Long-Term Results of Modified Fontan Operation for Single-Ventricle Patients Associated With Atrioventricular Valve Regurgitation

Evaluating the Prevalence and Factors Associated With an Optimal Neurodevelopmental Outcome in 4- to 6-Year-Old Children With Fontan Circulation

BACKGROUND

We sought to evaluate the prevalence and factors associated with "optimal" neurodevelopmental outcomes in 4- to 6-year-old children with Fontan circulation.

METHODS

Patients followed through the Western Canadian Complex Pediatric Therapies Follow-Up Program, and born between September 1996 and December 2015, were included. Optimal neurodevelopmental outcome was defined as full-scale intelligence quotient; visual-motor integration; adaptive behaviour assessment system-general adaptive composite scores of ≥ 80 each; and the absence of chronic motor disability, permanent hearing loss, visual impairment, and seizure disorder. Multivariable regression models and decision algorithms evaluated variables associated with optimal outcomes.

RESULTS

The Fontan procedure was completed on 225 children, with neurodevelopmental outcome data available for 205 (mean [standard deviation]) age at Fontan 3.4 (0.9) years, 37% female). Optimal neurodevelopmental outcome was identified in 55% (112 of 205). Factors independently associated with optimal neurodevelopmental outcome were female sex (odds ratio [OR], 2.1; 95% confidence interval [CI] 1.1-4.1), years of maternal schooling (OR, 1.2 [1.1-1.4]), age at Fontan (years) (OR, 0.97 [0.94-1.0]), need for concomitant atrioventricular valve (AVV) intervention (OR, 0.4 [0.2-1.0]), and time (hours) for lactate to be ≤ 2 mmol/L (OR, 0.9 [0.8-1.0]). Of those with Fontan completion < 3.25 years, without concomitant AVV intervention and lactate normalization within 8 hours post-Fontan, 87% (27 of 31) had optimal neurodevelopmental outcomes.

CONCLUSIONS

Optimal neurodevelopmental outcome was present in more than one-half of 4- to 6-year-old children with Fontan circulation in this cohort study, with important associated factors identified, including potentially modifiable factors such as younger age at Fontan surgery and lack of concomitant AVV intervention.

27 years of experience with the Fontan procedure: characteristics and clinical outcomes of children in a tertiary referral hospital

BACKGROUND

The Fontan operation has improved the survival of children born with congenital heart disease with single ventricle physiology. The most widely adopted variations of the Fontan procedure are the extracardiac conduit, the lateral tunnel ve the intra/extracardiac conduit with fenestration. Despite advances in the treatment and prevention of early and late complications that may develop after Fontan surgery, morbidity still remains an important problem.

METHODS

304 patients who underwent Fontan surgery in our center between 1995 and 2022 were included in our study. The complications that developed in patients who underwent primary Fontan or lateral tunnel surgery and extracardiac conduit Fontan application were compared.

RESULTS

Classic Fontan surgery and lateral tunnel surgery were performed in 26 of the patients, and extracardiac Fontan surgery was performed in 278 patients. 218 of 304 cases were patients with single ventricular pathology. 86 cases were patients with two ventricular morphologies but complex cardiac pathology. Fenestration was performed in only 6 patients, other patients did not require fenestration. The mean follow-up period of our patients was 12 years (3 months-27 years). When the complications between Fontan procedures were compared in our study, it was found that the length of hospital stay and mortality were statistically significantly reduced in patients who underwent extracardiac Fontan surgery. There was no significant difference in terms of complications that can be seen after Fontan surgery and the length of stay in the intensive care unit.

CONCLUSION

Fontan complex is a palliative surgery for children with complex heart disease. Palliative surgical operations aimed at the preparation of the Fontan circulation lead to the preparation of the pulmonary vascular bed and the preservation of ventricular function. The techniques applied in Fontan surgery affect the early and long-term complications and the survival of the patients. In our study, when we examined the patients who extracardiac conduit Fontan procedure for the non-cardiac route, we found that mortality and morbidity were minimal.

Long-term outcomes of atrioventricular septal defect and single ventricle: A multicenter study

OBJECTIVE

The study objective was to analyze survival and incidence of Fontan completion of patients with single-ventricle and concomitant unbalanced atrioventricular septal defect.

METHODS

Data from 4 Dutch and 3 Belgian institutional databases were retrospectively collected. A total of 151 patients with single-ventricle atrioventricular septal defect were selected; 36 patients underwent an atrioventricular valve procedure (valve surgery group). End points were survival, incidence of Fontan completion, and freedom from atrioventricular valve reoperation.

RESULTS

Median follow-up was 13.4 years. Cumulative survival was 71.2%, 70%, and 68.5% at 10, 15, and 20 years, respectively. An atrioventricular valve procedure was not a risk factor for mortality. Patients with moderate-severe or severe atrioventricular valve regurgitation at echocardiographic follow-up had a significantly worse 15-year survival (58.3%) compared with patients with no or mild regurgitation (89.2%) and patients with moderate regurgitation (88.6%) (P = .033). Cumulative incidence of Fontan completion was 56.5%, 71%, and 77.6% at 5, 10, and 15 years, respectively. An atrioventricular valve procedure was not associated with the incidence of Fontan completion. In the valve surgery group, freedom from atrioventricular valve reoperation was 85.7% at 1 year and 52.6% at 5 years.

CONCLUSIONS

The long-term survival and incidence of Fontan completion in our study were better than previously described for patients with single-ventricle atrioventricular septal defect. A concomitant atrioventricular valve procedure did not increase the mortality rate or decrease the incidence of Fontan completion, whereas patients with moderate-severe or severe valve regurgitation at follow-up had a worse survival. Therefore, in patients with single-ventricle atrioventricular septal defect when atrioventricular valve regurgitation exceeds a moderate degree, the atrioventricular valve should be repaired.

Survival and predictors of mortality in patients after the Fontan operation

BACKGROUND

As a result of the surgical techniques now being employed, the survival rate in patients after undergoing the Fontan operation has improved. The aims of this study were focused on determining the survival rate and predictors of early mortality.

METHODS

In a retrospective cohort study, 117 consecutive patients who underwent the Fontan operation were recruited. Multivariate Cox proportional regression analysis was used to assess the predictors of early mortality, defined as death within 30 days after the Fontan operation.

RESULTS

The median follow-up time was 6.1 years. The median age at the time of the Fontan operation was 5.7 years. Survival rates in the patients at 5, 10, and 15 years postoperatively were 92%, 87% and 84%, respectively. Using univariate Cox regression analysis, the predictors of early mortality were found to be postoperative mean pulmonary artery pressure ≥23 mm Hg (hazard ratio 26.0), renal failure (hazard ratio 9.5), heterotaxy syndrome (hazard ratio 5.3), and uncorrected moderate or severe atrioventricular valve regurgitation (hazard ratio 9.4). After adjusting for confounding factors using multivariate Cox regression analysis, the predictors of early mortality were found to be postoperative mean pulmonary artery pressure ≥23 mm Hg (hazard ratio 23.2) and uncorrected moderate or severe atrioventricular valve regurgitation (hazard ratio 8.2).

CONCLUSIONS

Uncorrected moderate or severe atrioventricular valve regurgitation and postoperative mean pulmonary artery pressure ≥23 mm Hg are independent predictors of early mortality after the Fontan operation. Patients with these factors should undergo aggressive management to minimize morbidity and mortality.

Heart failure in single right ventricle congenital heart disease: physiological and molecular considerations

Because of remarkable surgical and medical advances over the past several decades, there are growing numbers of infants and children living with single ventricle congenital heart disease (SV), where there is only one functional cardiac pumping chamber. Nevertheless, cardiac dysfunction (and ultimately heart failure) is a common complication in the SV population, and pharmacological heart failure therapies have largely been ineffective in mitigating the need for heart transplantation. Given that there are several inherent risk factors for ventricular dysfunction in the setting of SV in addition to probable differences in molecular adaptations to heart failure between children and adults, it is perhaps not surprising that extrapolated adult heart failure medications have had limited benefit in children with SV heart failure. Further investigations into the molecular mechanisms involved in pediatric SV heart failure may assist with risk stratification as well as development of targeted, efficacious therapies specific to this patient population. In this review, we present a brief overview of SV anatomy and physiology, with a focus on patients with a single morphological right ventricle requiring staged surgical palliation. Additionally, we discuss outcomes in the current era, risk factors associated with the progression to heart failure, present state of knowledge regarding molecular alterations in end-stage SV heart failure, and current therapeutic interventions. Potential avenues for improving SV outcomes, including identification of biomarkers of heart failure progression, implications of personalized medicine and stem cell-derived therapies, and applications of novel models of SV disease, are proposed as future directions.

Identification of Risk Factors for Early Fontan Failure

Despite improvements in operative and perioperative care, the risk of significant morbidity and mortality for children undergoing Fontan procedures persists. Previous investigations have identified peri-Fontan characteristics that may predict early adverse events. The purpose of this study was to identify characteristics from throughout a patient's lifespan, including all perioperative stages, that might predict early Fontan failure-defined as death, Fontan takedown, or listing for cardiac transplantation before hospital discharge or within 30 postoperative days. A single-center retrospective study of all patients undergoing a Fontan procedure was performed. Patient and intervention-related characteristics were examined from birth through Fontan. Data were described using standard summary statistics. Univariable, logistic regression was used to examine associations with early Fontan failure. In total, 191 patients met inclusion criteria. The incidence of early Fontan failure was 4% (n = 8: 6 deaths, 2 Fontan takedowns). Neonatal balloon atrial septostomy was the only patient characteristic significantly associated with Fontan failure. Patients who underwent balloon septostomy had 8.5 times higher odds of Fontan failure (confidence interval (CI) 2.6-28.1, P < 0.001) than those who did not. Children who require balloon septostomy as neonates remain at higher risk of Fontan takedown, listing for heart transplantation, or death in the early post-Fontan period.

Clinical Outcomes in Adolescents and Adults After the Fontan Procedure

BACKGROUND

Long-term outcomes of Fontan patients who survive to age ≥16 years have not been well characterized. The Australian and New Zealand Fontan Registry (ANZFR) provides a unique opportunity to understand survival and complication rates in Fontan patients who transition to adult congenital heart disease centers.

OBJECTIVES

This study sought to describe the survival and complications of adult patients who have had a Fontan procedure.

METHODS

The study analyzed outcomes in patients ≥16 years of age who were prospectively enrolled in the ANZFR.

RESULTS

Data from all 683 adult survivors from the ANZFR were analyzed. Mortality status was confirmed from the National Death Index. There were 201 atriopulmonary (AP) connections and 482 total cavopulmonary connections (249 lateral tunnels and 233 extracardiac conduits). For these subjects, the survival rate at age 30 years was 90% (95% CI: 87% to 93%), and it was 80% (95% CI: 75% to 87%) at 40 years of age. Survival at age 30 years was significantly worse for the patients with AP connections (p = 0.03). At latest follow-up, only 53% of patients were in New York Heart Association functional class I. After the age of 16 years, 136 (20%) had experienced at least 1 new arrhythmia, 42 (6%) required a permanent pacemaker, 45 (7%) had a thromboembolic event, and 135 (21%) required a surgical reintervention. Only 41% (95% CI: 33% to 51%) of Fontan patients were free of serious adverse events at 40 years of age.

CONCLUSIONS

This comprehensively followed cohort showed that a variety of morbid complications is common in Fontan adults, and that there is a substantial incidence of premature death, particularly in patients with AP connections.

Midterm results and risk factors of functional single ventricles with extracardiac total anomalous pulmonary venous connection

OBJECTIVES

To evaluate the clinical outcomes of surgical repair of an extracardiac total anomalous pulmonary venous connection (TAPVC) in a functional single-ventricle (f-SV) strategy.

METHODS

This was a retrospective analysis of 48 consecutive cases of extracardiac TAPVC repair, from 1998 to 2015. Demographic and clinical variables were as follows: median age, 24 (range 0-744) days; median weight, 3.1 (range 2.0-9.6) kg; type of TAPVC-supracardiac, 21 patients, infracardiac, 8, and mixed, 19; right atrial isomerism, 45 patients; pulmonary atresia, 24 patients; and obstructed TAPVC, 30 patients. Concomitant procedures included systemic-to-pulmonary shunting in 15 patients, pulmonary artery banding in 12, ventricle-to-pulmonary artery shunting in 2, a Norwood procedure in one, a bidirectional Glenn procedure in 16, and a Fontan procedure in 1.

RESULTS

The 1- and 5-year cumulative survival rates were 66.0% and 58.0%, respectively. Of the 28 survivors, 22 (78.6%) underwent Fontan completion and 4 (14.3%) a bidirectional Glenn procedure, and 1 (3.6%) was awaiting a bidirectional Glenn procedure. Recurrent pulmonary venous stenosis (PVS) was observed in 17 patients, with a 1- and 5-year rates of freedom from recurrent PVS 59.8% and 53.5%, respectively. Of the 20 post-operative deaths, only 4 were PVS related. Only pre-operative pulmonary atresia was identified as an independent risk factor of mortality after TAPVC repair.

CONCLUSIONS

The midterm surgical outcomes of f-SV with extracardiac TAPVC were acceptable. Moreover, among survivors, Fontan completion can be sufficiently expected. Further improvement, with the development of a comprehensive treatment strategy, is required for this patient group.

Outcomes of Common Atrioventricular Valve Repair in Patients With Single-Ventricle Physiology - Indication, Timing and Repair Techniques

BACKGROUND

Common atrioventricular valve (CAVV) repair in patients with a single ventricle remains a great challenge and a refractory issue for pediatric cardiac surgeons. Methods and Results: From January 2007 to April 2018, 37 consecutive patients with a single ventricle who underwent CAVV repair were included in the study group. Patients were divided into 2 groups based on the repair technique: patients in Group A were treated using the bivalvation technique, and patients in Group B underwent conventional repair techniques; baseline data were similar between groups. The inhospital and follow-up mortality were 5.4% (2/37) and 11.4% (4/35), respectively. After a follow-up of 65.5±29.3 months, the estimated 1-, 5-, and 10-year overall survival rates were 94.6%, 83.4%, and 77.0%, respectively. The rates of freedom from CAVV failure were 94.3%, 72.7%, and 62.9% after 1, 5, and 10 years, respectively. In the multivariate analysis, the independent factors for CAVV repair failure were repair technique (P=0.004) and heterotaxy syndrome (P=0.003). A total of 30 patients (81.1%) completed total cavopulmonary connection (TCPC); 3 patients required re-intervention; 24 of 31 patients (77.4%) were in New York Heart Association classes II and I at the latest follow-up.

CONCLUSIONS

Outcomes of CAVV repair in patients palliated by single-ventricular surgery are acceptable. The bivalvation technique is a simple and effective technique.

Clinical standard for valve area after common atrioventricular valve plasty for a single ventricle

OBJECTIVES

To determine a clinical standard for post-repair common atrioventricular valve orifice area based on mid- to long-term valve function in patients with a functional single ventricle.

METHODS

The medical records of 19 single-ventricle patients who underwent common atrioventricular valve plasty from July 1988 to January 2013 were retrospectively reviewed. Bivalvation valvuloplasty was performed in 7 patients with relatively hypoplastic leaflets. The relationship between the orifice area of the repaired common atrioventricular valve measured intraoperatively and valve function and ventricular volume in the early postoperative period (median, 9.5 months) and at mid- to long-term follow-up (median, 4 years) were analysed.

RESULTS

Post-repair valve area was significantly positively correlated with valve regurgitation severity in the early postoperative period (P = 0.001, r = 0.69) and at mid- to long-term follow-up (P = 0.02, r = 0.57). Patients who did not undergo bivalvation had favourable valve function at mid- to long-term follow-up and in the early postoperative period when the post-repair valve area was 96-136% of the normal mitral valve area. Bivalvation patients had significantly more valve regurgitation in the early postoperative period than patients without bivalvation, despite equivalent repaired valve area (P = 0.02).

CONCLUSIONS

The post-repair orifice area of the common atrioventricular valve is significantly related to postoperative valve function. The clinical standard of post-repair valve orifice area might be 96-136% of the normal mitral valve area in patients undergoing repair without bivalvation. Patients undergoing bivalvation require greater reduction to obtain favourable mid- to long-term valve function.

Clinical-Physiological Considerations in Patients Undergoing Staged Palliation for a Functionally Single Ventricle

OBJECTIVES

The objectives of this review are to discuss the pathophysiology of the circulation with a functionally univentricular heart, with a focus on the unique physiologic characteristics, which provide the underpinnings for the management of these complex patients.

DATA SOURCE

MEDLINE and PubMed.

CONCLUSIONS

The circulation of the patient with a functionally univentricular heart displays unique physiologic characteristics, which are quite different from those of the normal biventricular circulation. There are profound differences within the heart itself in terms of ventricular function, interventricular interactions, and myocardial architecture, which are likely to have significant implications for the efficiency of ventricular ejection and metabolism. The coupling between the systemic ventricle and the aorta also displays unique features. The 3D orientation of the Fontan anastomosis itself can profoundly impact cardiac output, although the "portal" pulmonary arterial bed is a crucial determinant of overall cardiovascular function. As a result, disease-specific approaches to improve cardiovascular function are required at all stages during the care of these complex patients.

Uncontrolled Antegrade Pulmonary Blood Flow and Delayed Fontan Completion After the Bidirectional Glenn Procedure: Real-World Outcomes in China

BACKGROUND

Given the low rate of Fontan completion, an aggressive policy for maintaining antegrade pulmonary blood flow (AnPBF) during the bidirectional Glenn procedure (BDG) was developed for the functional single ventricle.

METHODS

From 2008 to 2013, 294 patients who underwent the BDG were divided into two groups: group 1 (uncontrolled AnPBF, n = 270) and group 2 (controlled AnPBF, n = 24). Pulmonary artery banding was performed because of the high central venous pressure in group 2. In group 1, the patients who underwent BDG from 2008 to 2012 were further divided into group DF (delayed Fontan completion, n = 109) and group FC (Fontan completion, n = 42).

RESULTS

The Fontan completion rate was 16.3%, and the average interval time was 2.2 ± 1.1 years. The delay of Fontan completion did not reduce body weight gain or the survival rate. Furthermore, oxygen saturation was slightly reduced in group DF. Although no impairments of heart function were observed, the uncontrolled AnPBF in group DF resulted in an increase in ventricular end-diastolic diameter and aggravation of atrioventricular valve regurgitation over 24 months after BDG. Logistic regression analysis revealed that systemic right ventricular morphology was a risk factor for the aggravation of valve regurgitation.

CONCLUSIONS

The low Fontan achievement rate is a critical issue in China. Although the patients with delayed Fontan completion exhibited an acceptable survival rate and acceptable body weight gain, uncontrolled AnPBF was associated with ventricular enlargement and aggravation of valve regurgitation. Strategies for improving the Fontan completion rate in China should be explored and could benefit outcomes.

Hemodynamic performance of the Fontan circulation compared with a normal biventricular circulation: a computational model study

The physiological limitations of the Fontan circulation have been extensively addressed in the literature. Many studies emphasized the importance of pulmonary vascular resistance in determining cardiac output (CO) but gave little attention to other cardiovascular properties that may play considerable roles as well. The present study was aimed to systemically investigate the effects of various cardiovascular properties on clinically relevant hemodynamic variables (e.g., CO and central venous pressure). To this aim, a computational modeling method was employed. The constructed models provided a useful tool for quantifying the hemodynamic effects of any cardiovascular property of interest by varying the corresponding model parameters in model-based simulations. Herein, the Fontan circulation was studied compared with a normal biventricular circulation so as to highlight the unique characteristics of the Fontan circulation. Based on a series of numerical experiments, it was found that 1) pulmonary vascular resistance, ventricular diastolic function, and systemic vascular compliance play a major role, while heart rate, ventricular contractility, and systemic vascular resistance play a secondary role in the regulation of CO in the Fontan circulation; 2) CO is nonlinearly related to any single cardiovascular property, with their relationship being simultaneously influenced by other cardiovascular properties; and 3) the stability of central venous pressure is significantly reduced in the Fontan circulation. The findings suggest that the hemodynamic performance of the Fontan circulation is codetermined by various cardiovascular properties and hence a full understanding of patient-specific cardiovascular conditions is necessary to optimize the treatment of Fontan patients.

The extracardiac conduit Fontan procedure in Australia and New Zealand: hypoplastic left heart syndrome predicts worse early and late outcomes

OBJECTIVES

To identify factors associated with hospital and long-term outcomes in a binational cohort of extracardiac conduit (ECC) Fontan recipients.

METHODS

All patients who underwent an ECC Fontan procedure from 1997 to 2010 in Australia and New Zealand were identified, and perioperative, follow-up, echocardiographic and reintervention data collected. Risk factors for early and late mortality, failure and adverse outcomes were analysed.

RESULTS

A total of 570 patients were identified, and late follow-up was available in 529 patients. The mean follow-up was 6.7 years (standard deviation: 3.5) and completeness of the follow-up was 98%. There were seven hospital mortalities (1%) and 21 patients (4%) experienced early failure (death, Fontan takedown/revision or mechanical circulatory support). Prolonged length of stay occurred in 10% (57 patients), and prolonged effusions in 9% (51 patients). Overall survival at 14 years was 96% (95% confidence interval [CI]: 93-98%), and late survival for patients discharged with intact Fontan was 98% (95% CI: 94-99%). The rates of late failure (late death, transplantation, takedown, New York Heart Association class III/IV or protein-losing enteropathy) and adverse events (late failure, reoperation, percutaneous intervention, pacemaker, thromboembolic event or supraventricular tachycardia) per 100 patient-years were 0.8 and 3.8, and their 14-year freedoms were 83% (95% CI: 70-91%) and 53% (95% CI: 41-64%), respectively. After adjustment for confounders, hypoplastic left heart syndrome (HLHS) was strongly associated with prolonged effusions (OR: 2.9, 95% CI: 1.4-5.9), late failure (hazard ratio [HR]: 2.8, 95% CI: 1.1-7.5) and adverse events (HR: 3.6, 95% CI: 1.3-7.5).

CONCLUSIONS

The extracardiac Fontan procedure provides excellent survival into the second decade of life, but half of patients will suffer a late adverse event by 14 years. Patients with HLHS are at higher risk of late adverse events than other morphological groups, but their survival is still excellent.