Right ventricle to pulmonary artery conduit reduces interim mortality after stage 1 Norwood for hypoplastic left heart syndrome

Tricuspid Valve Regurgitation in Hypoplastic Left Heart Syndrome: Current Insights and Future Perspectives

Hypoplastic Left Heart Syndrome (HLHS) is a congenital heart defect that requires a three-stage surgical palliation to create a single ventricle system in the right side of the heart. Of patients undergoing this cardiac palliation series, 25% will develop tricuspid regurgitation (TR), which is associated with an increased mortality risk. Valvular regurgitation in this population has been extensively studied to understand indicators and mechanisms of comorbidity. In this article, we review the current state of research on TR in HLHS, including identified valvular anomalies and geometric properties as the main reasons for the poor prognosis. After this review, we present some suggestions for future TR-related studies to answer the central question: What are the predictors of TR onset during the three palliation stages? These studies involve (i) the use of engineering-based metrics to evaluate valve leaflet strains and predict tissue material properties, (ii) perform multivariate analyses to identify TR predictors, and (iii) develop predictive models, particularly using longitudinally tracked patient cohorts to foretell patient-specific trajectories. Regarded together, these ongoing and future efforts will result in the development of innovative tools that can aid in surgical timing decisions, in prophylactic surgical valve repair, and in the refinement of current intervention techniques.

Autologous Umbilical Cord Blood-Derived Mononuclear Cell Therapy Promotes Cardiac Proliferation and Adaptation in a Porcine Model of Right Ventricle Pressure Overload

Congenital heart diseases, including single ventricle circulations, are clinically challenging due to chronic pressure overload and the inability of the myocardium to compensate for lifelong physiological demands. To determine the clinical relevance of autologous umbilical cord blood-derived mononuclear cells (UCB-MNCs) as a therapy to augment cardiac adaptation following surgical management of congenital heart disease, a validated model system of right ventricular pressure overload due to pulmonary artery banding (PAB) in juvenile pigs has been employed. PAB in a juvenile porcine model and intramyocardial delivery of UCB-MNCs was evaluated in three distinct 12-week studies utilizing serial cardiac imaging and end-of-study pathology evaluations. PAB reproducibly induced pressure overload leading to chronic right ventricular remodeling including significant myocardial fibrosis and elevation of heart failure biomarkers. High-dose UCB-MNCs (3 million/kg) delivered into the right ventricular myocardium did not cause any detectable safety issues in the context of arrhythmias or abnormal cardiac physiology. In addition, this high-dose treatment compared with placebo controls demonstrated that UCB-MNCs promoted a significant increase in Ki-67-positive cardiomyocytes coupled with an increase in the number of CD31+ endothelium. Furthermore, the incorporation of BrdU-labeled cells within the myocardium confirmed the biological potency of the high-dose UCB-MNC treatment. Finally, the cell-based treatment augmented the physiological adaptation compared with controls with a trend toward increased right ventricular mass within the 12 weeks of the follow-up period. Despite these adaptations, functional changes as measured by echocardiography and magnetic resonance imaging did not demonstrate differences between cohorts in this surgical model system. Therefore, this randomized, double-blinded, placebo-controlled pre-clinical trial establishes the safety of UCB-MNCs delivered via intramyocardial injections in a dysfunctional right ventricle and validates the induction of cardiac proliferation and angiogenesis as transient paracrine mechanisms that may be important to optimize long-term outcomes for surgically repaired congenital heart diseases.

Ventriculotomy Decreases Agreement Between Assessment of Right Ventricular Function by Echocardiography and Cardiac Magnetic Resonance Imaging in Patients with Hypoplastic Left Heart Syndrome

Accurate assessment of the right ventricular (RV) volume and function is important in patients with hypoplastic left heart syndrome (HLHS). We sought to investigate the effect of ventriculotomy on the correlation of RV functional assessments by two-dimensional echocardiography (2DE) to cardiac magnetic resonance (CMR)-derived RV ejection fraction (EF) in patients with HLHS. A retrospective re-analysis of CMR imaging with matched 2DE was performed from the institutional HLHS registry. Echocardiographic RV functional parameters were analyzed and correlated with CMR-derived EF. Intraclass correlation coefficient was used to determine interobserver reliability. A total of 58 matched echocardiograms and CMR imaging studies from 46 patients was evaluated. Median duration between CMR imaging and echocardiogram was 1 day (range 0-6 days). No significant difference was seen in CMR RV EF between patients with and without a ventriculotomy (EF - 43.6% vs 44.7%, p = 0.85). The presence of a ventriculotomy significantly decreased the correlation of biplane FAC (r = 0.86 vs 0.52; p = 0.02), triplane FAC (r = 0.84 vs 0.49; p = 0.03), and 2DE visually estimated EF (r = 0.83 vs 0.49; p = 0.02). The correlation of circumferential and longitudinal strains to CMR-derived EF was not significantly affected by the presence of a ventriculotomy. A prior ventriculotomy significantly affected correlation between 2DE FAC and visually estimated EF with CMR-derived EF. The dyskinetic myocardial segment due to ventriculotomy, which is often not visualized by 2DE, may be the reason for this discrepancy.

Aortic or Pulmonary Valved Homograft Right Ventricle to Pulmonary Artery Conduit in the Norwood Procedure

BACKGROUND

Several modifications of the Norwood procedure utilizing valved right ventricle to pulmonary artery conduits have recently been reported. Our group has been using aortic or pulmonary valved homografts combined with PTFE tube grafts for now 16 years.

METHODS

In this report, we review our technique in detail and describe any changes that have occurred over the years. We provide detailed illustrations of our preferred surgical technique, report outcome data, and compare it to the other conduit options available.

RESULTS

Between 2006 and 2015, 130 stage I Norwood procedures were performed at our institution, 100 of them using valved conduits. Our technique is described and illustrated in detail. Early mortality was 15%. Postoperative percutaneous intervention on the conduit was required in 29% of cases.

CONCLUSIONS

While a randomized trial comparing different valved conduits is lacking, we believe a composite conduit made from homograft aortic or pulmonary valves and PTFE tube grafts is an excellent choice in stage I Norwood procedure.

Experience of a single institution with femoral vein homograft as right ventricle to pulmonary artery conduit in stage 1 Norwood operation

OBJECTIVE

Femoral vein homograft can be used be used as valved right ventricle to pulmonary artery conduit in the Norwood operation. We describe the results of this approach, including pulmonary artery growth and ventricular function.

METHODS

A retrospective chart review of 24 consecutive neonates with hypoplastic left heart syndrome or complex single ventricle undergoing this approach between June 2012 and December 2017 was performed. Conduit valve competency and ventricular function were estimated using transthoracic echocardiogram, and pulmonary artery growth was measured using Nakata's index. Changes in ventricular function pre-Glenn and at latest follow-up were assessed by ordinal logistic regression with a general linear model to account for the correlation within the same patient over time.

RESULTS

Median age at surgery was 4 days, and mean weight was 3 kg. There was no interstage mortality. A total of 21 patients have undergone Glenn operation, and 9 patients have completed the Fontan operation. None of the conduits developed thrombosis. Sixty-three percent of conduits remained competent in the first month, and 33% remained competent after 3 months of operation. Catheter interventions on conduits were necessary in 14 patients. Median Nakata index at pre-Glenn catheterization was 228 mm²/m² (interquartile range, 107-341 mm²/m²). Right ventricular function was preserved in 83% of patients at a median follow-up of 34 (interquartile range, 10-46) months.

CONCLUSIONS

Femoral vein homograft as a right ventricle to pulmonary artery conduit in the Norwood operation is safe and associated with good pulmonary artery growth and preserved ventricular function as assessed by subjective echocardiography. Catheter intervention of the conduit may be necessary.

Hypoplastic left heart syndrome [HLHS]: treatment options in present era

Hypoplastic left heart syndrome (HLHS) is the most severe form of congenital heart defect (CHD). The first successful intervention for it was undertaken by Norwood in 1983. Since then, there have been much development in the pre, intra, and postoperative treatment option in staged palliative surgical procedures. Early diagnostic management, prenatal interventions, innovative diagnostic methods, constantly modified surgical techniques, and hybridization contribute to a significant progress in treatment options. This will allow for defining an optimal strategy of improving survival and quality of life in HLHS patients. The development of intervention cardiology makes possible the stepwise treatment of the defect with one operation only. The first and third stage may be done by hybrid or interventional methods, then only the second stage of treatment needs to be done surgically. The world experience and all the available literature says that the 1st-stage procedure could be done now safely either directly or with a bridge to Norwood followed by the stage 2 with a Glen or Hemi-Fontan and followed by a Fontan down the lane surgically.

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.

The blalock and taussig shunt revisited

The systemic to pulmonary artery shunts are done as palliative procedures for cyanotic congenital heart diseases ranging from simple tetralogy of Fallots (TOFs)/pulmonary atresia (PA) to complex univentricular hearts. They allow growth of pulmonary arteries and maintain regulated blood flow to the lungs till a proper age and body weight suitable for definitive corrective repair is reached. We have reviewed the BT shunt with its anaesthtic considerations and management of associated complications.

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.

Femoral vein homograft as Sano shunt results in improved pulmonary artery growth after Norwood operation

OBJECTIVE

To evaluate differences in interstage growth of pulmonary arteries between use of polytetrafluoroethylene and femoral vein homograft as Sano shunt during stage-I Norwood palliation.

METHODS

A retrospective review of all patients who survived to the second stage following Norwood-Sano operation at two institutions was performed. Either polytetrafluoroethylene or the valved segment of femoral vein homograft was used for construction of the Sano shunt. The size of pulmonary arteries was compared at pre-Glenn catheterisation.

RESULTS

A total of 48 neonates with the diagnosis of hypoplastic left heart syndrome or its variants comprised the study population. Femoral vein homograft of 5-6 mm diameter was used in 14 and polytetrafluoroethylene graft of 5 mm was used in 34 patients. The two groups were comparable in terms of preoperative demographics and age at time of pre-Glenn catheterisation (3.9±0.7 versus 3.4±0.8 months, p=0.06). Patients who received femoral vein homograft demonstrated a significantly higher pre-Glenn Nakata index [264 (130-460) versus 165 (108-234) mm2/m2, p=0.004]. The individual branch pulmonary arteries were significantly larger in the femoral vein group (right, 7.8±3.6 versus 5.0±1.2, p=0.014; left, 7.2±2.1 versus 5.6±1.9, p=0.02). There were no differences in cardiac index, Qp:Qs, ventricular end-diastolic pressure or systemic oxygen saturations.

CONCLUSIONS

Utilisation of a valved segment of femoral vein homograft as right ventricle to pulmonary artery conduit during Norwood-Sano operation confers better interstage growth of the pulmonary arteries. Further studies are needed to evaluate the impact of femoral vein homograft on single ventricle function.

Femoral Vein Homograft as Right Ventricle to Pulmonary Artery Conduit in Stage 1 Norwood Operation

BACKGROUND

The polytetrafluoroethylene tube used as right ventricle to pulmonary artery conduit in the stage 1 Norwood operation is associated with risks of suboptimal branch pulmonary artery growth, thrombosis, free insufficiency, and long-term right ventricular dysfunction. Our experience with use of valved femoral vein homograft as right ventricle to pulmonary artery conduit is described.

METHODS

Between June 2012 and December 2015, 15 neonates with hypoplastic left heart syndrome or complex single ventricle underwent stage 1 Norwood operation with valved segment of femoral vein homograft as right ventricle to pulmonary artery conduit. The median age at surgery was 3 days and the mean weight was 3 kg. The size of the femoral vein homograft was 5 mm in 8 patients and 6 mm in 7 patients.

RESULTS

There was no hospital or interstage mortality. Fourteen patients underwent Glenn operation, and 6 have undergone Fontan operation to date. The median Nakata index at pre-Glenn catheterization was 262 mm²/m² (interquartile range: 121 to 422 mm²/m²). No patient had thrombosis of conduit. Most femoral vein conduits remained competent in the first month after stage 1 Norwood operation, although most became incompetent by 3 months. Catheter intervention on the conduit was necessary in 7 patients. Right ventricular function was preserved in most patients at follow-up.

CONCLUSIONS

The use of femoral vein homograft as right ventricle to pulmonary artery conduit in the Norwood operation is safe and associated with good pulmonary artery growth and preserved ventricular function. Balloon dilation of the conduit may be necessary during the interstage period.

Long-term progression and survival following Norwood Single Ventricle Reconstruction

PURPOSE OF REVIEW

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

RECENT FINDINGS

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

SUMMARY

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

Right-ventricular global longitudinal strain may predict neo-aortic arch obstruction after Norwood/Sano procedure in children with hypoplastic left heart syndrome

Neo-aortic arch obstruction (NAAO) is a common complication following the Norwood/Sano procedure (NP) for hypoplastic left heart syndrome (HLHS) and is associated with increased morbidity and mortality. However, there is currently no objective method for predicting which patients will develop NAAO. This study was designed to test the hypothesis that hemodynamic changes from development of NAAO after NP in patients with HLHS will lead to changes in myocardial dynamics that could be detected before clinical symptoms develop with strain analysis using velocity vector imaging. Patients with HLHS who had at least one cardiac catheterization after NP were identified retrospectively. Strain analysis was performed on all echocardiograms preceding the first catheterization and any subsequent catheterization performed for intervention on NAAO. Twelve patients developed NAAO and 30 patients never developed NAAO. Right ventricular strain was worse in the group that developed NAAO (-6.2 vs. -8.6 %, p = 0.040) at a median of 59 days prior to diagnosis of NAAO. Those patients that developed NAAO following NP were significantly younger at the time of first catheterization than those that did not develop NAAO (92 ± 50 vs. 140 ± 36 days, p = 0.001). This study demonstrates that right ventricular GLS is abnormal in HLHS patients following NP and worsening right ventricular strain may be predictive of the future development of NAAO.

Transplantation-free survival and interventions at 3 years in the single ventricle reconstruction trial

BACKGROUND

In the Single Ventricle Reconstruction (SVR) trial, 1-year transplantation-free survival was better for the Norwood procedure with right ventricle-to-pulmonary artery shunt (RVPAS) compared with a modified Blalock-Taussig shunt (MBTS). At 3 years, we compared transplantation-free survival, echocardiographic right ventricular ejection fraction, and unplanned interventions in the treatment groups.

METHODS AND RESULTS

Vital status and medical history were ascertained from annual medical records, death indexes, and phone interviews. The cohort included 549 patients randomized and treated in the SVR trial. Transplantation-free survival for the RVPAS versus MBTS groups did not differ at 3 years (67% versus 61%; P=0.15) or with all available follow-up of 4.8±1.1 years (log-rank P=0.14). Pre-Fontan right ventricular ejection fraction was lower in the RVPAS group than in the MBTS group (41.7±5.1% versus 44.7±6.0%; P=0.007), and right ventricular ejection fraction deteriorated in RVPAS (P=0.004) but not MBTS (P=0.40) subjects (pre-Fontan minus 14-month mean, -3.25±8.24% versus 0.99±8.80%; P=0.009). The RVPAS versus MBTS treatment effect had nonproportional hazards (P=0.004); the hazard ratio favored the RVPAS before 5 months (hazard ratio=0.63; 95% confidence interval, 0.45-0.88) but the MBTS beyond 1 year (hazard ratio=2.22; 95% confidence interval, 1.07-4.62). By 3 years, RVPAS subjects had a higher incidence of catheter interventions (P<0.001) with an increasing HR over time (P=0.005): <5 months, 1.14 (95% confidence interval, 0.81-1.60); from 5 months to 1 year, 1.94 (95% confidence interval, 1.02-3.69); and >1 year, 2.48 (95% confidence interval, 1.28-4.80).

CONCLUSIONS

By 3 years, the Norwood procedure with RVPAS compared with MBTS was no longer associated with superior transplantation-free survival. Moreover, RVPAS subjects had slightly worse right ventricular ejection fraction and underwent more catheter interventions with increasing hazard ratio over time.

CLINICAL TRIAL REGISTRATION URL

http://www.clinicaltrials.gov. Unique identifier: NCT00115934.

Establishment of right ventricle-pulmonary artery continuity as the first-stage palliation in older infants with pulmonary atresia with ventricular septal defect may be preferable to use of an arterial shunt

OBJECTIVES

Right ventricle-pulmonary artery (RV-PA) conduit and systemic-to-pulmonary artery (S-PA) shunt in younger infants for the first-stage palliation with pulmonary atresia with ventricular septal defect (PAVSD) obtained good results. However, the pulmonary arteries (PA) grow slow in older infants undergoing an S-PA shunt. We compared the clinical outcomes of the two procedures in older infants with PAVSD.

METHODS

A total of 48 patients with PAVSD underwent the first-stage palliative procedure between January 2010 and July 2012. Patients were divided into the RV-PA group and the S-PA group based on whether they had an RV-PA conduit (n = 24) or an S-PA shunt (n = 24). The early and late outcomes were compared between groups.

RESULTS

There was no significant difference in in-hospital mortality, mechanical ventilation time, paediatric intensive care unit stay and hospital stay between groups (all P > 0.05). The RV-PA conduits were associated with better PA growth compared with the S-PA shunts (P < 0.001). The RV-PA group had a higher rate of second-stage biventricular surgery compared with the S-PA group (P = 0.03). The early outcomes among different conduits of the RV-PA conduit were not different (all P > 0.05). A positive correlation was found between the size of conduits and body weight (R(2) = 0.684, P < 0.001).

CONCLUSIONS

In older infants with PAVSD who underwent the first-stage palliative procedure, early outcomes showed no difference between the RV-PA conduit group and the S-PA shunt group. The RV-PA conduits were associated with better growth of the PA and higher rates of second-stage biventricular repair. Autologous pericardium is a good choice for RV-PA conduits, and there is a correlation between body weight and size of conduit.

Surgical approach to hyploplastic left heart syndrome - Norwood Stage I

Hypoplastic left heart syndrome (HLHS) is characterized by left ventricular and ascending aorta hypoplasia. The treatment of this condition usually involves three surgical stages beginning with the Norwood Stage I operation and culminating in the Fontan-Kreutzer procedure with an intermediate cavopulmonary shunt. We will illustrate our current surgical approach for the Norwood Stage I reconstructive procedure.

Impact of pre-stage II hemodynamics and pulmonary artery anatomy on 12-month outcomes in the Pediatric Heart Network Single Ventricle Reconstruction trial

OBJECTIVE

To compare the interstage cardiac catheterization hemodynamic and angiographic findings between shunt types for the Pediatric Heart Network Single Ventricle Reconstruction trial. The trial, which randomized subjects to a modified Blalock-Taussig shunt (MBTS) or right ventricle-to-pulmonary artery shunt (RVPAS) for the Norwood procedure, demonstrated the RVPAS was associated with a smaller pulmonary artery diameter but superior 12-month transplant-free survival.

METHODS

We analyzed the pre-stage II catheterization data for the trial subjects. The hemodynamic variables and shunt and pulmonary angiographic data were compared between shunt types; their association with 12-month transplant-free survival was also evaluated.

RESULTS

Of 549 randomized subjects, 389 underwent pre-stage II catheterization. A smaller size, lower aortic and superior vena cava saturation, and higher ventricular end-diastolic pressure were associated with worse 12-month transplant-free survival. The MBTS group had a lower coronary perfusion pressure (27 vs 32 mm Hg; P<.001) and greater pulmonary blood flow/systemic blood flow ratio (1.1 vs 1.0, P=.009). A greater pulmonary blood flow/systemic blood flow ratio increased the risk of death or transplantation only in the RVPAS group (P=.01). The MBTS group had fewer shunt (14% vs 28%, P=.004) and severe left pulmonary artery (0.7% vs 9.2%, P=.003) stenoses, larger mid-main branch pulmonary artery diameters, and greater Nakata indexes (164 vs 134, P<.001).

CONCLUSIONS

Compared with the RVPAS subjects, the MBTS subjects had more hemodynamic abnormalities related to shunt physiology, and the RVPAS subjects had more shunt or pulmonary obstruction of a severe degree and inferior pulmonary artery growth at pre-stage II catheterization. A lower body surface area, greater ventricular end-diastolic pressure, and lower superior vena cava saturation were associated with worse 12-month transplant-free survival.

Laparoscopic antireflux surgery in infants with single ventricle physiology: a review

Laparoscopic fundoplication and gastrostomy tube placement have grown in popularity within the pediatric population for treatment of gastroesophageal reflux disease and failure to thrive, respectively. One population that has an increased need for gastric surgery in infancy is patients with congenital heart defects, especially those with "single ventricle physiology." The most common defect included in this population is hypoplastic left heart syndrome (HLHS). Because of the abnormal physiology present in this condition, there are concerns with regard to the use of laparoscopic procedures for gastric surgery in patients treated with a three-staged reconstruction. We review the staged reconstruction of infants with HLHS, address safety concerns of interstage noncardiac procedures on this patient population, and review the current literature regarding outcomes of laparoscopic gastric surgery on patients with single ventricle physiology.

Improving surgical outcome following the Norwood procedure

Background

The Norwood procedure consists of three palliative operations, performed in neonates with hypoplastic left heart syndrome. Especially the first stage (Norwood I) is associated with the highest mortality rates in paediatric cardiac surgery (up to 25%). During surgery, the aorta is reconstructed and a systemic-to-pulmonary shunt is applied. Originally the modified Blalock-Taussig shunt was used, but recently the right-ventricle-to-pulmonary-artery shunt is increasingly being employed. We reviewed the results of our operative strategy, where an individualised choice of shunt is made. Furthermore, attempts to reduce interstage mortality (between Norwood I and II) were assessed.

Methods

All neonates who underwent Norwood stage I palliation from August 2004 until November 2010 were included in this retrospective analysis. Mortality rates and management strategies were compared.

Results

Thirty-six patients were available for analysis. Overall 30-day mortality was 5.6% (2 patients) and interstage mortality after discharge was 14% (5 patients). In 2006, a novel clinical protocol was introduced, aimed at reduction of mortality during the interstage period. This resulted in reduction of interstage mortality from 23% to 9% (3 of 13 infants, versus 2 of 23), with a cumulative survival of 82% (maximum follow-up 4 years).

Conclusion

Early surgical results following the Norwood procedure using an individualised shunt choice are favourable.

Staged palliation of hypoplastic left heart syndrome: trends in mortality, cost, and length of stay using a national database from 2000 through 2009

Staged surgical palliation has revolutionized the care of patients with hypoplastic left heart syndrome (HLHS), although the outcomes of survival and cost at a national level remain unclear. This study sought to evaluate (1) trends in HLHS surgical outcomes including in-hospital mortality, length of stay (LOS), and cost, and (2) patient and hospital risk factors associated with these outcomes. Hospitalizations for patients with HLHS, including stage I, II, and III palliations, were analyzed using the Kids' Inpatient Database from 2000 through 2009. Trends in mortality, LOS, and cost were analyzed and chi-squared tests were used to test association between categorical variables. Patient and hospital characteristics associated with death were analyzed using logistic regression and associations with LOS were analyzed using ordinary least squared regression. There were 16,923 hospital admissions in patients with HLHS of which 5,672 (34%) included surgical intervention. Total (3,201-5,102) and surgery-specific admissions (1,165-1,618) increased from 2000 to 2009. Mortality decreased 14% per year in stage III palliations (odds ratio [OR] 0.86; 95% confidence interval [CI]: 0.79-0.94) and 6% per year for stage I palliations (OR 0.94; 95% CI 0.90-0.99) but not for stage II palliations (OR 1.01; 95% CI; 0.89-1.14). Length of stay increased for stage I and II palliations; however, per-patient hospital cost decreased in 2009. In conclusion, recent decrease in per patient cost for staged surgical palliation for HLHS has correlated temporally with improved mortality.

Home monitoring program reduces interstage mortality after the modified Norwood procedure

BACKGROUND

From 2002 to 2005, the interstage mortality after a modified Norwood procedure was 7% in our program. An interstage home monitoring program (HMP) was established to identify Norwood procedure patients at increased risk of decompensation and to reduce interstage mortality.

METHODS

Results of the first 5 years of the Norwood HMP were reviewed retrospectively. Interstage was defined as the time between Norwood hospital discharge and admission for second stage surgical palliation. In the HMP, families documented oxygen saturation, heart rate, weight, and feedings daily. Nurse practitioners called each family at least weekly, and when issues arose, action plans were determined based on symptom severity.

RESULTS

Between October 2005 and October 2010 there were 46 Norwood procedure patients who survived to hospital discharge. All were enrolled in the HMP. Forty-five patients had a Norwood procedure with right ventricle to pulmonary artery conduit, and 1 patient had a modified Blalock-Taussig shunt. Interstage survival was 100%. Nineteen patients (41%) were admitted interstage; 5 patients were admitted twice, 1 patient was admitted 4 times. Seventeen patients (37%) required interstage interventions. Eight patients (17%) required major interventions: conduit stenting, aortic arch balloon angioplasty, emergent shunt, or early Glenn surgery. Minor interventions included supplemental oxygen, blood transfusion, intravenous hydration, diuresis, anti-arrhythmic therapy, or feeding adjustments.

CONCLUSIONS

In the first 5 years of the HMP, all infants discharged after a modified Norwood procedure survived the interstage period. The HMP altered clinical management in 37% of patients. Home monitoring of oxygen saturation, heart rate, weight, and feedings, along with comprehensive care coordination, allowed timely interventions and reduced interstage mortality from 7% to 0%.

Impact of pharmacotherapy on interstage mortality and weight gain in children with single ventricle

OBJECTIVE.: Infants with single ventricle physiology have a high mortality and poor somatic growth during the interstage period. We retrospectively assessed the impact of pharmacotherapy in this population using a multicenter database. DESIGN AND RESULTS.: Records for 395 patients (63.5% boys) with single ventricle were obtained from the National Pediatric Cardiology Quality Improvement Collaborative registry. Median of five medications were prescribed per patient at discharge after stage 1 palliation (interquartile range 3 to 6); the most common medications being aspirin (95.7%), diuretics (90.4%), angiotensin convertase enzyme inhibitors (37.7%), proton pump inhibitors (33.4%), H2 receptor blockers (30.6%), and digoxin (27.6%). Interstage mortality was 9.4%. Digoxin use was associated with lower risk of death (P =.03) on univariable analysis, however no single medication was an independent predictor on regression analysis. Change in weight-for-age z-score was studied as outcome of somatic growth with 36.3% patients showing a decrease during the interstage period. Total number of medications prescribed to a patient showed a negative correlation with the interstage change in z-score (r = -0.19, P =.002). On univariable comparisons, use of metoclopramide and lansoprazole were associated with decreased z-score (P =.004 and.041, respectively) although linear regression failed to identify any agent as independent predictor. CONCLUSIONS.: Children with single ventricle have high mortality and a profound medication burden. No individual medication is independently associated with better survival or weight gain during interstage period. Despite widespread use, proton pump inhibitors and prokinetic agents are not associated with better outcomes and may be associated with poor growth.

Size of the right ventricle-to-pulmonary artery conduit impacts mid-term outcome after the Norwood procedure in patients weighing less than 3 kg

OBJECTIVE

The optimal shunt size for patients who have the Norwood operation with a right ventricle-to-pulmonary artery conduit is controversial. The goal of this study is to compare outcomes of 2 shunt sizes in this population.

METHODS

Between 2002 and 2010, 75 consecutive patients diagnosed with hypoplastic left heart syndrome and its variants underwent the Norwood procedure with a right ventricle-to-pulmonary artery conduit. The outcomes of 20 neonates weighing <3 kg were analyzed.

RESULTS

The cumulative 30-day stage 1 survival [corrected] was 97% (95% confidence interval, 88%-99%) for all patients (73/75), 20 of whom weighed <3 kg. Nine patients had a 6-mm (group 1) and 11 patients had a 5-mm (group 2) right ventricle-to-pulmonary artery conduit. Thirty-day stage 1 survival was 88% (8/9) in group 1 and 90% (10/11) in group 2 (P = .88). The central pulmonary artery confluence size at prebidirectional cavopulmonary shunt catheterization was 4.5 ± 1.2 mm in group 1 and 2.5 ± 1.0 mm in group 2 (P = .009). The mean transpulmonary gradient was higher in group 2 (7.8 ± 3.1 mm Hg vs 4.2 ± 1.9 mm Hg; P = .036). The incidence of pulmonary artery intervention was 16% (1/7) in group 1 and 75% (6/8) in group 2 (P = .030). Survival rate at 6 months was 66% (6/9) in group 1 and 70% (7/10) in group 2 (P = .89).

CONCLUSIONS

Use of a 6-mm right ventricle-to-pulmonary artery conduit showed better central pulmonary artery growth and less need for pulmonary artery intervention in the authors' experience.

Can Randomized Clinical Trials Impact the Surgical Approach for Hypoplastic Left Heart Syndrome?

The Eighth International Conference of the Pediatric Cardiac Intensive Care Society was held in Miami, Florida, December 8 to 11, 2010. The program included a session dedicated to the management of hypoplastic left heart syndrome (HLHS), with particular emphasis on the innovations that have led to contemporary schemes of management and the role of clinical trials in the evolution and acceptance of these strategies. An invited panel of experts reviewed the historical evolution of staged surgical reconstruction, the randomized clinical trials that have been undertaken thus far, and the extent to which these have, or have not, influenced individual and institutional approaches to management of HLHS.

The impact of a dedicated single-ventricle home-monitoring program on interstage somatic growth, interstage attrition, and 1-year survival

OBJECTIVE

There has been considerable improvement in survival after the first stage of palliation for single-ventricle heart disease. Yet, interstage mortality continues to plague this population. Home monitoring has been proposed to reduce interstage mortality. We review our experience after creation of a Single Ventricle Program.

METHODS

All infants with a single ventricle heart defect who were admitted to Texas Children's Hospital from the inception of the Single Ventricle Program on September 1, 2007, to January 1, 2010, were included in the Single Ventricle Program cohort. Infants with a single ventricle presenting between January 1, 2002, and August 31, 2007, comprised the pre-Single Ventricle Program group. Anatomic, operative, and postoperative details were noted for all patients. End points included in-hospital death after the first stage of palliation, interstage death (defined as after discharge from the first stage of palliation and before the second stage of palliation), and death or heart transplantation by 1 year of age. Interstage weight gain was also compared.

RESULTS

A total of 137 infants with a single ventricle were included in the pre-Single Ventricle Program cohort, and 93 infants were included in the Single Ventricle Program cohort. Anatomic subtypes were similar between groups. There was significant improvement in rate of interstage weight gain, whereas age at the second stage of palliation was significantly reduced in the Single Ventricle Program group. In-house mortality decreased during the Single Ventricle Program era (P = .021). Interstage mortality did not significantly decrease in the Single Ventricle Program group. However, 1-year transplant-free survival improved during the Single Ventricle Program era (P = .002).

CONCLUSIONS

The Single Ventricle Program improved interstage weight gain, thereby allowing for early second-stage palliation at an equivalent patient weight. Interstage mortality was not significantly reduced by our program. However, 1-year transplant-free survival was significantly improved in patients in the Single Ventricle Program.

Norwood with right ventricle-to-pulmonary artery conduit is more effective than Norwood with Blalock-Taussig shunt for hypoplastic left heart syndrome: mathematic modeling of hemodynamics

OBJECTIVE

The introduction of right ventricle to pulmonary artery (RV-PA) conduit in the Norwood procedure for hypoplastic left heart syndrome resulted in a higher survival rate in many centers. A higher diastolic aortic pressure and a higher mean coronary perfusion pressure were suggested as the hemodynamic advantage of this source of pulmonary blood flow. The main objective of this study was the comparison of two models of Norwood physiology with different types of pulmonary blood flow sources and their hemodynamics.

METHOD

Based on anatomic details obtained from echocardiographic assessment and angiographic studies, two three-dimensional computer models of post-Norwood physiology were developed. The finite-element method was applied for computational hemodynamic simulations. Norwood physiology with RV-PA 5-mm conduit and Blalock-Taussig shunt (BTS) 3.5-mm shunt were compared. Right ventricle work, wall stress, flow velocity, shear rate stress, energy loss and turbulence eddy dissipation were analyzed in both models.

RESULTS

The total work of the right ventricle after Norwood procedure with the 5-mm RV-PA conduit was lower in comparison to the 3.5-mm BTS while establishing an identical systemic blood flow. The Qp/Qs ratio was higher in the BTS group.

CONCLUSIONS

Hemodynamic performance after Norwood with the RV-PA conduit is more effective than after Norwood with BTS. Computer simulations of complicated hemodynamics after the Norwood procedure could be helpful in establishing optimal post-Norwood physiology.

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

OBJECTIVES

Delayed first-stage palliation of children with hypoplastic left heart syndrome and related pathologies can be associated with poor outcomes because of development of progressive pulmonary vascular disease and volume load effects on the systemic ventricle and atrioventricular valve. We examine the current era's survival in this subgroup.

METHODS

Fifty-five infants older than 2 weeks underwent the Norwood operation (2003-2007). Separate competing risk analyses were performed to model outcomes (death and transition to the next stage) after the Norwood operation and after bidirectional cavopulmonary connection.

RESULTS

Median age was 32 days (range, 15-118 days). Forty-seven percent had hypoplastic left heart syndrome, and 53% had other complex univentricular variants. Mean ascending aortic size was 4.4 ± 1.9 mm, 10% had impaired ventricular function, 11% had moderate atrioventricular valve regurgitation, and 32% had restrictive pulmonary venous return. Pulmonary blood flow was established through an aortopulmonary shunt (n = 30) or Sano shunt (n = 25). After the Norwood operation, patients required longer ventilation and more oxygen and nitric oxide and had higher inotropic scores compared with those undergoing the traditional management protocol. Competing risks analysis showed that 2 years after the Norwood operation, 39% had died, and 57% underwent bidirectional cavopulmonary connection. Four years after bidirectional cavopulmonary connection, 15% had died, and 85% underwent the Fontan operation. Overall 3-year survival after the Norwood operation was 53%. Factors associated with mortality were age, lower weight at the time of the Norwood operation, impaired ventricular function, longer circulatory arrest, and lower pre-bidirectional cavopulmonary connection saturation.

CONCLUSIONS

Children older than 2 weeks undergoing the Norwood operation frequently require postoperative pulmonary vasodilatation and high inotropic support. A significant hazard of death persists through all steps of multistage palliation. Increased pulmonary vascular resistance and volume load effects, such as systemic ventricular impairment and atrioventricular valve regurgitation, are commonly evident in patients in whom treatment fails or who do not qualify to proceed to the next stage of palliation. Those patients should be closely monitored for timely referral for heart transplantation when indicated.

Stage II palliation of hypoplastic left heart syndrome without cardiopulmonary bypass

OBJECTIVES

Bidirectional cavopulmonary anastomosis has been performed without cardiopulmonary bypass for some single-ventricle heart defects. Limited data are available for the outcomes of off-pump bidirectional cavopulmonary anastomosis in infants with hypoplastic left heart syndrome. The purpose of this study is to determine the early outcomes for stage II palliation of hypoplastic left heart syndrome without cardiopulmonary bypass.

METHODS

This is a retrospective review of infants having surgical palliation of hypoplastic left heart syndrome from April 2003 to March 2010 at a single institution.

RESULTS

Seventy-five infants had a modified Norwood procedure, 65 with a right ventricle-pulmonary artery conduit, 10 with an aortopulmonary shunt, 2 with atrioventricular valve repair, and 3 with extracorporeal life support. Sixty-eight patients had hypoplastic left heart syndrome or one of its variants, and 7 had other single-ventricle lesions. There were 2 stage I deaths. Stage I survival was 97% (95% confidence interval, 88%-99%). Another 5 infants succumbed in the interstage period. Of the 68 stage I and interstage survivors, 61 had bidirectional cavopulmonary anastomoses, 20 without cardiopulmonary bypass. Median age was 6 months (range, 4-13 months), and median weight was 6.1 kg (range, 5.2-9.0 kg). There were no conversions to cardiopulmonary bypass when off-pump bidirectional cavopulmonary anastomosis was attempted. There were no hospital deaths. Median ventilation duration was 10 hours (range, 6-18 hours), and length of stay was 5 days (range, 4-9 days). Follow-up was available on all infants at a median duration of 17 months (range, 3-43 months), with no unplanned reinterventions.

CONCLUSIONS

Bidirectional cavopulmonary anastomosis without the use of cardiopulmonary bypass can be performed safely and with low mortality for selected infants with hypoplastic left heart syndrome. Midterm to long-term outcomes remain to be determined.

Norwood-sano operation using a stentless pulmonary valved conduit

The Sano modification of Norwood's operation has the potential to generate an excess volume load on the single right ventricle as a consequence of diastolic reversal of flow through the conduit. This article describes the use of a new, small, biological conduit with a porcine valve inside. This new conduit has been used in modified Norwood procedures. It is interposed between the right ventricle and the confluence of the pulmonary arteries. The use of a valved conduit should prevent the retrograde diastolic blood flow observed with use of nonvalved conduits and may improve postoperative hemodynamics. The use of a new stentless valved conduit in 3 recent Norwood procedures is reported herein.

Comparison of Norwood shunt types: do the outcomes differ 6 years later?

BACKGROUND

A modification to the Norwood procedure involving a right ventricle-to-pulmonary artery (RV-PA) shunt may improve early postoperative outcomes. Concerns remain about the effect of the right ventriculotomy required with this shunt on long-term ventricular function.

METHODS

Between January 2000 and April 2005, 76 patients underwent the Norwood procedure, 35 with a modified Blalock-Taussig shunt (mBTS) and 41 with a RV-PA shunt. Patients were monitored until death or September 1, 2009, with an average follow-up of 6.8 years. Cardiac catheterization, echocardiograms, perioperative Fontan courses, and need for cardiac transplantation were compared between groups.

RESULTS

Cumulative survival was 63% (22 of 35) in the mBTS group vs 78% (32 of 41) in the RV-PA group (p = 0.14). Pre-Fontan echocardiography revealed poorer ventricular function in RV-PA patients (p = 0.03). Cardiac transplantation was required in 6 of 32 (19%) patients with a prior RV-PA shunt vs 1 of 23 (4%) in the mBTS group (p = 0.06). This results in an almost identical cumulative transplant-free survival between groups; 60% (21 of 35) in the mBTS group and 63% (26 of 41) in the RV-PA group (p = 0.95).

CONCLUSIONS

Neither shunt offers a clear survival advantage through an average follow-up of 6.8 years. The RV-PA shunt results in impaired late ventricular function that may result in an increased need for cardiac transplantation.

Comparison of shunt types in the Norwood procedure for single-ventricle lesions

BACKGROUND

The Norwood procedure with a modified Blalock-Taussig (MBT) shunt, the first palliative stage for single-ventricle lesions with systemic outflow obstruction, is associated with high mortality. The right ventricle-pulmonary artery (RVPA) shunt may improve coronary flow but requires a ventriculotomy. We compared the two shunts in infants with hypoplastic heart syndrome or related anomalies.

METHODS

Infants undergoing the Norwood procedure were randomly assigned to the MBT shunt (275 infants) or the RVPA shunt (274 infants) at 15 North American centers. The primary outcome was death or cardiac transplantation 12 months after randomization. Secondary outcomes included unintended cardiovascular interventions and right ventricular size and function at 14 months and transplantation-free survival until the last subject reached 14 months of age.

RESULTS

Transplantation-free survival 12 months after randomization was higher with the RVPA shunt than with the MBT shunt (74% vs. 64%, P=0.01). However, the RVPA shunt group had more unintended interventions (P=0.003) and complications (P=0.002). Right ventricular size and function at the age of 14 months and the rate of nonfatal serious adverse events at the age of 12 months were similar in the two groups. Data collected over a mean (+/-SD) follow-up period of 32+/-11 months showed a nonsignificant difference in transplantation-free survival between the two groups (P=0.06). On nonproportional-hazards analysis, the size of the treatment effect differed before and after 12 months (P=0.02).

CONCLUSIONS

In children undergoing the Norwood procedure, transplantation-free survival at 12 months was better with the RVPA shunt than with the MBT shunt. After 12 months, available data showed no significant difference in transplantation-free survival between the two groups. (ClinicalTrials.gov number, NCT00115934.)

Acute interventions for stenosed right ventricle-pulmonary artery conduit following the right-sided modification of Norwood-Sano procedure

INTRODUCTION

The Norwood stage 1 procedure was modified by Sano with right ventricle-pulmonary artery (RV-PA) conduit replacing BT shunt. In our institution, this has been further modified by placing the conduit from the RV outflow tract to the right side of the neo-aorta.

PATIENTS AND METHODS

Between April 2002 and October 2008, 227 modified Norwood procedures were performed. Eighteen had the Sano modification with the conduit to the left of the neo-aorta whereas 209 had the right-sided modification, which is the study population. A total of 18 (8.6%) patients presented with cyanosis due to conduit stenosis with median age 4 months and median weight 6.3 kg.

RESULTS

Twelve patients underwent transcatheter stent placement in stenosed RV-PA conduit. A total of 16 coronary stents were implanted in 12 patients with 4 patients each receiving 2 stents. The mean saturations increased from 60% to 74%. There was one late mortality which was non-procedure related. Five patients treated with surgical take down of the RV-PA conduit and creation of a cavo-pulmonary shunt, whilst one patient had replacement of RV-PA conduit. There were no early postoperative deaths. The mean saturations improved from 54% to 75%.

CONCLUSIONS

The RV-PA conduit stenosis is a life-threatening complication after the modified Norwood Stage I procedure. This may require urgent surgery to replace the conduit or to perform a cavo-pulmonary shunt but as an alternative, transcatheter stent placement can be used with equal effectiveness and with a low risk of complications. The catheter approach is less invasive and the results show that it is an excellent option to relieve the stenosis even in the right-sided RV-PA conduit.

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.

Hypoplastic left heart syndrome

Hypoplastic left heart syndrome is a rare congenital heart defect in which the left side of the heart is underdeveloped. Surgical management of hypoplastic left heart syndrome has changed the prognosis of the condition that was previously regarded as fatal. We discuss surgical strategies based on staged procedures, with the right ventricle supporting both systemic and pulmonary circulation. We also discuss other management options, such as neonatal transplantation and the recent innovation of hybrid techniques. Surgical techniques and the understanding of the pathophysiology of this condition have been at the forefront of neonatal cardiac surgery and intensive care. The management of the syndrome remains a challenge because affected children grow into adolescence and adulthood posing various new problems and demands.

Two-Year Survival and Mental and Psychomotor Outcomes After the Norwood Procedure

Background— The Norwood procedure for stage 1 palliation of hypoplastic left heart syndrome is performed with either the modified Blalock-Taussig (MBTS) or the right ventricle–to–pulmonary artery (RVPA) shunt. In our institution, surgical practice changed from use of the MBTS to use of the RVPA shunt in 2002. We analyzed survival and mental and psychomotor outcomes of the 2 consecutive surgical eras.

Methods and Results— Between September 1996 and July 2005, 94 neonates with hypoplastic left heart syndrome underwent the Norwood procedure. Patients were recruited as neonates and followed up prospectively. Health, mental, and psychomotor outcomes (Bayley Scales of Infant Development-II) were assessed at 2 years. The study subjects were from the Norwood-MBTS era (n=62; 1996 to 2002) or the Norwood-RVPA era (n=32; 2002 to 2005). In the MBTS era, early and 2-year mortality rates were 23% (14/62) and 52% (32/62); the mean (SD) mental and psychomotor developmental indices were 79 (18) and 67 (19). In the RVPA era, early and 2-year mortality rates were 6% (2/32) and 19% (6/32); the mean (SD) mental and psychomotor developmental indices were 85 (18) and 78 (18). The 2-year mortality rate ( P =0.002) and the psychomotor developmental index ( P =0.029) were improved in the more recent surgical era. On multivariable Cox regression analysis, postoperative highest serum lactate independently predicted 2-year mortality in the MBTS and RVPA eras.

Conclusions— Analysis of 2 consecutive surgical eras of hypoplastic left heart syndrome patients undergoing the Norwood procedure showed a significant improvement in 2-year survival and psychomotor development in the more recent era. Adverse neurodevelopmental outcome in this patient population remains a concern.

Risk factors for interstage death after stage 1 reconstruction of hypoplastic left heart syndrome and variants

OBJECTIVE

The risk of death during the interstage period remains high after stage 1 reconstruction for single ventricle lesions, despite improved surgical results. The purpose of this study is to identify risk factors for interstage death and to describe the events leading to interstage death.

METHODS

A nested case-control study was conducted of 368 patients who underwent stage 1 reconstruction at a single center between January 1998 and April 2005.

RESULTS

Among the 313 (85%) hospital survivors, there were 33 (10.5%) interstage deaths. Cases more frequently presented with intact or restrictive atrial septum (9 [27%] vs 4 [4%]; P < .001), were older at the time of surgery (5 [2-40] vs 3 [1-42] days; P = .005), had more postoperative arrhythmias (12 [36%] vs 15 [15%]; P = .01), and a higher incidence of airway or respiratory complications (12 [36%] vs 19 [19%]; P = .04). By multivariate analysis, only intact atrial septum (odds ratio 7.6; 95% confidence intervals 1.9-29.6; P = .003) and age at operation greater than 7 days (odds ratio 3.8; 95% confidence intervals 1.3-11.2; P = .017) were predictors of interstage death.

CONCLUSIONS

The presence of intact atrial septum and older age at the time of surgery are associated with a higher risk of interstage death. In addition, postoperative arrhythmia and airway complications are associated with a higher risk of interstage death in univariate analysis. The results of this study provide a focus for interstage monitoring and risk stratification of these high-risk infants, which may improve overall survival.

Postoperative course in the cardiac intensive care unit following the first stage of Norwood reconstruction

The medical records of all patients born between 1 September, 2000, and 31 August, 2002, and undergoing the first stage of Norwood reconstruction, were retrospectively reviewed for details of the perioperative course. We found 99 consecutive patients who met the criterions for inclusion. Hospital mortality for the entire cohort was 15.2%, but was 7.3%, with 4 of 55 dying, in the setting of a "standard" risk profile, as opposed to 25.0% for those with a "high" risk profile, 11 of 44 patients dying in this group. Extracorporeal membrane oxygenation was utilized in 7 patients, with 6 deaths. Median postoperative length of stay in the hospital was 14 days, with a range from 2 to 85 days, and stay in the cardiac intensive care unit was 11 days, with a range from 2 to 85 days. Delayed sternal closure was performed in 18.2%, with a median of 1 day until closure, with a range from zero to 5 days. Excluding isolated delayed sternal closure, and cannulation and decannulation for extracorporeal support, 24 patients underwent 33 cardiothoracic reoperations, including exploration for bleeding in 12, diaphragmatic plication in 4; shunt revision in 4, and other procedures in 13. The median duration of total mechanical ventilation was 4.0 days, with a range from 0.7 to 80.5 days. Excluding those who died, the median total duration of mechanical ventilation was 3.8 days, with a range from 0.9 to 46.3 days. Reintubation for cardiorespiratory failure or upper airway obstruction was performed in 31 patients. Postoperative electroencephalographic and/or clinical seizures occurred in 13 patients, with 7 discharged on anti-convulsant medications. Postoperative renal failure, defined as a level of creatinine greater than 1.5 mg/dl, was present in 13 patients. Eleven had significant thrombocytopenia, with fewer than 20,000 platelets per microl, and injury to the vocal cords was identified in eight patients. Risk factors for longer length of stay included lower Apgar scores, preoperative intubation, early reoperations, reintubation and sepsis, but not weight at birth, genetic syndromes, the specific surgeon, or the duration of surgery. Although mortality rates after the first stage of reconstruction continue to fall, the course in the intensive care unit is remarkable for significant morbidity, especially involving the cardiac, pulmonary and central nervous systems. These patients utilize significant resources during the first hospitalization. Further studies are necessary to stratify the risks faced by patients with hypoplasia of the left heart in whom the first stage of Norwood reconstruction is planned, to determine methods to reduce perioperative morbidity, and to determine the long-term implications of short-term complications, such as diaphragmatic paresis, injury to the vocal cords, prolonged mechanical ventilation, and postoperative seizures.

Hypoplastic Left Heart Syndrome With Intact or Highly Restrictive Atrial Septum: Surgical Experience From a Single Center

BACKGROUND

The presence of an intact or highly restrictive atrial septum (I/HRAS) has long been recognized as a predictor of poor outcome among patients with hypoplastic left heart syndrome (HLHS), although the rarity of this condition has precluded conclusive study. The purpose of this review is to summarize recent surgical outcomes for these patients at our center and to identify predictors.

METHODS

We retrospectively identified all neonates with a diagnosis of HLHS and I/HRAS who underwent stage I palliation at Children's Hospital Boston between January 2001 and December 2006. Chart review enabled analysis of patient and procedural variables.

RESULTS

All 32 patients underwent left atrial decompression in utero or postnatally before surgery. Fourteen patients (44%) underwent fetal intervention, either atrial septoplasty (n = 9) or aortic valvuloplasty (n = 5). Twenty-nine of the 32 patients had postnatal left atrial hypertension and underwent transcatheter atrial septoplasty as neonates before surgery; 3 did not require postnatal atrial septoplasty after successful fetal atrial septoplasty. After stage I, hospital survival was 69% (22 of 32). Need for shunt revision (p = 0.02) and for extracorporeal membrane oxygenation use (p < 0.001) were associated with hospital mortality. Survival at 6 months was 69% for patients who had fetal intervention, and 38% for those who were treated only postnatally (p = 0.2).

CONCLUSIONS

Surgical outcome for patients with HLHS and I/HRAS continues to improve. Prenatal decompression of the left atrium may be associated with greater hospital survival. Proposed effects of fetal intervention on lung pathology and longer-term survival are subjects for future study in this unique group of patients.

Catheter interventional treatment of Sano shunt obstruction in patients following modified Norwood palliation for hypoplastic left heart syndrome

Shunts placed between the right ventricle and the pulmonary arteries, called Sano shunts, recently modified Norwood surgery for hypoplastic left heart syndrome. Patients with Sano shunts tend to be more stable thus reducing the interstage mortality of this still challenging complex cardiac anomaly. However, Sano shunt stenosis may develop and is a life threatening complication. We report on our experience in patients with Sano shunt obstruction.

PATIENTS

Eight infants presenting with decreasing transcutaneous oxygen saturations (43-63%, median 58%) following modified Norwood procedures were shown to have relevant Sano shunt stenosis. None was suited for early stage two surgery (cavopulmonary Glenn anastomosis). Catheterization was performed at the age of 21 to 112 (median 85) days. Weight was 3.9 to 6.0 (median 4.8) kg.

TECHNIQUE

Femoral 5F venous access. Long sheaths were not used. The shunt was entered with a 4F right Judkins catheter and a selective angiography was performed. The stenosis was localized proximal in 5, distal in 1 and proximal and distal in 2 patients. Ten coronary stents were implanted.

RESULTS

There were no procedure related complications. Oxygen saturation increased immediately to 75-86% (median 80%) and remained above 70% during follow-up in all. Seven patients had successful stage two surgery 61-288 (median 134) days after stent implantation, one is awaiting this.

CONCLUSIONS

Sano shunt obstruction can be treated safely and effectively by stent implantation. Early in-stent restenosis does not seem to be a problem.