Outcomes for patients with unbalanced atrioventricular septal defects

Staged ventricular recruitment following single-ventricular palliation in unbalanced atrioventricular septal defect with heterotaxy syndrome

A newborn with unbalanced atrioventricular septal defect and heterotaxy syndrome underwent early surgeries for single-ventricular palliation due to a small left ventricle. Following procedures, including the modified Damus-Kaye-Stansel, there was a notable increase in left ventricular size. This progression allowed successful biventricular repair at 7 months. This case highlights potential ventricular development after palliative procedures in patients with borderline ventricular size.

Cleft closure and other predictors of contemporary outcomes after atrioventricular canal repair in patients with parachute left atrioventricular valve

OBJECTIVES

Parachute left atrioventricular valve (LAVV) complicates atrioventricular septal defect (AVSD) repair. We evaluate outcomes of AVSD patients with parachute LAVV and identify risk factors for adverse outcomes.

METHODS

We evaluated all patients undergoing repair of AVSD with parachute LAVV from 2012 to 2021. The primary outcome was a composite of time-to-death, LAVV reintervention and development of greater than or equal to moderate LAVV dysfunction (greater than or equal to moderate LAVV stenosis and/or LAVV regurgitation). Event-free survival for the composite outcome was estimated using Kaplan-Meier methodology and competing risks analysis. Cox proportional hazards regression was used to identify predictors of the primary outcome.

RESULTS

A total of 36 patients were included with a median age at repair of 4 months (interquartile range 2.3-5.5 months). Over a median follow-up of 2.6 years (interquartile range 1.0-5.6 years), 6 (17%) patients underwent LAVV reintervention. All 6 patients who underwent LAVV reintervention had right-dominant AVSD. Sixteen patients (44%) met the composite outcome, and all did so within 2 years of initial repair. Transitional AVSD (versus complete), prior single-ventricle palliation, leaving the cleft completely open and greater than or equal to moderate preoperative LAVV regurgitation were associated with a higher risk of LAVV reintervention in univariate analysis. In multivariate analysis, leaving the cleft completely open was associated with the composite outcome.

CONCLUSIONS

Repair of AVSD with parachute LAVV remains a challenge with a significant burden of LAVV reintervention and dysfunction in medium-term follow-up. Unbalanced, right-dominant AVSDs are at higher risk for LAVV reintervention. Leaving the cleft completely open might independently predict poor overall outcomes and should be avoided when possible.

CLINICAL TRIAL REGISTRATION NUMBER

IRB-P00041642.

National outcomes of the Fontan operation with endocardial cushion defect

BACKGROUND

The traditional outcomes of the Fontan operation (FO) in endocardial cushion defect (ECD) patients have been suboptimal. Previous studies have been limited by the smaller number of ECD patients, longer study period with an era effect, and do not directly compare short-term outcomes of FO in ECD patients with non-ECD patients. Our study aims to address these shortcomings.

METHODS

A retrospective analysis of the Kids Inpatient Database (2009, 2012, and 2016) for the FO was done. The groups were divided into those who underwent FO with ECD as compared to non-ECD diagnosis. The data were abstracted for demographics, clinical characteristics, and operative outcomes. Standard statistical tests were used.

RESULTS

Three thousand three hundred eighty patients underwent the FO of which 360 patients (11%) were FO-ECD. ECD patients were more likely to have Down syndrome, Heterotaxy syndrome, transposition/DORV, and TAPVR as compared to non-ECD patients. FO-ECD had a higher discharge-mortality (2.84% vs. 0.45%, p = .04). The length of stay (16 vs. 13 days, p = .05) and total charges incurred ($283, 280 vs. $234, 106, p = .03) for the admission were higher in the FO-ECD as compared to non-ECD patients. In multivariable analysis, ECD diagnosis, cardiac arrest, acute kidney injury, and postoperative hemorrhage were predictors of mortality.

CONCLUSION

Contemporary outcomes for FO are excellent with very low overall operative mortality. However, the outcomes in ECD patients are inferior with higher operative mortality than in non-ECD patients. The occurrence of postoperation complications and a diagnosis of ECD were predictive of a negative outcome.

Risk analysis for patients with a functionally univentricular heart after systemic-to-pulmonary shunt placement

OBJECTIVES

To investigate risk factors for mortality after systemic-to-pulmonary (SP) shunt procedures in patients with a functionally univentricular heart using the Japan Cardiovascular Surgery Database registry.

METHODS

Clinical data from 75 domestic institutions were collected. Overall, 812 patients with a functionally univentricular heart who underwent initial SP shunt palliation were eligible for analysis. Patients with pulmonary atresia with an intact ventricular septum and patients with a SP shunt as part of the Norwood procedure were excluded. Risk factors for 30- and 90-day mortalities were analysed using a logistic regression model.

RESULTS

Median age and body weight at SP shunt placement were 41 days and 3.6 kg, respectively. Modified Blalock-Taussig shunt, central shunt and other types of SP shunts were applied in 689 (84.9%), 94 (11.8%) and 30 (3.7%) patients, respectively. Cardiopulmonary bypass was utilized in 410 patients (51%) for 128 min (median, 19-561). There were 411 isolated SP shunt procedures. Median hospital stay was 27 days, and 742 (91.4%) patients were discharged. The 30- and 90-day mortality rates were 3.4% and 6.0%, respectively. Placement of a central shunt was identified as a risk factor for 30-day mortality, while lower body weight, preoperative ventilator support, right atrial isomerism and coexistence of major aortopulmonary collateral arteries and an unbalanced atrioventricular septal defect were identified as risk factors for 90-day mortality.

CONCLUSIONS

SP shunt carries a high mortality rate in patients with a functionally univentricular heart when it is performed in smaller patients with complex cardiac anomalies.

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.

Restriction of Atrial Septal Defect Leads to Growth of Hypoplastic Ventricle in Patients with Borderline Right or Left Heart

Patients with borderline hypoplastic right or left ventricle and VSD may be candidates for either single ventricle palliation or staged ventricular recruitment (SVR) followed by eventual biventricular conversion. Components of SVR include restriction of atrial septal defects (ASD) without ventricular septal defects (VSD) closure and addition of accessory pulmonary blood flow. This study evaluated the impact of ASD restriction on ventricular growth and function. We retrospectively reviewed patients with borderline ventricular hypoplasia and VSD who underwent a staged ventricular recruitment (SVR) procedure from 2012 to June 2019. Pre- and post-recruitment MRI and echocardiogram data were compared and analyzed. We excluded cases in which we intentionally restricted VSD with simultaneous ASD restriction. Forty-six patients (41 with right-dominant ventricle, 25 with risk factors for Fontan procedure) underwent SVR at a median age of 15.1 months' (interquartile range (IQR), 7.2-37.2 months'). The median indexed ventricular end-diastolic volume, end-systolic volume, and stroke volume according to cardiac MRI significantly increased at median 11.0 months' (IQR:7.8~14.1 months') after recruitment. Among them, except 2 operative mortalities after SVR, 26 patients underwent bi-ventricular repair (56.5% including one and a half ventricle repair) at a median of 8.0 months' (IQR: 6.2-12.2 months') after recruitment. Fifteen patients await biventricular completion, and 3 patients underwent single ventricle palliation. Pulmonary blood flow (Qp) tended to increase after recruitment regardless of type of pulmonary blood flow modification without statistical significance. Six patients died at a median duration of 6.5 months' (IQR: 2.9-11.7) after SVR; 3 patients died after biventricular completion, 2 after recruitment, and 1 after returning to single ventricle palliation. All of them were considered poor Fontan candidates due to severe atrioventricular valve regurgitation, pulmonary hypertension, pulmonary vein stenosis, or airway stenosis. Restriction of the atrial septum leads to the growth of hypoplastic ventricle in patients with ventricular septal defects who undergo SVR regardless of the preoperative characteristics, and eventual biventricular repair can be performed in a subgroup of these patients. Future work is necessary to optimize timing of SVR and method of accessory pulmonary blood flow.

Single-ventricle palliation in children with atrioventricular septal defect and transposition of the great arteries: 45 years of experience

BACKGROUND

The association of atrioventricular septal defect and transposition of the great arteries is very rare. As a rule, these patients have unbalanced ventricles. However, there have been no studies describing the results of single-ventricle palliation in these children.

METHODS

All children who underwent surgery with a diagnosis of atrioventricular septal defect and transposition of the great arteries were included in the study. Data were obtained from medical records.

RESULTS

A total of 38 patients with atrioventricular septal defect and transposition of the great arteries underwent single-ventricle palliation at the study institution between 1971 and 2016. The mean follow-up was 12.4 years (median: 14.6 years, range 2-43.3 years). Most children had unbalanced atrioventricular septal defect (94.7%, 36/38). Survival was 67.6% (95% confidence interval [CI]: 50.0-80.2%) at 10 years and 57.8% (95% CI: 38.0-73.4%) at 20 years. By 10 years, 58.6% (95% CI: 40.8-72.7%) had progressed to Fontan completion, while 32.5% (95% CI: 18.2-47.6%) had died. In patients achieving Fontan completion, 20-year event-free survival was 73.3% (95% CI: 34.8-91.3%), while 5.0% (95% CI: 0.4-20.5%) had undergone cardiac transplantation and 21.7% (95% CI: 3.2-50.8%) had undergone takedown of the Fontan circulation. Freedom from atrioventricular valve surgery was 57.0% (95% CI: 37.2-72.7%) at 10 and 20 years.

CONCLUSIONS

The association of atrioventricular septal defect and transposition of the great arteries is very rare, and most of these children have unbalanced ventricles. Single-ventricle palliation results in 25-year overall survival of 50%. However, in patients, who had Fontan completion, survival was 75% at 25 years after Fontan operation.

Outcomes of Multistage Palliation of Infants With Single Ventricle and Atrioventricular Septal Defect

Background:

Published palliation outcomes of infants with functional single ventricle (SV) and common atrioventricular septal defect (AVSD) are poor due to associated cardiac and extracardiac anomalies and development of atrioventricular valve (AVV) regurgitation. We report current palliation results.

Methods:

From 2002 to 2012, 80 infants with functional SV with AVSD underwent multistage palliation. Competing-risks analyses modeled events after first-stage surgery and Glenn (death/transplantation vs next palliation surgery) and examined factors associated with survival and AVV intervention.

Results:

Sixty-eight (80%) patients received neonatal palliation: modified Blalock-Taussig shunt (n = 33, 41%), Norwood (n = 20, 25%), and pulmonary artery band (n = 15, 19%), whereas 12 (15%) received primary Glenn. On competing-risks analysis, one-year following first-stage surgery, 29% of patients had died or received transplantation and 62% had undergone Glenn. Five years following Glenn, 9% of patients had died or received transplantation and 68% had undergone Fontan. Overall eight-year survival was 64% and was lower in patients with genetic syndromes (53% vs 82%), patients requiring concomitant total anomalous pulmonary venous connection repair (53% vs 69%), and those requiring neonatal palliation (48% vs 100%). Factors associated with mortality were unplanned reoperation (hazard ratio [HR]: 3.7 [1.7-8.0], P = .001) and extracorporeal membrane oxygenation use (HR: 7.1 [3.0-16.6], P < .001). Initial AVV regurgitation ≥ moderate was associated with AVV intervention (HR: 6.2 [2.4-16.1], P = .002) with eight-year freedom from death or AVV intervention of 25% in those patients.

Conclusions:

Patients with SV with AVSD are a distinct group and commonly have associated cardiac and extracardiac malformations that complicate care and affect survival. The development of AVV regurgitation requiring intervention is common but does not affect survival.

Recent advances in managing septal defects: ventricular septal defects and atrioventricular septal defects

This review discusses the management of ventricular septal defects (VSDs) and atrioventricular septal defects (AVSDs). There are several types of VSDs: perimembranous, supracristal, atrioventricular septal, and muscular. The indications for closure are moderate to large VSDs with enlarged left atrium and left ventricle or elevated pulmonary artery pressure (or both) and a pulmonary-to-systemic flow ratio greater than 2:1. Surgical closure is recommended for large perimembranous VSDs, supracristal VSDs, and VSDs with aortic valve prolapse. Large muscular VSDs may be closed by percutaneous techniques. A large number of devices have been used in the past for VSD occlusion, but currently Amplatzer Muscular VSD Occluder is the only device approved by the US Food and Drug Administration for clinical use. A hybrid approach may be used for large muscular VSDs in small babies. Timely intervention to prevent pulmonary vascular obstructive disease (PVOD) is germane in the management of these babies. There are several types of AVSDs: partial, transitional, intermediate, and complete. Complete AVSDs are also classified as balanced and unbalanced. All intermediate and complete balanced AVSDs require surgical correction, and early repair is needed to prevent the onset of PVOD. Surgical correction with closure of atrial septal defect and VSD, along with repair and reconstruction of atrioventricular valves, is recommended. Palliative pulmonary artery banding may be considered in babies weighing less than 5 kg and those with significant co-morbidities. The management of unbalanced AVSDs is more complex, and staged single-ventricle palliation is the common management strategy. However, recent data suggest that achieving two-ventricle repair may be a better option in patients with suitable anatomy, particularly in patients in whom outcomes of single-ventricle palliation are less than optimal. The majority of treatment modes in the management of VSDs and AVSDs are safe and effective and prevent the development of PVOD and cardiac dysfunction.

Long-Term Outcome After Pulmonary Artery Banding in Children With Atrioventricular Septal Defects

BACKGROUND

Patients with atrioventricular septal defect (AVSD) may require pulmonary artery banding (PAB), either as a part of a staged univentricular palliation or to allow delayed biventricular repair in patients presenting with early heart failure. The long-term outcomes of PAB in children with AVSD have not been previously reported.

METHODS

All children with AVSD who underwent PAB at a single institution were included in the study. Data were obtained from medical records and correspondence with general practitioners and cardiologists.

RESULTS

A total of 68 patients with complete AVSD underwent PAB, of whom 58.8% of patients (40 of 68) had balanced AVSD (bAVSD) and underwent PAB with intent to subsequently perform biventricular repair. The remaining 41.2% of patients (28 of 68) had unbalanced AVSD (uAVSD) and underwent PAB as part of staged univentricular repair. PAB was not associated with a short-term increase in atrioventricular valve (AVV) regurgitation (p = 0.24). In patients with bAVSD, 83.8% (95% confidence interval [CI]: 67.4% to 92.4%) achieved biventricular repair. Survival was 73.4% (95% CI: 54.3% to 85.5%) and freedom from left AVV operation was 60.0% (95% CI: 36.1% to 77.4%) at 20 years of follow-up. In patients with uAVSD, 61.9% (95% CI: 40.5% to 77.5%) had achieved Fontan completion at 10 years of follow-up. Survival was 60.9% (95% CI: 36.2% to 78.5%) and freedom from AVV operation was 78.6% (95% CI: 55.5% to 90.6%) at 20 years.

CONCLUSIONS

PAB can be used in patients with AVSD without compromising AVV function. Most patients with bAVSD progress to biventricular repair, albeit with a high rate of AVV reoperation. Patients with uAVSD who undergo PAB have similar outcomes to the overall uAVSD population.

Attrition in patients with single ventricle and trisomy 21: outcomes after a total cavopulmonary connection

OBJECTIVES

Data are limited regarding the management of children with trisomy 21 (T21) syndrome and a functional single ventricle (FSV). We evaluated patients with T21 and a FSV who had a total cavopulmonary connection (TCPC).

METHODS

From September 1999 to August 2012, 139 patients with a FSV underwent a TCPC. Sixty-five had unbalanced atrioventricular septal defect. Thirteen had T21. Three (of 13) had heterotaxy syndrome. The mean age at the Fontan operation was 27.6 ± 12.1 months.

RESULTS

The initial procedure was pulmonary artery banding in 9 patients, systemic-to-pulmonary shunt in 2 and Damus-Kaye-Stansel/Norwood procedure in 2. Median follow-up was 69 months (interquartile range 25-75, 21-99). There was 1 death after a Damus-Kaye-Stansel/Norwood procedure and one interstage death after a bidirectional Glenn procedure. Nine (of 11) survivors underwent a Fontan operation. A fenestrated Fontan procedure was the predominate operation in 78%. One patient was deemed unsuitable for a Fontan operation. There was 1 takedown and 1 late death after the Fontan operation. Heterotaxy syndrome did not affect outcome ( P  > 0.05). There was no statistical difference in the pre-Fontan McGoon ratio, hospital length of stay, duration of pleural drainage and Fontan-related adverse events between patients with a dominant right ventricle and those with a left ( P  > 0.05).

CONCLUSIONS

A TCPC in patients with T21 and an FSV is associated with reproducible, satisfactory outcomes. An assisted-Glenn procedure with pulsatile pulmonary blood flow and a fenestrated Fontan may be associated with attenuated perioperative morbidity and late attrition.

Preoperative single ventricle function determines early outcome after second-stage palliation of single ventricle heart

Background

Second-stage palliation with hemi-Fontan or bidirectional Glenn procedures has improved the outcomes of patients treated for single-ventricle heart disease. The aim of this study was to retrospectively analyze risk factors for death after second-stage palliation of single-ventricle heart and to compare therapeutic results achieved with the hemi-Fontan and bidirectional Glenn procedures.

Material and methods

We analyzed 60 patients who had undergone second-stage palliation for single-ventricle heart. Group HF consisted of 23 (38.3%) children who had been operated with the hemi-Fontan method; Group BDG consisted of 37 (61.7%) who had been operated with the bidirectional Glenn method. The analysis focused on 30-day postoperative mortality rates, clinical and echocardiographic data, and early complications.

Results

The patients’ ages at the time of repair was 33 ± 11.2 weeks; weight was 6.7 ± 1.2 kg. The most common anatomic subtype was hypoplastic left heart syndrome, in 36 (60%) patients. The early mortality rate was 13.3%. Significant preoperative atrioventricular valve regurgitation, single-ventricle heart dysfunction, pneumonia/sepsis, and arrhythmias were associated with higher mortality rates after second-stage palliation. Multivariate analysis identified significant preoperative single-ventricle heart dysfunction as an independent predictor of early death after second-stage palliation. No differences were found in the analyzed variables after bidirectional Glenn compared with hemi-Fontan procedures.

Conclusion

Significant preoperative atrioventricular valve regurgitation, arrhythmias and pneumonia/sepsis are closely correlated with mortality in patients with single-ventricle heart after second-stage palliation. Preoperative significant single-ventricle heart dysfunction is an independent mortality predictor in this group of patients. There are no differences in clinical, echocardiographic data, or outcomes in patients treated with the hemi-Fontan compared with bidirectional Glenn procedures.

Perioperative and Anesthetic Considerations in Atrioventricular Septal Defect

Atrioventricular septal defect results from a failure of normal endocardial cushion fusion during embryologic cardiac development. This developmental aberration results in defects in the atrial and/or ventricular septum and malformation of the atrioventricular valves. The pathophysiology of atrioventricular septal defect is variable, and ranges from mild left to right shunting similar to a simple atrial septal defect to complex single-ventricle heart disease. This review focuses on the spectrum of atrioventricular septal defect from partial to complete, without associated cardiac defects.

Right-Dominant Unbalanced Atrioventricular Septal Defect: Echocardiography in Surgical Decision Making

BACKGROUND

Management of right-dominant atrioventricular septal defect (AVSD) remains a challenge given the spectrum of ventricular hypoplasia. The purpose of this study was to assess whether reported echocardiographic indices and additional measurements were associated with operative strategy in right-dominant AVSD.

METHODS

A blinded observer retrospectively reviewed preoperative echocardiograms of patients who underwent surgery for right-dominant AVSD (January 2000 to July 2013). Ventricular dimensions, atrioventricular valve index (AVVI; left valve area/right valve area), and right ventricular (RV)/left ventricular (RV/LV) inflow angle were measured. A second observer measured a subset of studies to assess agreement. Pearson correlation analysis was performed to examine the relationship between ventricular septal defect size (indexed to body surface area) and RV/LV inflow angle in systole. A separate validation cohort was identified using the same methodology (August 2013 to July 2016).

RESULTS

Of 46 patients with right-dominant AVSD (median age, 1 day; range, 0-11 months), overall survival was 76% at 7 years. Twenty-eight patients (61%) underwent single-ventricle palliation and had smaller LV dimensions and volumes, AVVIs (P = .005), and RV/LV inflow angles in systole (P = .007) compared with those who underwent biventricular operations. Three patients undergoing biventricular operations underwent transplantation or died and had lower indexed LV end-diastolic volumes compared with the remaining patients (P = .005). Interobserver agreement for the measured echocardiographic indices was good (intraclass correlation coefficient = 0.70-0.95). Ventricular septal defect size and RV/LV inflow angle in systole had a strong negative correlation (r = -0.7, P < .001). In the validation cohort (n = 12), RV/LV inflow angle in systole ≤ 114° yielded sensitivity of 100% and AVVI ≤ 0.70 yielded sensitivity of 88% for single-ventricle palliation.

CONCLUSIONS

Mortality remains high among patients with right-dominant AVSD. RV/LV inflow angle in systole and AVVI are reproducible measurements that may be used in conjunction with several echocardiographic parameters to support suitability for a biventricular operation in right-dominant AVSD.

Current Outcomes of the Norwood Operation in Patients With Single-Ventricle Malformations Other Than Hypoplastic Left Heart Syndrome

Background:

Subsequent to increased experience with the Norwood operation in children with hypoplastic left heart syndrome (HLHS), its application has expanded to allow palliation of single-ventricle (SV) malformations other than HLHS. We describe current palliation outcomes in this group of SV patients.

Methods:

Between 2002 and 2012, 65 of the 303 Norwood operations were performed in non-HLHS SV patients. Competing risk analysis modeled events after Norwood and after subsequent Glenn and examined risk factors affecting outcomes.

Results:

Competing risk analysis showed that one year following Norwood, 24% of patients had died or received transplantation, 72% had undergone Glenn, and 4% were alive awaiting Glenn/Kawashima. Five years following Glenn, 9% of patients had died, 68% had undergone Fontan, and 23% were alive awaiting Fontan. Overall seven-year survival following Norwood was 68%. On multivariable analysis, mortality risk factors were unplanned cardiac reoperation (hazard ratio [HR]: 4.0 [1.5-10.6], P = .006), right dominant ventricle morphology (HR: 3.3 [1.3-8.3], P = .012), and postoperative extracorporeal membrane oxygenation (HR: 3.1 [1.1-9.0], P = .035).

Conclusions:

Operative death and interstage mortality continue to be problematic following Norwood palliation for non-HLHS SV variants. Outcomes seem comparable to those reported for HLHS, however they are influenced by underlying pathology; children with dominant left ventricle morphology (tricuspid atresia and double inlet left ventricle) have superior survival compared to those with dominant right ventricle morphology (mitral atresia, unbalanced atrioventricular septal defect, and most patients with atrial isomerism). Unplanned reoperations for technical imperfections diminish survival. Large multicenter studies might be warranted to better identify high-risk patients and provide guidance toward improving their survival.

Atrioventricular valve regurgitation at diagnosis in single-ventricle patients: does it affect longitudinal outcomes?

INTRODUCTION

Significant atrioventricular valve regurgitation at diagnosis in single-ventricle patients has been associated with mortality and morbidity. However, longitudinal data on the effect of valve regurgitation at diagnosis on outcomes in the era of surgical valve interventions are scarce.

MATERIALS AND METHODS

This is a retrospective review of single-ventricle patients admitted to a regional centre from 2005 to 2008. Data were reviewed from birth to 18 months, and association of atrioventricular valve regurgitation at diagnosis with mortality and morbidity was evaluated.

RESULTS

A total of 118 patients were studied, 73% with a single right ventricle. At diagnosis, 37 patients (31%) had mild, 5 (4%) had mild to moderate, and 4 (3%) had ≥ moderate atrioventricular valve regurgitation. Moderate or greater valve regurgitation was associated with mortality (HR 5.51, 95% CI 1.24-24.61, p = 0.025), and all four patients with ≥ moderate valve regurgitation died. However, valve regurgitation was not associated with mortality for left ventricle patients. In all, 12 patients (10%) had surgical atrioventricular valve interventions. There were no independent predictors of valve intervention, and no patient having an intervention had > mild valve regurgitation at diagnosis. There was no association between valve regurgitation and days of hospitalisation or chest tube drainage.

CONCLUSION

Significant atrioventricular valve regurgitation at diagnosis remains a risk factor for mortality in single-ventricle patients, although it may be less important for single left ventricle patients. However, it is not associated with increased morbidity or surgical atrioventricular valve intervention in survivors. Reliably predicting surgical atrioventricular valve intervention remains a challenge in single-ventricle patients.

Atrioventricular septal defects among infants in Europe: a population-based study of prevalence, associated anomalies, and survival

OBJECTIVE

To describe the epidemiology of chromosomal and non-chromosomal cases of atrioventricular septal defects in Europe.

METHODS

Data were obtained from EUROCAT, a European network of population-based registries collecting data on congenital anomalies. Data from 13 registries for the period 2000-2008 were included.

RESULTS

There was a total of 993 cases of atrioventricular septal defects, with a total prevalence of 5.3 per 10,000 births (95% confidence interval 4.1 to 6.5). Of the total cases, 250 were isolated cardiac lesions, 583 were chromosomal cases, 79 had multiple anomalies, 58 had heterotaxia sequence, and 23 had a monogenic syndrome. The total prevalence of chromosomal cases was 3.1 per 10,000 (95% confidence interval 1.9 to 4.3), with a large variation between registers. Of the 993 cases, 639 cases were live births, 45 were stillbirths, and 309 were terminations of pregnancy owing to foetal anomaly. Among the groups, additional associated cardiac anomalies were most frequent in heterotaxia cases (38%) and least frequent in chromosomal cases (8%). Coarctation of the aorta was the most common associated cardiac defect. The 1-week survival rate for live births was 94%.

CONCLUSION

Of all cases, three-quarters were associated with other anomalies, both chromosomal and non-chromosomal. For infants with atrioventricular septal defects and no chromosomal anomalies, cardiac defects were often more complex compared with infants with atrioventricular septal defects and a chromosomal anomaly. Clinical outcomes for atrioventricular septal defects varied between regions. The proportion of termination of pregnancy for foetal anomaly was higher for cases with multiple anomalies, chromosomal anomalies, and heterotaxia sequence.

Unbalanced atrioventricular septal defect: definition and decision making

Unbalanced atrioventricular septal defect is an uncommon lesion with widely varying anatomic manifestations. When unbalance is severe, diagnosis and treatment is straightforward, directed toward single-ventricle palliation. Milder forms, however, pose a challenge to current diagnostic and therapeutic approaches. The transition from anatomies that are capable of sustaining biventricular physiology to those that cannot is obscure, resulting in uneven application of surgical strategy and excess mortality. Imprecise assessments of ventricular competence have dominated clinical decision making in this regard. Malalignment of the atrioventricular junction and its attendant derangement of inflow physiology is a critical factor in determining the feasibility of biventricular repair in the setting of unbalanced atrioventricular septal defect. The atrioventricular valve index accurately identifies unbalanced atrioventricular septal defect and also brings into focus a zone of transition from anatomies that can support a biventricular end state and those that cannot.

Echocardiographic features defining right dominant unbalanced atrioventricular septal defect: a multi-institutional Congenital Heart Surgeons' Society study

BACKGROUND

Definition and management of right dominant unbalanced atrioventricular septal defect (AVSD) remains challenging because unbalance entails a spectrum of left heart hypoplasia. Previous work has highlighted atrioventricular valve (AVV) index as a reasonable defining echocardiographic measure. We sought to assess which additional echocardiographic features might provide further characterization.

METHODS AND RESULTS

From a multi-institutional cohort of complete AVSD, 52 preoperative echocardiograms of patients with presumed right dominant unbalanced AVSD (based on AVV index) and 60 randomly selected preoperative echocardiograms from patients with presumed balanced AVSD were reviewed. Cluster analysis of echocardiographic variables was used to group patients with similar features. Discriminant function analysis was used to explore which variables differentiated these groups. Three groups were identified from the cluster analysis. Echocardiographic variables that differentiated these groups were right ventricle:left ventricle inflow angle, LV width/LV length, left AVV color diameter at smallest inflow, left AVV color diameter at annulus, right AVV overriding left atrium, and LV width. Based on procedures and outcomes, 1 group likely represented balanced patients, whereas 2 groups with similar outcomes likely represented unbalanced patients. The dominant differentiating echocardiographic variable between the 3 cluster groups was the right ventricle:LV inflow angle (partial R²=0.86), defined as the angle between the base of the right ventricle and LV free wall, using the crest of the ventricular septum as apex of the angle.

CONCLUSIONS

The angle of right ventricle/LV inflow and other surrogates of inflow may be important defining echocardiographic measures of right dominant unbalanced AVSD, although confirmation is needed.

Unbalanced atrioventricular septal defect: defining the limits of biventricular repair

Unbalanced atrioventricular septal defect (uAVSD) is a challenging lesion with suboptimal outcomes in the current era. Severe forms of uAVSD mandate univentricular repair with well-documented outcomes. Determining the feasibility of biventricular repair (BVR) in patients with moderate forms of uAVSD is difficult. Ventricular hypoplasia has traditionally formed the cornerstone of defining uAVSD. However, malalignment of the atrioventricular junction and related derangements of the anatomy and physiology of the atrioventricular inflow play a central role in establishing and sustaining a biventricular end state. Atrioventricular valve index, left ventricular inflow index, and right ventricle/left ventricle inflow angle are important recently described measures of inflow physiology. Additional patient anatomic and physiologic factors that impact BVR feasibility undoubtedly exist. A recently launched Congenital Heart Surgeons Society prospective inception cohort study will address these and other issues that impair our ability to predict BVR feasibility in uAVSD.

The pathogenesis of atrial and atrioventricular septal defects with special emphasis on the role of the dorsal mesenchymal protrusion

Partitioning of the four-chambered heart requires the proper formation, interaction and fusion of several mesenchymal tissues derived from different precursor populations that together form the atrioventricular mesenchymal complex. This includes the major endocardial cushions and the mesenchymal cap of the septum primum, which are of endocardial origin, and the dorsal mesenchymal protrusion (DMP), which is derived from the Second Heart Field. Failure of these structures to develop and/or fully mature results in atrial septal defects (ASDs) and atrioventricular septal defects (AVSD). AVSDs are congenital malformations in which the atria are permitted to communicate due to defective septation between the inferior margin of the septum primum and the atrial surface of the common atrioventricular valve. The clinical presentation of AVSDs is variable and depends on both the size and/or type of defect; less severe defects may be asymptomatic while the most severe defect, if untreated, results in infantile heart failure. For many years, maldevelopment of the endocardial cushions was thought to be the sole etiology of AVSDs. More recent work, however, has demonstrated that perturbation of DMP development also results in AVSD. Here, we discuss in detail the formation of the DMP, its contribution to cardiac septation and describe the morphological features as well as potential etiologies of ASDs and AVSDs.

Mitral and tricuspid valve repair and growth in unbalanced atrial ventricular canal defects

OBJECTIVE

Congenital mitral and tricuspid valve abnormalities in unbalanced atrioventricular canal defects are complex. We designed procedures to both repair and induce growth of hypoplastic atrioventricular valves and ventricles to achieve 2-ventricle repairs. Midterm data were assessed for reliability of catch-up growth, resulting quality of atrioventricular valves, and adequacy of 2-ventricle repairs.

METHODS

The 24 consecutive infants (14 female and 10 male) with unbalanced atrioventricular canal defects had significant hypoplasia of 1 atrioventricular valve and/or ventricle (an echocardiography-derived z value of ≤-3.0 standard errors of the mean below expected). Operative approaches included the following: (1) Staged repair was performed, with complete valve repair, partial closure of the atrial septal, and ventricular septal defects, and (usually) pulmonary artery banding. After adequate growth, repair was completed. A vestigial mitral valve (4-7 mm) in 3 patients led to partitioning the large tricuspid valve, creating a second mitral valve. (2) Repair with a shift in atrioventricular valve partitioning was performed to increase hypoplastic atrioventricular valve size. (3) Repair with snared atrial septal defects and ventricular septal defect was performed to allow intracardiac shunting. The hypoplastic atrioventricular valves and hypoplastic ventricles were reassessed on local follow-up (5-15 years).

RESULTS

The initial z scores were -2.8 to -7.4 for hypoplastic atrioventricular valves and -1.0 to -7.5 for hypoplastic ventricles. Follow-up z scores were -0.6 to -2.7 for hypoplastic atrioventricular valves and -2.0 to +1.8 for hypoplastic ventricles. Another 11 patients were also judged to be within normal limits. Three reoperations were for mitral valve regurgitation, and 1 reoperation was for mitral valve replacement. One patient died of central nervous system bleed just before extracorporeal membrane oxygenation weaning, and 2 patients died of late potassium overdose, for an 88% survival. Survivors are well with 2-ventricle repairs, and 15 of 19 patients are not taking cardiac medications.

CONCLUSIONS

Increasing atrioventricular valve flow reliably induced growth. Valve repair and growth achieved a 2-ventricle repair in all patients.

Outcomes of hypoplastic left heart syndrome in low-birth-weight patients

The objective of this study was to assess outcomes of hypoplastic left heart syndrome (HLHS) patients weighing ≤ 2.5 kg throughout staged palliation. We performed a single-center retrospective review. Abstracted data included gestational age, birth weight, presence of noncardiac anomalies, and survival through Fontan. Fifty-two patients met inclusion criteria, with a median birth weight of 2.14 kg and gestational age of 36 weeks. Five patients received comfort care only. Of 47 patients who underwent initial surgical palliation, 51% survived to initial hospital discharge. Birth weight and gestational age (GA) were similar between survivors and nonsurvivors. Compared with survivors, risk factors for death prior to initial hospital discharge were as follows: small for GA (P = 0.005), noncardiac anomalies (P = 0.04), need for post-perative extracorporeal membrane oxygenation (P = 0.0004), and conversion from initial palliation to Sano shunt (n = 5, no survivors). Operative survival following Stage 2 palliation was 91% (21/23) and 94% after Fontan (17/18). Overall survival for palliated patients from birth through Fontan was 36%. Low-birth-weight neonates with HLHS have poor overall survival through the Fontan operation, with highest mortality following Stage 1 palliation. Being small for GA and the presence of noncardiac anomalies are important preoperative risk factors for early mortality.

Usefulness of left ventricular inflow index to predict successful biventricular repair in right-dominant unbalanced atrioventricular canal

The outcome of biventricular (BV) repair for right-dominant unbalanced atrioventricular canal has remained poor, because it is difficult to predict left ventricular (LV) adequacy before surgery. Our aim was to determine whether preoperative echocardiographic parameters, specifically analysis of color inflow into the LV, would predict survival after BV repair in patients with right-dominant unbalanced atrioventricular canal. Subjects with right-dominant unbalanced atrioventricular canal diagnosed from 1994 to 2007 were included. The echocardiographic parameters were analyzed blinded to the palliation strategy and survival. The LV inflow index (LVII) was calculated as the secondary color inflow diameter indexed to the left atrioventricular valve (AVV) annulus diameter. Univariate analysis, survival analysis, and multivariate modeling with stepwise logistic regression were performed. Of the 45 subjects, 23 (51%) underwent single ventricle (SV) palliation and 22 (49%) underwent BV repair. Of the 23 who underwent SV palliation, 15 (65%) survived compared to 18 (82%) of 22 who underwent BV repair (p = 0.34). In the BV group, a greater LVII predicted survival (R2 = 0.46, p = 0.03). No subjects with a LVII <0.5 survived BV repair. Mortality in the BV group was associated with younger age at initial surgery (p <0.01) and abnormal left AVV morphology (p = 0.02). Of the BV subjects with a patent ductus arteriosus at the initial operation (n = 11), the nonsurvivors were more likely to have retrograde flow in the transverse arch (p <0.01). In the BV group, reoperation within 30 days of the initial repair was strongly associated with mortality (p <0.01). In conclusion, in cases of mild or moderate LV hypoplasia, a greater LVII predicted survival after BV repair in patients with right-dominant unbalanced atrioventricular canal. We propose incorporation of the LVII into the echocardiographic assessment of these patients.

Perioperative monitoring in high-risk infants after stage 1 palliation of univentricular congenital heart disease

OBJECTIVE

Survival of high-risk patients with univentricular heart disease after Norwood palliation is reduced. We hypothesized that early goal-directed monitoring with venous oximetry and near-infrared spectroscopy would offset their increased vulnerability and improve survival.

METHODS

A prospective database of patients undergoing stage 1 palliation was used to assess differences in outcomes across risk groups in the setting of a comprehensive, goal-directed monitoring program. High-risk criteria included gestational age 35 weeks or less, birth weight less than 2.5 kg, and additional cardiac or extracardiac anomalies. Outcomes included survival to defined end points and measures of postoperative support.

RESULTS

From September 2000 to September 2008, 162 patients underwent stage 1 palliation: 28% (45/162) high-risk and 72% (117/162) standard-risk patients. Lesions other than hypoplastic left heart syndrome were more common among high-risk patients (38%, 17/45, vs 15%, 18/117, P = .003). Operative survival was not statistically different(87%, 39/45, high risk vs 95%, 111/117, standard risk, P = .1). High-risk patients were more likely to receive inpatient treatment until stage 2 palliation (24%, 11/45, vs 10%, 12/117, P = .001) and had lower 1-year survival (78% vs 93%, P = .01) and survival to date (71% vs 92%, P = .001).

CONCLUSIONS

Intensive monitoring partially offset biologic vulnerability of high-risk patients, helping attain comparable early outcomes. Vulnerability persisted throughout the interstage period, however, and increased mortality beyond cavopulmonary shunt was seen only among high-risk patients. Although enhanced monitoring reduced early mortality, high resource use and attrition after stage 2 palliation suggest an ongoing need to evaluate our current palliative strategy for this subset of patients.

Echocardiographic definition and surgical decision-making in unbalanced atrioventricular septal defect: a Congenital Heart Surgeons' Society multiinstitutional study

BACKGROUND

Although identification of unbalanced atrioventricular septal defect (AVSD) is obvious when extreme, exact criteria to define the limits of unbalanced are not available. We sought to validate an atrioventricular valve index (AVVI) (left atrioventricular valve area/total atrioventricular valve area, centimeters squared) as a discriminator of balanced and unbalanced forms of complete AVSD and to characterize the association of AVVI with surgical strategies and outcomes.

METHODS AND RESULTS

Diagnostic echocardiograms and hospital records of 356 infants with complete AVSD at 4 Congenital Heart Surgeons' Society (CHSS) institutions (2000-2006) were reviewed and AVVI measured (n=315). Patients were classified as unbalanced if AVVI≤0.4 (right dominant) or ≥0.6 (left dominant). Surgical strategy and outcomes were examined across the range of AVVI. Competing risks analysis until the time of commitment to a surgical strategy examined 4 end states: biventricular repair (BVR), univentricular repair (UVR), pulmonary artery banding (PAB), and death before surgery. A prediction nomogram for surgical strategy based on AVVI was developed. The majority of patients had balanced AVSD (0.4<AVVI<0.6) and underwent BVR. Patients with AVVI<0.19 uniformly underwent UVR. Heterogeneous repair strategies were found when 0.19≤AVVI≤0.39 (UVR and BVR), with a disproportionate number of deaths in this range. AVVI≥0.6 (left dominant) was less common. The proportion of subjects predicted for the end states at 12 months after diagnosis are: BVR, 86%; UVR, 7%; PAB, 1%; death without surgery, 1%; alive without surgery, 5%.

CONCLUSIONS

AVVI effectively characterizes the transition between balanced and unbalanced AVSD with important correlation to anatomic substrate and selected surgical strategy.