Giessen Procedure as Comprehensive Stage II Palliation With Aortic Arch Reconstruction After Hybrid Bilateral Pulmonary Artery Banding and Ductal Stenting for Hypoplastic Left Heart Syndrome

Comparison of Morbidity and Mortality Outcomes between Hybrid Palliation and Norwood Palliation Procedures for Hypoplastic Left Heart Syndrome: Meta-Analysis and Systematic Review

Background/Objectives: Hybrid palliation (HP) procedures for hypoplastic left heart syndrome (HLHS) are increasing. Our objective was to compare mortality and morbidity following HP and NP (Norwood palliation) procedures. Methods: Systematic review and meta-analysis of HLHS patients of peer-reviewed literature between 2000 and 2023. Mortality and/or heart transplantation in HP versus NP in the neonatal period, interstage period, and at 1, 3 and 5 years of age, and morbidity including completion of Stage II and Stage III palliation, unexpected interventions, pulmonary artery pressures, right ventricle function, neurodevelopmental outcomes and length of hospital stay were evaluated. Results: Twenty-one (meta-analysis: 16; qualitative synthesis: 5) studies evaluating 1182 HLHS patients included. HP patients had higher interstage mortality (RR = 1.61; 95% CI: 1.10-2.33; p = 0.01) and 1-year mortality (RR = 1.22; 95% CI: 1.03-1.43; p = 0.02) compared to NP patients without differences in 3- and 5-years mortality. HP procedure in high-risk HLHS patients had lower mortality (RR = 0.48; 95% CI: 0.27-0.87; p = 0.01) only in the neonatal period. HP patients underwent fewer Stage II (RR = 0.90; 95% CI: 0.81-1.00; p = 0.05) and Stage III palliation (RR = 0.78; 95% CI: 0.69-0.90; p < 0.01), had more unplanned interventions (RR = 3.38; 95% CI: 2.04-5.59; p < 0.01), and longer hospital stay after Stage I palliation (weighted mean difference = 12.88; 95% CI: 1.15-24.62; p = 0.03) compared to NP patients. Conclusions: Our study reveals that HP, compared to NP for HLHS, is associated with increased morbidity risk without an improved survival rate.

Outcomes After Hybrid Palliation for Infants With Critical Left Heart Obstruction

BACKGROUND

Hybrid palliation (bilateral pulmonary artery banding with or without ductal stenting) is an initial management strategy for infants with critical left heart obstruction and serves as palliation until subsequent operations are pursued.

OBJECTIVES

This study sought to determine patient characteristics and factors associated with subsequent outcomes for infants who underwent hybrid palliation.

METHODS

From 2005 to 2019, 214 of 1,236 prospectively enrolled infants within the Congenital Heart Surgeons' Society's critical left heart obstruction cohort underwent hybrid palliation across 24 institutions. Multivariable hazard modeling with competing risk methodology was performed to determine risk and factors associated with outcomes of biventricular repair, Fontan procedure, transplantation, or death.

RESULTS

Preoperative comorbidities (eg, prematurity, low birth weight, genetic syndrome) were identified in 70% of infants (150 of 214). Median follow-up was 7 years, ranging up to 17 years. Overall 12-year survival was 55%. At 5 years after hybrid palliation, 9% had biventricular repair, 36% had Fontan procedure, 12% had transplantation, 35% died without surgical endpoints, and 8% were alive without an endpoint. Factors associated with transplantation were absence of ductal stent, older age, absent interatrial communication, smaller aortic root size, larger tricuspid valve area z-score, and larger left ventricular volume. Factors associated with death were low birth weight, concomitant genetic syndrome, cardiopulmonary bypass use during hybrid palliation, moderate to severe tricuspid valve regurgitation, and smaller ascending aortic size.

CONCLUSIONS

Mortality remains high after hybrid palliation for infants with critical left heart obstruction. Nonetheless, hybrid palliation may facilitate biventricular repair for some infants and for others may serve as stabilization for intended functional univentricular palliation or primary transplantation.

Norwood operation versus comprehensive stage II after bilateral pulmonary artery banding palliation for infants with critical left heart obstruction

OBJECTIVE

To determine patient characteristics and outcomes after Norwood versus comprehensive stage II (COMPSII) for infants with critical left heart obstruction who had prior hybrid palliation (bilateral pulmonary artery banding ± ductal stent).

METHODS

From 23 Congenital Heart Surgeons' Society institutions (2005-2020), 138 infants underwent hybrid palliation followed by either Norwood (n = 73, 53%) or COMPSII (n = 65). Baseline characteristics were compared between Norwood and COMPSII groups. Parametric hazard model with competing risk methodology was used to determine risk and factors associated with outcomes of Fontan, transplantation, or death.

RESULTS

Infants who underwent Norwood versus COMPSII had a higher prevalence of prematurity (26% vs 14%, P = .08), lower birth weight (median 2.8 vs 3.2 kg, P < .01) and less frequent ductal stenting (37% vs 99%; P < .01). Norwood was performed at a median age of 44 days and median weight of 3.5 kg, versus COMPSII at 162 days and 6.0 kg (both P < .01). Median follow-up was 6.5 years. At 5 years after Norwood and COMPSII, respectively; 50% versus 68% had Fontan (P = .16), 3% versus 5% had transplantation (P = .70), 40% versus 15% died (P = .10), and 7% versus 11% are alive without transition, respectively. For factors associated with either mortality or Fontan, only preoperative mechanical ventilation occurred more frequently in the Norwood group.

CONCLUSIONS

Higher prevalence of prematurity, lower birth weight, and other patient-related characteristics in the Norwood versus COMPSII groups may influence differences in outcomes that were not statistically significant for this limited risk-adjusted cohort. The clinical decision regarding Norwood versus COMPSII after initial hybrid palliation remains challenging.

Impact of hybrid procedure on pulmonary arterial dimensions and right ventricular load after biventricular repair

BACKGROUND

Hybrid procedure with ductal stenting and bilateral pulmonary banding offers a temporary approach in high-risk neonates with complex congenital heart defects aiming biventricular repair. This procedure may also have negative impact concerning post-banding pulmonary stenosis resulting in right ventricular pressure load.

METHODS

Between 2010 and 2021 we identified 5 patients with interrupted aortic arch and complex congenital heart defect who underwent hybrid procedure and staged biventricular repair ("hybrid-group"). Other 7 cases with interrupted aortic arch were corrected in the neonatal phase without hybrid procedure ("nonhybrid-group"). Detailed intra- and extracardiac features and surgical procedures were documented as well as pulmonary interventions during follow up. Pulmonary vessel size was assessed by diameter of left and right pulmonary artery in absolute and indexed values. RV pressure was evaluated invasively via catheterization.

RESULTS

Survival in cases with hybrid procedure and staged biventricular repair was 91% for a follow-up time of 40.7 months (95% CI 26-55 months) and 100% in the non-hybrid-group. Postoperative results concerning left ventricular function showed normal LV dimensions and systolic function without relevant stenosis on distal aortic arch. Hybrid procedure was associated with impaired local pulmonary arterial diameter after debanding resulting in increased right ventricular pressure and need for interventions (number intervention per patient: hybrid group 1.7 ± 0.95, non-hybrid group 0.17 ± 0.41; P 0.003).

CONCLUSIONS

Hybrid procedure in high-risk cases with interrupted aortic arch and staged biventricular repair shows good postoperative results with low perioperative mortality and normal left ventricular function. Due to potential risk of relevant pulmonary stenosis and right ventricular pressure load, follow up examinations must not only focus on left but also on the right heart.

In vitro performance of Lifetech IBS Angel™ (iron-based bioresorbable scaffold) stents during overdilation for use in pediatric patients

Objectives

The objective of this study was to assess the mechanical performance of the Lifetech IBS Angel stents during overdilation as is often required in pediatric applications; including time of first fracture, foreshortening, and the type of fracturing that occurs.

Materials and methods

In vitro testing was performed and repeated for each stent three times under physiologic conditions with continuous audiovisual imaging allowing for post-testing evaluations. Assessment of sheath fit was also completed.

Results

A total of 47 stents on monorail system were overdilated to complete fracture after passing through either a 4 or 5 French sheath. First strut fracture occurred in 4 and 6 mm stents when they reached greater than 50% overexpansion. Larger stents could achieve at least 30% increased diameter prior to first strut fracture. No fragmentation of any of the stents was seen throughout testing.

Conclusion

The IBS Angel has thin struts allowing for a lower profile with increased maneuverability and use with smaller sheaths. Embolization potential of strut fragments was not seen. Increased diameter well beyond design parameters was seen in all with acceptable foreshortening.

Miniature Minimally Invasive Pulmonary Banding in Neonates (MINI-MICS): A Novel Technique

Single-ventricular cardiopathies are challenging conditions requiring multiple surgical interventions to hopefully achieve adulthood. In neonates, pulmonary artery banding allows ventricular adaptation and pulmonary vascular bed protection. Here we present a novel minimally invasive approach to pulmonary artery banding through a 1.5 cm left parasternal minithoracotomy. This technique not only allows for a less traumatic first procedure but also a less manipulated mediastinum and untouched sternum for the consequent surgeries to come. This technique is reproducible in experienced hands and shows favorable and promising results when performed properly.

Hypoplastic Left Ventricle: Left Ventricular Recruitment With Hybrid Approach

Decision-making for biventricular repair (BVR) or univentricular palliation is challenging in neonates with hypoplastic left heart complex (HLHC). Hybrid strategy can be used successfully to achieve BVR in some of these patients. Between June 1998 and January 2022, 342 patients with a diagnosis of HLHS/variants, ductal-dependent lower body circulation with two ventricles, or HLHC with borderline left ventricle (LV) underwent initial bilateral pulmonary artery banding and ductal stenting in our institution. Among these 342 patients, 224 patients were defined as HLHS/variants and underwent univentricular palliation. 118 patients were determined to have borderline LV and hypoplastic left ventricular structures (HLHC, n = 48) or ductal-dependent lower body circulation with two ventricles (n = 70) considered suitable for BVR. 48 patients had multilevel obstructions including both aortic and mitral valve hypoplasia, aortic arch hypoplasia, and borderline LV. These were considered to have HLHC. These 48 HLHC patients are the subject of this report. Neonatal hybrid palliation at a median age of seven days was performed in 48 patients and 46 patients underwent BVR at a median age of 156 days. In 46 patients who underwent BVR, hospital mortality was not observed. The median follow-up was 66 months, with no late mortality. Heart transplant-free survival at 5, 10, and 15 years was 95.7%. 12 patients (26%) required reoperation and 9 (19.5%) required catheter reinterventions. Hybrid palliation may increase the chances for biventricular circulation in patients with borderline LV and small left-sided structures. Giessen hybrid approach as a left ventricular recruitment strategy achieves excellent early and long-term results.

Hypoplastic Left Heart Syndrome Palliation: Technical Aspects and Common Pitfalls of the Hybrid Approach

The Giessen hybrid strategy is used for initial palliation of HLHS and variants when the intent is to pursue further staged palliative reconstruction toward Fontan circulation. It is also used for initial palliation of HLHC and other anomalies with potential for eventual biventricular repair. From June 1998 - October 2021, 197 patients with HLHS and related variants underwent hybrid stage 1. Follow-up is complete (median 8.3 [range 0-23.3] years). Operative mortality for hybrid stage I was 3.6% (7/197); reduced to 2.8% since 2010 (4/141). Interstage mortality was 4.1% (8/197). Operative mortality for comprehensive stage II was 5.8% (10/172), and since 2010 was 1.8% (2/113 patients). Fontan completion has been accomplished in 117 patients, and 33 are still awaiting stage III. Twelve patients underwent heart transplantation. Over 23 years, overall survival is 77.7% and transplant-free survival is 73.6%.

Incidence of and Risk Factors for Aortic Arch Interventions After the Comprehensive Stage II Procedure for Hypoplastic Left Heart Syndrome

Minimal data exist about the incidence and risk factors for arch intervention after comprehensive stage II (CSII). Goal of this study was to document incidence of arch interventions after CSII and determine if any differences existed between those who underwent an arch intervention (aiCSII) versus those did not have an intervention. Single-center retrospective chart review of all hypoplastic left heart syndrome patients who underwent a CSII between 6/1/2005 and 2/1/2020 was performed. Univariate analysis was conducted in addition to principal components analysis (PCA). One hundred patients were evaluated. Sixteen patients underwent 24 arch interventions. Age at initial arch reintervention was 1.3 ± 1.2 years (median 1.0 years, range 0.5-2.2 years). Univariate analysis showed that the aiCSII group were more likely to be female, to have had a retrograde arch intervention post-hybrid procedure, and to be younger at time of CSII. On echocardiograms, aiCSII group had significantly higher pre-CSII patent ductus arteriosus velocities, arch velocities on their 1st post-operative and discharge study post-CSII, and arch velocities pre-Fontan. Gradients were higher in the aiCSII via pre-Fontan catheterization. With PCA, echocardiographic and catheterization data remained significantly associated with aiCSII versus those who did not undergo an arch intervention (OR = 4.5 (1.9, 19.8), p = 0.008). Incidence of arch intervention post-CSII was 16%. Echocardiographic arch velocities during the CSII hospitalization were the strongest predictors for subsequent aortic arch interventions. Further studies are needed to determine any modifiable variables that may reduce the incidence of arch interventions.

Ascending aortic extension to increase aortopulmonary space after comprehensive stage II palliation

Aortic reconstruction at the time of the comprehensive stage II (CSII) procedure can be complicated by compression within the aortopulmonary space resulting in airway or pulmonary artery narrowing. We describe our experience with 2 patients with hypoplastic left heart syndrome and pulmonary artery stenosis after the CSII procedure. Both patients underwent an aortic extension with a Hemashield interposition graft to open up the aortopulmonary space. The patients were discharged from the hospital. In all cases the aortopulmonary space was enlarged, and the pulmonary arteries and airway were free from compression. Aortic extension is an option to be considered in children with pulmonary artery compression who previously had a CSII procedure.

Hybridizing the hybrid: a "serendipitous bridge" to heart transplantation in a child with hypoplastic left heart syndrome

We report a unique experience with stage 1 palliation of hypoplastic left heart syndrome (HLHS) using the hybrid approach. The tortuous anatomy of the ductus arteriosus precluded stenting. Persistent ductal patency and ability to support the systemic circulation adequately after prolonged prostaglandin E1 (PGE1) infusion and its subsequent discontinuation presented us with a novel approach to hybrid palliation of hypoplastic left heart syndrome. Our experience offers a tempting approach, but it should not be considered a standard alternative management option to stage I hybrid palliation based on a single case report.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12055-020-01088-8.

Hypoplastic Left Heart: Stage-I Will be Performed Interventionally, Soon

The hypoplasia of left-sided heart structures shows great variability and complexity. What the many variants have in common is that their heart structures are neither fully developed before nor after birth. Fetuses and newborns require an individual therapy depending on anatomy and function of the heart. Fetal interventions focus on improving left heart structures by catheter-based interventions and maternal hyperoxygenation which promotes growth as the left ventricular preload and blood flow within the cavity increase. Stage-I management of newborns with single ventricle physiology is usually based on the Norwood/Sano surgery or the Hybrid approach. Two more steps are required to ultimately achieve a Fontan circulation. Some centers also use the Hybrid approach for subsequent Norwood operation beyond the neonatal period. After the Hybrid approach, a comprehensive stage-II or corrective surgery is performed, the latter if a bi-ventricular circulation is possible. With progressively improved catheter-based interventions, particularly ductal stenting and manipulations of the atrial septum, the next advance is to develop a bespoke flow restrictor that can be easily inserted into the branches of the pulmonary artery. The main goal is to avoid complex heart operations under general anesthesia, followed by substantial intensive care in the neonatal period, especially for patients with complex heart defects. Based on the current state of the art of surgical treatment of hypoplastic left heart syndrome and variants with the Norwood surgery or the Hybrid approach, our main focus is on an alternative percutaneous transcatheter technique in the sense of a completely non-surgical stage-I approach.

Outcomes of hybrid and Norwood Stage I procedures for the treatment of hypoplastic left heart syndrome and its variants

Background

In this study, we present the outcomes of hybrid and Norwood Stage I procedures for the treatment of hypoplastic left heart syndrome and its variants.

Methods

In this study, a total of 97 pediatric patients who were operated due to hypoplastic left heart syndrome and its variants between March 2011 and October 2018 were retrospectively analyzed. Thirty-two of the patients (28 males, 4 females; median age 5 days; range, 1 to 25 days) underwent Norwood Stage I operation (Group N), while the remaining 65 patients (44 males, 21 females; median age 6 days; range, 1 to 55 days) underwent a hybrid procedure (Group H). Both treatment strategies were compared.

Results

The median body weight in Group H was significantly lower and the number of patients with a low birth weight (<2,500 g) was significantly higher than Group N (p=0.002 and 0.004, respectively). The postoperative early mortality rate was similar between the groups. Univariate and multivariate analyses revealed that the need for preoperative mechanical ventilation was a significant factor for mortality (p=0.004 and 0.003, respectively). Syndromic appearance was also a significant factor the multivariate analysis (p=0.03). There was a statistically significant difference between the groups in terms of the inter-stage mortality rates (p=0.0045). Second-stage procedure was performed in 32 patients. The early mortality rate after the Glenn operation was 7.6%. Six patients died after comprehensive Stage II operation. Five patients underwent biventricular repair and 8 patients had third-stage fenestrated extracardiac Fontan operation (Group N, n=7 and Group H, n=1). The Kaplan-Meier survival curve demonstrated that Group N had a higher survival rate at both one and five years than Group H, although the difference was not statistically significant (p=0.15). Subgroup analysis showed that the Norwood procedure with Sano modification had the highest survival rate with 40% at five years.

Conclusion

Our study results show that patients undergoing the Norwood procedure have a more uneventful course of inter-stage period and Stage II and III, despite drawbacks early after Stage I procedure. Based on our experiences, we recommend performing the hybrid intervention in patients with a poor clinical condition and a body weight of <2,500 g.

Ideal intensive care unit course following comprehensive stage II in hypoplastic left heart syndrome

Comprehensive stage II is the advanced surgical part of the staged treatment of a newborn with hypoplastic left heart syndrome (HLHS) palliated initially by a Giessen-Hybrid approach. We report an almost ideal course following comprehensive stage II operation with focus on postoperative intensive care strategy. Following a short introduction of the postnatally performed Giessen-Hybrid approach, in which the surgical part is focused on bilateral pulmonary banding and duct stenting as well as manipulation of the atrial septum is postponed to transcatheter approach, it should be emphasized, that the quality of inter-stage I is eminently important for the success of the following comprehensive stage II. Furthermore, the interplay of the responsible surgeon, anesthesiologist, cardiologist and intensivist is mandatory for working as a team with a similar pathophysiological background. Presupposed a sophisticated surgical and anesthesiologic management, the immediate post-operative intensive care is crucial for the patient's final outcome, not only in terms of mortality but even morbidity (long-term neurological condition). Detailed treatment strategies are presented by pathophysiological reasonable hypotheses and the current pharmacological knowledge. Aiming to improve systemic and regional oxygen delivery and lowering oxygen consumption, as a sine qua none for a favorable patient's outcome.

Early results of ring-reinforced conduit and curved porcine patch in Sano-Norwood procedure

BACKGROUND

Patch augmentation of the aortic arch as well as construction of an unobstructed pulmonary blood supply are two important surgical targets in patients with hypoplastic left heart syndrome. In this report, we aimed to present our preliminary results with a combination of two relatively new approaches in Norwood-Sano procedure.

METHODS

A retrospective analysis was performed in 10 newborns with the diagnosis of hypoplastic left heart syndrome. Our surgical approach incorporated the interposition of a 6.0-mm ring-reinforced tube graft with the "dunked technique" between the right ventricle and the pulmonary artery; and reconstruction of the aortic arch using a curved porcine pericardial patch which is specifically designed for the Norwood procedure.

RESULTS

Mean age and body weight at the time of the Sano-Norwood operation were 7.3 ± 2.4 days and 3164 ± 406 g, respectively. We encountered 1 (10%) early and 1 (10%) late mortality. All of the patients were discharged without any residual gradients at the aortic arch. Four out of eight patients underwent stage 2 bidirectional cavopulmonary anastomosis at a median age of 5 months (range, 4-6 months). Pericardial patch augmentation of the left pulmonary artery was deemed mandatory in one of our patients.

CONCLUSIONS

The dunked technique of interposing a ring-reinforced conduit between the right ventricle and pulmonary artery along with the utilization of a curved porcine pericardial patch specifically designed for aortic arch reconstruction are promising modifications of the Sano-Norwood procedure in newborns with hypoplastic left heart syndrome.

Interrelationship Between Hemodynamics, Brain Volumes, and Outcome in Hypoplastic Left Heart Syndrome

BACKGROUND

The long-term impact of altered hemodynamics after stage II in children with hypoplastic left heart syndrome (HLHS) and hypoplastic left heart complex (HLHC) on cerebral growth and neurodevelopmental outcome is unknown. We aimed to investigate whether elevated central venous and atrial filling pressures before the Fontan procedure may be associated with smaller brain volumes and poorer neurodevelopmental outcome after the initial hybrid procedure.

METHODS

In a two-center cohort study semiautomated segmentation of cerebral magnetic resonance imaging scans was conducted in 25 children with HLHS/HLHC (25 hybrid) before the Fontan procedure (27.6 ± 4.3 months) and in 8 healthy control subjects (29.7 ± 9.5 months). Study patients were evaluated with the Bayley Scales of Infant and Toddler Development III (Bayley-III) and a neurologic examination. Hemodynamic measures after stage II were assessed with cardiac catheterization at 2 years of age before Fontan completion. Children with known genetic comorbidities were excluded.

RESULTS

In HLHS/HLHC patients higher atrial filling pressures (6 ± 3 mm Hg; range, 2-14) were correlated with reduced brain volumes and lower language composite score, whereas higher Glenn pressures (10 ± 3 mm Hg; range, 6-16) were related to higher cerebrospinal fluid, reduced brain volumes, and lower cognitive, language, and motoric composite scores in the Bayley-III. Compared with control subjects white matter volumes were reduced and cerebrospinal fluid volumes increased in study patients.

CONCLUSIONS

These data suggest that altered cardiovascular hemodynamics after stage II influence brain growth and neurodevelopmental outcome in infants with HLHS/HLHC.