Surgical management of hypoplastic left heart syndrome

The care of the patients with hipoplastic left heart syndrome in places of social and economic vulneability. An ethical analysis

The birth of a child means hope and joy, particularly for the parents and the healthcare team. When this child is born with a severe malformation and a poor prognosis, as in the case of hypoplastic left heart syndrome, the scenario is one of great uncertainty and emotional suffering. The role of the health team becomes fundamental for the identification of conflicts of values and for the search for shared decisions that promote the best benefit to the child. When the diagnosis is made during fetal life, it is necessary to develop counseling strategies appropriate to the context of each family. In places with limited care resources, precarious prenatal care and short temporal conditions, the recommended counseling is compromised. Indication of treatment requires technical competence and a detailed analysis of ethical issues, and consultation with institutional clinical bioethics services or commissions is important. The article proposes to address the moral conflicts of two clinical cases and the respective bioethical analysis that involves principles and values in contexts of vulnerability and uncertainty, contrasting two situations where the indication of treatment was based on accessibility to treatment.

Cell-based therapy to boost right ventricular function and cardiovascular performance in hypoplastic left heart syndrome: Current approaches and future directions

Congenital heart disease remains one of the most frequently diagnosed congenital diseases of the newborn, with hypoplastic left heart syndrome (HLHS) being considered one of the most severe. This univentricular defect was uniformly fatal until the introduction, 40 years ago, of a complex surgical palliation consisting of multiple staged procedures spanning the first 4 years of the child's life. While survival has improved substantially, particularly in experienced centers, ventricular failure requiring heart transplant and a number of associated morbidities remain ongoing clinical challenges for these patients. Cell-based therapies aimed at boosting ventricular performance are under clinical evaluation as a novel intervention to decrease morbidity associated with surgical palliation. In this review, we will examine the current burden of HLHS and current modalities for treatment, discuss various cells therapies as an intervention while delineating challenges and future directions for this therapy for HLHS and other congenital heart diseases.

Failures of the Fontan System in Univentricular Hearts and Mortality Risk in Heart Transplantation: A Systematic Review and Meta-Analysis

The Fontan procedure (FP) is the standard surgical treatment for Univentricular heart diseases. Over time, the Fontan system fails, leading to pathologies such as protein-losing enteropathy (PLE), plastic bronchitis (PB), and heart failure (HF). FP should be considered as a transitional step to the final treatment: heart transplantation (HT). This systematic review and meta-analysis aims to establish the risk of death following HT according to the presence of FP complications. There was a total of 691 transplanted patients in the 18 articles, immediate survival 88% (n = 448), survival from 1 to 5 years of 78% (n = 427) and survival from 5.1 to 10 years of 69% (n = 208), >10 years 61% (n = 109). The relative risk (RR) was 1.12 for PLE (95% confidence interval [CI] = 0.89-1.40, p = 0.34), 1.03 for HF (0.7-1.51, p = 0.88), 0.70 for Arrhythmias (0.39-1.24, p = 0.22), 0.46 for PB (0.08-2.72, p = 0.39), and 5.81 for CKD (1.70-19.88, p = 0.005). In patients with two or more failures, the RR was 1.94 (0.99-3.81, p = 0.05). After FP, the risk of death after HT is associated with CKD and with the presence of two or more failures.

Permanent pacing post-Fontan is not associated with reduced long-term survival

BACKGROUND

The Fontan procedure is the final stage of surgical palliation for a single-ventricle circulation. Significant complications are common including rhythm disturbance necessitating implantation of a permanent pacemaker. This has been widely considered a negative prognostic indicator.

METHODS

This single-centre, retrospective case control study involved all patients who underwent the Fontan procedure at the Leeds Congenital Heart Unit between 1990 and 2015 and have had regular follow-up in Yorkshire and Humber, United Kingdom. 167 Fontan patients were identified of which 2 were excluded for having a pre-procedure pacemaker. Of the remainder, 23 patients required a pacemaker. Outcomes were survival, early and late complications, need for further intervention and oxygen saturation in long-term follow-up.

RESULTS

There was no difference in survival (30-day survival pacemaker 92.6%, sinus rhythm 90.5%, p = 0.66, 1-year pacemaker 11.1%, sinus rhythm 10.1%, p = 1). The pacemaker group was more likely to have cerebral or renal complications in the first-year post-procedure (acute kidney injury: sinus rhythm 0.8%, pacemaker 19.1%, p = 0.002). No difference was observed in longer term complications including protein losing enteropathy (sinus rhythm 3.5%, pacemaker 0% p = 1). There was no difference in saturations between the two groups at follow-up. Paced patients were more likely to have required further intervention, with a higher incidence of cardiopulmonary bypass procedures (sinus rhythm 6.3%, pacemaker 35%, p < 0.001).

CONCLUSIONS

Despite an increase in early complications and the need for further interventions, pacemaker requirement does not appear to affect long-term survival following the Fontan procedure.

Early Outcomes of Hypoplastic Left Heart Syndrome Infants: Meta-Analysis of Studies Comparing the Hybrid and Norwood Procedures

The hybrid strategy is an alternative to the traditional Norwood procedure for initial palliation of infants with hypoplastic left heart syndrome (HLHS) who are deemed to be at high surgical risk. Numerous single-center studies have compared the two procedures, showing similar early outcomes, although the cohort sizes are likely insufficiently powered to detect significant differences. The current meta-analysis aims to explore the early morbidity and mortality associated with the hybrid compared to the Norwood procedure. MEDLINE, Cochrane Libraries, and Embase were systematically searched, and 14 studies were included for statistical synthesis, comprising 263 hybrid and 426 Norwood patients. Early mortality was significantly higher in the hybrid patients (relative risk [RR] = 1.54, P < .05, 95% confidence interval [CI]: 1.02-2.34), whereas interstage mortality was comparable between the two groups (RR = 0.88, P > .05, 95% CI: 0.46-1.70). Six-month (RR = 0.89, P < .05, 95% CI: 0.80-1.00) and one-year (RR = 0.88, P < .05, 95% CI: 0.78-1.00) transplant-free survival was also inferior among the hybrid patients. Furthermore, the hybrid patients required more reinterventions following initial surgical palliation (RR = 1.48, P < .05, 95% CI: 1.09-2.01), although the two groups had comparable length of hospital and intensive care unit stay postoperatively. In conclusion, our results suggest that the hybrid procedure is associated with worse early survival compared to the traditional Norwood when used for initial palliation of infants with HLHS. However, due to the hybrid being used preferentially for high-risk patients, definitive conclusions regarding the efficacy of the procedure cannot be drawn.

Long term survival of hypoplastic left heart syndrome infants: Meta-analysis comparing outcomes from the modified Blalock-Taussig shunt and the right ventricle to pulmonary artery shunt

BACKGROUND

Stage 1 palliation of hypoplastic left heart syndrome (HLHS) involves the Norwood procedure combined with a modified Blalock-Taussig shunt (mBTS) or right ventricle to pulmonary artery shunt (RVPAS). Short-term survival has been described previously, whereas longer-term outcomes remain a subject of debate. This meta-analysis aimed to describe the short and long-term survival outcomes of these two shunts, and explore factors that might influence survival.

METHODS

Medline, Cochrane Libraries and EMBASE were systematically searched, and 32 studies were included for statistical synthesis, comprising 1348 mBTS and 1258 RVPAS patients.

RESULTS

While early in-hospital survival was superior in the RVPAS group (RR=1.5, p<0.05, 95% CI: 1.21-1.85), this difference was lost from 2years post-stage 1 palliation (RR=0.91, p>0.05, 95% CI: 0.79-1.04), and maintained unchanged up to 6years. This shift in survival was also reflected in inter-stage survival, with superior RVPAS outcomes between stage 1 and 2 (RR=1.62, p<0.05, 95% CI: 1.39-1.88), and equivalent outcomes between stage 2 and 3. Potential contributors to this included a significantly higher rate of pulmonary artery stenosis in the RVPAS group and an increased requirement for shunt re-intervention in this group prior to stage 2.

CONCLUSIONS

Despite early advantages, RVPAS and mBTS for palliation of hypoplastic left heart syndrome produced comparable long-term survival. The RVPAS patients experienced more pulmonary artery stenosis and requirement for shunt re-intervention. The impact of shunt type on quality and survival with a Fontan is yet to be assessed.

Anesthetic Considerations in Infants With Hypoplastic Left Heart Syndrome

Hypoplasia of the left ventricle is a congenital cardiac lesion that is almost universally fatal if left untreated. Six decades of improved diagnostic modalities, greater understanding of single ventricle physiology, and earlier surgical and palliative options have given many of these patients an opportunity of surviving well into adulthood. This review will summarize these advances and focus on the anesthetic implications of this challenging disease from diagnosis to beyond the first palliative surgery.

Right Ventricle-to-Pulmonary Artery Shunt in Norwood Procedure: Early Results

The aim of this study was to evaluate experience and predictors of early mortality in patients with hypoplastic left heart syndrome (HLHS)–type defects undergoing Norwood procedure (NP) with right ventricle-to-pulmonary artery (RV-PA) shunt. Between 2001 and 2009, a consecutive series of 229 children with HLHS-type single ventricle underwent NP with application of RV-PA shunt. Demographic, echocardiographic, and clinical perioperative data were retrospectively analyzed. The mean duration of follow-up of survivors was 4.5 ± 2.1 years (60 days to 8.1 years). Follow-up was complete for 92.1% of patients. Major early postoperative complications included sepsis/generalized infection in 40 (17.5%), pericardial effusion in 9 (3.9%), and wound infection in 8 (3.5%). The early (30-day) survival was 87.8% (n = 201). In the late postoperative period, 12 (5.9%) died. Early nonsurvivors were more frequently older than 14 days ( P = .045) at initial surgery, had lower operative weight ( P = .024), had more frequent associated cardiac ( P < .001) and/or extracardiac anomalies ( P < .001), and were more likely to have a restrictive interatrial communication before operation ( P = .024). Use of the right RV-PA shunt has helped to mitigate some previously described predictors of early death after NP. Longer follow-up will be required to determine whether the RV-PA shunt modification confers an important survival benefit.

Staged surgical palliation in hypoplastic left heart syndrome and its variants

BACKGROUND

Surgical options for infants with hypoplastic left heart syndrome (HLHS) and/or its variants are cardiac transplantation or the heart-preserving staged palliation with Norwood operation,followed by a two-staged Fontan procedure. We describe our 17-year experience with staged palliation of HLHS and/or its variants.

METHODS

Between December 1989 and December 2006, 64 patients with HLHS and/or its variants underwent a Norwood procedure (mean age/weight, 11.8+/-2.5 days/3.4 kg). Forty-four patients had classical HLHS. Twenty-eight percent had associated congenital cardiac, structural, and genetic anomalies. Subsequently, 25 patients underwent a bidirectional Glenn procedure (stage II) and 11 patients a modified Fontan procedure (stage III). Others await stage II and/or stage III. The follow-up was 143.2 patient-years.

RESULTS

Including the learning curve, overall early mortality from 1989 to 1999 after the Norwood procedure was 39.06%. This decreased tremendously for the last seven years, and reduced to 12.8% in 2000 to 2003 until 0% in 2004 to 2006 (p < 0.005). The causes of mortality were sepsis, capillary leak,or heart failure. Three patients died between stages II and III. One patient underwent heart transplantation after the second stage because of heart failure. Among 34 Norwood survivors, four are slightly tachypneic from a mild pulmonary hyperperfusion; one presents symptoms of minimal brain disease.

CONCLUSION

This report identified an outcome improvement after staged palliation of HLHS, attributed to an increase in experience and expertise gained over time. Lower operative weight, ascending aortic size, prolonged duration of cardiopulmonary bypass, and hypothermic circulatory arrest were identified to significantly influence early mortality after the Norwood procedure.

Design and rationale of a randomized trial comparing the Blalock-Taussig and right ventricle-pulmonary artery shunts in the Norwood procedure

OBJECTIVE

The initial palliative procedure for patients born with hypoplastic left heart syndrome and related single right ventricle anomalies, the Norwood procedure, remains among the highest risk procedures in congenital heart surgery. The classic Norwood procedure provides pulmonary blood flow with a modified Blalock-Taussig shunt. Improved outcomes have been reported in a few small, nonrandomized studies of a modification of the Norwood procedure that uses a right ventricle-pulmonary artery shunt to provide pulmonary blood flow. Other nonrandomized studies have shown no differences between the two techniques.

METHODS

The Pediatric Heart Network designed a randomized clinical trial to compare outcomes for subjects undergoing a Norwood procedure with either the right ventricle-pulmonary artery or modified Blalock-Taussig shunt. Infants with a diagnosis of single, morphologically right ventricle anomaly who are undergoing a Norwood procedure are eligible for inclusion in this study. The primary outcome is death or cardiac transplant 12 months after random assignment. Secondary outcomes include postoperative morbidity after Norwood and stage II palliation procedures, right ventricular function and pulmonary arterial growth at stage II palliation, and neurodevelopmental outcomes at 14 months old. Incidence of adverse events will also be compared between treatment groups.

CONCLUSION

This study will make an important contribution to the care of patients with hypoplastic left heart syndrome and related forms of single, morphologically right ventricle. It also establishes a model with which other operative interventions for patients with congenital cardiovascular malformations can be evaluated in the future.

The effect of left ventricular size on right ventricular hemodynamics in pediatric survivors with hypoplastic left heart syndrome

BACKGROUND

Outcome status in patients with hypoplastic left heart syndrome (HLHS) is partially dependent on right ventricular (RV) systolic function. In other disease states, ventricular function is impacted by anatomy and physiology of the contralateral ventricle. In HLHS, it is suggested that a relatively larger left ventricular (LV) size may negatively impact RV function because it becomes a "passenger" without providing any systolic or diastolic physiologic benefit. The purpose of this study was to determine whether LV size adversely affects RV systolic function in surviving patients with HLHS.

METHODS

The hospital database was searched for all patients with HLHS and technically adequate echocardiograms born in the last 6 years and who had survived at least the Norwood procedure. LV size was assessed by echocardiographic measurement of LV end-diastolic short-axis and apical area. RV function was assessed by short-axis and apical fractional area change as well as the myocardial performance index (Tei). Measurements were made at up to 4 time points depending on duration of follow-up (1 - pre-Norwood; 2 - pre-Glenn; 3 - pre-Fontan; and 4- post-Fontan).

RESULTS

A total of 48 patients were studied. LV size showed sufficient variability in the patient population (1.0-21 cm(2)/body surface area, pre-Norwood). RV function tended to worsen across the time periods but these changes did not reach statistical significance. Regression analysis showed no effect of LV size on RV function before Norwood operation. Significant correlations existed between LV size indices and RV functional indices before Glenn shunt but these were inconsistent in the direction of their effect. Only before Fontan operation did the correlation between LV size and RV function become both consistent and statistically significant; specifically larger LV size correlated significantly with poor RV systolic function (short-axis RV fractional area change vs LV area r = -0.4, P = .03 and RV Tei vs LV area r = 0.5, P = .02). These relationships were not apparent after Fontan operation.

CONCLUSION

In surviving patients with HLHS, larger LV size does not seem to negatively impact RV function before or after Norwood procedure nor does it seem to have an adverse effect on RV function chronically (after Fontan). However, further study with larger population size will be necessary to see whether these findings remain negative and are true for nonsurvivors as well.

Cardiac emergencies in the first year of life

Cardiac emergencies in the first year of life can be anxiety provoking for the health care provider. An understanding of the pathophysiology involved in the most common emergency department presentations is crucial to the development of appropriate treatment plans. This article discusses the most common causes of cyanotic and acyanotic heart disease in infants.

Norwood procedure for hypoplastic left heart syndrome: BT shunt or RV-PA conduit?

BACKGROUND

The Norwood procedure is the first stage palliative procedure for hypoplastic left heart syndrome (HLHS). Traditionally the pulmonary circulation has been supplied via a modified Blalock Taussig (BT) shunt but a recent modification, adopted in some UK centres, substitutes a conduit between right ventricle and pulmonary arteries (RV-PA conduit). It is argued that this will result in a more favourable balance between pulmonary and systemic circulations.

AIM

To compare the early postoperative haemodynamic profile between patients undergoing a BT shunt or an RV-PA conduit.

METHODS

Retrospective review in a tertiary referral PICU of 51 children with HLHS undergoing the Norwood procedure with either a BT shunt (Group 1; n = 23) or an RV-PA conduit (Group 2; n = 28). Data items were extracted at 10 set time points in the initial 96 h, postoperatively.

RESULTS

Diastolic BP was significantly lower in Group 1 (p<0.001) with a trend towards a higher systolic BP and no difference in mean BP. No between-group differences were found in markers of pulmonary blood flow (PaO2, PaCO2, PaO2/FiO2 ratio), or in markers of systemic blood flow (blood lactate, oxygen extraction ratio), or in estimated ratio of pulmonary:systemic blood flow (Qp:Qs). Despite lower diastolic blood pressure in Group 1 renal and hepatic function did not differ over five post-operative days between groups.

CONCLUSIONS

With the exception of a higher diastolic blood pressure in the RV-PA conduit group, we found no difference in the early haemodynamic profile between patients undergoing an RV-PA conduit or a BT shunt.

New developments in the treatment of hypoplastic left heart syndrome

In the current decade, the prognosis of newborns with hypoplastic left heart syndrome, previously considered a uniformly fatal condition, has dramatically improved through refinement of rapidly evolving treatment strategies. These strategies include various modifications of staged surgical reconstruction, orthotopic heart transplantation, and hybrid palliation using ductal stenting and bilateral pulmonary artery banding. The variety of treatment approaches are based on different surgical philosophies, and each approach has its unique advantages and disadvantages. Nonetheless, multiple experienced centers have reported improved outcomes in each one of those modalities. The purpose of this review is to outline recent developments in the array of currently available management strategies for neonates with hypoplastic left heart syndrome. Because the vast majority of deaths in this patient population occur within the first months of life, the focus of the review will be evaluation of the impact of these management strategies on survival in the neonatal and infant periods.

Impaired Power Output and Cardiac Index With Hypoplastic Left Heart Syndrome: A Magnetic Resonance Imaging Study

BACKGROUND

Unfavorable cardiac mechanics in children with hypoplastic left heart syndrome (HLHS) when compared with other single-ventricle defects may affect long-term morbidity and outcome. Using noninvasive phase contrast magnetic resonance imaging (PC MRI), we examined cardiac mechanics in children with HLHS and compared the results to other single-ventricle defects.

METHODS

Eighteen children with HLHS and 18 children with other single-ventricle defects were studied after the Fontan operation. Phase contrast MRI scans were obtained perpendicular to the ascending aorta, and flow was quantified using an in-house segmentation and reconstruction scheme. The total power output was determined using the modified Bernoulli equation along with cardiac output and systemic vascular resistance index.

RESULTS

Compared with non-HLHS congenital heart defects, children with HLHS had significantly lower power output (1.40 +/- 0.39 versus 1.78 +/- 0.38 W/m2, p < 0.004) and cardiac index (3.15 +/- 0.97 versus 4.09 +/- 1.23 L x Min(-1) x m(-2), p < 0.009) with a concomitant higher systemic vascular resistance index (28.94 +/- 11.5 versus 22.7 +/- 8.53 WU, p < 0.03) despite generating similar systolic blood pressures (112.9 +/- 22.4 versus 115.2 +/- 23 mm Hg, p > 0.05).

CONCLUSIONS

Minimally invasive measurements with PC MRI in children with HLHS showed significantly lower power output and cardiac index when compared with other single-ventricle physiologies. Abnormal aortic flow patterns may contribute to power loss and may have long-term survival and morbidity implications associated with the Fontan procedure. Elevated systemic vascular resistance index despite similar blood pressure opens avenues for therapeutic intervention for afterload reduction.

A risk assessment scoring system predicts survival following the Norwood procedure

No one set of characteristics has been consistently predictive of perioperative mortality and morbidity associated with the Norwood procedure. The purpose of the current study is to further validate a scoring system shown to be predictive of mortality following the Norwood procedure. We performed a retrospective review of all infants with the diagnosis of hypoplastic left heart syndrome (HLHS) who underwent the Norwood procedure at St. Louis Children's Hospital from July 1, 1994, to December 31, 2002. A weighted score for each of six factors comprised the scoring system. The factors included ventricular function, tricuspid regurgitation, ascending aortic diameter, atrial septal defect blood flow characteristics, blood type, and age. A score of > or = 7 points indicated lower reconstructive mortality risk, and a total score of < 7 points indicated a higher mortality risk. A total of 57 patients were analyzed. Twenty-five infants (44%) had a low risk score. These infants had a significantly greater survival at 48 hours compared to infants with a score of < 7 (92 vs 75%, p < 0.05). Infants with a high risk score had a significantly greater relative risk of mortality at 48 hours [OR = 2.04; confidence interval (CI) 1.04-4.00; p = 0.036]. The area under the receiver operating characteristic (ROC) curve is 0.8534 (95% CI, 0.78-0.922). This suggests that the scoring system has a very good degree of discriminatory power in selecting children who did not survive. Based on the results of the ROC, a cutoff score of >7 gives the best sensitivity and specificity for survival. When applied retrospectively, the survival outcomes predicted by our scoring system significantly correlated with actual outcomes. This supports the conclusion that a specific population of HLHS patients may have a higher mortality risk independent of surgical technique and postoperative care based on factors that can be assessed preoperatively.

Prevention of early sudden circulatory collapse after the Norwood operation

BACKGROUND

After modifications in our perioperative management protocol, we have observed a decrease in sudden circulatory collapse after the Norwood operation. The current study examines early outcomes after the Norwood operation in our unit in an attempt to identify variables that may have altered the risk of unexpected circulatory collapse.

METHODS AND RESULTS

We studied 105 consecutive neonates who underwent a Norwood operation in our institution. Our treatment protocol has changed in the past 3 years to include the use of alpha-blockade with phenoxybenzamine (POB) for systemic afterload reduction and selective cerebral perfusion. Forty-eight infants had selective cerebral perfusion. Forty-two infants received POB. Sixty patients had hypoplastic left heart syndrome. There was no difference in age, diagnosis, number of neonates with weight <2.5 kg, aortic size diameter <2 mm, highest preoperative lactate level, and shunt size indexed to body weight among patients with or without use of POB. Twenty-five infants had circulatory collapse during the first 72 hours. Twelve of them could be explained by technical issues. Thirteen others who appeared clinically stable had early sudden circulatory collapse without an apparent cause. Sixteen out of 25 neonates died. Of those with technical problems, 8 out of 12 died. Based on the hazard function, 3 incremental risk factors for early circulatory collapse were technical issue at operation (P<0.001), longer cross-clamp time (P<0.007), and no use of POB (P<0.002). For a technically successful operation, freedom from circulatory collapse at 72 hours is 95% with the use of POB versus 69% without (P<0.002). Diagnosis, aortic size, atrioventricular valve function, birth weight, age at operation, and total circulatory arrest time and were not predictive of early sudden circulatory collapse.

CONCLUSIONS

Recent changes in our treatment protocol have resulted in a decrease incidence of sudden circulatory collapse after the Norwood operation. Optimal surgical technique is the most important predictor of early survival. The use of aggressive afterload reduction with POB reduced the risk of early sudden arrest.

The effect of surgical case volume on outcome after the Norwood procedure

OBJECTIVES

We analyze the effect of surgical case volume on the survival of infants with hypoplastic left heart syndrome who underwent stage I surgical palliation (the Norwood procedure). The purpose of our study was to understand more clearly the relative effects of institution and surgeon experience on patient outcome.

METHODS

Using the Pediatric Health Information System database belonging to the pediatric hospital members of the Child Health Corporation of America, we identified newborn infants (< 30 days old on admission) from 1998 through 2001 admitted with the diagnosis of hypoplastic left heart syndrome. Stepwise multiple regression analysis was used to examine the association between both institutional and surgeon case volume with 28-day survival after the Norwood procedure.

RESULTS

Twenty-nine hospitals and 87 surgeons performed 801 Norwood procedures during the study period. In the 4 of 29 institutions that averaged 1 or more Norwood procedures per month during the study period, survival averaged 78%. The remaining 25 institutions averaged 1 Norwood procedure every 9.6 weeks, with a survival of 59%. Data analysis revealed that higher institutional volume (P = .02) but not the number of cases performed by surgeons (P = .13) increased survival after the Norwood procedure. There was no such association with average length of stay in survivors or the time to mortality in nonsurvivors.

CONCLUSION

Survival after the Norwood procedure is associated with institutional Norwood procedure volume but not with individual surgeon case volume, suggesting the need for improvements in institutional-based approaches to the care of children with hypoplastic left heart syndrome and the need for establishing regional referral centers for such high-risk procedures to improve patient survival.

Cardiac transplantation for hypoplastic left heart syndrome

Future improvements can be expected in cardiac transplantation in children. We continue to advance our understanding of the immune system, and to develop more specific immunosuppressive agents. Ultimately, the future for recipients may be improved by strategies such as induction therapy or donor-derived chimeric destined transfusions, designed to enhance the tolerance of the host to a human leukocyte antigen incompatible graft. Improvements in tolerance of the host would allow for reduction or elimination of many, if not all, of the immunosuppressive agents, and for longevity extending well into the adulthood. Survival, particularly for infants, has improved dramatically in the last decade. The most recent results from the registry of the International Society of Heart and Lung Transplantation/United Network for Organ Sharing show that recipients less than one year old at transplantation, who survive the first year, have greater than a 95% survival to four years (Fig. 1). As late outcomes continue to improve, transplantation will provide a better quality and duration of life for infants with hypoplastic left heart syndrome. It is possible, nonetheless, that some infants will require retransplantation, since the half life of a transplanted heart in children has been about 12 years. The alternative is conventional surgery with multiple palliative operations, and the need for later transplantation as end-stage cardiac function is reached. Efforts to increase potential donors and donor utilization can be supported by innovative schemes, such as ABO incompatible transplants. Additional efforts are made more urgent when the current data indicate excellent outcomes after transplantation, but a high mortality while waiting for transplantation.

Effect of a selection and postoperative care protocol on survival of infants with hypoplastic left heart syndrome

BACKGROUND

We report the development and implementation of a program designed to assign patients preoperatively to either transplant or Norwood procedure based on a score derived from known risk factors and to enhance postoperative care of infants undergoing the Norwood procedure.

METHODS

A weighted score for each of six variables comprised the scoring system: ventricular function, tricuspid regurgitation, ascending aortic diameter, atrial septal defect blood flow characteristics, blood type, and age. The scoring system was used to prospectively assign mortality risk and lead to recommendation of either Norwood procedure or transplantation.

RESULTS

Survival following the Norwood procedure significantly improved after the management program was implemented (88% versus 40% at 48 hours, 57% versus 10% at 30 days, and 50% versus 10% at 1 year, p < 0.0001 at each time point). The survival of the group that received a score of 7 or less (high risk) who underwent the Norwood procedure was 78% at 48 hours, 44% at 30 days, and 33% at 1 year; survival rates among patients considered lower risk (greater than 7) were 100% at 48 hours and 80% at 30 days and 1 year. Transplant outcomes remained unchanged.

CONCLUSIONS

We report improved survival following the Norwood procedure after the implementation of an institutional management approach aimed at improving the outcome of infants with hypoplastic left heart syndrome and may help neutralize historical biases toward Norwood procedure or transplantation.

The Southern Thoracic Surgical Association 50th anniversary celebration: the impact of STSA pediatric cardiothoracic surgery manuscripts on surgical practice

BACKGROUND

Members of the Southern Thoracic Surgical Association (STSA) have presented important pediatric cardiothoracic surgery papers at the annual meetings over the last 50 years. In order to determine the influence of these presentations on the practice of surgery, a review was undertaken. Early papers were characterized by emerging advances in open-heart surgery, anatomic congenital heart studies, and electrophysiologic discoveries that extended life with pacemakers. Later years were characterized by innovative myocardial preservation methods, improved cardiopulmonary bypass techniques, expanded homograft availability, emphasis on accurate repairs, intraoperative transesophageal echocardiography, and cardiopulmonary transplantation.

METHODS

All but one of the scientific programs of the annual meetings (that of 1964) were located. The programs were reviewed and 180 presentations were identified on topics in congenital heart disease, pediatric thoracic disease, and pediatric thoracic wall abnormalities. Of those 180 oral presentations, 155 manuscripts (86%) were eventually published or in press and available for critical review and analysis. Manuscripts were grouped by diagnosis or therapeutic intervention. We determined a "cumulative citation frequency" (CCF), which measures the number of times an article is cited in the bibliography of related papers in the universe of participating journals. The selected manuscripts were compared with the historic landmark contributions and the existing trends at the time, and the number of articles both by individual authors and from institutions were tallied.

RESULTS

Grouping by authors and institutions showed that 100 of 155 pediatric cardiothoracic manuscripts (65%) originated from 13 institutions. The CCF for the 20 leading articles ranged from 26 to 93.

CONCLUSIONS

This historical STSA 50-year record of pediatric cardiothoracic advances was accomplished in a milieu of collegial respect and camaraderie. Our annual meetings over the years have provided a venue for thoracic surgeons to share their ideas, innovations, and scientific inquiry. These contributions have significantly affected the practice of pediatric cardiothoracic surgery. The STSA has worked for 50 years and we trust that it will work for another 50 years and beyond.

Suitable shunt size for regulation of pulmonary blood flow in a canine model of univentricular parallel circulations

OBJECTIVE

We examined the influence of shunt size on regulation of the pulmonary blood flow in a canine model of a univentricular heart because specific guidelines regarding suitable shunt size in the Norwood operation remain undetermined.

METHODS

Beagle dogs (n = 8) 3 to 7 months old and weighing 3.0 to 5.0 kg were used. Atrial septectomy and patch closure of the tricuspid valve were performed, and a systemic-pulmonary arterial shunt was created by interposing a 3.5- or 4.0-mm graft between the right subclavian artery and main pulmonary artery. After cardiopulmonary bypass, hemodynamic variables including pulmonary and systemic blood flow were measured consecutively according to physiologically respiratory manipulations. The ratio of shunt size to body weight ranged from 0.80 to 1.33 mm/kg (1.08 +/- 0.16 mm/kg).

RESULTS

Each dog with a ratio of shunt size to body weight of 0.8 to 1.1 showed significant negative correlation between the pulmonary/systemic blood flow ratio and arterial Pco(2), but those with a ratio of shunt size to body weight of 1.1 to 1.4 did not. Consequently each dog with a ratio of shunt size to body weight of 0.8 to 1.0 got adequate systemic flow, whereas a ratio of 1.0 to 1.4 resulted in inadequate systemic flow and acidic status. Similar phenomena were shown with the grouped data on relationship between the pulmonary/systemic blood flow ratio and inspired oxygen fraction.

CONCLUSIONS

These findings imply that when the ratio of shunt size to body weight is 0.8 to 1.1, the pulmonary/systemic blood flow ratio is controllable by physiologic respiratory manipulations. Larger shunts make pulmonary blood flow excessive and uncontrollable. We recommend that a ratio of shunt size to body weight of 0.9 to 1.0 be considered a useful index for suitable systemic-pulmonary arterial shunt in the Norwood operation.

Noncardiac surgery in children with hypoplastic left heart syndrome

BACKGROUND/PURPOSE

Hospital mortality rate among children with hypoplastic left heart syndrome (HLHS) after cardiac repair is well documented, but comparable data after noncardiac, surgical procedures are unknown. The authors hypothesized an increasing number of noncardiac procedures were being performed on children with HLHS, less than 2 years of age, from 1988 to 1997, and that these procedures were associated with a substantial mortality rate.

METHODS

A retrospective review of hospital discharge data for 2,457 children less than 2 years of age with HLHS for 1988 through 1997 was performed. The authors examined the outcomes of HLHS children undergoing only noncardiac surgical procedures during their hospital stay. Differences in hospital mortality rates between 1988 through 1992 versus 1993 through 1997 were assessed using the Chi2 square statistic.

RESULTS

Nineteen percent of the 147 children with HLHS undergoing noncardiac, surgical procedures died (95% CI, 13% to 25%). Comparing the 2 study periods, there was no significant change in outcome among HLHS children undergoing noncardiac, surgical procedures (78% v. 83%; P >.1). There was no significant difference in the percentage of hospital discharges with noncardiac, surgical procedures performed per year.

CONCLUSIONS

Although children with HLHS were not undergoing an increase in the number of noncardiac surgical procedures performed annually, even minor surgical procedures were associated with considerable mortality. Outcomes after noncardiac surgery in high-risk children with congenital heart disease warrant further investigation.

Modified Norwood operation for hypoplastic left heart syndrome

BACKGROUND

We examined early results in infants with hypoplastic left heart syndrome undergoing the Norwood operation with perioperative use of inhaled nitric oxide and application of extracorporeal membrane oxygenation.

METHODS

Medical records were reviewed retrospectively.

RESULTS

Between April 1997 and March 2001, 50 infants underwent a modified Norwood operation for hypoplastic left heart syndrome. Mean age at operation was 7.5 +/- 5.7 days, and mean weight was 3.1 +/- 0.5 kg. Five infants had a delayed operation because of sepsis. The mean diameter of the ascending aorta by echocardiography was 3.6 +/- 1.8 mm. Ductal cannulation was used to establish cardiopulmonary bypass in all patients. Mean circulatory arrest time was 39.4 +/- 4.8 minutes. The size of the pulmonary-systemic shunt was 3.0 mm in 6 infants, 3.5 mm in 37, and 4.0 mm in 7. Infants with persistent hypoxia (partial pressure of oxygen < 30 mm Hg) received nitric oxide after they were weaned from cardiopulmonary bypass. Extracorporeal membrane oxygenation was initiated in 8 infants in the pediatric intensive care unit primarily for low cardiac output and in 8 in the operating room because of the inability to separate them from cardiopulmonary bypass. The 30-day mortality rate was 22% (11 of 50 patients), and the hospital mortality rate was 32% (16 of 50 patients). Mean follow-up was 17 months. Ten patients (20%) underwent stage-two repair, with one operative death. One survivor had a Fontan procedure, and 2 underwent heart transplantation, with one death.

CONCLUSIONS

Early application of extracorporeal membrane oxygenation for hemodynamic instability and selective use of nitric oxide for persistent hypoxia in the immediate postoperative period may improve survival of patients with hypoplastic left heart syndrome. Renal failure requiring hemofiltration during extracorporeal membrane oxygenation (p < 0.05) and cardiopulmonary arrest in the pediatric intensive care unit (p < 0.05) were predictors of hospital mortality.

Outcome of staged reconstructive surgery for hypoplastic left heart syndrome following antenatal diagnosis

BACKGROUND AND AIMS

Staged reconstructive surgery has radically altered the prognosis of hypoplastic left heart syndrome (HLHS). Antenatal diagnosis allows for appropriate counselling, and time to consider treatment options. We report outcome from a centre where most cases are antenatally diagnosed and delivered on site.

METHODS

Information was collated on 188 consecutive cases of HLHS between 1995 and 2000, including timing of diagnosis, outcome of pregnancy, and age and outcome at each stage of surgery. At Guy's Hospital, 174 cases were diagnosed antenatally, of whom 50 underwent surgery. Fourteen others (five diagnosed antenatally at other centres, and nine diagnosed postnatally) also underwent surgery.

RESULTS

Survival after stage I (the Norwood operation) was 52% (33/64). Postoperative survival after stage II (the hemi-Fontan operation, performed in 29), and stage III (the Fontan operation, performed in 10), was 100%. Two late deaths occurred 3 and 10 months after stage II, giving overall survival of 48% (31/64). At follow up, three children have neurological impairment, and one had poor right ventricular function necessitating cardiac transplantation.

CONCLUSIONS

Antenatal diagnosis allows informed decisions about treatment options, and facilitates preoperative care. Mortality following stage I is high, irrespective of timing of diagnosis, but medium term outcome for survivors is good.

A comparison of treatment strategies for hypoplastic left heart syndrome using decision analysis

OBJECTIVES

We sought to identify the optimal treatment strategy for hypoplastic left heart syndrome (HLHS).

BACKGROUND

Surgical treatment of HLHS involves either transplantation (Tx) or staged palliation of the native heart. Identifying the best treatment for HLHS requires integrating individual patient risk factors and center-specific data.

METHODS

Decision analysis is a modeling technique used to compare six strategies: staged surgery; Tx; stage 1 surgery as an interim to Tx; and listing for transplant for one, two, or three months before performing staged surgery if a donor is unavailable. Probabilities were derived from current literature and a dataset of 231 patients with HLHS born between 1989 and 1994. The goal was to maximize first-year survival.

RESULTS

If a donor is available within one month, Tx is the optimal choice, given baseline probabilities; if no donor is found by the end of one month, stage 1 surgery should be performed. When survival and organ donation probabilities were varied, staged surgery was the optimal choice for centers with organ donation rates < 10% in three months and with stage 1 mortality <20%. Waiting one month on the transplant list optimized survival when the three-month organ donation rate was > or =30%. Performing stage 1 surgery before listing, or performing stage 1 surgery after an unsuccessful two- or three-month wait for transplant, were almost never optimal choices.

CONCLUSIONS

The best strategy for centers that treat patients with HLHS should be guided by local organ availability, stage 1 surgical mortality and patient risk factors.

Norwood-type operation with adjustable systemic-pulmonary shunt using hemostatic clip

The postoperative course of a patient with hypoplastic left heart syndrome after a first-stage Norwood operation is governed to a large extent by the balance between the systemic and pulmonary circulations. Here we describe a simple and convenient technique for establishing an optimally sized systemic-pulmonary shunt by the application of a hemostatic clip. The method has been used in 6 patients.

Outcomes of transcatheter balloon angioplasty of obstruction in the neo-aortic arch after the Norwood operation

Obstruction of the reconstructed aortic arch, or the neoaortic arch, is now known to be an important factor increasing mortality after the Norwood operation for hypoplastic left heart syndrome. Transcatheter balloon angioplasty has been shown to provide effective relief of both native aortic coarctation and obstructions of the aortic arch occurring subsequent to therapeutic intervention. We sought to determine the outcomes of balloon angioplasty used as an initial treatment for obstruction of the neoaortic arch occurring after the Norwood operation. We gathered the characteristics of 58 patients with such obstruction from 8 institutions, noting procedural factors and outcomes of initial balloon dilation. Obstruction occurred at a median interval of 4 months, with a range from 1.5 months to 6.3 years, after a Norwood operation. Ventricular dysfunction was present before dilation in 13 patients. Mean peak to peak systolic pressure gradients were acutely reduced from 31+/-20 mm Hg to 6+/-9 mmHg (p<0.001), with outcome subjectively judged to be successful in 89%. Three patients with pre-existing ventricular dysfunction died within 48 hours of dilation. There were 10 additional deaths during the period of follow-up, with Kaplan Meier estimates of survival after intervention of 87% at 1 month, 77% at 12 months, and 72% after 15 months. In addition, 9 patients required re-intervention during the period of follow-up, with Kaplan Meier estimates of freedom from re-intervention after dilation of 87% at 6 months, 78% at 12 months and 74% after 18 months. Although transcatheter dilation of neoaortic arch obstructions after Norwood operation is successful, there is a high risk of re-intervention and ongoing mortality in this subgroup of patients. Close follow-up is recommended.

Stage one norwood procedure results: The green lane experience

AIMS

This study examined the presentation outcome, morbidity and mortality of infants who have undergone the stage one Norwood procedure for single ventricle reconstruction.

METHODS

A retrospective review was done on the first 20 patients to undergo this procedure at Green Lane Hospital, Auckland, New Zealand. Seven patients were diagnosed antenatally. Fetal cardiology records in the same time period were reviewed.

RESULTS

Twelve of the 20 patients (60%) have survived, and all of these patients have undergone their bi-directional Glenn procedure with no mortality. Eight patients died, with five of the deaths occurring in the perioperative period. Initial surgical mortality was 75%, decreasing to 25% since 1998. Antenatal diagnosis has not improved surgical outcome to date.

CONCLUSION

With advances in surgical technique and pre- and postoperative care, neonates born with single ventricle anatomy have an acceptable surgical option. Babies who survive the Norwood operation have a good chance of surviving the later stages of the cardiac reconstruction process, and they have a reasonable outlook in the intermediate term.

Two-dimensional echocardiographic assessment of right ventricular function as a predictor of outcome in hypoplastic left heart syndrome

This study was undertaken to assess the importance of right ventricular function at the time of initial presentation on early and intermediate outcome in patients with hypoplastic left heart syndrome (HLHS). Several studies have attempted to define physiologic risk factors for poor early outcome following the Norwood palliation for HLHS. No clinical or hemodynamic factors including right ventricular function have been found to reliably predict Norwood I operative survival. The relation between initial ventricular function and later survival has not been investigated. To assess the importance of right ventricular (RV) function at the time of initial presentation on outcome in patients with HLHS, systolic function was determined by qualitative and quantitative methods in 60 consecutive patients before surgical intervention. The effects on stage I operative survival, survival to stage II, and overall survival were analyzed. Initial RV function did not impact on stage I survival. However, analysis of later outcome of the stage I survivors showed that those with prestage I RV dysfunction had significantly greater mortality before stage II. Actuarial survival 18 months after Norwood surgery was 93% for patients with initially normal RV function compared with 47% for those with abnormal function (p = <0.005). The relative risk for later mortality was approximately 11 times greater for patients with initial RV dysfunction. Thus, RV dysfunction identifiable soon after initial presentation does not impact on early survival after Norwood I operation for HLHS. Intermediate and overall survival, however, is significantly decreased in patients with initially diminished RV function.

Survival analysis and risk factors for mortality in transplantation and staged surgery for hypoplastic left heart syndrome

OBJECTIVES

We compared survival in treatment strategies and determined risk factors for one-year mortality for hypoplastic left heart syndrome (HLHS) using intention-to-treat analysis.

BACKGROUND

Staged revision of the native heart and transplantation as treatments for HLHS have been compared in treatment-received analyses, which can bias results.

METHODS

Data on 231 infants with HLHS, born between 1989 and 1994 and intended for surgery, were collected from four pediatric cardiac surgical centers. Status at last contact for survival analysis and mortality at one year for risk factor analysis were the outcome measures.

RESULTS

Survival curves showed improved survival for patients intended for transplantation over patients intended for staged surgery. One-year survival was 61% for transplantation and 42% for staged surgery (p < 0.01); five-year survival was 55% and 38%, respectively (p < 0.01). Survival curves adjusted for preoperative differences were also significantly different (p < 0.001). Waiting-list mortality accounted for 63% of first-year deaths in the transplantation group. Mortality with stage 1 surgery accounted for 86% of that strategy's first-year mortality. Birth weight <3 kg (odds ratio [OR] 2.4), highest creatinine > or =2 mg/dL (OR 4.7), restrictive atrial septal defect (OR 2.7) and, in staged surgery, atresia of one (OR 4.2) or both (OR 11.0) left-sided valves produced a higher risk for one-year mortality.

CONCLUSIONS

Transplantation produced significantly higher survival at all ages up to seven years. Patients with atresia of one or both valves do poorly in staged surgery and have significantly higher survival with transplantation. This information may be useful in directing patients to the better strategy for them.

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.

Results of Norwood stage I operation: comparison of hypoplastic left heart syndrome with other malformations

OBJECTIVE

We compared the Norwood stage I operation for hypoplastic left heart syndrome and other complex malformations with ductus-dependent systemic circulation.

METHODS

A retrospective study of 194 patients who underwent a Norwood stage I palliation between 1990 and 1998 was conducted. Malformations in 131 patients were classified as hypoplastic left heart syndrome, defined as aortic and mitral atresia or severe stenosis, normal segmental anatomy, intact ventricular septum, and hypoplasia of the left ventricle. Sixty three patients had other lesions: hypoplastic left ventricle with ventricular septal defect (n = 18), unbalanced complete atrioventricular canal (n = 9), complex double-outlet right ventricle (n = 14), double-inlet left ventricle (n = 11), tricuspid atresia with transposition of the great arteries (n = 6), and others (n = 5), including heterotaxia.

RESULTS

Operative (>30 days) and 1-year survivals were lower for patients with hypoplastic left heart syndrome than for those with other lesions (63.4% vs 81%, P =.008, and 51.2% vs 71.4%, P =.02, respectively). The presence of a nonhypoplastic left ventricle (n = 27) was associated with higher operative and 1-year survivals (96.3% vs 64.7%, P =.002; 88.9% vs 52. 7%, P <.001). A restrictive atrial septal defect and prematurity tended to increase mortality across both groups. Cox proportional hazards regression indicated that a single right ventricle was the most important independent predictor of death (P <.001). Operative mortality for all patients undergoing the stage I procedure decreased from 38.5% (1990-1994) to 21.4% after 1994 (P =.02).

CONCLUSIONS

The survival of patients with malformations other than hypoplastic left heart syndrome after the Norwood procedure is greater than for those with hypoplastic left heart syndrome. Staged palliation is valid surgical therapy in these patients, with good results in intermediate follow-up.

Adjustable tourniquet to manipulate pulmonary blood flow after Norwood operations

BACKGROUND

Survival after first-stage palliative Norwood operations for single ventricle with systemic outflow obstruction is mainly dependent on a balanced ratio of pulmonary blood flow to systemic blood flow. Here we report the clinical results using a modified technique that allows a controlled systemic-to-pulmonary shunt flow to prevent pulmonary overcirculation.

METHODS

From 1995 to 1998, of 26 infants undergoing first-stage palliative Norwood operations, 7 had placement of an adjustable tourniquet around a modified right Blalock-Taussig shunt.

RESULTS

Hospital survival was 20 of 26 patients (77%). All 7 patients in whom snaring of the shunt was indicated survived. Two patients underwent repeated adjustment, in 5 patients the tourniquet could be removed during delayed sternal closure, and 2 patients were discharged with the shunt partially snared.

CONCLUSIONS

The snare-controlled systemic-to-pulmonary shunt allows improved hemodynamic stability after reconstructive surgery for hypoplastic left heart syndrome or other similar complex cardiac defects by reducing the risk of pulmonary overcirculation. It is simple and rapidly executed. The option of graded banding of the shunt depending on the hemodynamic situation increases flexibility and safety after cardiopulmonary bypass or at any time in the postoperative period.

Pulmonary failure after Norwood procedure: indication for extracorporeal membrane oxygenation? A case report

Today some authors consider univentricular repair a contraindication for postoperative cardiac extracorporeal membrane oxygenation (ECMO). The question is whether or not ECMO is indicated as pulmonary support in case of an overwhelming pulmonary infection during the postoperative course after a Norwood procedure. During the prolonged weaning period after a Norwood procedure using a 4 mm aortopulmonary shunt, proven respiratory syncytial virus (RSV) bronchiolitis occurred at the time of expected weaning from artificial ventilation. Venovenous ECMO was able to improve oxygenation, but when pulmonary opacification failed to resolve, ECMO was terminated after 12 days.

Hemi-Fontan procedure for hypoplastic left heart syndrome: outcome and suitability for Fontan

BACKGROUND

Following the Norwood procedure for hypoplastic left heart syndrome (HLHS), pulmonary artery distortion and hypoplasia are common and may negatively impact late outcome. The hemi-Fontan procedure (HFP) augments the central pulmonary arteries and establishes a connection between the right atrial/superior vena cava junction and the pulmonary arteries, while excluding the inferior vena cava.

METHODS

The hospital records of all 114 patients undergoing a HFP for HLHS between August 1993 and April 1998 were reviewed to assess patient, procedural, and morphologic determinations of outcome. The results of cardiac catheterization, Doppler/echocardiography, 12 lead electrocardiograms, hospital and subsequent course, as well as suitability and outcome for the Fontan procedure were analyzed.

RESULTS

Mean age was 5.4 months (range 1.5 to 15 months). Right ventricular function was normal in 95 patients, moderately depressed in 14, and severely depressed in five. Tricuspid regurgitation was absent or mild in 91 patients, moderate in 13, and severe in 10. Concomitant procedures included left superior vena cava to pulmonary artery anastomosis (12), tricuspid valve repair (10), pulmonary artery stent placement (3), coarctation repair (2), and aortic pseudoaneurysm repair (1). Hospital survival was 112/114, 98% (95% confidence interval [CI]: 95% to 100%). There were two late deaths, one noncardiac. Sinus rhythm is present in 105 patients (92%, 95% CI: 87% to 97%). To date, 79 of these patients have undergone the Fontan procedure with 74 survivors (94%, 95% CI: 89% to 99%).

CONCLUSIONS

The HFP may be performed with excellent results for HLHS. It effectively augments the central pulmonary arteries while preserving sinus rhythm in the majority. In addition, the HFP facilitates the subsequent Fontan procedure and has significantly improved the overall outcome.

Prenatally diagnosed hypoplastic left heart syndrome--outcomes after postnatal surgery

OBJECTIVE

To identify prenatally diagnosed cases of hypoplastic left heart syndrome (HLHS) and then to determine postnatal outcomes after surgical interventions.

METHODS

An ultrasound and pediatric cardiology database was used to identify all fetuses diagnosed prenatally from 1991-1996 with HLHS. Fetal karyotypes were performed on cultured amniocytes. After diagnosis, parents were given several management options: pregnancy termination before 22 weeks, postnatal hospice care, or surgery using the Norwood procedure or cardiac transplantation. Ultrasound and echocardiography findings were later compared to karyotype results and postnatal outcome data.

RESULTS

Fifteen fetuses with HLHS were identified. Two (16%) chromosome abnormalities and three (20%) structural defects were detected. Three mothers (20%) opted for pregnancy termination, two (13%) chose postnatal hospice care, and one aneuploid fetus had an intrauterine death. Nine parents (60%) chose surgery for their infants; however, one infant was not an appropriate surgical candidate due to a coexisting diaphragmatic hernia. Eight infants underwent surgery and two survived (25%). Of the four infants scheduled to undergo the Norwood procedure, one died preoperatively, two died intraoperatively, and one infant survived and is doing well at age 8 months. Of the four infants scheduled for cardiac transplantation, two died awaiting transplant and one died postoperatively. One infant survived cardiac transplantation but has microcephaly and developmental delay at age two.

CONCLUSIONS

In prenatally diagnosed HLHS at our institution, the survival rate following surgery for infants felt to be the best candidates was only 25%.

The modified Norwood procedure for hypoplastic left heart syndrome: early to intermediate results of 120 patients with particular reference to aortic arch repair

BACKGROUND

Classic first-stage Norwood repair of hypoplastic left heart syndrome uses a homograft patch enlargement to obtain an unobstructed aorta and coronary arteries. Because of possible disadvantages of the homograft, such as lack of growth, degeneration and calcification, and availability, we have tried to repair the aorta without patch supplementation.

METHODS

Between February 1993 and September 1997, 120 patients, aged birth to 47 days (median 4 days) and weighing 1.7 to 4.4 kg (median 3.1 kg), underwent first-stage palliation for hypoplastic left heart syndrome. The diameter of the ascending aorta ranged from 1.5 to 8.0 mm (median 3.0 mm). Eight patients had an aberrant right subclavian artery arising from the descending thoracic aorta. In 95 patients (group I), all duct tissue was excised and the descending aorta was anastomosed to the aortic arch, which had been opened back into the ascending aorta. Then to this confluence was anastomosed the proximal main pulmonary artery. In the remaining 25 patients (group II), continuity of the aortic arch was maintained and the repair was performed with a Damus-Kaye-Stansel anastomosis. The size of the systemic-to-pulmonary shunt was 3 mm in 48 patients, 3.5 mm in 70, and 4.0 mm in 2.

RESULTS

Circulatory arrest time ranged from 19 to 105 minutes (median 54 minutes). A homograft patch was necessary for the arch reconstruction in 18 patients (15%); 9 group I patients (10%) and 9 group II (36%) (P =.001). There were 82 hospital survivors (68%); 69 group I patients (73%) and 13 group II (52%) (P =.04), 71 patients without a patch (70%) and 11 with a patch (61%) (P >.2). By multiple logistic regression, the aberrant right subclavian artery was a significant risk factor for hospital death (P =.008). There were 6 late deaths. Sixteen of 71 patients (23%) who underwent second-stage palliation had a neoaortic arch obstruction develop, with a peak gradient greater than 10 mm Hg; 14 group I patients (23%) and 2 group II (22%) ( P >.2), 15 without a patch (23%) and 1 with a patch (17%) (P >.2). Overall survivals were 57% at 1 year and 55% at 2 years.

CONCLUSION

The modified Norwood procedure for first-stage palliation of hypoplastic left heart syndrome is possible in the majority of patients without the use of exogenous materials and does not result in an increased incidence of neoaortic arch obstruction. Repair of the aorta without patch supplementation may improve the potential for long-term growth of the new aorta.

Left ventricular outflow obstruction

Patients with LVOT obstruction require lifelong follow-up because the obstruction may be progressive or recurrent. Several procedures are usually required, either by surgery or by interventional cardiac catheterization, to repair or palliate the obstructive lesion. The treatment of these patients continues to evolve, and, despite the complexity of these patients' lesions, the morbidity and mortality rates have decreased and are expected to decrease further in the future.

Counselling strategies for parents of infants with congenital heart disease

Congenital heart disease is a significant cause of morbidity and mortality in the newborn. Its diagnosis may lead to a crisis in the affected families; there are the perceived implications of having an abnormality of so vital an organ. To that may be added the assumed guilt or blame, grief and at times anger, frequently experienced by parents of abnormal infants. It often befalls the paediatric cardiologist to initiate counselling while providing the expert information concerning the abnormality and its optimum management. Such counselling differs from that needed for minor lesions as compared for more complex abnormalities where a fatal outcome may ensure. While it is important to provide an accurate diagnosis and management plan to the parents, early detailed information is often confusing and may not be assimilated at a time of great stress. The parents seem more concerned as to whether the infant will survive, what the long term outlook will be, whether he or she will attend school, play, work and so on. With the more severe cardiac abnormalities, especially where there is a family history, one need be aware of the often perceived guilt of the parents. At times, it may be necessary to help the parents retain sufficient 'self-control', delaying the grieving process to enable them to contribute to the decision making. Where the infant has died, a follow-up appointment can facilitate grieving and help deal with unresolved issues. Through skilled counselling, the cardiologist in addition to his/her diagnostic and management skills, may meaningfully influence the ongoing care of the infant. They may help avoid the development of unrealistic fears or an over-optimistic outlook, thereby fostering the normal development of the child.

Pulmonary hypertension after operations for congenital heart disease: analysis of risk factors and management

BACKGROUND

Management of pulmonary hypertension, a potentially fatal complication of operations to correct congenital heart disease, has evolved through the last 15 years. Monitoring of pulmonary arterial pressure and mixed venous saturation became available, and prophylactic use of alpha-blockers and other vasodilators increased. This study examines risk factors for morbidity and mortality from pulmonary hypertension after operations to correct congenital heart disease and evaluates the impact of management changes on outcomes.

METHODS

By means of multivariable logistic regression analysis, 880 high-risk patients with congenital heart disease (of 2484 patients undergoing cardiopulmonary bypass between January 1980 and December 1994) were analyzed to determine which were at risk for postoperative pulmonary hypertension and its associated morbidity and mortality.

RESULTS

Patients with atrioventricular canal (n = 182), truncus arteriosus (n = 47), total anomalous pulmonary venous connection (n = 90), transposition of great arteries (n = 97), hypoplastic left heart syndrome (n = 50), and ventricular septal defect (n = 414) demonstrated a higher risk of postoperative pulmonary hypertension. By multivariable logistic regression, preoperative pulmonary hypertension (p < 0.0001), absence of mixed venous saturation monitoring (p < 0.0001), and absence of prophylactic alpha-blockade (p = 0.0004) significantly increased postoperative pulmonary hypertension. Preoperative pulmonary hypertension (p < 0.001) and absence of prophylactic alpha-blockers (p = 0.0004) were significant risk factors for in-hospital death related to pulmonary hypertension. Repair at older age (except in the case of total anomalous pulmonary venous connection) was a significant risk for postoperative pulmonary hypertension (p = 0.03).

CONCLUSION

Mixed venous saturation monitoring and alpha-receptor blockade reduced the incidence of pulmonary hypertension after operations for congenital heart disease. Early definitive repair reduced morbidity and mortality from postoperative pulmonary hypertension.