Biventricular repair in patients with heterotaxy syndrome

A Review of Biventricular Repair for the Congenital Cardiac Anesthesiologist

The management of children with a borderline ventricle has been debated for many years. The pursuit of a biventricular repair in these children aims to avoid the long-term sequelae of single ventricle palliation. There is a lack of anesthesia literature relating to the care of this complex heterogenous patient population. Anesthesiologists caring for these patients should have an understanding on the many different forms of physiology and the impact on provision of anesthesia and hemodynamic parameters, the goals of biventricular staging and completion as well as the pre-operative, intra-operative, and post-operative considerations relating to this high-risk group of patients.

Conduction mapping during complex congenital heart surgery: Creating a predictive model of conduction anatomy

OBJECTIVES

The study objectives were to report on a growing experience of conduction system mapping during complex congenital heart surgery and create a predictive model of conduction anatomy.

METHODS

Patients undergoing complex cardiac repair with conduction mapping were studied. Intraoperative mapping used a multielectrode catheter to collect His bundle electrograms in the open, decompressed, beating heart. Patient anatomy, operative details, His bundle location, and postoperative conduction status were analyzed. By using classification and regression tree analysis, a predictive model of conduction location was created.

RESULTS

A total of 109 patients underwent mapping. Median age and weight were 1.8 years (range, 0.2-14.9) and 10.8 kg (range, 3.5-50.4), respectively. Conduction was identified in 96% (105/109). Median mapping time was 6 minutes (range, 2-33). Anatomy included atrioventricular canal defect, double outlet right ventricle, complex transposition of the great arteries, and multiple ventricular septal defects. By classification and regression tree analysis, ventricular looping and visceroatrial situs were the greatest discriminators of conduction location. A total of 94 of 105 patients (89.5%) were free of complete heart block. Only 1 patient (2.9%) with heterotaxy syndrome developed complete heart block.

CONCLUSIONS

The precise anatomic location of the conduction system in patients with complex congenital heart defects can be difficult for the surgeon to accurately predict. Intraoperative conduction mapping enables localization of the His bundle and adds to our understanding of the anatomic factors associated with conduction location. Predictive modeling of conduction anatomy may build on what is already known about the conduction system and help surgeons to better anticipate conduction location preoperatively and intraoperatively.

Analysis of outcomes in patients with abnormal laterality undergoing congenital heart surgery

OBJECTIVE

Laterality anomalies are almost always associated with severe cardiac anomalies. Demographic properties, type of the procedures, associated anomalies, and early and mid-term prognosis of four types of laterality anomalies were analysed.

METHODS

A total of 64 consecutive patients with laterality anomalies were enrolled between July 2014 and July 2020. We grouped the patients as situs solitus dextrocardia (SSD) (n = 12; 18.7%); situs inversus (SI) (n = 16; 25%); right atrial isomerism (RAI) (n = 29; 45.3%); and left atrial isomerism (LAI) (n = 7; 10.9%). TAPVC was only present in the RAI group (31%). Incidence of mitral or tricuspid atresia was higher in the SSD group (25%). All the patients were followed up with a mean of 19.06 ± 17.6 (0.1-72) months.

RESULTS

Early postoperative mortality was 17 patients, among 107 procedures (15.8%). Twelve patients were in the neonatal period. All ten patients survived after isolated ductal stenting. Fourteen of the deaths were in the RAI group (48.3%). The 3-year survival rates were 85% in LAI, 78.7% in SI, 55.8% in SSD, and 38% in RAI groups. According to the multivariable Cox regression model, mechanical ventilation, kidney injury, RAI, and complex surgery in the neonatal period were independent risk factors for early mortality.

CONCLUSION

Laterality anomalies are one of the most challenging patients who commonly had univentricular physiology. The most prevalent anomaly was RAI, and RAI had the worst outcome and survival. Ductal stent is an acceptable first intervention during the neonatal period in suitable patients. Complex procedures may carry a high risk of death in the neonatal period.

Outcomes of Biventricular and Single Ventricle Heterotaxy Patients: A Single Center 5-Decade Experience

BACKGROUND

Surgical palliation of patients with heterotaxy syndrome has proven challenging. Long-term outcomes have historically been poor. Factors contributing to these outcomes are not completely understood.

METHODS

The institutional databases were queried for patients with heterotaxy syndrome from 1973-2021. Comparisons were made between patients managed with single ventricle (SV) and biventricular (BiV) physiology.

RESULTS

Heterotaxy syndrome was identified in 230 patients [polysplenia (47%), asplenia (53%)]. 199 patients had SV physiology, 180 (78%) had undergone Fontan palliation. 31 patients had BiV, including 20 (9%) with surgical intervention and 11 (5%) without surgical intervention. Median age at Fontan was 7.5 (IQR 8.8) years. Median follow-up was 20 (IQR 21) years. Kaplan Meier analysis showed decreased survival with SV physiology (SV 53±4% vs. BiV 93±5% at 30 years, p=0.001), as well as asplenia compared to polysplenia (49±5% vs. 68±5% at 30 years, p<0.001). Polysplenia patients with BiV demonstrated the best survival (100% of polysplenia BiV alive vs. 53±25% of asplenia BiV at 30 years, p<0.001). Overall 8 (3.5%) underwent cardiac transplantation at a median of 17 years of age. On multi-variable analysis, risk factors associated with mortality included SV physiology (OR 7.2, 95% CI 2.4-21.7), no prior Glenn (OR 3.6, 95% CI 1.9-6.7), need for permanent pacemaker (OR 2.3, 95% CI 1.2-4.6), and asplenia (OR 2.7, 95% CI 1.5-5.0).

CONCLUSIONS

Overall, patients with asplenia demonstrated decreased survival compared to those with polysplenia, and SV physiology had decreased survival compared to BiV. BiV physiology with polysplenia had the best survival.

A Rare Case of Polysplenia Syndrome Associated with Severe Cardiac Malformations and Congenital Alveolar Dysplasia in a One-Month-Old Infant: A Complete Macroscopic and Histopathologic Study

Polysplenia syndrome represents a type of left atrial isomerism characterized by multiple small spleens, often associated with cardiac malformations and with situs ambiguus of the abdominal organs. The case presented is of a one-month-old male infant, weighing approximately 3000 g, born at the County Clinical Emergency Hospital of Sibiu, who was hospitalized from birth until death. The patient suffered cardio-respiratory arrest due to severe hypoxia and septicemia on the background of a series of complex cardiac malformations associated with congenital abdominal organ anomalies. Examination of the body revealed a common atrium with complete atrioventricular canal defect, left ventricular hypertrophy, right ventricle hypoplasia, truncus arteriosus, superior vena cava duplication, bilobation of the lungs, situs ambiguous of the abdominal organs with right-sided stomach, a midline liver, gall bladder agenesis, multiple right-sided spleens and complete inversion of the intestines and pancreas. Histopathology concluded that the patient suffered cardiac lesions consistent with infantile lactic acidosis, as well as pulmonary modifications suggesting congenital alveolar dysplasia and altered hepatic architecture compatible with fibrosis.

Incidental Finding of Heterotaxy Syndrome in a Patient With Pulmonary Embolism: A Case Report and Concise Review

Heterotaxy syndrome, also called atrial isomerism, is a rare congenital condition in which the internal organs are abnormally arranged across the left-right axis of the body. It is classified into polysplenia syndrome or left atrial isomerism and asplenia syndrome or right atrial isomerism. It is associated with high morbidity and mortality due to the severity of cardiac anomalies. It is important to be aware of the syndrome findings as they can be incidentally found on imaging in adults. Here, we report a case of a 33-year-old female who presented with worsening shortness of breath, found to have a pulmonary embolism, and heterotaxy was incidentally identified on her imaging. A concise review follows.

Utility of Three-Dimensional Printed Model in Biventricular Repair of Complex Congenital Cardiac Defects: Case Report and Review of Literature

Heterotaxy is a rare syndrome associated with cardiac complexity, anatomic variability and high morbidity and mortality. It is often challenging to visualize and provide an accurate diagnosis of the cardiac anatomy prior to surgery with the use of conventional imaging techniques. We report a unique case demonstrating how the use of three-dimensional (3D) cardiac printed model allowed us to better understand the anatomical complexity and plan a tailored surgical approach for successful biventricular repair in a patient with heterotaxy syndrome.

Human Laterality Disorders: Pathogenesis, Clinical Manifestations, Diagnosis, and Management

Human laterality disorders comprise a group of diseases characterized by abnormal location (situs) and orientation of thoraco-abdominal organs and vessels across the left-right axis. Situs inversus totalis is mirror image reversal of thoraco-abdominal organs/great vessels. Situs ambiguus, better known as heterotaxy, is abnormal arrangement of thoraco-abdominal organs across the left-right axis excluding situs inversus totalis. Heterotaxy, also referred to as atrial or atrial appendage isomerism, is characterized by abnormal location of left-sided or right-sided organs with loss of asymmetry of normally paired asymmetric organs. It is associated with a variety of anomalies involving the heart, great vessels, lungs and intra-abdominal organs. Right and left atrial isomerism are associated with multiple complex congenital cardiac and vascular anomalies, many of which are lethal when untreated. Isomerism may also affect the lungs, spleen, liver, gall bladder, and intestines. Innovative surgical therapy of heterotaxy/isomerism has reduced early mortality and markedly improved long-term prognosis.

Left isomerism with bilateral superior vena cava, interrupted inferior vena cava and tetralogy of Fallot

The association of left isomerism with tetralogy of Fallot (TOF) is rare and reported as scattered case reports. Complex congenital cardiac and noncardiac malformations are known to be associated with left isomerism, but right-sided obstructive lesions are rare. We present our experience with a case of left isomerism with bilateral superior vena cava, interrupted inferior vena cava, and TOF managed by atrial septation and intracardiac repair.

The heterotaxy syndrome: associated congenital heart defects and management

Heterotaxy syndrome (HS) constitutes a spectrum of anomalies arising from embryological errors that result in abnormalities of lateralization involving thoraco-abdominal viscera and culminate in loss of normal asymmetric arrangement of these organs. Besides the unique challenges involved in planning and execution of surgical procedures aimed at correction or palliation of these anomalies, they have the potential to cause profound physiological and immunological consequences in the individual patient due to their cardiac and extra-cardiac manifestations. This article aims to review the literature on this rare and extraordinary subset of developmental anomalies with the intention of familiarizing the reader on the modes of presentation, manifestations, and the variations thereof while dealing with this anomaly. In our institutional experience with HS, 75 consecutive patients were seen between January 2011 and September 2018. Of these, 48 (64%) were confirmed to have isomerism of right atrial appendages (IRAA) and the rest had isomerism of left atrial appendages (ILAA). The cardiac and extra-cardiac manifestations of these patients were listed out. Fifty-four patients (34 with IRAA and 20 with ILAA) underwent 83 surgical procedures. While 49 patients were palliated on the univentricular pathway, 5 underwent biventricular repair. The in-hospital mortality was 7 (13%) in both groups combined (5 for patients with IRAA and 2 for ILAA). In conclusion, the surgical management of HS is associated with satisfactory outcomes in current era.

Surgical Management of Heterotaxy Syndrome: Current Challenges and Opportunities

Introduction:

Heterotaxy syndrome presents a unique challenge in surgical management, even in the current era. We hypothesized that certain anatomic subsets merit novel strategies.

Methods:

We analyzed morphologic details, surgeries, comorbidities, subsequent admissions, and survival using Kaplan-Meier methods and multivariable risk models from a single-institution experience of 103 consecutive patients with heterotaxy who underwent cardiac surgery between January 1, 1990, and May 31, 2016.

Results:

Of the 103 patients (50 males and 53 females), 31 had left atrial isomerism, 64 had right atrial isomerism (RAI), and 8 patients’ isomerism was indeterminate (IND), with first cardiac operation at a mean 1.0 year (standard deviation ±3.0 years) of age. Kaplan-Meier overall survival estimate was 83.1% at six months, 77.8% at one year, 65.9% at five years, and 52.1% at ten years. Survival was particularly low among RAI following repair of total anomalous pulmonary venous connection (TAPVC) at first operation, with one- and five-year survival of 57% and 46%, respectively. By multivariable analysis, the only risk factor for death during the early phase (hazard model) was repair of TAPVC at the first cardiac operation (hazard ratio [HR]: 4.4, P = .01), and risk factors during the longer term constant phase were atrioventricular valve (AVV) regurgitation (HR: 4.2, P < .01), male gender (HR: 3.7, P < .01), and two-ventricle repair (HR: 3.0, P = .02). Patients with heterotaxy undergoing the Fontan procedure had excellent subsequent survival (85% at ten years).

Conclusions:

This analysis of over 100 patients with heterotaxy identified TAPVC requiring initial repair as the major risk factor for early death and important AVV regurgitation as the major risk factor in the longer term. Survival with RAI and early repair of TAPVC were poor, with one-year mortality exceeding 40%. Patients with single ventricle completing the Fontan operation enjoyed outstanding ten-year survival (85%). Initial management of RAI requiring early repair of TAPVC remains challenging. For this high-risk subset, alternative strategies such as early referral for cardiac transplantation evaluation warrant consideration.

Noncompaction cardiomyopathy and heterotaxy syndrome

Left ventricular noncompaction cardiomyopathy (LVNC) is characterized by compact and trabecular layers of the left ventricular myocardium. This cardiomyopathy may occur with congenital heart disease (CHD). Single cases document co-occurrence of LVNC and heterotaxy, but no data exist regarding the prevalence of this association. This study sought to determine whether a non-random association of LVNC and heterotaxy exists by evaluating the prevalence of LVNC in patients with heterotaxy. In a retrospective review of the Indiana Network for Patient Care, we identified 172 patients with heterotaxy (69 male, 103 female). Echocardiography and cardiac magnetic resonance imaging results were independently reviewed by two cardiologists to ensure reproducibility of LVNC. A total of 13/172 (7.5%) patients met imaging criteria for LVNC. The CHD identified in this subgroup included atrioventricular septal defects [11], dextrocardia [10], systemic and pulmonary venous return abnormalities [7], and transposition of the great arteries [5]. From this subgroup, 61% (n = 8) of the patients developed arrhythmias; and 61% (n = 8) required medical management for chronic heart failure. This study indicates that LVNC has increased prevalence among patients with heterotaxy when compared to the general population (0.014-1.3%) suggesting possible common genetic mechanisms. Interestingly, mice with a loss of function of Scrib or Vangl2 genes showed abnormal compaction of the ventricles, anomalies in cardiac looping, and septation defects in previous studies. Recognition of the association between LVNC and heterotaxy is important for various reasons. First, the increased risk of arrhythmias demonstrated in our population. Secondly, theoretical risk of thromboembolic events remains in any LVNC population. Finally, many patients with heterotaxy undergo cardiac surgery (corrective and palliative) and when this is associated with LVNC, patients should be presumed to incur a higher peri-operative morbidity based on previous studies. Further research will continue to determine long-term and to corroborate genetic pathways.

Predictors of poor outcome among children with heterotaxy syndrome: a retrospective review

Objective

To determine predictors of poor outcome in patients with heterotaxy syndrome.

Methods

A retrospective review of children with heterotaxy syndrome, in a single tertiary paediatric cardiology centre, was conducted between 1 January 1997 and 1 January 2014 to determine predictors of poor outcome. Poor outcome was defined as death, cardiac transplantation or New York Heart Association (NYHA) functional class III or IV.

Results

There were 35 patients diagnosed with heterotaxy syndrome, 17 of whom were diagnosed antenatally. 22 patients had right atrial isomerism and 13 had left atrial isomerism. The median age of postnatal diagnosis was 2.5 days old (1 day to 19 months). 12 patients had a poor outcome; 6 patients died, 1 underwent cardiac transplantation and 5 had an NYHA functional class of >III. 5 patients had a biventricular repair and the remaining 30 had a univentricular repair. Type of atrial isomerism, univentricular or biventricular anatomy, severity of atrioventricular valve regurgitation or ventricular dysfunction, obstructed pulmonary venous return, occurrence of arrhythmia and presence of pulmonary atresia did not predict poor outcome. Fetal diagnosis also did not confer a survival advantage. The median duration of follow-up in this cohort was 65 months (2 days to 16.8 years).

Conclusions

Survival for patients with heterotaxy syndrome was 83% over a median follow-up of 65 months. 34% of patients had a poor outcome. None of the variables studied were predictive of death, transplantation or NYHA classification III or IV.

Impact of Era, Type of Isomerism, and Ventricular Morphology on Survival in Heterotaxy: Implications for Therapeutic Management

BACKGROUND

Heterotaxy has been demonstrated to reduce survival. There are several different subgroups of patients, however, and no single study has had a large number of patients and analyzed survival across the different subgroups such as patients born in different eras, patients with right and left isomerism, and patients with biventricular or functionally univentricular hearts. This study pools previously reported data from Kaplan-Meier curves and performs such subgroup analysis.

METHODS

A systematic review of the literature was performed to identify studies reporting survival of patients with the so-called "heterotaxy" by means of Kaplan-Meier survival curves. Data were extracted from these survival curves and then pooled together. A polynomial regression was then used to generate a pooled survival curve. This was done for all patients, those born in a more recent era, those with right and left isomerism, and those with biventricular or functionally univentricular hearts.

RESULTS

Those born in the more recent era (after 2000) had increased survival compared to the overall cohort. Those with left isomerism tended to have a survival benefit compared to those with right isomerism until about 16 years of age, beyond which those with right isomerism developed a survival benefit. Those with biventricular hearts had a survival benefit compared to those with left isomerism.

CONCLUSION

Survival in the so-called heterotaxy syndrome is based on several factors, which include era of birth, sidedness of isomerism, and whether the heart is biventricular or functionally univentricular.

Heterotaxy Syndrome: Proceedings From the 10th International PCICS Meeting

A session dedicated to heterotaxy syndrome was included in the program of the Tenth International Conference of the Pediatric Cardiac Intensive Care Society in Miami, Florida in December 2014. An invited panel of experts reviewed the anatomic considerations, surgical considerations, noncardiac issues, and long-term outcomes in this challenging group of patients. The presentations, summarized in this article, reflect the current approach to this complex multiorgan syndrome and highlight future areas of clinical interest and research.

Early- and Middle-Term Surgical Outcomes in Patients with Heterotaxy Syndrome

Objectives: Heterotaxy syndrome is a recognized risk factor for surgical cardiac interventions. We evaluated the early- and middle-term results of a surgical intervention for patients with heterotaxy syndrome. Methods: A total of 42 patients with heterotaxy syndrome were enrolled (September 2008 to March 2015). Left and right atrial isomerism were identified in 26% (11 out of 42) and 74% of patients (31 out of 42), respectively. The median age of the patients at the time of surgery was 6.8 months (range: 5 days to 22.3 years). Biventricular repair was completed in 3 patients with left atrial isomerism. Seventeen out of 39 patients who were scheduled for single ventricular repair completed a modified Fontan procedure. Results: The hospital mortality rate was 4.7% (2 out of 42). Another 5 deaths occurred in the remaining survivors following hospital discharge with a follow-up duration of 45.8 ± 23.6 months (range: 13-111 months). The 1-year and 5-year survival rates were 88.1% (37/42) and 83.3% (35/42), respectively. Univariate analysis and multivariate analysis identified pulmonary venous obstruction and atrioventricular valve replacement as additional risk factors for mortality. Conclusions: Right ventricular bypass surgery remains the preferred palliative procedure for patients with heterotaxy syndrome. Based on the current results, the early- and middle-term outcomes are satisfactory.

Biventricular repair in heterotaxy patients

BACKGROUND

Heterotaxy patients' hearts may or may not be suitable for biventricular repair depending on anatomy. Even in the subset that are amenable to surgical septation, cardiac anatomy may present multiple difficulties in achieving a satisfactory repair. However, it is also well known that heterotaxy patients are not ideal candidates for univentricular repair.

METHODS

From 2007 until 2012, a total of 20 patients (11 male) with heterotaxy syndrome underwent biventricular repair (left atrial isomerism: 10 and right atrial isomerism: 10) in our center. Their median age at surgery was 40 (range: 3-108) months. Ten patients had dextrocardia. Eleven patients presented with bilateral superior vena cava, three with inferior vena cava (IVC) draining into left atrium, and six with IVC interruption with azygos or hemiazygos continuation. Anomalous pulmonary venous drainage was present in eight patients. One had a common atrium. Atrioventricular septal defect (AVSD) occurred in nine (complete AVSD in seven) patients. Eight patients had double outlet right ventricle (DORV), one had d-transposition of great arteries (d-TGA), and two had congenitally corrected transposition of the great arteries (CC-TGA). Prior palliative procedures included pulmonary artery banding in three patients and left modified Blalock-Taussig shunt in one patient. Complex intra-atrial baffle constructions were required in all patients to direct pulmonary and systemic venous inflow to the appropriate ventricle. Complete AVSDs were corrected using two-patch technique. Intraventricular tunnel repair was done for DORV. Combined atrial and arterial switch was required to rectify abnormal connections in a child with congenitally corrected transposition with normal pulmonary valve, while a Rastelli + Senning was needed in two children with CC-TGA with pulmonary atresia (n = 1) and double outlet of the right ventricle (n = 1).

RESULTS

Major early postoperative complications included intestinal gangrene in four patients for which they underwent bowel resection. Two of these patients could not be salvaged. One patient required coiling of aortopulmonary collateral for early postoperative pulmonary hemorrhage. Two patients needed a tracheostomy for prolonged mechanical ventilatory support. Five patients had a pacemaker implanted for complete heart block. There were no instances of atrial baffle stenosis. Median follow-up was 27 (range: 2-46) months. There was one late death secondary to pneumonia.

CONCLUSIONS

Satisfactory survival outcomes can be achieved in heterotaxy patients who undergo hemodynamically acceptable biventricular repair. Borderline ventricular hypoplasia and trivial atrioventricular valve regurgitation should not be considered as discouraging factors in anatomically suitable heterotaxy patients as it is possible to adopt a two-stage repair in such patients to achieve biventricular repair at a later stage. Anticipating a higher incidence of conduction problems and gut malrotation preemptively can help reduce the morbidity.

Racial disparities in heterotaxy syndrome

BACKGROUND

Heterotaxy syndrome (HTX) is a constellation of defects including abnormal organ lateralization and often including congenital heart defects. HTX has widely divergent population-based estimates of prevalence, racial and ethnic predominance, and mortality in current literature.

METHODS

The objective of this study was to use a population-based registry to investigate potential racial and ethnic disparities in HTX. Using the Texas Birth Defects Registry, we described clinical features and mortality of HTX among infants delivered from 1999 to 2006. We calculated birth prevalence and crude prevalence (cPR) ratios for infant sex, maternal diabetes, and sociodemographic factors.

RESULTS

A total of 353 HTX cases were identified from 2,993,604 births (prevalence ratio = 1.18 per 10,000 live births. HTX prevalence was approximately 70% higher among infants of Hispanic and non-Hispanic black mothers and 28% higher among female infants (cPR = 1.28; 95% confidence interval,1.04-1.59). There was a twofold higher female preponderance for infants of mothers who were non-Hispanic white or black. Mothers with diabetes were three times more likely to have a child with HTX compared with nondiabetics (cPR = 3.13; 95% confidence interval, 2.12-4.45). Among nondiabetics, HTX cases were 86% more likely to have a Hispanic mother and 72% a non-Hispanic black mother. First-year mortality for live born children with HTX was 30.9%.

CONCLUSION

This study represents one of the largest population-based studies of HTX to date, with a novel finding of higher rates of HTX among Hispanic infants of mostly Mexican origin, as well as among female infants of only non-Hispanic white and black mothers. These findings warrant further investigation.

Perinatal and infant outcomes of prenatal diagnosis of heterotaxy syndrome (asplenia and polysplenia)

Patients with heterotaxy syndrome (HS) have a range of anomalies and outcomes. There are limited data on perinatal outcomes after prenatal diagnosis. To determine the factors influencing perinatal and infant outcomes, we analyzed prenatal and postnatal variables in fetuses with HS from 1995 to 2011. Of 154 fetuses with HS, 61 (40%) had asplenia syndrome (ASP) and 93 (60%) had polysplenia syndrome (PSP). In the ASP group, 22 (36%) patients were elected for termination of pregnancy, 4 (10%) had fetal death, and 35 of 39 (90%) continued pregnancies were live born. In the PSP group, 12 (13%) patients were elected for termination of pregnancy, 5 (6%) had fetal death (4 with bradyarrhythmia), and 76 of 81 (94%) continued pregnancies were live born. Bradyarrhythmia was the only predictor of fetal death. In the live-born ASP group, 43% (15 of 35) died, 7 because of pulmonary vein stenosis, 4 postoperatively, and 4 because of noncardiac causes. In the live-born PSP group, 13% (10 of 76) died, 5 postoperatively, 2 from bradyarrhythmia, 1 from a cardiac event, and 2 from noncardiac causes. Pulmonary vein stenosis and noncardiac anomalies were independent risk factors for postnatal death. Only 8% of ASP patients achieved biventricular circulation, compared with 65% of PSP patients. In the live-born cohort, the 5-year survival rate was 53% for ASP and 86% for PSP. In conclusion, most PSP patients are currently alive with biventricular circulation in contrast with few ASP patients. Bradyarrhythmia was the only predictor of fetal death. Pulmonary vein stenosis and noncardiac anomalies were predictors of postnatal death.

Management and outcomes of heterotaxy syndrome associated with pulmonary atresia or pulmonary stenosis

BACKGROUND

Historic outcomes of patients with heterotaxy and pulmonary atresia or pulmonary stenosis (PA/PS) have been poor and in the current era are incompletely described. We reviewed our management of these patients and associated risk factors for death.

METHODS

We retrospectively reviewed the records of all patients with heterotaxy and PA/PS treated in our institution from January 1, 2002, to August 31, 2012. Death data were also confirmed with the Social Security Death Index. The log-rank test was done to assess six risk factors for death.

RESULTS

We identified 42 patients with heterotaxy and PA/PS. Median age at the first operation was 6.5 days, and median follow-up was 3.5 years. Death data were complete for all patients. Overall mortality was 19% (8 of 42). The 30-day, 1-year, and 5-year mortality estimation was 4.76%, 12.3%, and 19.1% respectively, as determined by the Kaplan-Meier method. The log-rank test showed total anomalous pulmonary venous return (TAPVR) (p<0.05) and obstructed TAPVR requiring an operation at less than 30 days (p=0.001) were significant risk factors for death.

CONCLUSIONS

In the current era, surgical treatment of heterotaxy and PA/PS can result in good outcomes. Associated TAPVR and obstructed TAPVR requiring neonatal correction were noted to be risk factors for death.

Heterotaxy syndrome: impact of ventricular morphology on resource utilization

Patients with heterotaxy syndrome (HS) have significant cardiac and extracardiac anomalies that impact outcome. To improve the management of this complex patient population, we performed a comprehensive analysis of their anatomic and clinical features along with an evaluation of resource utilization data. The objectives were to describe anatomic and clinical features of patients with HS syndrome treated at a single center from 1992 to 2011 focusing on the impact of ventricular morphology (univentricular [UV] vs. biventricular [BV]) on clinical outcomes and resource utilization. Clinical and echocardiographic data from patients with HS were abstracted from medical records. Health care costs were indexed to inflation. Seventy-eight patients were identified with HS ranging in age from 1 day to 29 years old. UV morphology was present in 46 patients (59 %), most commonly with right-ventricular dominance (36 of 46). The presence of extra cardiac anomalies did not differ between the UV and BV groups (82 vs. 78 %) nor did morbidities, such as need for enteral tube feedings (47 vs. 25 %) or pacemaker placement (24 vs. 25 %). Mortality was 28 % in the entire cohort: 39 % in univentricuar patients versus 10.5 % in those with biventricular anatomy. Hospital length of stay for medical illnesses was similar in both groups, but length of stay after surgery was significantly longer in UV than BV patients. Among survivors, UV patients had greater median hospital costs (TeX 67,732, p < 0.001), but when this was adjusted for mortality and variable follow-up, there were no differences in health care costs within the first year of life. Significant health care dollars are used to manage children with HS, the majority of which involve expenses related to surgical care. Although patients with biventricular morphology have better survival, morbidity and resource utilization are similar to those for UV patients especially within the first year of life.

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.

Strategies to maintain biventricular circulation in patients with high-risk anatomy

Although hypoplasia of left heart structures presents with a spectrum of severity, management decisions are typically dichotomous: single-ventricle palliation or biventricular repair. Since the long-term outcomes of single-ventricle palliation are sub-optimal, strategies to aggressively pursue biventricular circulation in patients with borderline left heart structures have been developed. Recent strategies and surgical techniques to rehabilitate the left heart in patients with borderline left heart are described.

Systemic venous anomalies in the Middle East

INTRODUCTION

Systemic venous anomalies are quite rare and can be associated with congenital heart disease requiring surgery.

MATERIALS AND METHODS

All consecutive patients (pts) undergoing surgery for congenital heart defects were retrospectively analyzed for presence of systemic venous anomalies: (a) Persistent left superior vena cava (PLSVC)(b) Inferior vena cava (IVC) interruption(c) Retro-aortic innominate vein Results: From 9/2010 to 5/2012 155 pts, median age 7 months, mean age 1.3 years (3 days-50 years), median weight 4 kg, mean weight 7.2 kg (0.6-110 kg) underwent congenital heart surgery. Twenty-nine systemic venous anomalies were identified in 28/155 patients (=18.1%). PLSVC was present in 21 pts (=13.5%), median age 4 months, mean age 2.7 years (3 days-22 years), median weight 6 kg, mean weight 10.1 kg (2.4-43.0 kg). IVC interruption was identified in 5 pts (=3.2%), median age 2 months, mean age 5.4 years (30 days-26 years), median weight 3.7 kg, median weight 17 kg (2.3-68.0 kg). Retro-aortic innominate vein was diagnosed in 3 pts (=1.9%), median age 5 years, mean age 3.7 years (10 months-5 years), median weight 12 kg, mean weight 10.1 kg (4.5-14 kg). Complete pre-operative diagnosis was obtained in 14/28 (=50%) pts with echocardiography and in other 8/28 (=28.6%) only after computed tomography (CT) scan, for a total of 22/28 (=78.6%) correct pre-operative diagnosis. In 6/28 (=21.4%) patients the diagnosis was intra-operative. Total incidence of systemic venous anomalies was 18.1% (vs. 4% in the literature, P = 0.0009), with presence of PLSVC = 13.5% (vs. 0.3-4.0%, respectively P = 0.0004 and P = 0.0012), IVC interruption = 3.2% (vs. 0.1-1.3%, N.S.), and retro-aortic innominate vein = 1.9% (vs. 0.2-1%, N.S.).

CONCLUSIONS

Our study showed an incidence of systemic venous anomalies in Middle Eastern pts with congenital heart defects higher than previously reported. In 78.6% of pts the diagnosis was correctly made before surgery (echocardiography or CT scan), with 21.4% of complete diagnosis made at surgery. A careful pre-operative screening should be performed in all pts with congenital heart defects from this region to better identify all systemic venous anomalies for a more accurate surgical planning.

Anatomic biventricular repair in right isomerism with noncommitted ventricular septal defect

Biventricular repair in right atrial isomerism is rarely feasible due to associated anomalies of venous connection, ventricular imbalance, nonroutabilty of the interventricular communication, a common atrioventricular junction, and inadequate pulmonary arterial branches. These patients are also often not ideal for univentricular repair due to some of the above associations. We describe a novel surgical technique that was utilized in such a patient for biventricular repair of a child with right atrial isomerism with total anomalous pulmonary venous connection, regurgitant common atrioventricular valve, hypoplastic left ventricle, nonroutable ventricular septal defect, and pulmonary stenosis.

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.

Heterotaxy syndrome

Heterotaxy is defined as an abnormality where the internal thoraco-abdominal organs demonstrate abnormal arrangement across the left-right axis of the body. This broad term includes patients with a wide variety of very complex cardiac lesions. Patients with heterotaxy can be stratified into the subsets of asplenia syndrome and polysplenia syndrome, or the subsets of heterotaxy with isomerism of the right atrial appendages and heterotaxy with isomerism of the left atrial appendages. Treatment of patients with isomerism is determined by the nature and severity of the associated cardiac and extracardiac lesions. Most cardiac operations for patients with isomerism are palliative in nature, since normal anatomy is rarely achieved and mortality rates remain high for patients with heterotaxy syndrome. Patients with left isomerism in general have less severe cardiac malformations than those with right isomerism and, hence, more chance of biventricular repair. For almost all patients with right isomerism, and for many with left isomerism, biventricular repair will not be feasible, and all palliative protocols are then staging procedures prior to a Fontan-type repair. Recent advances in medical management, and improvements in surgical techniques have resulted in improved survival for these patients, and the surgical outcomes are comparable to those with Fontan circulation irrespective of the presence or absence of heterotaxy.

Surgical Management of the Neonate With Heterotaxy and Long-Term Outcomes of Heterotaxy

A review of the many challenges facing the neonate with heterotaxy has identified total anomalous pulmonary venous connection, atrioventricular valve abnormalities, pulmonary atresia, and arrhythmias including heart block as particular risk factors for the child who will pursue a single-ventricle pathway. Experience varies widely between different centers as to the percentage of patients who are suitable for biventricular repair, ranging from less than 20% to greater than 50%. Biventricular repair may only require simple baffling of anomalous systemic or pulmonary veins or may involve complex intraventricular baffle repair of double-outlet right ventricle with common atrioventricular valve. The long-term complications of heterotaxy include accelerated development of pulmonary arteriovenous malformations after the Kawashima procedure, high mortality and morbidity for the Fontan procedure (although improving results have been reported more recently), and the development of late arrhythmias. Extracardiac problems include a high risk of volvulus if malrotation is present, suggesting the need for an elective Ladd procedure. The presence of associated ciliary dyskinesia appears to be associated with an increased risk of postoperative morbidity, particularly ventilator dependence and other respiratory complications. The child with heterotaxy faces many challenges that are often underappreciated by both caregivers and families.

Impact of prenatal diagnosis and anatomical subtype on outcome in double outlet right ventricle

BACKGROUND

We sought to investigate the influence of prenatal diagnosis and risk factors for adverse outcomes in double outlet right ventricle (DORV) not associated with heterotaxy.

METHODS

Patients with a pre or postnatal diagnosis of DORV from 2000 to 2007 were identified and classified into 3 subgroups: subaortic ventricular septal defect (VSD) and normal great artery (GA) arrangement (=VSD type), tetralogy of Fallot type, and transposition of the GA type (=TGA type). Patients with heterotaxy, atrioventricular septal defect, valve atresia, and ventricular hypoplasia were excluded. Complex postnatal care was defined as prematurity, need for prostaglandins, surgical repair <2 months, or univentricular palliation. Risk factors for complex postnatal care and demise were sought in multivariable logistic regression models. One hundred fort-five patients were included (93 prenatal, 52 postnatal).

RESULTS

There were 24 pregnancy terminations and 7 in utero deaths. Fetal demise was associated with abnormal karyotype (odds ratio [OR] 1.9, P = .01), any tricuspid valve regurgitation (OR 10.6, P = .01), and hydrops (OR 23.8, P = .02). Of 114 liveborn patients, 23 were tetralogy-type, 67 VSD-type, and 24 TGA-type patients. Postnatal survival of liveborn patients at 1 year was similar in pre- versus postnatally diagnosed patients (84% vs 85%). Abnormal GA relationship (OR 2.9, P = .02), subpulmonary VSD (OR 6.0, P = .001), unobstructed pulmonary blood flow at birth (OR 2.8, P = .05), and aortic coarctation (OR 9.0, P = .007) were associated with suboptimal postsurgical outcomes.

CONCLUSION

Double outlet right ventricle, even without heterotaxy, is associated with complex postnatal care and high risk of early demise. Morphologic subtype, irrespective of pre- or postnatal diagnosis, is a major determinant of outcome.

Intraatrial baffle repair of anomalous systemic venous return without hepatic venous drainage in heterotaxy syndrome

A 7-month-old boy with heterotaxy syndrome had partial atrioventricular septal defect and interrupted inferior vena cava with hemiazygos continuation to a left superior vena cava. The left side of the common atrium receiving all the venous drainage was in connection with the left ventricle and the aorta. The small atrium and the proximity of the pulmonary and hepatic vein orifices precluded complete baffling. This report describes an intraatrial baffle repair of anomalous systemic venous return without hepatic venous drainage. This resulted in good oxygenation postoperatively, with oxygen saturation ranging from 93% to 98%.

Left atrial isomerism: biventricular repair

OBJECTIVE

Biventricular repair of hearts with left atrial isomerism often necessitates complex atrial and ventricular baffle procedures. We analysed our experience with an accent on baffle techniques.

METHODS

From 1997 until 2008, 12 patients (four male) with left atrial isomerism received biventricular repair. Their median age at surgery was 9 (range: 1-24) months. Four patients had dextrocardia. Nine patients presented with left superior vena cava, three with absent right superior vena cava, five with unroofed coronary sinus and nine others with inferior vena cava interruption with (hemi)azygos continuation. Anomalous pulmonary venous drainage was present in three patients. Eight had a monoatrium. Atrioventricular septal defect (AVSD) occurred in six (complete AVSD in two), One patient with complete AVSD had right pulmonary agenesia with long segment tracheal stenosis. Multiple VSDs presented in one whereas three patients had double-outlet right ventricle (DORV) (one with borderline LV hypoplasia). Two had previous pulmonary artery banding. Complex intra-atrial baffle constructions were performed in seven patients. Complete AVSDs were corrected using two patches and all other AVSDs had one patch repair. Multiple VSDs were closed directly. DORV patients had intraventricular tunnel repair.

RESULTS

No early mortality occurred. Median follow-up was 54 (range: 2-134) months. One patient with complete AVSD and pulmonary agenesia died late after tracheal repair. Four patients needed five re-operations (closure of residual ASD (one), relief of left (two) or right (two) ventricular outflow obstruction, pulmonary artery branch plasty (one)). There was no atrial baffle stenosis. Four received a pacemaker. All survivors are in NYHA class I.

CONCLUSIONS

Survival and functional status of left isomerism patients after biventricular repair is good. Complex repairs with atrial or ventricular baffles are frequent. Arrhythmias were common and pose a concern late after repair.