Current treatment and prognosis in children with functionally univentricular hearts

Cyanotic Congenital Heart Disease in Pregnancy: A Review of Pathophysiology and Management

The advancement of medical treatment and surgical technique, along with the invention of cardiopulmonary bypass, has allowed for long-term survival of patients with cyanotic congenital heart disease (CHD)-with many women with CHD now reaching child-bearing age and wishing to become pregnant. Pregnancy in these women is a major concern as the physiologic adaptations of pregnancy, including an increased circulating volume, increased cardiac output, reduced systemic vascular resistance, and decreased blood pressure, place a substantial load on the cardiovascular system. These changes are essential to meet the increased maternal and fetal metabolic demands and allow for sufficient placental circulation during gestation. However, in women with underlying structural heart conditions, they place an additional hemodynamic burden on the maternal body. Overall, with appropriate risk stratification, pre-conception counseling, and management by specialized cardiologists and high-risk obstetricians, most women with surgically corrected CHDs are expected to carry healthy pregnancies to term with optimization of both maternal and fetal risks. In this article, we describe the current understanding of 5 cyanotic CHDs-Tetralogy of Fallot, Transposition of the Great Arteries, Truncus Arteriosus, Ebstein's Anomaly, and Eisenmenger Syndrome-and explore the specific hemodynamic consequences, maternal and fetal risks, current guidelines, and outcomes of pregnancy in women with these conditions.

Role of cardiac MRI in the prediction of pre-Fontan end-diastolic ventricular pressure

BACKGROUND

Growing evidence has emphasised the importance of ventricular performance in functionally single-ventricle patients, particularly concerning diastolic function. Cardiac MRI has been proposed as non-invasive alternative to pre-Fontan cardiac catheterisation in selected patients.

AIM OF THE STUDY

To identify clinical and cardiac magnetic resonance predictors of high pre-Fontan end-diastolic ventricular pressure.

METHOD

In a retrospective single-centre study, 38 patients with functionally univentricular heart candidate for Fontan intervention, who underwent pre-Fontan cardiac catheterisation, beside a comprehensive cardiac MRI, echocardiographic, and clinical assessment were included. Medical and surgical history, cardiac magnetic resonance, cardiac catheterisation, echocardiographic, and clinical data were recorded. We investigated the association between non-invasive parameters and cardiac catheterisation pre-Fontan risk factors, in particular with end-diastolic ventricular pressure. Moreover, the impact of conventional invasive pre-Fontan risk factor on post-operative outcome as also assessed.

RESULTS

Post-operative complications were associated with higher end-diastolic ventricular pressure and Mayo Clinic indexes (p < 0.01 and p = 0.05, respectively). At receiver operating characteristic curve analysis end-diastolic ventricular pressure ≥ 10.5 mmHg predicted post-operative complications with a sensitivity of 75% and specificity of 88% (AUC: 0.795, 95% CI 0.576;1.000, p < 0.05). At multivariate analysis, both systemic right ventricle (OR: 23.312, 95% CI: 2.704-200.979, p < 0.01) and superior caval vein indexed flow (OR: 0.996, 95% CI: 0.993-0.999, p < 0.05) influenced end-diastolic ventricular pressure ≥ 10.5 mmHg.

CONCLUSIONS

A reduced superior caval vein flow, evaluated at cardiac magnetic resonance, is associated with higher end-diastolic ventricular pressure a predictor of early adverse outcome in post-Fontan patients.

The Epidemiology of Persons Living with Fontan in 2020 and Projections for 2030: Development of an Epidemiology Model Providing Multinational Estimates

Introduction

Fontan surgery is a palliative procedure performed in children with a functionally univentricular heart. Improvements in surgical technique over the past 30 years have increased life expectancy in this rare population. However, the epidemiology of persons living with Fontan is poorly understood. This study aimed to estimate the 2020 and 2030 prevalence of persons living with a Fontan circulation in 11 countries across the US, Europe, Australia and New Zealand, by procedure type: [atriopulmonary connection (AP), lateral tunnel total cavopulmonary connection (LT-TCPC) or extracardiac total cavopulmonary connection (EC-TCPC)]; and age group: [children (< 12 years), adolescents (12–17 years), and adults (≥ 18 years old)] by building an epidemiologic model.

Methods

The annual number of Fontan surgeries by country in 2010–2020 were extracted from hospital or claims databases, via procedure codes. The epidemiology of persons living with Fontan was modelled by applying these surgery frequencies to mid-year populations from 1972 to 2020 and overlaying an uptake curve. A literature search identified: 30-day mortality rates, long-term survival, and median age at surgery. Averages of these estimates were inputted into the model to project prevalence in 2030.

Results

The number of persons living with Fontan in 2020 across the 11 countries was estimated to be 47,881 [66 people per million (ppm)], rising to 59,777 (79 ppm) by 2030. In 2020, this population was 55% adults, 17% adolescents and 28% children shifting to 64%, 13% and 23%, respectively, in 2030. Among all persons living with Fontan, 74%/18%/9% are estimated to have EC-TCPC/LT-TCPC/AP, respectively, in 2020, and 83%/14%/4% in 2030.

Conclusions

According to this epidemiology model, the Fontan population is growing, partly driven by increased survival rates with the more recent LT-TCPC and EC-TCPC procedures (compared with AP). The 2020/2030 prevalence of persons living with Fontan is 66/79 ppm.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12325-021-02002-3.

Growth and Nutritional Intake of Infants with Univentricular Circulation

OBJECTIVES

To evaluate the nutritional status and early nutritional intake of infants with univentricular congenital heart disease.

STUDY DESIGN

The included infants underwent a Norwood procedure or hybrid intervention (stage 1) within the first 6 weeks of life, between January 2014 and January 2019, at Children's Health Ireland at Crumlin. Demographic, anthropometric, nutritional intake, and morbidity data were collected.

RESULTS

Data were collected on 90 infants and 1886 neonatal admission days. There was a significant drop in mean weight-for-age z-score (WAZ) between measurements at birth, -0.01 and on discharge post stage 1 surgery -1.45 (P < .01). On hospital discharge (median hospital stay, 25 days) 32% of infants had a WAZ <-2 and 11% had a WAZ <-3. Pre-stage 1, 26% received trophic feeds and 39% received parenteral nutrition. Basal metabolic requirements and target caloric intake (120 kcal/kg) were met on 56% and 13% of admission days, respectively. Infants referred to a dietitian had a shorter time to any form of nutrition support, enteral feeds, and target caloric intake (P < .001, P = .016, and P = .048, respectively). At stage 3 (Fontan) surgery, 15% of infants were classified as stunted (length-for-age z-score [LAZ] <-2).

CONCLUSIONS

The greatest decline in nutritional status occurs in the neonatal period, followed by significant growth stunting by the time of the Fontan procedure. Early involvement of dietitians is critical in the care of this nutritionally fragile group. With the currently low rate of preoperative nutritional support, there may be opportunities to improve intake at this critical stage.

Arterial Stiffness in Congenital Heart Disease

Transposition of the great arteries (TGA), coarctation of the aorta (CoA), single ventricle (SV) and tetralogy of Fallot (ToF) are forms of congenital heart disease (CHD). Despite advances in treatment, cardiovascular and cerebrovascular complications in patients with repaired CHD occur earlier in life compared to healthy subjects. A factor that may contribute to this increased risk is elevated arterial stiffness. This systematic review provides a critical assessment of current evidence on central arterial stiffness in patients with CHD compared to healthy controls. In July 2020, Medline OVID, EMBASE and Scopus were searched using keywords and MeSH terms. Articles were included if they reported indices of aortic or carotid artery stiffness in patients with TGA, CoA, SV or ToF, and compared these to controls. Additional studies were screened from the reference lists of included articles. Of 1,033 studies identified, 43 were included in the final review. Most studies identified at least one index of central arterial stiffness, commonly in the aortic root or ascending aorta, that was higher in patients with CHD compared to controls. The commonly reported surrogate markers of stiffness were pulse wave velocity, aortic distensibility and the β stiffness index. There was a relatively small number of original studies, and synthesis of data was limited by methodological heterogeneity, highlighting the need for further studies with standardised methods. However, there was consistent evidence of early and/or accelerated arterial stiffening in CHD patients, which may contribute to the increased risk of adverse cardiovascular and cerebrovascular events in this population.

The Nutritional Status of Pediatric Patients with Single Ventricle Undergoing a Bidirectional Glenn Procedure

Single ventricle (SV) physiology is associated with growth retardation in children. The nutritional status of pediatric patients with SV undergoing a bidirectional Glenn (BDG) procedure vitally affects the feasibility of the next operation stages. To explore the nutritional status and to identify specific anthropometric parameters relevant to short-term surgical outcomes in children with SV after the BDG procedure, this study included 151 patients who underwent the BDG procedure. Anthropometric assessments and Infant and Child Feeding Index (ICFI) scores were used to evaluate nutritional status. There was a significant statistical correlation between ICFI and malnutrition in both the height-for-age Z-score (HAZ) and weight-for-age Z-score (WAZ) groups (P < 0.05). The clinical data, including ventilation time, nosocomial infection presence, pressure injury presence, peritoneal dialysis status, and total intensive care unit days, after BDG surgery were significantly different among the HAZ groups (P < 0.05), while nosocomial infection was different among the WAZ groups (P < 0.05). Children after BDG procedure had a high incidence of malnutrition, in addition to disease factors, the type and frequency of dietary intake were also important factors leading to worse clinical outcomes during hospitalization. Therefore, it is vital to maintain an optimal nutritional status in infants with SV who are undergoing a series of surgical procedures.

Tricuspid atresia: Where are we now?

Tricuspid atresia (TA) is a complex congenital heart disease that presents with cyanosis in the neonatal period. It is invariably fatal if left untreated and requires multiple stages of palliation. Early recognition and timely surgical intervention are therefore pivotal in the management of these infants. This literature review considers the pathophysiology, presentation, investigations, and classification of TA. Moreover, it discusses the evidence upon which the latest medical and surgical treatments are based, as well as numerous recent case reports. Further work is needed to elucidate the etiology of TA, clarify the role of pharmacotherapy, and optimize the surgical management that these patients receive.

Cardiovascular complications in patients with total cavopulmonary connection: A nationwide cohort study

BACKGROUND

Long-term outcomes are not well established at the population level after completion of the total cavopulmonary connection (TCPC) among patients with functional univentricular hearts.

PURPOSE

To evaluate the incidence of cardiovascular events after TCPC completion.

METHODS

From a validated population-based cohort, we identified 178 patients with TCPC circulation completed after January 1, 1995. We established a comparison cohort by frequency-matching patients 1:200 on sex, and month and year of birth to the general Danish population (n = 35,600 population controls). We started follow-up at date of TCPC completion for cases and, for controls, at the index date of their matched case. The risks of cardiovascular events were assessed using cumulative incidence rates and Poisson regression models adjusted for age, sex, and calendar year.

RESULTS

The median age at TCPC completion was 3.3 years (interquartile range 2.6 to 5.3 years). Over a median follow-up of 12.5 years, 10 (5.6%) TCPC patients died and 7 (4.5%) had a heart transplantation compared with a 0.2% mortality in the matched population. In TCPC patients, 15.7% had an arrhythmia (11.8% supraventricular tachycardia), 3.4% had a stroke (all ischemic), and 21.4% of TCPC patients initiated a combination of a diuretic and a renin-angiotensin system (RAS)-inhibitor. These rates were >50-fold higher than in the comparison cohort: 0.2% arrhythmia, 0.06% stroke, and 0.04% starting a diuretic and a RAS-inhibitor.

CONCLUSIONS

Patients with TCPC circulation face a high risk of cardiovascular events during intermediate term follow-up.

Molecular Approaches in Single Ventricle Management

Advances in medical and surgical management have significantly improved early outcomes in single ventricle congenital heart disease over the last 2 decades. Despite these advances, long-term outcomes remain suboptimal and therapeutic options to address systemic ventricular and/or Fontan failure are limited even in the modern era. Intricate molecular biologic techniques have shed light into the mechanisms of development of single ventricle disease. Efforts are underway to leverage this knowledge to improve clinical diagnosis, therapy, and prognostication. Cell-based therapies aimed at inducing cardiomyocyte proliferation and preventing delayed cardiac dysfunction have already entered the clinical realm. Several more novel biological therapies are expected to become available for patients with single ventricle disease in the near future. These scientific advancements provide us hope and reaffirm our faith that molecular medicine will usher in the next generation of therapies for single ventricle management.

A restrictive ventilatory pattern is common in patients with univentricular heart after Fontan palliation and associated with a reduced exercise capacity and quality of life

AIM

The Fontan circulation is highly dependent on ventilation, improving pulmonary blood flow and cardiac output. A reduced ventilatory function is reported in these patients. The extent of this impairment and its relation to exercise capacity and quality of life is unknown and objective of this study.

METHODS

This multicenter retrospective/cross-sectional study included 232 patients (140 females, age 25.6 ± 10.8 years) after Fontan palliation (19.8% atrioventricular connection; 20.3% atriopulmonary connection; 59.9% total cavopulmonary connection). Resting spirometry, cardiopulmonary exercise tests, and quality-of-life assessment (SF-36 questionnaire) were performed between 2003 and 2015.

RESULTS

Overall, mean forced expiratory volume in one second (FEV₁ ) was 74.7 ± 17.8%predicted (%pred). In 59.5% of the patients, FEV₁ was <80%pred., and all of these patients had FEV₁ /forced vital capacity (FVC) > 80%, suggestive of a restrictive ventilatory pattern. Reduced FEV₁ was associated with a reduced peakVO₂ of 67.0 ± 17.6%pred. (r = 0.43, P < .0001), even if analyzed together with possible confounding factors (sex, BMI, age, years after palliation, number of interventions, scoliosis, diaphragmatic paralysis). Synergistically to exercise capacity, FEV₁ was associated to quality of life in terms of physical component summary (r = 0.30, P = .002), physical functioning (r = 0.25, P = .008), bodily pain (r = 0.22, P = .02), and general health (r = 0.16, P = .024). Lower FEV₁ was associated with diaphragmatic paralysis (P = .001), scoliosis (P = .001), higher number of interventions (P = .002), and lower BMI (P = .01). No correlation was found to ventricular morphology, type of surgeries, or other perioperative/long-term complications.

CONCLUSIONS

This study shows that the common restrictive ventilatory pattern in Fontan patients is associated with lower exercise capacity and quality of life. Risk factors are diaphragmatic paralysis, scoliosis, a high total number of interventions and low BMI.

Understanding Stage II Bidirectional Cavopulmonary Shunts

Despite improvements in surgical technique and medical management, single-ventricle lesions remain one of the most challenging congenital heart anomalies to treat, and mortality rates are high. Most infants who have single-ventricle palliation undergo a sequence of surgeries to optimize pulmonary and systemic blood flow. The first surgery to separate pulmonary and systemic blood flow is the bidirectional cavopulmonary shunt. This article describes single-ventricle lesions and gives a basic overview of outcomes and strategies to improve interstage mortality. Preoperative investigations that evaluate stage II candidacy are reviewed along with surgical approaches and postoperative physiology. Although mortality rates are low and decreasing in patients with bidirectional cavopulmonary shunts, morbidity is still a challenge. Nurses must understand the pertinent anatomy and physiology and recognize postoperative complications early in order to reduce morbidity. Postoperative complications, management, outcomes and nursing care are discussed.

Comparative Noninvasive Measurement of Cardiac Output Based on the Inert Gas Rebreathing Method (Innocor®) and MRI in Patients with Univentricular Hearts

There are many complex cardiac malformations that are characterized by a functionally univentricular physiology. Staged surgical repair according to the Fontan principle separates the systemic and pulmonary circulations by connecting the systemic venous return to the pulmonary arteries. However, long-term follow-up studies demonstrate a gradual deterioration of cardiac function, particularly from the second or third decade. Noninvasive evaluation of the cardiac function is, therefore, important in the follow-up of these patients. The cardiac index (CI) is a reliable hemodynamic parameter and represents an important marker of cardiac function. We compared CI values determined by cardiac MRI (CMRI) with values obtained by noninvasive inert gas rebreathing (IGR; Innocor® system). Sixteen patients (age range: 7.2-32.7 years) with functionally univentricular hearts (UVH) following total cavopulmonary connection (TCPC) were compared with 12 healthy subjects (age range: 8.5-18.6 years). The standard treadmill protocol of the German Society of Pediatric Cardiology was used for exercise testing. CI was determined at rest and at two standardized submaximal exercise levels. In all subjects, CI increased under exercise conditions, but the values were significantly lower in patients with UVH. There was no significant difference between patients with UVH and predominantly right- or left-ventricular morphology. In comparison with CMRI measurements, the CI values obtained by the IGR method tended to be lower, with a mean difference of 1.02 l/min/m². Noninvasive measurement of CI with the IGR method is feasible at rest and during exercise, and appears to be suited for routine determination of CI in patients with UVH following TCPC.

Anatomical Repair Conversion After Bidirectional Cavopulmonary Shunt for Complex Cardiac Anomalies: Palliation is Not a One-Way Path

Complex cardiac anomalies are sometimes channeled toward Fontan palliation for various reasons. Nevertheless, anatomical repair after bidirectional cavopulmonary shunt may be another option with theoretical benefits. In this study, we report our experience with anatomical repair conversion in challenging patients who had been palliated with bidirectional cavopulmonary shunt. Retrospective review was conducted in patients who underwent anatomical repair conversion from prior bidirectional cavopulmonary shunt palliation between January 2008 and March 2016. Patients who underwent a planned staged 1½-ventricular repair were excluded. Twenty-three patients underwent anatomical repair conversion at a median age of 6.5 years (range 2.7-20.0 years). The interval time between palliation and conversion was 4.6 ± 2.4 years (range 0.9-12.4). Indications for conversion were high-risk Fontan candidates (n = 11) and preference for biventricular anatomy (n = 12). In eight of the patients, bidirectional cavopulmonary shunts were taken down and superior vena cava was reconnected to the right atrium with Gore-Tex tube or bovine jugular venous tube. Mean cardiopulmonary bypass and aortic cross-clamp times were 225.6 ± 107.0 and 138.3 ± 76.6 min, respectively. After a mean follow-up of 2.7 ± 2.2 years, there was no mortality and reoperation. No patients presented sinoatrial node dysfunction and superior venous cave stenosis. All the patients were in the New York Heart Association functional class I or II. Patients with previous bidirectional cavopulmonary shunt should be re-evaluated before completion of Fontan and, if cardiac anatomy allows, anatomical repair conversion may be considered, especially in patients with high-risk Fontan completion. Initial bidirectional cavopulmonary shunt palliation should not be considered as a one-way path to Fontan. Although technically challenging, early- and mid-term clinical results of anatomical repair conversion were satisfactory.

[Safety of repeat median sternotomy in the palliative treatment of patients with a univentricular heart]

OBJECTIVE

To establish the morbidity and mortality of patients with univentricular hearts who underwent a repeat median sternotomy at the Instituto Nacional de Pediatría.

METHOD

A retrospective review was performed on the clinical charts of all patients who underwent a repeat median sternotomy from 2001 to 2016.

RESULTS

Sixty-five patients underwent 76 surgeries by repeat median sternotomy. Fifty-nine patients had a first repeat median sternotomy, with a mean age of 36 months (range: 4-176 months) and a mean weight of 12.2 kg (range: 3.2-21.5 kg). Forty patients had a Glenn procedure, and 19 patients had a Fontan procedure. There were 17 patients with a second repeat median sternotomy, with a mean age of 89 months (range 48-156 months), and a mean weight of 22.7 kg (14.4-41 kg). A Fontan procedure was performed on all these 17 patients. A section of the right coronary artery with electrocardiographic changes and a right atrium tear that caused hypotension occurred during first repeat sternotomy. An aortic tear occurred during a second repeat sternotomy with massive bleeding and subsequent death. This represents 3.9% of re-entry injuries.

CONCLUSION

It is concluded that repeat median sternotomy is a safe procedure.

Major stroke in a 19-year-old patient with a univentricular heart

Patients with univentricular heart malformations are at increased risk of suffering from thromboembolic events. We present a case of a 19-year-old woman born with a univentricular heart who suffered a major stroke while being treated with only salicylic acid. At least 20% of patients with univentricular hearts have been reported to experience thromboembolic events, of which 25% are fatal. Despite the high incidence of thromboembolic events, no consensus has been reached regarding the role of long-term anti-thrombotic treatment in this group of patients. This lack of consensus warrants future studies that compare the different therapeutic strategies.

Use of a self-expanding custom-made stent graft to treat lateral tunnel leak, stenosis, and fenestration in the Fontan pathway

A 12-year-old girl with hypoplastic right heart, double inlet left ventricle, and transposition of the great arteries had a lateral tunnel Fontan operation 8 years previously. She developed symptoms related to a combination of stenosis in the inferior caval venous pathway, a fenestration, and leak in the lateral tunnel. These were successfully treated with a custom-made stent graft.

Functional health status of adolescents after the Fontan procedure -- comparison with their siblings

BACKGROUND

Studies have suggested that patients who have undergone the Fontan procedure experience lower functional health status and diminished exercise capacity compared with other children.

OBJECTIVES

To compare the functional health status of Fontan patients with and without siblings, assess whether there are any differences between Fontan patients and their siblings, and determine associated factors.

METHODS

A cross-sectional, single-centre, observational study was performed on Fontan patients 10 to 20 years of age, and their sibling closest in age, followed in a tertiary pediatric hospital. Functional health status was measured by the Child Health Questionnaire Child Form and the Pediatric Quality of Life Inventory.

RESULTS

A total of 68 patients and 38 siblings were enrolled. Patients with siblings scored significantly lower on numerous domains of physical functional status than those without siblings. Compared with their matched siblings, Fontan patients reported significantly lower scores in all domains of the Pediatric Quality of Life Inventory and on physical (but not psychosocial) domains of the Child Health Questionnaire Child Form. Factors associated with increased patient-sibling differences included younger patient age, female sex, intracardiac lateral tunnel Fontan connection and lower ejection fraction at the time of study enrollment.

CONCLUSIONS

Adolescents with Fontan physiology reported a lower functional health status in physical domains than their siblings, but had similar status in psychosocial domains. Having a sibling was associated with lower reported functional health status, suggesting an important effect of self-perceived physical limitations over true limitations.

Hemodynamic performance of stage-2 univentricular reconstruction: Glenn vs. hemi-Fontan templates

Flow structures, hemodynamics and the hydrodynamic surgical pathway resistances of the final stage functional single ventricle reconstruction, namely the total cavopulmonary connection (TCPC) anatomy, have been investigated extensively. However, the second stage surgical anatomy (i.e., bi-directional Glenn or hemi-Fontan template) has received little attention. We thus initiated a multi-faceted study, involving magnetic resonance imaging (MRI), phase contrast MRI, computational and experimental fluid dynamics methodologies, focused on the second stage of the procedure. Twenty three-dimensional computer and rapid prototype models of 2nd stage TCPC anatomies were created, including idealized parametric geometries (n = 6), patient-specific anatomies (n = 7), and their virtual surgery variant (n = 7). Results in patient-specific and idealized models showed that the Glenn connection template is hemodynamically more efficient with (83% p = 0.08 in patient-specific models and 66% in idealized models) lower power losses compared to hemi-Fontan template, respectively, due to its direct end-to-side anastomosis. Among the several secondary surgical geometrical features, stenosis at the SVC anastomosis or in pulmonary branches was found to be the most critical parameter in increasing the power loss. The pouch size and flare shape were found to be less significant. Compared to the third stage surgery the hydrodynamic resistance of the 2nd stage is considerably lower (both in idealized models and in anatomical models at MRI resting conditions) for both hemi- and Glenn templates. These results can impact the surgical design and planning of the staged TCPC reconstruction.

Relative cardiac expression of growth hormone receptor and insulin-like growth factor-I mRNA in congenital heart disease

GH may exert direct growth-promoting and metabolic actions on target tissues, but most of its effects are mediated by circulating (endocrine) or local (auto-/paracrine) IGF-I. The GH/IGF-I system has an important role in cardiac development and in maintaining the structure and function of the heart. A subgroup of children with pronounced heart defects will eventually need transplants, owing to congestive heart failure. Since the symptoms are often severe and may progress while waiting for surgery, it is necessary to develop supportive medical treatment. GH has been proposed as a therapeutic agent in adults with heart failure, but to date studies are lacking on children and more information is necessary. We have examined the expression of IGF-I mRNA and GH-receptor (GH-R) mRNA in children undergoing surgery for congenital heart disease. Eighteen children scheduled for open-heart surgery were included in the study. Right auricular biopsies were taken at the time of venous catheterization preceding cardiac bypass. The specimens were analysed using realtime PCR. We were able to show expression of both IGF-I mRNA and GH-R mRNA in the pediatric heart. The relative expressions were intercorrelated (r=0.75, p<0.001). GH-R mRNA correlated positively to standardized weight (r=0.65, p=0.004), body mass index (BMI) (r=0.59, p=0.01), and standardized BMI (r=0.59, p=0.01). IGF-I mRNA only correlated to BMI (r=0.50, p=0.04). This is the first study displaying cardiac expression of IGF-I mRNA and GH-R mRNA in children with congenital heart disease, although further studies are needed to define a role for GH in the treatment of these patients.

Clinical Implications of Major Aortopulmonary Collateral Arteries in Patients With Right Isomerism

BACKGROUND

The presence of major aortopulmonary collateral arteries (MAPCA) in patients with right isomerism may alter the prognosis, which is still unclear.

METHODS

From 1994 to 2003, 138 out of 155 patients (89%) with right isomerism had pulmonary stenosis or pulmonary atresia and constituted the study population.

RESULTS

Two groups of patients were identified, one with MAPCA and the other without. The MAPCA originating from descending thoracic aorta or aortic arch was noted in 9 patients (6.5%), with a median number of MAPCA being 3 (range, 2 to 4). Patients with MAPCA commonly had congestive heart failure (8/9, 89%) and frequent lower airway infection (6/9, 67%). In comparison with patients with MAPCA and without, the intrapericardial pulmonary artery was more frequently absent (2 of 9 vs 1 of 129, p < 0.001), and the pulmonary arterial size was smaller (McGoon ratio <1.5, 8 of 9 vs 57 of 129, p = 0.009) in the MAPCA group. The mean pulmonary arterial pressure measured was often higher than the suggested limit for Fontan circulation. Major aortopulmonary collateral arteries were addressed at a median of 6 months old (2 to 19 months old) in 5 patients. Although surgical mortality was not different for first-stage palliation and Glenn shunt in both groups, total cavopulmonary connection could only be performed in one patient with MAPCA with poor results. However, the 5-year survival of patients with and without MAPCA was not statistically different (74.1% vs 55.2%, p = 0.19).

CONCLUSIONS

The presence of MAPCA was uncommon but still noted in patients with right isomerism. It may cause heart failure and a less favorable pulmonary vasculature for a complete Fontan-type operation.

Fontan's operation: evolution from a procedure to a process

It was in 1971, Fontan and Baudet1published their experience using a surgical procedure to restore a physiologic circulation in three patients with tricuspid atresia. Of the three patients, two survived, thus ushering a new era in the treatment of children with complex forms of congenital cardiac disease. This operation itself, however, was the culmination of a series of experimental and clinical observations that underlined the clinical possibility totally to bypass the right side of the heart.