Older children at the time of the Norwood operation have ongoing mortality vulnerability that continues after cavopulmonary connection

Achieving an Optimal Outcome After Stage 1 Palliation for Hypoplastic Left Heart Syndrome and Variants: Frequency, Associated Factors, and Subsequent Outcomes

BACKGROUND

We sought to measure frequency of achieving an optimal outcome after stage 1 palliation (S1P) for hypoplastic left heart syndrome and variants, determine factors associated with optimal outcomes, and compare outcomes after stage 2 palliation (S2P) using the National Pediatric Cardiology Quality Improvement Collaborative database (2008-2016).

METHODS AND RESULTS

This is a retrospective cohort study with optimal outcome defined a priori as meeting all of the following: (1) discharge after S1P in <19 days (top quartile), (2) no red flag or major event readmissions before S2P, and (3) performing S2P between 90 and 240 days of age. Optimal outcome was achieved in 256 of 2182 patients (11.7%). Frequency varied among centers from 0% to 25%. Factors independently associated with an optimal outcome after S1P were higher gestational age (odds ratio [OR], 1.1 per week [95% CI, 1.0-1.2]; P=0.02); absence of a genetic syndrome (OR, 2.5 [95% CI, 1.2-5]; P=0.02); not requiring a post-S1P catheterization (OR, 2.7 [95% CI, 1.5-4.8]; P=0.01), intervention (OR, 1.5 [95% CI, 1.1-2]; P=0.006), or a procedure (OR, 4.5 [95% CI, 2.8-7.1]; P<0.001) before discharge; and not having a post-S1P complication (OR, 2.7 [95% CI, 1.9-3.7]; P<0.001). Those with an optimal outcome after S1P had improved S2P outcomes including shorter length of stay, less ventilator days, shorter bypass time, and fewer postoperative complications.

CONCLUSIONS

Identifying patients at lowest risk for poor outcomes during the home interstage period could shift necessary resources to those at higher risk, alter S2P postoperative expectations, and improve quality of life for families at lower risk.

Combined Norwood and cavopulmonary shunt as the first palliation in late presenters with hypoplastic left heart syndrome and single-ventricle lesions

OBJECTIVE

A primary cavopulmonary shunt as a component of the initial Norwood palliation could be an option in patients with hypoplastic left heart syndrome and single-ventricle lesions. We present our initial experience with this approach in carefully selected patients with unrestricted pulmonary blood flow and low pulmonary vascular resistance.

METHODS

The study included 16 patients; the mean age was 137.9 ± 84.2 days. All patients underwent a Norwood palliation consisting of atrial septectomy, Damus-Kaye-Stansel connection, and arch augmentation in addition to the cavopulmonary shunt as the initial palliation.

RESULTS

The mean preoperative pulmonary to systemic blood flow (Qp/Qs) ratio on room air (n = 9) and with 100% oxygen (n = 8) was 5.3 ± 3.2 and 8.6 ± 4.3, respectively. The mean pulmonary vascular resistance on room air (n = 10) and 100% oxygen (n = 9) was 4.8 ± 3.1 and 1.7 ± 0.97 WU/m², respectively. Delayed chest closure was needed in 12 patients, and 6 patients required postoperative inhaled nitric oxide. One patient underwent takedown of the cavopulmonary shunt and construction of the right ventricle to pulmonary artery conduit after 1 month. The mean intensive care unit stay was 18.9 ± 15.4 days. There were 2 in-hospital deaths (48 hours and 8 days after surgery) and 2 postdischarge deaths (6 months and 2 years after hospital discharge). Seven patients have undergone the Fontan completion successfully, and 5 patients await further surgery.

CONCLUSIONS

First-stage Norwood palliation with cavopulmonary shunt for patients with hypoplastic left heart syndrome or single-ventricle lesions is feasible in late presenters with low pulmonary vascular resistance.

Timing of Transfer and Mortality in Neonates with Hypoplastic Left Heart Syndrome in California

Maternal race/ethnicity is associated with mortality in neonates with hypoplastic left heart syndrome (HLHS). We investigated whether maternal race/ethnicity and other sociodemographic factors affect timing of transfer after birth and whether timing of transfer impacts mortality in infants with HLHS. We linked two statewide databases, the California Perinatal Quality Care Collaborative and records from the Office of Statewide Health Planning and Development, to identify cases of HLHS born between 1/1/06 and 12/31/11. Cases were divided into three groups: birth at destination hospital, transfer on day of life 0-1 ("early transfer"), or transfer on day of life ≥ 2 ("late transfer"). We used log-binomial regression models to estimate relative risks (RR) for timing of transfer and Cox proportional hazard models to estimate hazard ratios (HR) for mortality. We excluded infants who died within 60 days of life without intervention from the main analyses of timing of transfer, since intervention may not have been planned in these infants. Of 556 cases, 107 died without intervention (19%) and another 52 (9%) died within 28 days. Of the 449 included in analyses of timing of transfer, 28% were born at the destination hospital, 49% were transferred early, and 23% were transferred late. Late transfer was more likely for infants of low birthweight (RR 1.74) and infants born to US-born Hispanic (RR 1.69) and black (RR 2.45) mothers. Low birthweight (HR 1.50), low 5-min Apgar score (HR 4.69), and the presence of other major congenital anomalies (HR 3.41), but not timing of transfer, predicted neonatal mortality. Late transfer was more likely in neonates born to US-born Hispanic and black mothers but was not associated with higher mortality.

Hypoplastic left heart syndrome: from fetus to fontan

The care of children with hypoplastic left heart syndrome is constantly evolving. Prenatal diagnosis of hypoplastic left heart syndrome will aid in counselling of parents, and selected fetuses may be candidates for in utero intervention. Following birth, palliation can be undertaken through staged operations: Norwood (or hybrid) in the 1st week of life, superior cavopulmonary connection at 4-6 months of life, and finally total cavopulmonary connection (Fontan) at 2-4 years of age. Children with hypoplastic left heart syndrome are at risk of circulatory failure their entire life, and selected patients may undergo heart transplantation. In this review article, we summarise recent advances in the critical care management of patients with hypoplastic left heart syndrome as were discussed in a focused session at the 12th International Conference of the Paediatric Cardiac Intensive Care Society held on 9 December, 2016, in Miami Beach, Florida.

Outcome of Norwood operation for hypoplastic left heart syndrome

Purpose

The Norwood procedure, the first surgical step of staged palliation for hypoplastic left heart syndrome (HLHS), is also applied for other complex single ventricle lesions. This study aimed to evaluate the outcome of the Norwood operation in a single center over 4 years and to identify clinical and anatomic risk factors for overall mortality.

Methods

A retrospective review of the pediatric cardiovascular surgery database was performed to identify infants with HLHS who underwent NP (Norwood procedure) at our institution between January 2007 and December 2011. Our study population consisted of 85 patients with HLHS.

Results

Early mortality (30 days postoperative period) between January 2007 and December 2011 for Norwood operation was 7 (8.2%) out of 85 patient, and overall mortality was 24 (28.2%).

Conclusion

Our single-center experience shows that the Norwood operation can be performed for complex single ventricle lesions with similarly good early outcomes regardless of the underlying anatomy.

Influence of weight at the time of first palliation on survival in patients with a single ventricle

BACKGROUND

Numerous advances in surgical techniques and understanding of single-ventricle physiology have resulted in improved survival. We sought to determine the influence of various demographic, perioperative, and patient-specific factors on the survival of single-ventricle patients following stage 1 palliation at our institution.

METHODS

We conducted a retrospective study of all single-ventricle patients who had undergone staged palliation at our institution over an 8-year period. Data were collected from the Society of Thoracic Surgeons Congenital Heart Surgery database and from patient charts. Information on age, weight at stage 1 palliation, prematurity, genetic abnormalities, non-cardiac anomalies, ventricular dominance, and type of palliation was collected. Information on mortality and unplanned reinterventions was also collected.

RESULTS

A total of 72 patients underwent stage 1 palliation over an 8-year period. There were 12 deaths before and one death after stage 2 palliation. There was no hospital mortality following Glenn or Fontan procedures. On univariate analysis, low weight at the time of stage 1 palliation and prematurity were found to be risk factors for mortality following stage 1 palliation. However, multivariable Cox regression analysis revealed weight at stage 1 palliation to be a strong predictor of mortality. The type of stage 1 palliation did not have any influence on the outcome. No difference in survival was noted following the Glenn procedure.

CONCLUSION

Low weight has a deleterious impact on survival following stage 1 palliation. This is mitigated by stage 2 palliation. The type of stage 1 palliation itself has no bearing on the outcome.

The comparative role of echocardiography and MRI for identifying critical lesions in patients with single-ventricle physiology, before bidirectional cavopulmonary connection

BACKGROUND

In the era of multi-modality imaging, this study compared contemporary, pre-operative echocardiography and cardiac MRI in predicting the need for intervention on additional lesions before surgical bidirectional cavopulmonary connection.

METHODS

A total of 72 patients undergoing bidirectional cavopulmonary connection for single-ventricle palliation between 2007 and 2012, who underwent pre-operative assessment using both echocardiography and MRI, were included. The pre-determined outcome measure was any additional surgical or catheter-based intervention within 6 months of bidirectional cavopulmonary connection. Indices assessed were as follows: indexed dimensions of right and left pulmonary arteries, coarctation of the aorta, adequacy of interatrial communication, and degree of atrioventricular valve regurgitation.

RESULTS

Median age at bidirectional cavopulmonary connection was 160 days (interquartile range 121-284). The following MRI parameters predicted intervention: Z score for right pulmonary artery (odds ratio 1.77 (95% confidence interval 1.12-2.79, p=0.014)) and left pulmonary artery dimensions (odds ratio 1.45 (1.04-2.00, p=0.027)) and left pulmonary artery report conclusion (odds ratio 1.57 (1.06-2.33)). The magnetic resonance report predicted aortic arch intervention (odds ratio 11.5 (3.5-37.7, p=0.00006)). The need for atrioventricular valve repair was associated only with magnetic resonance regurgitation fraction score (odds ratio 22.4 (1.7-295.1, p=0.018)). Echocardiography assessment was superior to MRI for predicting intervention on interatrial septum (odds ratio 27.7 (6.3-121.6, p=0.00001)).

CONCLUSION

For branch pulmonary arteries, aortic arch, and atrioventricular valve regurgitation, MRI parameters more reliably predict the need for intervention; however, echocardiography more accurately identified the adequacy of interatrial communication. Approaching bidirectional cavopulmonary connection, the diagnostic strengths of MRI and echocardiography should be acknowledged when considering intervention.

Introduction to a Norwood program in an emerging economy: learning curve of a single center

BACKGROUND

There has been a notable improvement in the outcome of stage 1 palliation for hypoplastic left heart syndrome (HLHS) in recent years. Nevertheless, developing a new Norwood program requires a steep learning curve, especially in emerging economies where rapid population growth brings a high volume of patients but, on the other hand, resources are limited. In this paper we aimed to summarize the initial results of a single center.

METHODS

Hospital records of 21 patients were reviewed for all patients having a stage 1 palliation procedure for HLHS between May 2011 and May 2013. There were 13 male (62%) and 8 female (38%) patients. Median age was 14 days (range, 4-74 days) and median weight was 3030 g (2600-3900 g). HLHS was defined as mitral or aortic stenosis or atresia (or both) in the presence of normally related great vessels and a hypoplastic left ventricle. Transthoracic echocardiography was the diagnostic modality used in all patients. All procedures but one were performed using an antegrade selective cerebral perfusion method and moderate hypothermia. Cerebral perfusion was monitored with cerebral oximetry in all patients. Modified ultrafiltration was routinely used in all patients.

RESULTS

Overall hospital mortality was 47.6% (n = 10). Mortality rates considerably decreased from the first year to second year (69% and 12.5% respectively). No risk factors were identified for mortality.

CONCLUSIONS

Surgical palliation of neonates with hypoplastic left heart syndrome continues to be a challenge. To decrease the overall mortality nationwide and improve outcomes, a referral center with a dedicated team is necessary in emerging economies.

Earlier stage 1 palliation is associated with better clinical outcomes and lower costs for neonates with hypoplastic left heart syndrome

OBJECTIVES

Our aim was to examine the effects of surgical timing on major morbidity, mortality, and total hospital reimbursement for late preterm and term infants with hypoplastic left heart syndrome (HLHS) undergoing stage 1 palliation within the first 2 weeks of life.

METHODS

We conducted a retrospective cohort study of infants aged ≥35 weeks gestation, with HLHS, admitted to our institution at age ≤5 days, between January 1, 2003, and January 1, 2013. Children with other cardiac abnormalities or other major comorbid conditions were excluded. Univariable and multivariable analyses were performed to determine the association between age at stage 1 palliation and major morbidity, mortality, and hospital reimbursement.

RESULTS

One hundred thirty-four children met inclusion criteria. Mortality was 7.5% (n = 10). Forty-three percent (n = 58) experienced major morbidity. Median costs were $97,000, in 2013 dollars (interquartile range, $72,000-$151,000). Median age at operation was 5 days (interquartile range, 3-7 days; full range, 1-14 days). All deaths occurred in patients operated on between 4 and 8 days of life. For every day later that surgery was performed, the odds of major morbidity rose by 15.7% (95% confidence interval, 2.5%-30.7%; P = .018) and costs rose by 4.7% (95% confidence interval, 0.9%-8.2%; P < .014).

CONCLUSIONS

Delay of stage 1 palliation for neonates with HLHS is associated with increased morbidity and health care costs, even within the first 2 weeks of life.

One size does not fit all: the influence of age at surgery on outcomes following Norwood operation

Background

Given our large catchment area that often results in later presentation age, we sought to understand our institutional outcomes for the Norwood operation in the context of published data. Specifically, we studied whether operative and late death post-Norwood are dependent on age at operation.

Methods

Retrospective review of 105 consecutive infants undergoing Norwood (2004–2011) at our institution. Patients were divided into those undergoing Norwood ≤ 7 days of age (N = 43; 41%) and those undergoing Norwood > 7 days of age (N = 63; 59%). Operative mortality (≥30 days), interstage mortality (between Norwood and superior bidirectional Glenn), STS-mortality (operative death + in-hospital death), and late mortality, occurring any time following hospital discharge were compared among groups. Multivariable factors for mortality at each time-point were compared using logistic regression models.

Results

Underlying diagnosis was HLHS in 67 (64%) with the remainder (N = 38; 36%) being other single ventricle variants. Median age at surgery was 8 days (range 1–63 days) and mean weight at surgery was 3.2 ± 0.6 kg. Pulmonary blood flow was provided by a right ventricle-pulmonary artery conduit in 94% (N = 99). Overall operative survival was 92%, with 73% (N = 66) undergoing bidirectional Glenn. Median age was higher for operative survivors compared to non-survivors (12 days vs. 5 days; P = 0.036), with operative mortality higher for infants ≤7 days at Norwood compared to infants >7 days at Norwood (14% vs. 3%; P = 0.04). After censoring for in-hospital death, age ≤ 7 days was also associated with increased risk for late death (26% vs. 5%; P = 0.005).

Conclusions

In contrast to other institutional series, infants at our center undergoing Norwood operation at an earlier age have worse outcomes. Adoption of published practice patterns could lead to different local outcomes because of intangible center-specific effects, underscoring the principle that results from one institution may not be generalizable to others. Targeted center-specific internal review, if possible, should precede externally recommended changes in practice.

Analysis of preoperative condition and interstage mortality in Norwood and hybrid procedures for hypoplastic left heart syndrome using the Aristotle scoring system

OBJECTIVE

The 'hybrid procedure', consisting of surgical banding of the pulmonary arteries with intraoperative stenting of the arterial duct, was developed as primary palliation in hypoplastic left heart syndrome (HLHS), avoiding the risks of cardiopulmonary bypass. In many centres, it is reserved for low birth weight, premature or unstable neonates; however, its role in such high risk cases of HLHS has yet to be defined.

METHODS

The preoperative condition of all patients with HLHS who underwent either the hybrid or the Norwood procedure for HLHS between 2005-2011 was analysed retrospectively, using a modified comprehensive Aristotle score. We then compared operative, interstage and 1 year mortalities between the groups after Aristotle adjustment via Cox proportional hazards analyses.

RESULTS

Of 138 patients with HLHS, 27 had hybrid and 111 Norwood procedures. The hybrid group had significantly higher Aristotle scores (mean 4.1 vs 1.8; p<0.001); however, there was no significant difference in mortality at any stage. At 1 year, the overall unadjusted survival among Norwood and hybrid patients was 58.6% and 51.9%, respectively, yielding an Aristotle adjusted hazard ratio for mortality among hybrid patients of 1.09 (95% CI 0.56 to 2.11, p=0.80).

CONCLUSIONS

Applying a hybrid approach to high risk patients with HLHS produces a comparable early and interstage mortality risk to lower risk patients undergoing the Norwood procedure. Prospective studies are needed to establish whether the hybrid procedure is a viable alternative to the Norwood procedure in all HLHS patients in terms of both mortality and long term morbidity.

Rapid 2-stage Norwood I for high-risk hypoplastic left heart syndrome and variants

OBJECTIVES

Preoperative comorbidities (PCMs) are known risk factors for Norwood stage I (NW1). We tested the hypothesis that short-term bilateral pulmonary arterial banding (bPAB) before NW1 could improve the prognosis of these high-risk patients.

METHODS

From January 2006 to October 2011, 17 high-risk patients with hypoplastic left heart syndrome (defined as having ≥4 of the following PCMs: prolonged mechanical ventilation; older age; sepsis; necrotizing enterocolitis; hepatic, renal, or heart failure; coagulopathy; pulmonary edema; high inotropic requirements; anasarca; weight <2.5 kg; and cardiac arrest) were identified. In addition to conventional treatment of PCMs, they underwent bPAB before NW1. bPAB was undertaken with Silastic slings and secured with ligaclips to a luminal diameter of approximately 3.5 to 4.0 mm. The patency of the ductus arteriosus was maintained with prostaglandin. NW1 was performed using a modified, right Blalock-Taussig shunt at a median interval of 8 days after bPAB. The data from these patients were retrospectively reviewed, and the 30-day mortality and 1-year survival were compared with the hypoplastic left heart syndrome population who underwent primary NW1 with <3 PCMs in the same period.

RESULTS

Of the bPAB patients, 5 (29.4%) died before NW1. All had ≥5 PCMs. Twelve patients (70.6%) survived to undergo NW1. One early death occurred after NW1 (8.3%). The 1-year survival rate for high-risk patients who underwent NW1 was 66.7%. The early mortality and 1-year survival for the 130 patients with <3 PCMs was 10% and 80%, respectively.

CONCLUSIONS

Optimizing the balance between the pulmonary and systemic blood flow with a short period of bPAB and ductal patency can improve the perioperative conditions of high-risk patients before NW1. Those who survived bPAB and underwent NW1 had early mortality and 1-year survival comparable to the standard risk category, despite the severity of their initial condition. A rapid 2-stage NW1 strategy with bPAB and prostaglandin to maintain ductal patency can avoid the risks of suboptimal palliation and vascular injuries associated with hybrid procedures.

Timing of neonatal cardiac surgery is not associated with perioperative outcomes

OBJECTIVE

The optimal timing for neonatal cardiac surgery is unknown. We aimed to determine the relationship between age at surgery and perioperative outcomes, hypothesizing that earlier intervention would be associated with lower morbidity and mortality.

METHODS

A retrospective review was performed of neonates who had undergone an arterial switch operation, stage 1 palliation for functional single ventricle, or systemic-to-pulmonary shunt for obstructed pulmonary blood flow from January 1, 2005, to December 31, 2010. The subjects with clinical indications for delayed surgery or prematurity were excluded. Age at surgery was evaluated as both a continuous and a categorical variable. The primary outcome was a composite endpoint of mortality or prolonged intensive care stay.

RESULTS

Of 344 subjects, 286 (77 arterial switch operation, 124 stage 1 palliation, 85 systemic-to-pulmonary shunt) met the inclusion criteria. In each group, age at surgery was not associated with the primary composite endpoint. The patients who died after systemic-to-pulmonary shunt had a median age at surgery of 3 days versus 6 days for the survivors (P = .04). A similar, but nonsignificant, pattern was seen for patients undergoing arterial switch operations (4.5 vs 7 days; P = .09). Earlier surgery was not associated with a reduced duration of vasoactive support, mechanical ventilation, or intensive care unit length of stay in any group. Stage 1 palliation subjects in the upper age quartile (≥8 days) at surgery were less likely to require prolonged mechanical ventilation (P = .03).

CONCLUSIONS

Younger age at intervention in the neonatal period was not associated with reduced morbidity or mortality in any procedural subgroup studied. In our cohort, earlier systemic-to-pulmonary shunt for obstructed pulmonary blood flow was associated with a greater likelihood of a poor outcome.

Bilateral pulmonary artery banding for resuscitation in high-risk, single-ventricle neonates and infants: a single-center experience

OBJECTIVES

Bilateral pulmonary artery banding with or without ductal stenting has been performed as a resuscitative intervention for patients considered at too high risk for conventional single ventricle palliation. The purpose of the present study was to determine the outcomes using this strategy.

METHODS

We performed a retrospective review of 24 patients with single ventricle anatomy who were younger than 3 months who had undergone bilateral pulmonary artery banding and ductal stenting or maintenance of prostaglandin E(1) from January 2007 to October 2011 at our institution. The echocardiographic, angiographic, operative, and clinical data were reviewed. Follow-up data were available for 100% of the patients.

RESULTS

All 24 patients (13 male patients) underwent bilateral pulmonary artery banding at a median age of 8 days (range, 2-44 days). Their gestational age was 38 weeks (range, 27-41 weeks), and their weight was 3.01 kg (range, 1.5-4.4 kg). The cardiac diagnoses included hypoplastic left heart syndrome/variant hypoplastic left heart syndrome in 18, unbalanced atrioventricular canal in 4, and tricuspid atresia in 2. In the hypoplastic left heart syndrome group, 9 (50%) had an intact or a highly restrictive atrial septum requiring open (n = 1) or transcatheter (n = 8) atrial septostomy with or without atrial stent placement (n = 4). Ductal stenting was performed in 14 patients, and 10 patients were continued with prostaglandin E(1). Fifteen patients (62.5%) survived to undergo a Norwood procedure (n = 7), comprehensive stage 2 (n = 1), or primary cardiac transplantation (n = 7). Of the 9 who died, support was withdrawn in 5 because of a contraindication to transplantation, 1 because of sepsis and/or multiorgan system failure, and 1 for whom palliative care was desired. Two died awaiting transplantation. All 7 patients who underwent a conventional Norwood operation survived to discharge, and 6 of the 7 (85.7%) underwent bidirectional Glenn shunt placement. Of the 7 patients who underwent transplantation, 6 (85.7%) were alive at a median follow-up of 33.6 months.

CONCLUSIONS

Bilateral pulmonary artery banding with or without ductal stenting is an effective method of resuscitation for high-risk neonates and infants with a single ventricle, allowing for reasonable survival to conventional first-stage palliation or primary transplantation.