Management of hypoplastic left heart syndrome in the 1990s

Patient-Specific Multi-Scale Model Analysis of Hemodynamics Following the Hybrid Norwood Procedure for Hypoplastic Left Heart Syndrome: Effects of Reverse Blalock-Taussig Shunt Diameter

INTRODUCTION

The hybrid Norwood (HN) is a relatively new first stage palliative procedure for neonates with hypoplastic left heart syndrome, in which a sustainable uni-ventricular circulation is established in a less invasive manner than with the standard Norwood procedure. A computational multiscale model of the circulation following the HN procedure was used to obtain detailed hemodynamics. Implementation of a reverse-BT shunt (RBTS), a synthetic bypass from the main pulmonary to the innominate artery placed to counteract aortic arch stenosis, and its effects on local and global hemodynamics were studied.

METHODS

A post-op patient-derived anatomy of the HN procedure was utilized with varying degrees of distal arch obstruction, or stenosis, (nominal and 90% lumenal area reduction) and varying RBTS diameters (3.0, 3.5, 4.0 mm). A closed lumped parameter model (LPM) for the proximal and peripheral circulations was coupled to a 3D computational fluid dynamics (CFD) model in order to obtain converged flow fields for analysis.

RESULTS

CFD analyses of patient-derived anatomic configurations demonstrated consistent trends of vascular bed perfusion, vorticity, oscillatory shear index and wall shear stress levels. In the models with severe stenosis, implementation of the RBTS resulted in a restoration of arterial perfusion to near-nominal levels regardless of the shunt diameter. Shunt flow velocity, vorticity, and overall wall shear stress levels decreased with increasing shunt diameter, while shunt flow and systemic oxygen delivery increased with increased shunt diameter. In the absence of distal arch stenosis, large (4.0 mm) grafts may risk thrombosis due to low velocities and flow patterns.

CONCLUSION

Among the three graft sizes, the best option seems to be the 3.5 mm RBTS which provides a more organized flow similar to that of the 3.0 mm configuration with lower levels of wall shear stress. As such, in the setting of this study and for comparable HN physiologies our results suggest that: (1) the 4.0 mm shunt is a generous shunt diameter choice that may be problematic particularly when implemented prophylactically in the absence of stenosis, and (2) the 3.5 mm shunt may be a more suitable alternative since it exhibits more favorable hemodynamics at lower levels of wall shear stress.

Hypoplastic Left Heart Syndrome: Exploring a Paradigm Shift in Favor of Surgery

We hypothesized that enthusiasm for surgery increased for infants with hypoplastic left heart syndrome (HLHS) at Columbia University Medical Center (CUMC) between 1995 and 2012. We sought to identify factors that engendered this paradigm shift. Confidential surveys were distributed to providers at CUMC in 1995 and 2012 to measure enthusiasm for surgical intervention for HLHS. Surgical preference scores are presented as median [interquartile range]. Surveys were completed by 99/176 providers (56 % response rate) in 1995 and 153/267 (57 %) in 2012. The median surgical preference score for infants with HLHS increased from 35 [25-45] in 1995 to 45 [35-50] in 2012, P < 0.001. 53 %, 95 % CI [42, 64] of respondents recommended surgical intervention for a ward of the court in 1995 compared to 81 % [73, 89] in 2012, P < 0.001. In 2012, 64 % [53, 75] of respondents were more likely to recommend surgery than 10 years prior. The percentage of respondents who saw good outcomes following three-stage repair increased from 49 % [38, 60] in 1995 to 84 % [78, 90] in 2012, P < 0.001. The majority believed that parents should have the option of comfort care, 91 % [85, 97] in 1995 and 85 % [79, 91] in 2012, P = 0.06. In both eras, prematurity and additional surgical problems dissuaded providers from recommending surgical intervention. Despite the fact that most providers have seen good outcomes and now recommend surgery for infants with HLHS, the majority of providers still believe that the option of comfort care should be available to families.

Long-term progression and survival following Norwood Single Ventricle Reconstruction

PURPOSE OF REVIEW

Much data exist concerning Norwood discharge mortality. Less is known about late survival. Examining the available data in light of the Single Ventricle Reconstruction trial is insightful as focus shifts toward long-term survival.

RECENT FINDINGS

Data from 2000 to 2001 demonstrated approximately 40-50% 10-year survival, 30-40% or less between 10 and 15 years. The shape of the curves was characteristic; the majority of deaths within the first year, followed by a late constant phase. Publications from 2001 to 2005 suggested that various combinations of technical and perioperative modifications allowed hospital discharge survivals as high as 90-94%. As results matured (2005-2010) a consistent message was that, although the shape of the newer curves was similar (highest hazard in the first 1 year), higher hospital survival shifted the later phase to yield better long-term survival (70-85% between 5 and 10 years). Some emphasized right ventricle-based shunts as a 'cause' of improving results. Since 2010, the Single Ventricle Reconstruction trial has matured and has increasingly shifted opinion away from the right ventricle shunt as a 'cause' of improved results. The survival of the right ventricle shunt group is slightly higher at 3 years, but the 1-year statistical significance has been lost and the two groups converge. As the Single Ventricle Reconstruction study was based on the interaction between randomized shunt and survival, the secondary and other endpoint analyses must be cautiously considered.

SUMMARY

The current English-language literature suggests a 60-80% 5-10 year survival expectation. The shape of the survival curve remains; the highest hazard remains the first year before a later, stable phase is reached. Rather than a 'magic bullet' theory surrounding one technique or practice, centers have differentially adopted various combinations to optimize Norwood survival. Optimizing interstage I survival is a challenge to further increase the percentage of patients reaching the late, stable phase.

A systematic review of the impact of volume of surgery and specialization in Norwood procedure

Background

The volume-outcome relationship is supposed to be stronger in high risk, low volume procedures. The aim of this systematic review is to examine the available literature on the effects of hospital and surgeon volume, specialization and regionalization on the outcomes of the Norwood procedure.

Methods

A systematic literature search was performed in Medline, Embase, and the Cochrane Library. On the basis of titles and abstracts, articles of comparative studies were obtained in full-text in case of potential relevance and assessed for eligibility according to predefined inclusion criteria. All relevant data on study design, patient characteristics, hospital volume, surgeon volume and other institutional characteristics, as well as results were extracted in standardized tables. Study selection, data extraction and critical appraisal were carried out independently by two reviewers.

Results

We included 10 studies. All but one study had an observational design. The number of analyzed patients varied from 75 to 2555. Overall, the study quality was moderate with a huge number of items with an unclear risk of bias. All studies investigating hospital volume indicated a hospital volume-outcome relationship, most of them even having significant results. The results were very heterogeneous for surgeon volume.

Conclusions

The volume-outcome relationship in the Norwood procedure can be supported. However, the magnitude of the volume effect is difficult to assess.

Use of an administrative database to determine clinical management and outcomes in congenital heart disease

We review our 16-year experience using the large, multi-institutional database of the University HealthSystem Consortium to study management and outcomes in congenital heart surgery for hypoplastic left heart syndrome, transposition of the great arteries, and neonatal coarctation. The advantages, limitations, and use of administrative databases by others to study congenital heart surgery are reviewed.

Choices doctors would make if their infant had hypoplastic left heart syndrome: comparison of survey data from 1999 and 2007

Data suggest that despite improved surgical outcomes for infants with hypoplastic left heart syndrome (HLHS), the past two decades have seen little change in parents' decisions whether to choose surgery or palliative treatment without life-prolonging intervention. Data also suggest that doctors' predictions of the choices they would make if their own infant were diagnosed with HLHS do not correlate with their predictions of surgical outcomes. Although previous studies have compared rates of surgery and palliative treatment without life-prolonging intervention over time, no studies have assessed changes in doctors' attitudes. The current study used descriptive and quantitative statistics to compare responses from American pediatric cardiologists and congenital cardiac surgeons from studies conducted in 1999 and 2007. These doctors were asked what choice they believe they would make for their own affected infant. Comparison of responses from 1999 and 2007 showed no difference in the responses of cardiologists: 1999 (44 % surgery, 17 % palliative treatment, 40 % uncertain) versus 2007 (45 % surgery, 20 % palliative treatment, 35 % uncertain). Among surgeons, there was a non-statistically significant trend away from choosing surgery: 1999 (77 % surgery, 5 % palliative treatment, 18 % uncertain) versus 2007 (56 % surgery, 8 % palliative treatment, 36 % uncertain). In conclusion, these analyses suggest that despite improving surgical outcomes, doctors are no more likely to predict that they would choose surgery for their own hypothetical infant with HLHS. Further research is needed to determine what factors influence choice making in the care of infants with HLHS.

Inpatient costs and charges for surgical treatment of hypoplastic left heart syndrome

OBJECTIVE

Hypoplastic left heart syndrome (HLHS) is one of the most serious congenital cardiac anomalies. Typically, it is managed with a series of 3 palliative operations or cardiac transplantation. Our goal was to quantify the inpatient resource burden of HLHS across multiple academic medical centers.

METHODS

The University HealthSystem Consortium is an alliance of 101 academic medical centers and 178 affiliated hospitals that share diagnostic, procedural, and financial data on all discharges. We examined inpatient resource use by patients with HLHS who underwent a staged palliative procedure or cardiac transplantation between 1998 and 2007.

RESULTS

Among 1941 neonates, stage 1 palliation (Norwood or Sano procedure) had a median length of stay (LOS) of 25 days and charges of $214,680. Stage 2 and stage 3 palliation (Glenn and Fontan procedures, respectively) had median LOS and charges of 8 days and $82,174 and 11 days and $79,549, respectively. Primary neonatal transplantation had an LOS of 87 days and charges of $582,920, and rescue transplantation required 36 days and $411,121. The median inpatient wait time for primary and rescue transplants was 42 and 6 days, respectively. Between 1998 and 2007, the LOS for stage 1 palliation increased from 16 to 28 days and inflation-adjusted charges increased from $122,309 to $280,909, largely because of increasing survival rates (57% in 1998 and 83% in 2007).

CONCLUSIONS

Patients with HLHS demand considerable inpatient resources, whether treated with the Norwood-Glenn-Fontan procedure pathway or cardiac transplantation. Improved survival rates have led to increased hospital stays and costs.

Population-based analysis of survival for hypoplastic left heart syndrome

OBJECTIVE

To analyze survival patterns among infants with hypoplastic left heart syndrome (HLHS) in the State of Michigan.

STUDY DESIGN

Cases of HLHS prevalent at live birth were identified and confirmed within the Michigan Birth Defects Registry from 1992 to 2005 (n=406). Characteristics of infants with HLHS were compared with a 10:1 random control sample.

RESULTS

Compared with 4060 control subjects, the 406 cases of HLHS were more frequently male (62.6% vs 51.4%), born prematurely (<37 weeks gestation; 15.3% vs 8.7%), and born at low birth weight (LBW) (<2.5 kg; 16.0% vs 6.6%). HLHS 1-year survival rate improved over the study period (P=.041). Chromosomal abnormalities, LBW, premature birth, and living in a high poverty neighborhood were significantly associated with death. Controlling for neighborhood poverty, term infants versus preterm with HLHS or LBW were 3.2 times (95% CI: 1.9-5.3; P<.001) more likely to survive at least 1 year. Controlling for age and weight, infants from low-poverty versus high-poverty areas were 1.8 times (95% CI: 1.1-2.8; P=.015) more likely to survive at least 1 year.

CONCLUSIONS

Among infants with HLHS in Michigan, those who were premature, LBW, had chromosomal abnormalities, or lived in a high-poverty area were at increased risk for early death.

The changing epidemiology of pediatric endocarditis at a children's hospital over seven decades

This study sought to determine whether improvements in the care of children with congenital heart disease (CHD) have changed the epidemiology of infective endocarditis (IE). A retrospective study of patients 18 years of age and younger treated for IE from 1992 to 2004 (era 3) was conducted at the authors' children's hospital in New York City. This study was compared with two previous studies conducted at the same hospital from 1930 to 1959 (era 1) and from 1977 to 1992 (era 2). During the three eras, IE was diagnosed for 205 children with a median age of 8 years during eras 1 and 2, which decreased to 1.5 years during era 3, partly because of IE after cardiac surgery for young infants. In era 3, nonstreptococcal and nonstaphylococcal pathogens associated with hospital-acquired IE increased. Complications from IE declined during era 3, but after the widespread availability of antibiotics in 1944, crude mortality rates were similar in eras 1 (32%), 2 (21%), and 3 (24%). However, in era 3, mortality occurred only among subjects with hospital-acquired IE. The epidemiology of pediatric IE has changed in the modern era. Currently, IE is most likely to occur among young children with complex congenital heart disease. Pediatric IE remains associated with high crude mortality rates when it is acquired in the hospital.

Attitudes and practices of cardiologists and surgeons who manage HLHS

OBJECTIVE

We conducted a survey to determine which management options pediatric cardiologists and cardiac surgeons in North America discuss and recommend when counseling parents after the diagnosis of hypoplastic left heart syndrome (HLHS).

METHODS

Pediatric cardiologists and cardiac surgeons across North America were asked to complete an anonymous, Internet-based survey about their attitudes and practices regarding the management of HLHS.

RESULTS

We contacted 1621 pediatric cardiologists and surgeons, of whom 749 (46%) completed the survey. When counseling parents of newborns with HLHS, 99.7% of respondents discussed staged palliative surgery, 67% discussed cardiac transplantation, and 62.2% discussed compassionate care without surgery. Only a minority (14.9%) discussed all of those options. Staged palliative surgery was recommended over cardiac transplantation or compassionate care without surgery by 76.2% of respondents. When counseling parents after prenatal diagnosis of HLHS, 98.8% of respondents discussed continuation of pregnancy with staged palliative surgery after birth, 53.5% discussed continuation of pregnancy with cardiac transplantation after birth, 56.9% discussed continuation of pregnancy with compassionate care after birth, and 74.3% discussed termination of pregnancy. Only 36.5% discussed all of those options. Continuation of pregnancy with staged palliative surgery after birth was recommended over the other options by 56% of respondents.

CONCLUSIONS

Virtually all North American pediatric cardiologists and cardiac surgeons surveyed discuss a surgical intervention when counseling parents about the care of their child or fetus with HLHS. However, only a minority discuss all options. Most physicians recommend staged palliative surgery for management of HLHS.

Evolution of treatment options and outcomes for hypoplastic left heart syndrome over an 18-year period

OBJECTIVES

We aimed to describe management strategies for neonates with hypoplastic left heart syndrome over the past 18 years in the United States and to identify determinants of institutional management decisions.

METHODS

Neonates with hypoplastic left heart syndrome were retrospectively identified by use of the Nationwide Inpatient Sample 1988-2005. Treatment was categorized as (1) transplantation, (2) Norwood operation (as defined by Risk Adjustment in Congenital Heart Surgery), (3) transfer to another facility, or (4) no surgical intervention (comfort care).

RESULTS

A total of 3286 neonates were identified, yielding a national estimate of 16,781 + or - 586 cases. Of these, 2% (348 + or - 47) underwent transplantation, 16% (2767 + or - 286) had Norwood operations, 25% (4143 + or - 156) were transferred to another facility, and 57% (9523 + or - 436) had comfort care. Changes in practice patterns occurred over time, with an increasing number of neonates undergoing Norwood, concomitant with decreasing numbers undergoing transplantation (P < .001). Bias toward the Norwood operation over time paralleled a significant, nearly linear decrease in the in-hospital mortality rate for the Norwood operation, from 86% in the earliest sextile to 24% in the most recent sextile (P < .001). Prevalence of transfer to definitive care hospitals remained constant over time, as did the number of infants (approximately half) who received no surgery (comfort care).

CONCLUSIONS

Despite improved surgical outcomes, the majority of infants continue to receive no surgical care. There has been an increase in the number of infants offered the Norwood operation for hypoplastic left heart syndrome over the past 2 decades, which seems to have come mostly owing to a decrease of transplants. The advent of prenatal diagnosis has not decreased the proportion of neonates born at institutions unequipped to provide definitive care.

Pediatric Cardiac Care Consortium: an instrument for evidence-based clinical decision support

Pediatric Cardiac Care Consortium is a registry of cardiac catheterizations, surgical operations, and autopsies performed for infants, children, and adults with congenital heart disease. Four examples of use of PCCC data to evaluate variability in morphology, management, and outcomes for the procedures are described. Consideration is given to the following clinical problems: (1) the experience with surgical heart block in operative closure of perimembranous VSD, (2) the transition away from atrial baffle operations to the arterial switch operation for simple transposition of the great arteries, (3) the experience of planned 3 stage palliation of hypoplastic left heart syndrome, and (4) the identification of a high risk combination of cardiovascular anomalies in Williams syndrome. Analysis of registry outcomes allows ongoing quality improvement at a cardiac center to consider not only its own experience but that of the overall group. The PCCC data can be used to personalize management of rare congenital cardiac anomalies and combinations of anomalies. The PCCC registry allows longitudinal consideration of issues such as staged repairs and incidence of unplanned reoperation. In future years, the PCCC can facilitate investigations into the etiology of congenital heart disease.

Cardiovascular magnetic resonance of pulmonary artery growth and ventricular function after Norwood procedure with Sano modification

For hypoplastic left heart syndrome (HLHS), there have been concerns regarding pulmonary artery growth and ventricular dysfunction after first stage surgery consisting of the Norwood procedure modified with a right ventricle-to-pulmonary artery conduit. We report our experience using cardiovascular magnetic resonance (CMR) to determine and follow pulmonary arterial growth and ventricular function in this cohort. Following first stage palliation, serial CMR was performed at 1 and 10 weeks post-operatively, followed by cardiac catheterization at 4-6 months. Thirty-four of 47 consecutive patients with HLHS (or its variations) underwent first stage palliation. Serial CMR was performed in 20 patients. Between studies, ejection fraction decreased (58 +/- 9% vs. 50 +/- 5%, p < 0.05). Pulmonary artery growth occurred on the left (6 +/- 1 mm vs. 4 +/- 1 mm at baseline, p < 0.05) but not significantly in the right. This trend continued to cardiac catheterization 4-6 months post surgery, with the left pulmonary artery of greater size than the right (8.8 +/- 2.2 mm vs. 6.7 +/- 1.9 mm, p < 0.05). By CMR, 5 had pulmonary artery stenoses initially, and at 2 months, 9 had stenoses. Three of the 9 underwent percutaneous intervention prior to the second stage procedure. In this cohort, reasonable growth of pulmonary arteries occurred following first stage palliation with this modification, although that growth was preferential to the left. Serial studies demonstrate worsening of ventricular function for the cohort. CMR was instrumental for detecting pulmonary artery stenosis and right ventricular dysfunction.

Variability in the preoperative management of infants with hypoplastic left heart syndrome

Infants with hypoplastic left heart syndrome (HLHS) commonly undergo initial surgical palliation during the first week of life. Few data exist on optimal preoperative management strategies; therefore, the management of these infants prior to surgery is anecdotal and variable. To more fully define this variability in preoperative care of infants with HLHS, a survey was designed to describe current preoperative management practices in the infant with HLHS. The questionnaire explored management styles as well as preoperative monitoring techniques and characteristics of the respondent's health care institution. The responses were compiled and are reported. A striking lack of consistency in preoperative management techniques for infants with HLHS is apparent. The impact of these preoperative strategies is unknown. Despite challenges in anatomic and hemodynamic variability at presentation, a prospective randomized controlled trial comparing ventilatory management techniques, enteral feeding strategies, and the utility of various monitoring tools on short- and long-term outcome is needed.

Outcomes of surgical treatment of infants with hypoplastic left heart syndrome: an institutional experience 1983-2004

AIM

To determine outcomes of surgical treatment of infants with hypoplastic left heart syndrome (HLHS).

METHODS

Retrospective analysis of medical records of infants with HLHS.

RESULTS

129 of 206 (63%) infants with HLHS were managed surgically over the period 1983-2004. Survival from all stages of surgical repair was 52 (40%) patients with significantly different (P < 0.001) survival according to surgical techniques and post-operative intensive care management recognisable in three eras. During 1983-1995 a classical Norwood stage 1 operation with a systemic-pulmonary shunt was performed for 61 infants with 13 (21%) survivors. From 1996 to 2002, pulmonary vasoconstriction and systemic vasodilatation after stage 1 operation were used to optimise systemic blood flow yielding a survival of 22 of 46 (48%) infants. From 2002 to 2004 a ventricular-pulmonary conduit was used with survival of 17 of 22 (77%) infants. Survival at 1, 6, 12 months and at 5, 10 and 15 years was 65%, 53%, 48%, 38%, 38% and 25%, respectively. The mean +/- SD number of surgical procedures was 4.5 +/- 3.7; duration of hospitalisation 53 +/- 52 days (median 38); number of hospital admissions 3.0 +/- 3.5; duration in intensive care 18 +/- 20 days (median 11); hours of mechanical ventilation 278 +/- 398 (median 151).

CONCLUSION

Short-term survival of HLHS has improved substantially over recent years with a ventricular-pulmonary conduit while long-term survival has been mediocre after arterial systemic-pulmonary shunts. Irrespective of type of primary surgery, infants undergo many operations and spend long periods in hospital and intensive care.

Safeguarding precarious survival: parenting children who have life-threatening heart disease

The purpose of this study is to describe the process of parenting a child with life-threatening heart disease. Despite advances in pediatric cardiac sciences, hypoplastic left heart syndrome remains difficult and controversial to treat. The Norwood surgical approach is a developing technology, and little is known about how mothers and fathers experience parenting a child who survives this treatment. Constructivist grounded theory informed this Canadian study that involved multiple interactive interviews with 9 mothers and 7 fathers of children with hypoplastic left heart syndrome who were at various stages of treatment. Extraordinary parenting in a context of uncertainty was evident as parents simultaneously safeguarded their child's precarious survival as well as their own survival. As technologically advanced treatment contributes to the survival of children with complex health conditions, health care professionals must consider how to promote and support parenting strategies that benefit the new survivors of technology as well as their families.

Hypoplastic left heart syndrome

Hypoplastic left heart syndrome(HLHS) refers to the abnormal development of the left-sided cardiac structures, resulting in obstruction to blood flow from the left ventricular outflow tract. In addition, the syndrome includes underdevelopment of the left ventricle, aorta, and aortic arch, as well as mitral atresia or stenosis. HLHS has been reported to occur in approximately 0.016 to 0.036% of all live births. Newborn infants with the condition generally are born at full term and initially appear healthy. As the arterial duct closes, the systemic perfusion becomes decreased, resulting in hypoxemia, acidosis, and shock. Usually, no heart murmur, or a non-specific heart murmur, may be detected. The second heart sound is loud and single because of aortic atresia. Often the liver is enlarged secondary to congestive heart failure. The embryologic cause of the disease, as in the case of most congenital cardiac defects, is not fully known. The most useful diagnostic modality is the echocardiogram. The syndrome can be diagnosed by fetal echocardiography between 18 and 22 weeks of gestation. Differential diagnosis includes other left-sided obstructive lesions where the systemic circulation is dependent on ductal flow (critical aortic stenosis, coarctation of the aorta, interrupted aortic arch). Children with the syndrome require surgery as neonates, as they have duct-dependent systemic circulation. Currently, there are two major modalities, primary cardiac transplantation or a series of staged functionally univentricular palliations. The treatment chosen is dependent on the preference of the institution, its experience, and also preference. Although survival following initial surgical intervention has improved significantly over the last 20 years, significant mortality and morbidity are present for both surgical strategies. As a result pediatric cardiologists continue to be challenged by discussions with families regarding initial decision relative to treatment, and long-term prognosis as information on long-term survival and quality of life for those born with the syndrome is limited.

Hybrid palliation in hypoplastic left heart syndrome

PURPOSE OF REVIEW

Despite progressive improvement in surgical results, hypoplastic left heart syndrome remains one of the congenital heart abnormalities with the greatest morbidity and mortality. Hybrid approaches to management, combining surgical and interventional catheterization procedures, have been introduced to minimize exposure to cardiopulmonary bypass, and improve outcomes for these high-risk infants.

RECENT FINDINGS

First-stage palliation of hypoplastic left heart syndrome has been performed as a hybrid procedure combining surgical pulmonary artery banding with catheterization stenting of the ductus arteriosus and balloon atrial septostomy, especially in high-risk patients. Additionally, several centers have performed second-stage palliation - bidirectional Glenn or hemi-Fontan procedures - in a manner that allows the subsequent 'Fontan' procedure to be completed in the catheterization laboratory with a covered stent.

SUMMARY

These innovative procedures offer the potential of an alternative management strategy for hypoplastic left heart syndrome. They have been applied to a very limited number of patients and long-term results are not available. Their role in management of hypoplastic left heart syndrome remains to be defined, especially as results of conventional surgical management continue to improve.

Intensive care course after stage 1 Norwood procedure: are there early predictors of failure?

OBJECTIVE

The purpose of this study was to review the early postoperative course of stage 1 Norwood with Blalock-Taussig shunt (BTS) or right ventricle-to-pulmonary artery conduit (RVPA) and to identify early predictors of failure.

MATERIAL AND METHODS

A retrospective analysis was conducted in 33 consecutive neonates who underwent BTS (n=19) or RVPA (n=14) stage 1 Norwood procedure between 2000 and 2005. Pre-, peri-, and postoperative data included: hourly hemodynamics and blood gases, pulmonary to systemic flow ratio, duration of mechanical ventilatory and inotrope support, intensive care and hospital stay. Failure was defined as death or transplantation.

RESULTS

Thirteen patients failed the procedure (39.4%): 10 BTS (52.6%) and 3 RVPA (21.4%). Failure decreased from 61.1% in 2000-2002 to 13.3% in 2003-2005 and was associated with: low systolic, mean and diastolic blood pressure, urine output, pH, base excess, bicarbonates, and high pulmonary to systemic flow ratio within 24 h postoperatively. Arterial oxygen and CO2 pressure, and oxygen saturation did not differ with failure. RVPA had higher diastolic blood pressure and more stable hemodynamics despite similar pulmonary to systemic flow ratio. Duration of mechanical ventilation, inotrope support, intensive care stay were shorter in RVPA. Postoperative echographic ventricular dysfunction and tricuspid regurgitation grade were correlated with failure.

CONCLUSIONS

Excessive pulmonary to systemic flow ratio and low blood pressure are associated with failure. High diastolic blood pressure more than low pulmonary to systemic flow ratio seems to account for more favorable outcomes in RVPA compared to BTS procedure.

Risk-stratified approach to hybrid transcatheter-surgical palliation of hypoplastic left heart syndrome

We prospectively employed a risk-stratified approach to first-stage palliation of hypoplastic left heart syndrome. High-risk features included severe tricuspid insufficiency, severe right ventricular dysfunction, a severely restrictive or intact atrial septum, an ascending aortic diameter < or = 2 mm, late presentation, weight < 2 kg, or significant extracardiac issues, Infants without high-risk features underwent a Norwood procedure (with Sano modification), whereas infants with high-risk features underwent a hybrid procedure consisting of bilateral pulmonary artery banding, ductal stenting, and atrial septostomy or a Norwood/Sano. Operative survival for 10 infants without high-risk features undergoing a Norwood/Sano procedure was 90%. Operative survival for 5 infants with high-risk features undergoing hybrid palliation was 100%, compared to 29% in 7 infants with high-risk features undergoing the Norwood/Sano procedure. Although only short-term data are available, this hybrid palliative procedure may have a role for infants with hypoplastic left heart syndrome and high-risk features.

Hypoplastic left heart syndrome: knowledge discovery with a data mining approach

Hypoplastic left heart syndrome (HLHS) affects infants and is uniformly fatal without surgical palliation. Post-surgery mortality rates are highly variable and dependent on postoperative management. A data acquisition system was developed for collection of 73 physiologic, laboratory, and nurse-assessed parameters. The acquisition system was designed for the collection on numerous patients. Data records were created at 30s intervals. An expert-validated wellness score was computed for each data record. To efficiently analyze the data, a new metric for assessment of data utility, the combined classification quality measure, was developed. This measure assesses the impact of a feature on classification accuracy without performing computationally expensive cross-validation. The proposed measure can be also used to derive new features that enhance classification accuracy. The knowledge discovery approach allows for instantaneous prediction of interventions for the patient in an intensive care unit. The discovered knowledge can improve care of complex to manage infants by the development of an intelligent bedside advisory system.

Informed consent and hypoplastic left heart syndrome

We present an ethical analysis from the perspective of shared decision-making and informed consent of a change in clinical management of infants born with hypoplastic left heart syndrome (HLHS). We reported a change in treatment of HLHS at the University of Alberta away from comfort care to life-saving surgery (LST) between 1987 and 1998. In a second review (1996-2001), 49/62 infants received LST, with 81% survival from the NICU and 58% at 35 mo. Eleven infants died preoperatively of non-cardiac conditions and two received elective comfort care. Sixteen infants had 18-mo Bayley Mental Development Index, mean score 84+/-19, but five scored <70. Although we continue to present the comfort care option to parents, since 2001 LST use for HLHS at our center is almost universal despite serious complications.

CONCLUSION

We conclude that these findings are inconsistent with an open, shared decision-making model of informed consent and we suggest that comfort care should remain an ethically valid choice until the rate of serious long-term complications of LST decreases.

The intensive care of infants with hypoplastic left heart syndrome

Until a little over two decades ago, hypoplastic left heart syndrome was considered an inoperable and fatal condition, with most deaths occurring in early infancy, and almost all of those affected dying before their first birthday. However, the advent of surgical palliation and advances in peri-operative care, have offered hope to these patients and their families.

Clinical outcomes and secondary diagnoses for infants born with hypoplastic left heart syndrome

OBJECTIVE

To explore clinical outcomes and secondary diagnoses present at discharge for infants born with hypoplastic left heart syndrome (HLHS), from a national perspective.

METHODS

We examined hospitalizations for infants < or =30 days of age who were born with HLHS, using hospital discharge data from the 1997 Kids Inpatient Database. To explore treatment choices, clinical outcomes, and resource use, we used International Classification of Diseases, 9th Revision, Clinical Modification diagnostic and procedure codes to classify discharges according to type of surgical intervention versus no surgical intervention. To investigate outcomes in more detail, we identified secondary diagnoses noted at discharge, using International Classification of Diseases, 9th Revision, Clinical Modification codes, and stratified results according to type of surgical intervention.

RESULTS

Of a total of 550 patients with HLHS, 234 underwent the Norwood procedure, 17 underwent orthotopic heart transplantation, and 106 died in the hospital with no reported surgical intervention. Although we found no demographic variables to be significantly associated with the type of treatment received, discharged patients who died without surgical intervention were significantly more likely to have received care in hospitals identified as small (odds ratio [OR]: 1.5; 95% confidence interval [CI]: 1.03-3.1) or not children's hospitals (OR: 2.02; 95% CI: 1.13-3.6). Secondary diagnoses of cardiac arrest (OR: 2.0; 95% CI: 1.1-3.4) and seizures (OR: 2.6; 95% CI: 1.2-5.5) occurred more frequently in orthotopic heart transplantation cases than in Norwood procedure cases.

CONCLUSIONS

These data from a national perspective reflect outcomes of infants with HLHS during a time when rates of initial survival after surgical intervention were considered to be improved. These findings may be useful to clinicians when they are considering and recommending initial medical and surgical strategies currently being proposed for the treatment of HLHS.

Technological advances in pediatrics: challenges for parents and nurses

Ongoing technological advances in pediatrics are improving the survival rates among babies born with life-threatening anomalies. For these neonates, surgeries like brain shunts, trachea, gut and heart reconstruction, and organ transplants are replacing palliative care. Although parents and health care professionals alike are celebrating the successes, advancing technology also raises issues for everyone involved. This paper incorporates Dunst and Trivette's Effective Helpgiving framework and the Calgary Family Intervention Model to recommend nursing care that moves beyond life-saving highly technical surgical procedures and responds to the challenges parents face with their children with complex congenital heart disease, for example, who have "beat the odds."

Hypoplastic left heart syndrome: new developments and current controversies

Prior to 1980, the diagnosis of hypoplastic left heart syndrome (HLHS) was almost uniformly lethal. Over the past 25 years, the development of operative options, including staged surgical palliation and infant heart transplant, have resulted in major improvements in survival and quality-of-life outcomes. Throughout this period, the optimal treatment strategy for children with HLHS has continued to be controversial. Current advances include fetal diagnosis, medical management, catheter intervention and operative techniques, and hold great promise for further improvements. However, as new techniques continue to evolve, controversies will continue to arise. This article will explore the treatment strategies for children with HLHS and review current controversies surrounding this complex congenital cardiac disease.

Right ventricle-pulmonary artery shunt in first-stage palliation of hypoplastic left heart syndrome

OBJECTIVE

Pulmonary overcirculation through a systemic-pulmonary shunt has been one of the major causes of early death after the Norwood procedure. To avoid this lethal complication, we constructed a right ventricle-pulmonary shunt in first-stage palliation of hypoplastic left heart syndrome.

METHODS

Between February 1998 and February 2002, 19 consecutive infants, aged 6 to 57 days (median, 9 days) and weighing 1.6 to 3.9 kg (median, 3.0 kg), underwent a modified Norwood operation with the right ventricle-pulmonary artery shunt. The procedure included aortic reconstruction by direct anastomosis of the proximal main pulmonary artery and a nonvalved polytetrafluoroethylene shunt between a small right ventriculotomy and a distal stump of the main pulmonary artery. The size of the shunt used was 4 mm in 5 patients and 5 mm in 14.

RESULTS

All patients were managed without any particular manipulation to control pulmonary vascular resistance. There were 17 survivors (89%), including 3 patients weighing less than 2 kg. Two late deaths occurred due to obstruction of the right ventricle-pulmonary artery shunt. Thirteen patients underwent a stage II Glenn procedure after a mean interval of 6 months, with 2 hospital deaths. To date, a stage III Fontan procedure has been completed in 4 patients. Overall survival was 62% (13/19). Right ventricular fractional shortening at the last follow-up (3-48 months after stage I) ranged from 26% to 43% (n = 13, mean, 33%).

CONCLUSION

Without delicate postoperative management to control pulmonary vascular resistance, the modified Norwood procedure using the right ventricle-pulmonary shunt provides a stable systemic circulation as well as adequate pulmonary blood flow. This novel operation may be particularly beneficial to low-birth-weight infants with hypoplastic left heart syndrome.

Post-transplant seizures in infants with hypoplastic left heart syndrome

Seizures are common in infants undergoing cardiac transplant and are usually attributed to a non-specific "post-pump" phenomenon. In this study, we determined which variables were associated with the occurrence of post-transplant seizures in infants with hypoplastic left heart syndrome and the need for continued treatment with antiepileptic medication. Of 127 infants studied over an 11-year period, 27 (21%), ages 9 to 90 days, had post-transplant seizures. These patients were compared to 27 age-matched transplanted infants without seizures. We compared multiple variables before, during, and after transplant including growth parameters, time of diagnosis, cyclosporine levels, maternal variables, circulatory and bypass parameters, laboratory data, neuroimaging and electroencephalographic studies, neurologic examination findings, and peri-operative complications. Post-transplant seizures were associated with total cardiopulmonary bypass time and the presence of post-transplant complications. Deep hypothermic circulatory arrest time was inversely correlated with seizure severity. Pre-transplant electroencephalographic abnormalities and total bypass time were associated with seizures requiring continued use of antiepileptic therapy. Post-transplant electroencephalograms were not associated with the need for continued treatment. Identification of variables associated with the development of post-transplant seizures is essential for early intervention to reduce long-term morbidity and mortality. Future studies to reduce risk of post-transplant seizures are warranted.