New developments in the treatment of hypoplastic left heart syndrome

Use of extracorporeal membrane oxygenation and cerebral oximetry in a stage 1 norwood repair for hypoplastic left heart syndrome

The role of extracorporeal membrane oxygenation (ECMO) and its indications in stage I Norwood palliation are controversial. The decision to initiate ECMO and its timing remains difficult with no definitive cut-off points or evidence-based guidelines. It varies on a case-to-case basis. We report a case where the use of ECMO was beneficial after stage I Norwood palliation with severe ventricular dysfunction. The systemic-to-pulmonary artery shunt was kept open to balance the systemic and pulmonary circulations. Cerebral oximetry can be useful as an additional monitoring modality to guide management, monitor cerebral perfusion, and help detect cerebral steal.

A Rare Combination of Chromosomal Abnormalities in an Infant With Turner Syndrome and Hypoplastic Left Heart Syndrome

Hypoplastic left heart syndrome (HLHS) is a fatal congenital complex heart defect where the heart's left side is critically undeveloped. However, its pathogenesis remains unknown. We report a unique case of HLHS because of the rare combination of two abnormalities in the cell lines: partial monosomy X (Turner syndrome) and partial trisomy 14 (14q11.2 microduplication syndrome).

Incidence and Timing of Thrombosis After the Norwood Procedure in the Single-Ventricle Reconstruction Trial

Background Thrombosis is common in infants undergoing staged surgeries for single-ventricle congenital heart disease. The reported incidence and timing of thrombosis varies widely, making it difficult to understand the burden of thrombosis and develop approaches for prevention. We aimed to determine the timing and cumulative incidence of thrombosis following the stage I Norwood procedure and identify clinical characteristics associated with thrombosis. Methods and Results We analyzed data from the Pediatric Heart Network Single Ventricle Reconstruction trial from 2005 to 2009 and identified infants with first-time thrombotic events. In 549 infants, the cumulative incidence of thrombosis was 21.2% (n=57) from stage I through stage II. Most events occurred during stage I (n=35/57, 65%), with a median time to thrombosis of 15 days. We used a Cox proportional hazards model to estimate the association of clinical variables with thrombosis. After adjusting for baseline variables, boys had a higher hazard of thrombosis (adjusted hazard ratio [HR], 2.69; 95% CI, 1.44-5.05; P=0.002), non-hypoplastic left heart syndrome cardiac anatomy was associated with a higher early hazard of thrombosis (adjusted HR, 3.93; 95% CI, 1.89-8.17; P<0.001), and longer cardiopulmonary bypass time was also associated with thrombosis (per 10-minute increase, adjusted HR, 1.07; 95% CI, 1.01-1.12; P=0.02). Lower oxygen saturation after the Norwood procedure increased the hazard for thrombosis in the unadjusted model (HR, 1.08; 95% CI, 1.02-1.14; P=0.011). Conclusions Thrombosis affects 1 in 5 infants through Stage II discharge, with most events occurring during stage I. Male sex, non-hypoplastic left heart syndrome anatomy, longer cardiopulmonary bypass time, and lower stage I oxygen saturation were associated with thrombosis.

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.

In-hospital mortality for children with hypoplastic left heart syndrome after stage I surgical palliation: teaching versus nonteaching hospitals

OBJECTIVES

Teaching hospitals are perceived to provide a higher quality of care for the treatment of rare disease and complex patients. A substantial proportion of stage I palliation for hypoplastic left heart syndrome (HLHS) may be performed in nonteaching hospitals. This study compares the in-hospital mortality of stage I palliation between teaching and nonteaching hospitals.

METHODS

The authors conducted a retrospective cohort study using the Kids' Inpatient Database 1997 and 2000. Patients with HLHS undergoing stage I palliation were identified using International Classification of Diseases, Ninth Revision, Clinical Modification diagnostic and procedural codes.

RESULTS

Seven hundred fifty-four and 880 discharges of children with HLHS undergoing stage I palliation in 1997 and 2000, respectively, were identified. The in-hospital mortality for the study population was 28% in 1997 and 24% in 2000. Twenty percent of stage I palliation operations were performed in nonteaching hospitals in 1997. Two percent of operations were performed in nonteaching hospitals in 2000. In 1997 only, in-hospital mortality remained higher in nonteaching hospitals after controlling for stage I palliation hospital volume and condition-severity diagnoses. Low-volume hospitals performing stage I palliation were associated with increased in-hospital mortality in 1997 and 2000.

CONCLUSIONS

Patients with HLHS undergoing stage I palliation in nonteaching hospitals experienced increased in-hospital mortality in 1997. A significant reduction in the number of stage I palliation procedures performed in nonteaching hospitals occurred between 1997 and 2000. This centralization of stage I palliation into teaching hospitals, along with advances in postoperative medical and surgical care for these children, was associated with a decrease in mortality. Patients in low-volume hospitals performing stage I palliation continued to experience increased mortality in 2000.

Clinical management of infants with hypoplastic left heart syndrome in the United States, 1988-1997

OBJECTIVES

To evaluate changes in the clinical management of infants with hypoplastic left heart syndrome (HLHS) over a 10-year period.

BACKGROUND

Orthotopic heart transplantation (OHT) and the Norwood procedure have emerged as the treatment options for HLHS over the last 2 decades.

METHODS

We used 1988-1997 hospital discharge data from the National Inpatient Sample dataset. Patients < or =30 days of age with a principal diagnosis of HLHS were identified. Clinical management included the Norwood procedure, OHT, in-hospital death without surgery, discharge home without surgery, and transfer to another hospital. Multivariate logistic regression was used to evaluate variables associated with the choice of management.

RESULTS

There were 1986 cases of HLHS with 812 in-hospital deaths, yielding a mortality rate 40.9%. The in-hospital mortality rate decreased from 54.4% in 1988 to 38.1% in 1997. The proportion of patients treated with the Norwood procedure increased from 8% in 1988 to 34% in 1997. The proportion of patients who died in the hospital without surgery decreased over time while the percentage discharged from the hospital without surgery or transferred to another hospital remained relatively unchanged. The in-hospital mortality rate was significantly lower in the OHT group compared with the Norwood group (26.2% vs 46.0%). We found no differences in gender, race, type of insurance, or home income between patients treated with the Norwood procedure compared with those who received comfort care. Patients from a later era, in the South, and in teaching hospitals were more likely to undergo the Norwood procedure.

CONCLUSIONS

Between 1988 and 1997, the proportion of infants with HLHS treated with the Norwood procedure increased while the use of comfort care decreased. Gender, race/ethnicity, type of medical insurance, and home income did not correlate with treatment choices.

Factors influencing early outcome of Norwood procedure for hypoplastic left heart syndrome

OBJECTIVE

[corrected] The operative outcome of the Norwood procedure for hypoplastic left heart syndrome is still not satisfactory. Conflicting reports concern factors associated with early Norwood procedure mortality and the reasons for the instability after surgery are not sufficiently understood. The purpose of this study was to determine some perioperative factors influencing early (30 days) outcome.

METHODS

We retrospectively analyzed a group of 30 consecutive children with hypoplastic left heart syndrome (aged 5-39 days) who underwent Norwood procedure in 1997 and 1998. The following factors were considered and statistically analyzed: operative age, birth weight, operative weight, serum level of bilirubin, aminotransferases, creatinine, urea, arterial blood gasses, anatomic subgroups, ascending aorta and arch size, systemic to pulmonary modified right Blalock-Taussig shunt size, cardiopulmonary circulatory arrest time, cardiopulmonary bypass time, and delayed chest closure. Eighteen patients underwent hemi-Fontan procedure with one late death and the modified Fontan operation was performed in 16 of them (one late death).

RESULTS

The early mortality was 37%. Seven deaths (64%) occurred during the first 24 h after operation. There was a significant difference between survivals and non-survivals in: birth weight (P=0.047), operative age (P=0.016), preoperative serum level of bilirubin (P=0.044), and cardiopulmonary circulatory arrest time (P=0.006). The other assessed factors were not found to be predictors of early mortality. All 16 survivals followed up are in New York Heart Association class I or II.

CONCLUSIONS

Anatomic and functional status of the patient, as well as procedural factors are related to Norwood operation early mortality. High mortality in hypoplastic left heart syndrome after stage I surgery indicates the necessity of assessing all factors which may determine further improvement in the outcome.

Hypoplastic left heart syndrome: Prognosis and management options

Few congenital heart malformations have raised as many surgical, ethical, social and economic issues as the therapy for infants diagnosed with hypoplastic left heart syndrome. Before the 1980s, this complex malformation was associated with 95% mortality within the first month of life. In the past two decades, palliative surgery and cardiac transplantation have become management options, in addition to comfort care for the infant. These innovations have forced parents and physicians to make difficult decisions because the long term results of the additional treatment options are not known. This article describes the current risk factors, diagnosis, treatment and outcome of infants with hypoplastic left heart syndrome. Prenatal diagnosis provides families with time for counselling and for becoming more informed about management options. Surgical therapy provides hope for the survival of these infants, but their long term outcomes are not well defined. Comfort care in either the home or hospital remains an acceptable management option. More investigations to determine the long term outcome following palliative surgery and transplantation are needed before they become the standards of care.