater risk of cardiac transplantation or death (HR: 9.09, 95% CI: 2.17-38.46, P < 0.001) and atrial arrhythmias (HR: 2.17, 95% CI: 1.20-4.00, P = 0.010) but not thromboembolic events (HR: 1.64, 95% CI: 0.86-3.16, P = 0.131). Conclusions: Fontan patients with uRV vs uLV morphology have a higher incidence of adverse cardiovascular events, including atrial arrhythmia, cardiac transplantation, and all-cause mortality.

A Case of Double Inlet Left Ventricle in a 63-Year-Old Female Patient.

This case report describes the medical history and presentation of an elderly patient who was born with single ventricle physiology, an anomaly that is both unique and complex. Patients with single ventricle cardiac anomalies may be susceptible to life-threatening complications. However, advances in medical treatment and understanding have allowed for clinicians to develop surgical and medical interventions to treat patients with univentricular cardiac defects. This case is unique in the sense that the patient has been able to demonstrate remarkable adaptability to this condition and have a sustained life with little intervention. This report serves to explore the pathophysiology of this condition as well as highlight the human body's astounding resilience to configure itself to abnormal conditions. The patient's presentation will be discussed as well as diagnostics and management utilized by the care providers. Despite its rare occurrence, understanding the manifestations of this complex cardiac abnormality can allow future providers to improve the prognosis and outcomes of patients born with a single ventricle.

Role and Applications of Experimental Animal Models of Fontan Circulation.

Over the last four decades, the Fontan operation has been the treatment of choice for children born with complex congenital heart diseases and a single-ventricle physiology. However, therapeutic options remain limited and despite ongoing improvements in initial surgical repair, patients still experience a multiplicity of cardiovascular complications. The causes for cardiovascular failure are multifactorial and include systemic ventricular dysfunction, pulmonary vascular resistance, atrioventricular valve regurgitation, arrhythmia, development of collaterals, protein-losing enteropathy, hepatic dysfunction, and plastic bronchitis, among others. The mechanisms leading to these late complications remain to be fully elucidated. Experimental animal models have been developed as preclinical steps that enable a better understanding of the underlying pathophysiology. They furthermore play a key role in the evaluation of the efficacy and safety of new medical devices prior to their use in human clinical studies. However, these experimental models have several limitations. In this review, we aim to provide an overview of the evolution and progress of the various types of experimental animal models used in the Fontan procedure published to date in the literature. A special focus is placed on experimental studies performed on animal models of the Fontan procedure with or without mechanical circulatory support as well as a description of their impact in the evolution of the Fontan design. We also highlight the contribution of animal models to our understanding of the pathophysiology and assess forthcoming developments that may improve the contribution of animal models for the testing of new therapeutic solutions.

Surgical Management of Norwood Procedure for Atypical Aortic Arch.

Background: Postoperative restenosis of the aortic arch after the Norwood procedure is still an important complication that significantly affects surgical outcomes. The rarity of the Norwood procedure for atypical aortic morphology means appropriate arch reconstruction methods and postoperative complications are still unknown. This study aimed to assess the rate of arch reintervention and clinical outcomes after the Norwood procedure for atypical aortic arch. Methods: This retrospective single-center study was conducted between 2001 and 2022. Sixteen patients were identified, eight with a right aortic arch, five with transposition of the great arteries, one with a right aortic arch and transposition of the great arteries, and two with a large tortuous patent ductus arteriosus connected to the opposite side of the descending aorta. We selected and performed four different surgical techniques depending on each aortic arch morphology. Results: Except for one case, autologous tissue-only arch reconstruction was possible. There was one operative death and four late deaths. Overall, no patients required any surgical or catheter-based reintervention for the aortic arch. On the other hand, left pulmonary artery stenosis due to a narrow subaortic space was found in two patients. Conclusions: The Norwood procedure for atypical aortic arch was performed with good results by choosing the appropriate technique for each morphology. On the other hand, pulmonary artery stenosis is likely to occur especially in the transposition of the great arteries group. Therefore, careful surgical method selection or further improvement of the technique that allows retroaortic space should be considered.

[Angioplasty with ductal stent: experience at Garrahan Hospital]. / Angioplastia con stent ductal: experiencia en el Hospital Garrahan.

Objective: To describe and evaluate the outcomes of ductal angioplasty with stent placement at a single high-complexity center during the period 2016-2022. Method: A retrospective descriptive cross-sectional study was conducted, including patients under 3 months of age who underwent ductal stent implantation as initial palliative treatment. Demographic, clinical, and anatomical data were collected before the intervention. Mortality, intra- and post-procedural complications, need for re-intervention, intensive care requirements, and hospital stay were recorded. The characteristics at the time of definitive surgery are described. Discrete variables are presented as percentages, and continuous variables are presented with their medians and respective interquartile ranges. Results: Twenty patients who underwent this treatment were reviewed, revealing a success rate of 80%. Complications due to stent dysfunction required surgical resolution. 95% of patients were dischargedfrom the institution after the procedure, and 17 patients reached a second definitive surgical stage. Three patients died afterthe procedure, but with no direct relation to it. Conclusions: Indications for ductal angioplasty with stent as an alternative treatment to systemic-pulmonary anastomosis by surgery are not yet fully defined; the strategy represents a valid alternative in appropriately selected patients. The presented experience shows results similar to international reference centers.

Objetivo: Describir y evaluar los resultados de la angioplastia con stent ductal en un único centro de alta complejidad durante el periodo 2016-2022. Método: Estudio descriptivo retrospectivo de corte transversal en el que se incluyeron pacientes menores de 3 meses a quienes se implantó un stent en el conducto arterioso como tratamiento paliativo inicial. Se recolectaron datos demográficos, clínicos y anatómicos previos a la intervención. Se registraron la mortalidad, las complicaciones intra- y posprocedimiento, la necesidad de reintervención, los requerimientos de cuidados intensivos y la estadía hospitalaria. Se describen las características al momento de la cirugía definitiva. Las variables discretas son presentadas con porcentajes, y las variables continuas con sus medianas y sus respectivos intervalos intercuartílicos. Resultados: Se revisaron 20 pacientes que habían recibido este tratamiento y se evidenció una tasa de éxito del 80%. Las complicaciones por disfunción del stent requirieron resolución quirúrgica. Egresaron de la institución el 95% de los pacientes luego del procedimiento y lograron arribar a un segundo estadio quirúrgico definitivo 17 pacientes. Fallecieron tres pacientes luego del procedimiento, pero sin relación directa con este. Conclusiones: Las indicaciones de angioplastia del conducto con stent como tratamiento alternativo a la realización de una anastomosis sistémico-pulmonar por cirugía todavía no están completamente definidas; la estrategia constituye una alternativa válida en pacientes adecuadamente seleccionados. La experiencia presentada muestra resultados similares a los de otros centros de referencia internacional.

Gabapentin as a novel adjunct for postoperative irritability after superior cavopulmonary connection operation in children.

OBJECTIVES: Describing our institution's off-label use of gabapentin to treat irritability after superior cavopulmonary connection surgery and its impact on subsequent opiate and benzodiazepine requirements. METHODS: This is a single-center retrospective cohort study including infants who underwent superior cavopulmonary connection operation between 2011 and 2019. RESULTS: Gabapentin was administered in 74 subjects (74/323, 22.9%) during the observation period, with a median (IQR) starting dose of 5.7 (3.3, 15.0) mg/kg/day and a maximum dose of 10.7 (5.5, 23.4) mg/kg/day. Infants who underwent surgery in 2015-19 were more likely to receive gabapentin compared with those who underwent surgery in 2011-14 (p < 0.0001). Infants prescribed gabapentin were younger at surgery (137 versus 146 days, p = 0.007) and had longer chest tube durations (1.8 versus 0.9 days, p < 0.001), as well as longer postoperative intensive care (5.8 versus 3.1 days, p < 0.0001) and hospital (11.5 versus 7.0 days, p < 0.0001) lengths of stays. The year of surgery was the only predisposing factor associated with gabapentin administration in multivariate analysis. In adjusted linear regression, infants prescribed gabapentin on postoperative day 0-4 (n = 64) had reduced benzodiazepine exposure in the following 3 days (-0.29 mg/kg, 95% CI -0.52 - -0.06, p = 0.01) compared with those not prescribed gabapentin, while no difference was seen in opioid exposure (p = 0.59). CONCLUSIONS: Gabapentin was used with increasing frequency during the study period. There was a modest reduction in benzodiazepine requirements associated with gabapentin administration and no reduction in opioid requirements. A randomised controlled trial could better assess gabapentin's benefits postoperatively in children with congenital heart disease.

Atrioventricular valve surgery in patients with univentricular heart and two separate atrioventricular valves.

OBJECTIVES: Atrioventricular valve regurgitation in patients with univentricular heart is a well-known risk factor for adverse outcomes and atrioventricular valve repair remains a particular surgical challenge. METHODS: We reviewed all surgical atrioventricular valve procedures in patients with univentricular heart and two separate atrioventricular valves who underwent surgical palliation. Endpoints of the study were reoperation-free survival and cumulative incidence of reoperation. RESULTS: Between 1994 and 2021, 202 patients with univentricular heart and two separate atrioventricular valve morphology underwent surgical palliation, with 15.8% (32/202) requiring atrioventricular valve surgery. Primary diagnoses were double inlet left ventricle (n = 14, 43.8%), double outlet right ventricle (n = 7, 21.9%), and congenitally corrected transposition of the great arteries (n = 7, 21.9%). Median weight at valve surgery was 10.6 kg (interquartile range, 7.9-18.9). Isolated left or right atrioventricular valve surgery was required in nine (28.1%) and 22 patients (68.8%), respectively. Concomitant left and right atrioventricular valve surgery was performed in one patient (3.1%). Closure of the left valve was conducted in four patients (12.5%) and closure of the right valve in three (9.4%). Operative and late mortality were 3.1% and 9.7%, respectively. Reoperation-free survival and cumulative incidence of reoperation at 10 years after surgery were 62.3% (standard error of the mean: 6.9) and 30.9% (standard error of the mean: 9.6), respectively. CONCLUSIONS: In patients with univentricular heart and two separate atrioventricular valves, surgical intervention on these valves is required in a minority of patients and is associated with low mortality but high incidence of reoperation.

In a porcine model of implantable pacemakers for pediatric unilateral diaphragm paralysis, the phrenic nerve is the best target.

BACKGROUND: A frequent complication of Fontan operations is unilateral diaphragmatic paresis, which leads to hemodynamic deterioration of the Fontan circulation. A potential new therapeutic option is the unilateral diaphragmatic pacemaker. In this study, we investigated the most effective stimulation location for a potential fully implantable system in a porcine model. METHODS: Five pigs (20.8 ± 0.95 kg) underwent implantation of a customized cuff electrode placed around the right phrenic nerve. A bipolar myocardial pacing electrode was sutured adjacent to the motor point and peripherally at the costophrenic angle (peripheral diaphragmatic muscle). The electrodes were stimulated 30 times per minute with a pulse duration of 200 µs and a stimulation time of 300 ms. Current intensity was the only variable changed during the experiment. RESULTS: Effective stimulation occurred at 0.26 ± 0.024 mA at the phrenic nerve and 7 ± 1.22 mA at the motor point, a significant difference in amperage (p = 0.005). Even with a maximum stimulation of 10 mA at the peripheral diaphragm muscle, however, no effective stimulation was observed. CONCLUSION: The phrenic nerve seems to be the best location for direct stimulation by a unilateral thoracic diaphragm pacemaker in terms of the required amperage level in a porcine model.

Borderline Ventricles: From Evaluation to Treatment.

A heart with a borderline ventricle refers to a situation where there is uncertainty about whether the left or right underdeveloped ventricle can effectively support the systemic or pulmonary circulation with appropriate filling pressures and sufficient physiological reserve. Pediatric cardiologists often deal with congenital heart diseases (CHDs) associated with various degrees of hypoplasia of the left or right ventricles. To date, no specific guidelines exist, and surgical management may be extremely variable in different centers and sometimes even in the same center at different times. Thus, the choice between the single-ventricle or biventricular approach is always controversial. The aim of this review is to better define when "small is too small and large is large enough" in order to help clinicians make the decision that could potentially affect the patient's entire life.