Results of Palliation With an Initial Modified Blalock-Taussig Shunt in Neonates With Single Ventricle Anomalies Associated With Restrictive Pulmonary Blood Flow

Impact of low birth weight on staged single-ventricle palliation

BACKGROUND

To assess the impact of low birth weight on early and late outcomes after staged palliation for single ventricle.

METHODS

Patients after stage 1 palliation for single ventricle in our institution were retrospectively included and divided into two weight groups: 2.5 kg or less (low birth weight) and more than 2.5 kg. The impact of low birth weight on mortality and on the progression to further palliation stages (bidirectional Glenn, stage 2, and total cavopulmonary connection, stage 3) was assessed.

RESULTS

A total of 452 patients were included. Patients with low birth weight (n = 37, 8 %) had more frequently associated prematurity and extracardiac anomalies. Early and inter-stage mortality after stage 1 was higher in patients with low birth weight, so that less of these patients reached the next palliation stage (57 % vs. 77 %, p = 0.01, and 38 % vs. 56 %, p = 0.05, for stage 2 and stage 3, respectively). After 5 years, overall survival was inferior in patients with low birth weight (48 % vs. 73 %, p < 0.001). Survival conditioned by stage 2 palliation was inferior in patients with low birth weight compared to the reference group (76 % vs. 89 % after 5 years, p = 0.04). Low birth weight was a risk factor for death in most patients' subgroups, inclusive those with restricted pulmonary blood flow after a systemic-to-pulmonary shunt procedure.

CONCLUSIONS

During staged palliation of single-ventricle physiology, low birth weight has a detrimental impact on survival extending to beyond stage 2. This study calls for increased vigilance of these patients beyond the first interstage.

Reintervention Before Bidirectional Cavopulmonary Shunt and Intermediate Outcomes in Children with Single Ventricle Who Underwent Main Pulmonary Artery Banding

Unplanned reinterventions following pulmonary artery banding (PAB) in single ventricle patients are common before stage 2 palliation (S2P) but associated risk factors are unknown. We hypothesized that reintervention is more common when PAB is placed at younger age and with a looser band, reflected by lower PAB pressure gradient. Retrospective single center study of single ventricle patients undergoing PAB between Jan 2000 and Dec 2020. The association with reintervention and successful S2P was modeled using exploratory cause-specific hazard regression. A multivariable model was developed adjusting for clinical and statistically relevant predictors. The cumulative proportion of patients undergoing reintervention were summarized using a competing risk model. 77 patients underwent PAB at median (IQR) 47 (24-66) days and 3.73 (3.2-4.5) kg. Within18 months of PAB, 60 (78%) reached S2P, 9 (12%) died, 1 (1%) transplanted and 7 (9%) were alive without S2P. Within 18 months of PAB 10 (13%) patients underwent reintervention related to pulmonary blood flow modification: PAB adjustment (n = 6) and conversion to Damus-Kaye-Stansel/Blalock-Taussig-Thomas shunt (n = 4). 6/10 (60%) reached S2P following reintervention. A trend toward higher intervention in patients with a genetic syndrome (p-0.06) and weight < 3 kg (p-0.057) at time of PAB was noted. Only genetic syndrome was a risk factor associated with poor outcome (p-0.025). PAB has a reasonable outcome in SV patients with unobstructed systemic and pulmonary blood flow, but with a high reintervention rate. Only a quarter of patients with genetic syndromes reach S2P and further study is required to explore the benefits from an alternative palliative strategy.

Blalock-Taussig Shunt versus Ductal Stenting as Palliation for Duct-Dependent Pulmonary Circulation

Objectives

There is limited data published from outside North America and Europe comparing the outcomes of a modified Blalock-Taussig shunt (MBTS) and ductal stenting as the first palliative procedure for infants with duct-dependent pulmonary circulation. This study reports the National Heart Center's, in Muscat, Oman, experience in comparing the outcomes of these 2 interventions.

Methods

This retrospective study included all infants with duct-dependent pulmonary circulation who received either a MBTS or ductal stenting from 2016-2019. The primary outcomes were death or re-interventions. Secondary outcomes included death, subsequent re-interventions, survival to subsequent surgical intervention, survival to hospital discharge, post-procedural mechanical ventilation and duration of intensive care unit stay.

Results

A total of 71 patients were included in the study, 33 (46%) of whom received ductal stenting. The prevalence of the primary outcome (death or re-intervention) in the patent ductus arteriosus (PDA) stent group was 54.5% versus 31.6% in the MBTS group but this was not statistically significant (P = 0.06). There was no difference between the 2 groups in terms of time to next surgical intervention (P = 0.233). The PDA stent group had shorter post-procedural, mechanical ventilation and intensive care unit stay durations (P <0.05). Syndromic patients were at higher risk of mortality compared to non-syndromic patients.

Conclusion

MBTS and ductal stenting are both acceptable modalities as a palliative intervention for infants with duct-dependant pulmonary circulation. Syndromic patients are at higher risk of mortality. This can be considered an important factor for patient selection.

A Single-Centre Retrospective Review of Modified Blalock-Taussig Shunts: A 22-Year Experience

INTRODUCTION

This single-centre retrospective study explores demographics and outcomes of patients who underwent a modified Blalock-Taussig shunt (MBTS) over a 22-year period. The predominant surgical approach in this study is a lateral thoracotomy, in contrast to a midline sternotomy. Risks and outcomes of this approach are compared with national and international literature.

MATERIALS AND METHODS

Demographic, anatomical, clinical, surgical and outcome data of all patients who underwent a MBTS between 2000 and 2022 were collected and analysed, excluding Norwood procedures, which are not performed at this institution. Short- and long-term morbidity and mortality is described.

RESULTS

Over the 22-year study period, 185 MBTS were performed in 162 patients, at a median age of 16 days (interquartile range [IQR] 5-59 days) and weight of 3.47 kg (IQR 3-4.25 kg, minimum weight 2 kg). Of these, 79% of patients had a biventricular circulation. Cardiac diagnoses included both univentricular and biventricular anatomy; tetralogy of Fallot (TOF) (36%), transposition of the great arteries/ventricular septal defect/pulmonary stenosis (TGA/VSD/PS) (11%), pulmonary atresia with intact ventricular septum (PA/IVS) (23%), pulmonary atresia with ventricular septal defect (PA/VSD) (14%), other (16%). The most common size of MBTS was 4 mm (71%); 93% were performed via a lateral thoracotomy. There were 47 cases of major operative morbidity, which did not differ significantly with cardiac diagnosis. Overall all-cause mortality was 13.5%. Early operative mortality was 4.3%. Mortality varied with cardiac diagnosis, 6% with TOF and 19% with PA/IVS. There was no era effect on mortality rates, however a lower frequency of major morbidity (23% vs 7%, p=0.03) was observed in the most recent third of the study period. Risk factors for shunt reintervention or mortality included weight <2.5 kg (HR=2.79 [1.37, 5.65], p=0.005), and pre- (HR=3.31 [1.86, 5.9], p<0.001) or postoperative lactic acidosis (HR=1.37 [1.25,1.5], p<0.001). These rates are comparable to those in the literature, with the predominant approach a midline sternotomy.

CONCLUSION

Mortality rates and risk factors for adverse outcomes are comparable to those previously reported for both univentricular and biventricular groups. These results highlight that outcomes of MBTS performed via lateral thoracotomy are comparable to those by midline sternotomy as reported in the literature. Operating via the lateral approach may be advantageous as it avoids the complications of a midline sternotomy.

Long-term outcomes of staged repair of tetralogy of Fallot

BACKGROUND

The optimal management strategy for symptomatic young infants with tetralogy of Fallot (TOF) is yet to be determined. We aimed to evaluate the long-term outcomes of a staged approach with initial shunt palliation followed by complete repair.

METHODS

Between January 1993 and July 2021, 160 children with TOF underwent a systemic-to-pulmonary shunt at our institution, including 65 neonates (41%). The mean duration of follow-up was 12.3 ± 8.1 years.

RESULTS

Hospital mortality was 3% (4 of 160), all occurring in patients with a shunt size-to-weight ratio ≥1.2 mm/kg. Composite morbidity-defined as cardiac arrest, postoperative mechanical circulatory support, or unplanned reoperation-occurred in 21% (33 of 160). On multivariable analysis, a shunt size-to-weight ratio ≥1.2 mm/kg and prematurity were independent predictors of composite morbidity. Interstage mortality was 3% (4 of 156). A limited transannular patch was used in 75% (113 of 150) of TOF repairs. Actuarial survival at 20 years after shunt was 90% (95% confidence interval [CI], 79%-95%). Actuarial freedom from reinterventions at 20 years after TOF repair was 40% (95% CI, 28%-52%). Neonates had comparable composite morbidity, mortality, and late risk of reinterventions to older children.

CONCLUSIONS

Staged repair of TOF in symptomatic young infants results in low mortality but high rates of reinterventions at long-term follow-up. A shunt size-to-weight ratio ≥1.2 mm/kg is a significant risk factor for mortality and morbidity prior to complete repair. Neonates undergoing shunt insertion have comparable outcomes to older children.

The Effects of the Mechanical Properties of Vascular Grafts and an Anisotropic Hyperelastic Aortic Model on Local Hemodynamics during Modified Blalock-Taussig Shunt Operation, Assessed Using FSI Simulation

Cardiovascular surgery requires the use of state-of-the-art artificial materials. For example, microporous polytetrafluoroethylene grafts manufactured by Gore-Tex^® are used for the treatment of cyanotic heart defects (i.e., modified Blalock–Taussig shunt). Significant mortality during this palliative operation has led surgeons to adopt mathematical models to eliminate complications by performing fluid–solid interaction (FSI) simulations. To proceed with FSI modeling, it is necessary to know either the mechanical properties of the aorta and graft or the rheological properties of blood. The properties of the aorta and blood can be found in the literature, but there are no data about the mechanical properties of Gore-Tex^® grafts. Experimental studies were carried out on the mechanical properties vascular grafts adopted for modified pediatric Blalock–Taussig shunts. Parameters of two models (the five-parameter Mooney–Rivlin model and the three-parameter Yeoh model) were determined by uniaxial experimental curve fitting. The obtained data were used for patient-specific FSI modeling of local blood flow in the “aorta-modified Blalock–Taussig shunt–pulmonary artery” system in three different shunt locations: central, right, and left. The anisotropic model of the aortic material showed higher stress values at the peak moment of systole, which may be a key factor determining the strength characteristics of the aorta and pulmonary artery. Additionally, this mechanical parameter is important when installing a central shunt, since it is in the area of the central anastomosis that an increase in stress on the aortic wall is observed. According to computations, the anisotropic model shows smaller values for the displacements of both the aorta and the shunt, which in turn may affect the success of preoperative predictions. Thus, it can be concluded that the anisotropic properties of the aorta play an important role in preoperative modeling.

Transition to Ductal Stenting for Single Ventricle Patients Led to Improved Survival: An Institutional Case Series

BACKGROUND

The use of systemic-to-pulmonary shunts (SPS) in neonates with single ventricle heart defects and ductal-dependent pulmonary blood flow (ddPBF) was historically associated with high morbidity and mortality at our center. As a result, we transitioned to the preferential use of ductus arteriosus stents (DS) when feasible. This report describes our initial results with this strategy.

METHODS

A single-center study of single ventricle patients that received DS or SPS from 2015 to 2019 was performed to assess whether DS was associated with decreased in-hospital morbidity and increased survival to stage II palliation.

RESULTS

A total of 34 patients were included (DS = 11; SPS = 23). Underlying cardiac anomalies were similar between groups and included pulmonary atresia, unbalanced atrioventricular septal defect, and tricuspid atresia. Procedure success was similar between groups (82% vs 83%). Two DS patients were converted to SPS, due to ductal vasospasm or pulmonary artery obstruction, and four SPS patients required surgical shunt revision. In DS patients, postprocedure mechanical ventilation duration was shorter (one vs three days, P = .009) and fewer required postprocedure extracorporeal membrane oxygenation (9% vs 39%, P = .11). A higher proportion of DS patients survived to stage II palliation (100% vs 64%, P = .035), and the probability of one-year survival was higher in DS patients (100% vs 61%, P = .02).

CONCLUSIONS

At our center, patients with single ventricle heart defects and ddPBF that received DS experienced reduced in-hospital morbidity and increased survival to stage II palliation compared to SPS.

Are early palliative procedures providing an adequate long-term benefit in young cyanotic infants from developing countries, despite advances in surgery and interventions?

OBJECTIVES

Ductal stents, right ventricular outflow tract stents, and aortopulmonary shunts are used to palliate newborns and infants with reduced pulmonary blood flow. Current long-term outcomes of these palliations from resource-restricted countries are unknown.

METHODS

This single-centre, retrospective, observational study analysed the technical success, immediate and late mortality, re-interventions, and length of palliation in infants ≤5 kg who underwent aortopulmonary shunts, ductal, and pulmonary outflow stents. Patients were grouped by their anatomy.

RESULTS

There were 69 infants who underwent one of the palliations. Technical success was 90% for aortopulmonary shunts (n = 10), 91% for pulmonary outflow stents (n = 11) and 100% for ductal stents (n = 48). Early mortality within 30 days in 12/69 patients was observed in 20% after shunts, 9% after pulmonary outflow stents, and 19% after ductal stents. Late mortality in 11 patients was seen in 20% after shunts, 18% after outflow stents, and 15% after ductal stents. Seven patients needed re-interventions; two following shunts, one following outflow stent, and four following ductal stents for hypoxia. Among the anatomical groups, 10/12 patients with pulmonary atresia, intact ventricular septum survived after valvotomy and ductal stenting. Survival to Glenn shunt after ductal stent for pulmonary atresia, intact ventricular septum and diminutive right ventricle was very low in two out of eight patients, but very good (100%) for other univentricular hearts. Among 35 patients with biventricular lesions, 22 survived to the next stage.

CONCLUSIONS

Cyanotic infants, despite undergoing technically successful palliation had a high inter-stage mortality irrespective of the type of palliation. Duct stenting in univentricular hearts and in pulmonary atresia with an intact ventricular septum and adequate sized right ventricle tended to have low mortality and better long-term outcome. Completion of biventricular repair after palliation was achieved only in 63% of patients, reflecting unique challenges in developing countries despite advances in intensive care and interventions.

Predictors of death after receiving a modified Blalock-Taussig shunt in cyanotic heart children: A competing risk analysis

Objective

To determine risk factors affecting time-to-death ≤90 and >90 days in children who underwent a modified Blalock-Taussig shunt (MBTS).

Methods

Data from a retrospective cohort study were obtained from children aged 0–3 years who experienced MBTS between 2005 and 2016. Time-to-death (prior to Glenn/repair), time-to-alive up until December 2017 without repair, and time-to-progression to Glenn/repair following MBTS were presented using competing risks survival analysis. Demographic, surgical and anesthesia-related factors were recorded. Time-to-death ≤90 days and >90 days was analyzed using multivariate time-dependent Cox regression models to identify independent predictors and presented by adjusted hazard ratios (HR) and 95% confidence intervals (CI).

Results

Of 380 children, 119 died, 122 survived and 139 progressed to Glenn/repair. Time-to-death probability (95% CI) within 90 days was 0.18 (0.14–0.22). Predictors of time-to-death ≤90 days (n = 63) were low weight (<3 kg) (HR 7.6, 95% CI:2.8–20.4), preoperative ventilator support (HR 2.7, 95% CI:1.3–5.6), postoperative shunt thrombosis (HR 5.0, 95% CI:2.4–10.4), bleeding (HR 4.5, 95% CI:2.1–9.4) and renal failure (HR 4.1, 95% CI:1.5–10.9). Predictors of time-to-death >90 days (n = 56) were children diagnosed with pulmonary atresia with ventricular septal defect and single ventricle (compared to tetralogy of fallot) (HR 3.2, 95% CI:1.2–7.7 and HR 3.1, 95% CI:1.3–7.6, respectively), shunt size/weight ratio >1.1 vs <0.65 (HR 6.8, 95% CI:1.4–32.6) and longer duration of mechanical ventilator (HR 1.002, 95% CI:1.001–1.004). Shunt size/weight ratio ≥1.0 (vs <1.0) and ≥0.65 (vs <0.65) were predictors for overall time-to-death in neonates and toddlers, respectively (HR 13.1, 95% CI:2.8–61.4 and HR 7.8, 95% CI:1.7–34.8, respectively).

Conclusions

Perioperative factors were associated with time-to-death ≤90 days, whereas particular cardiac defect, larger shunt size/weight ratio, and longer mechanical ventilation were associated with time-to-death >90 days after receiving MBTS. Larger shunt size/weight ratio should be reevaluated within 90 days to minimize the risk of shunt over flow.

New Horizon of Intervention in Congenital Heart Disease: AFR in a Complex Cyanotic Patient

Double-inlet left ventricle (DILV) is the commonest form of the anatomic univentricular heart which has different ventriculoarterial connection; generally, the most prevalent type is DILV with the hypoplastic right ventricle on the left side. The disease is associated with several heart defects, and the treatment method is different based on the anatomy of the heart, but treatment methods are almost always palliative. In this paper, we described one adult patient with DILV and severe left AV (atrioventricular valve) stenosis who is managed with a novel palliative intervention; it means AFR (atrial flow regulator) device implantation for the first time.

Outcomes of systemic-to-pulmonary artery shunt for single ventricular heart with extracardiac total anomalous pulmonary venous connection

OBJECTIVES

A few studies have described the outcomes of systemic-to-pulmonary artery shunt (SPS) for functional single ventricular heart with extracardiac total anomalous pulmonary venous connection (TAPVC). This study aimed to examine the outcomes of SPS with extracardiac TAPVC and identify the predictors of mortality before bidirectional Glenn operation (BDG).

METHODS

Medical records of 41 children with single ventricular heart and extracardiac TAPVC who underwent SPS between 1998 and 2019 were reviewed retrospectively. The median age and body weight at SPS were 36 days and 3.4 kg, respectively. Surgical outcomes and predictors of mortality were investigated.

RESULTS

Four operative deaths (10%) and 10 late deaths (27%) occurred before BDG. Of all the children, 19 underwent BDG at a median of 10 months since SPS and eight are waiting for BDG. In the multivariate analysis, preoperative pulmonary venous obstruction (p = 0.01) at initial surgery was most predictive of death before BDG. Patients who underwent simultaneous SPS and TAPVC repair were younger, had high preoperative rate of pulmonary venous obstruction, and more deaths before BDG.

CONCLUSIONS

Survival outcomes of SPS for SVH with extracardiac TAPVC were improved as a whole due to the increase in knowledge and technique of management SPS. However, the patients who have preoperative pulmonary venous obstruction (PVO) and need SPS and TAPVC repair concomitantly in the early postnatal period have poor outcomes and still challenging. In such a case, staged TAPVC repair and SPS may be beneficial.

Outcomes of Multistage Palliation of Infants With Single Ventricle and Atrioventricular Septal Defect

Background:

Published palliation outcomes of infants with functional single ventricle (SV) and common atrioventricular septal defect (AVSD) are poor due to associated cardiac and extracardiac anomalies and development of atrioventricular valve (AVV) regurgitation. We report current palliation results.

Methods:

From 2002 to 2012, 80 infants with functional SV with AVSD underwent multistage palliation. Competing-risks analyses modeled events after first-stage surgery and Glenn (death/transplantation vs next palliation surgery) and examined factors associated with survival and AVV intervention.

Results:

Sixty-eight (80%) patients received neonatal palliation: modified Blalock-Taussig shunt (n = 33, 41%), Norwood (n = 20, 25%), and pulmonary artery band (n = 15, 19%), whereas 12 (15%) received primary Glenn. On competing-risks analysis, one-year following first-stage surgery, 29% of patients had died or received transplantation and 62% had undergone Glenn. Five years following Glenn, 9% of patients had died or received transplantation and 68% had undergone Fontan. Overall eight-year survival was 64% and was lower in patients with genetic syndromes (53% vs 82%), patients requiring concomitant total anomalous pulmonary venous connection repair (53% vs 69%), and those requiring neonatal palliation (48% vs 100%). Factors associated with mortality were unplanned reoperation (hazard ratio [HR]: 3.7 [1.7-8.0], P = .001) and extracorporeal membrane oxygenation use (HR: 7.1 [3.0-16.6], P < .001). Initial AVV regurgitation ≥ moderate was associated with AVV intervention (HR: 6.2 [2.4-16.1], P = .002) with eight-year freedom from death or AVV intervention of 25% in those patients.

Conclusions:

Patients with SV with AVSD are a distinct group and commonly have associated cardiac and extracardiac malformations that complicate care and affect survival. The development of AVV regurgitation requiring intervention is common but does not affect survival.

Impact of Gestational Age on Surgical Outcomes in Patients With Functionally Single Ventricle

BACKGROUND

Younger gestational age (GA) is known to be associated with worse outcomes after congenital cardiac surgery. We sought to determine the impact of GA on surgical outcomes of single-ventricle palliation.

METHODS

Among the 284 patients with functionally single ventricle who were born between January 2005 and December 2014, 50 neonates were born prematurely (GA < 37 weeks) and 113 neonates in the early term period (37 weeks ≤ GA < 39 weeks). Initial palliation was required in 251 patients, whereas 33 patients received primary bidirectional cavopulmonary anastomosis (BCPA).

RESULTS

BCPA and the completion Fontan operation were performed in 200 and 169 patients, respectively. Overall survival at 5 years were 62.5% ± 2.9%. On Cox regression younger GA (hazard ratio, 1.14 per 1-week decrease; P = .007) was identified as a risk factor for increased interstage mortality (ISM) between initial palliation and BCPA. On subgroup analysis of the preterm or early-term patients with initial palliation (n = 145), younger postmenstrual age at initial palliation was associated with increased ISM before BCPA (hazard ratio, 1.18; P = .005). After BCPA, however, younger GA did not increase the risk of ISM between BCPA and the Fontan operation (P = .47).

CONCLUSIONS

Younger GA is a risk factor for ISM between initial palliation and BCPA. Deferral of initial palliation may be beneficial to decrease the risk of ISM in patients who were born at preterm or early term. Adverse effects of younger GA on survival disappeared once BCPA was performed.

[Percutaneous management of pulmonary atresia with intact ventricular septum and critical pulmonary stenosis]

INTRODUCTION

Pulmonary atresia with intact ventricular septum and critical pulmonary stenosis in newborns encompasses a wide spectrum of disease, including cases with significant right ventricular hypoplasia and coronary artery to right ventricle fistulae, which may be considered a contraindication for decompression of the right ventricle. The aim of this study was to review the middle- and long-term outcomes of these patients over 20 years and identify differential factors between both groups, including patients with coronary artery fistulae.

PATIENTS AND METHODS

We performed a descriptive retrospective study by identifying all patients that received a diagnosis of pulmonary atresia with intact ventricular septum and critical pulmonary stenosis between January 1996 and January 2018. We collected and analysed data regarding right ventricular morphology, surgical management, percutaneous intervention and medium- and long-term outcomes.

RESULTS

51 patients were admitted. A total of 9 patients (17.6%) died during the followup. None of the deceased patients had coronary artery to right ventricle fistulae. The median length of follow up in the 42 survivors was 8.9 years (1-16). The functional class based on the latest revision of the New York Heart Association classification was 1.2 for the overall sample. Survivors of critical pulmonary stenosis had a functional class of 1.1, and survivors of pulmonary atresia with intact ventricular septum a functional class of 1.6. There were no differences based on the presence or absence of coronary artery to right ventricle fistulae.

CONCLUSIONS

Coronary artery to right ventricle fistulae may not be a contraindication for biventricular strategy. Patients with critical pulmonary stenosis had better outcomes compared to patients with pulmonary atresia with intact ventricular septum. The aggressive strategy of opening the pulmonary valve early on was associated with a good overall survival and correlated to a good functional class.

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.

Effects of protocol-based management on the post-operative outcome after systemic to pulmonary shunt

Objectives

Systemic to pulmonary shunt (commonly known as Modified Blalock-Taussig shunt) is a palliative procedure in cyanotic heart diseases to overcome inadequate blood flow to the lungs. Based on the most recent risk stratification score, the mortality and morbidity of this procedure is still high especially in neonates and over-shunting patients. We developed and implemented protocol-based management in March 2013 to better standardize the management of these patients. The aim of this study is to evaluate the effects of applying this protocol-based management in our center.

Methods

We conducted a retrospective cohort study through chart review analysis.We included all children who underwent MBTS from January 2000 till December 2015. We compared the early postoperative outcome of patients operated after the protocol-based management implementation (March 2013 till December 2015) (protocol group) with patients operated before implementing the MBTS protocoled management (control group).

Results

197 patients underwent MBTS from January 2000 till December 2015. Of the 197 patients, 25 patients were in the protocol group and 172 patients were in the control group. There was a significant improvement in the postoperative course and less morbidity after protocoled management implementation as reflected in ventilation time, reintubation rate, inotropic support duration, intensive care unit ICU stay and significantly lower postoperative complications in the protocol group. Mortality of the control group versus protocol group (19.3% VS 8%) with Standardized Mortality Ratio (SMR) dropped from 2.27 before protocoled management to 0.94 after protocoled management (protocol group).

Conclusion

The study suggests that protocoled management of patients with MBTS can improve the postoperative course and early outcome.

Factors Associated With Interstage Mortality Following Neonatal Single Ventricle Palliation

Background:

Several advances have led to improved hospital survival following neonatal palliation (NP) of single ventricle (SV) anomalies. Nonetheless, a number of patients continue to suffer from interstage mortality (ISM) prior to subsequent Glenn. We aim to study patients’ characteristics and anatomic, surgical, and clinical details associated with ISM.

Methods:

A total of 453 SV neonates survived to hospital discharge following NP. Competing risk analysis modeled events after NP (Glenn, transplantation, or death) and examined variables associated with ISM.

Results:

Competing risk analysis showed that one year following NP, 10% of patients had died, 87% had progressed to Glenn, 1% had received heart transplantation, and 2% were alive without subsequent surgery. On multivariable analysis, factors associated with ISM were as follows: weight ≤2.5 kg (hazard ratio, HR = 2.4 [1.2-4.6], P = .013), premature birth ≤36 weeks (HR = 2.0 [1.0-4.0], P = .05), genetic syndromes (HR = 3.2 [1.7-6.1], P < .001), unplanned cardiac reoperation (HR = 2.1 [1.0-4.4], P = .05), and prolonged intensive care unit (ICU) stay >30 days following NP (HR = 2.5 [1.4-4.5], P < .001). Palliative surgery type (shunt, Norwood, band) was not associated with ISM, although aortopulmonary shunt circulation after Norwood was (HR = 5.4 [1.5-19.2] P = .01). Of interest, underlying SV anatomy was not associated with ISM (HR = 1.1 [0.6-2.2], P = .749).

Conclusions:

In our series, ISM following NP occurred in 10% of hospital survivors. As opposed to hospital death, underlying SV anomaly was not associated with ISM. Conversely, several patient factors (prematurity, low weight, and genetic syndromes) and clinical factors (unplanned reoperation and prolonged ICU stay following NP) were associated with ISM. Vigilant outpatient management that is individualized to specific clinical and social needs, taking into account all associated factors, is warranted to improve survival in high-risk patients.

Simultaneous Systemic to Pulmonary Shunt and Pulmonary Artery Banding is a Viable Option for Neonatal Palliation of Single Ventricle Physiology

A subset of neonates with single ventricle (SV) physiology has antegrade pulmonary blood flow that is deemed unlikely to be reliable until Glenn. We have used systemic to pulmonary shunt (SPS) with pulmonary artery banding (PAB) to optimize pulmonary blood flow while maintaining reserve antegrade flow. We hypothesize that this is an effective strategy that can be accomplished without the routine need for cardiopulmonary bypass. We retrospectively reviewed the records of 60 neonates who underwent combined SPS + PAB between 2004 and 2015. Data are presented as median with quartiles. Children were 8 (4-19) days old at surgery and included 38 (63%) boys. Atresia or severe stenosis of the subpulmonary atrioventricular (AV) valve associated with pulmonary blood flow across a bulboventricular foramen was present in 37 (62%). In 20 (33%), heterotaxy-associated unbalanced AV canal with pulmonary stenosis with or without anomalous pulmonary venous drainage was present. First-stage palliation was accomplished without cardiopulmonary bypass in 44 patients (73%). There were 7 (12%) hospital deaths, 4 among the 20 (20%) with heterotaxy. Fifty-three children were followed for a median 5.1 (1.8-8.2) years. Three early reinterventions were required after initial palliation (1 PAB adjustment, 2 SPS balloon angioplasties). Five additional heterotaxy patients experienced late mortality during follow-up. There were no early or emergent Glenn. Thirty-nine patients have reached Fontan circulation with a median pre-Fontan PA pressure of 14 (12-18) mm Hg. One patient converted to biventricular physiology and the remaining await completion Fontan. Heterotaxy was the only independent predictor of mortality (hazard ratio 10 (2.3-44, P < 0.001). In SV patients with unreliable antegrade PA flow, SPS + PAB is an effective first-stage palliation. SV patients with heterotaxy are at increased risk for mortality.

Staged Palliation of Cyanotic Obstructive Lesions With a Modified Right Ventricular Outflow Procedure

BACKGROUND

Traditional palliation for biventricular cyanotic congenital heart lesions often involves staging with systemic-to-pulmonary arterial shunts to secure pulmonary blood flow (PBF) in the newborn period prior to complete repair. However, shunts may lead to life-threatening events secondary to shunt occlusion or acute coronary steal. They may be associated with morbidity secondary to diastolic runoff, systemic steal and volume loading, and do not provide pulsatile flow which has the potential to promote pulmonary artery (PA) growth. We have alternatively performed modified right ventricular outflow (mRVO) procedures by establishing antegrade right ventricle-to-PA flow.

METHODS

Retrospective review of data on all patients who underwent the mRVO procedure from 2013 to 2016, including anatomy, number of interstage catheterizations, reoperations, intensive care unit admissions, hypercyanotic episodes, interval to complete repair, and mortality.

RESULTS

Seventeen nonconsecutive patients included tetralogy of Fallot (n = 14), pulmonary valve stenosis (n = 2), and 1 with pulmonary atresia-intact septum; 14 had significant branch PA stenosis. Median age of first mRVO procedure was 14 days (range 5-193), and median duration of follow-up was 15.3 months (range 4-47 months). No patients had post-palliation acute hypercyanotic episodes. Nine were admitted to the ICU for persistent interstage hypoxemia, 7 of whom required reintervention prior to complete repair, which was achieved in 11 patients. Two late deaths unrelated to mRVO occurred.

CONCLUSIONS

The mRVO procedure is a potential option with satisfactory results. It avoids potential shunt-related sudden death. The physiology of the mRVO palliation may provide unique benefits by providing antegrade pulsatile PBF, facilitates catheter interventions, and avoids branch PA distortion and stenosis.

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.

Mathematical Analysis and Physical Profile of Blalock-Taussig Shunt and Sano Modification Procedure in Hypoplastic Left Heart Syndrome: Review of the Literature and Implications for the Anesthesiologist

The first stage of surgical treatment for hypoplastic left heart syndrome (HLHS) includes the creation of artificial systemic-to-pulmonary connections to provide pulmonary blood flow. The modified Blalock-Taussig (mBT) shunt has been the technique of choice for this procedure; however, a right ventricle-pulmonary artery (RV-PA) shunt has been introduced into clinical practice with encouraging but still conflicting outcomes when compared with the mBT shunt. The aim of this study is to explore mathematical modeling as a tool for describing physical profiles that could assist the surgical team in predicting complications related to stenosis and malfunction of grafts in an attempt to find correlations with clinical outcomes from clinical studies that compared both surgical techniques and to assist the anesthesiologist in making decisions to manage patients with this complex cardiac anatomy. Mathematical modeling to display the physical characteristics of the chosen surgical shunt is a valuable tool to predict flow patterns, shear stress, and rate distribution as well as energetic performance at the graft level and relative to ventricular efficiency. Such predictions will enable the surgical team to refine the technique so that hemodynamic complications be anticipated and prevented, and are also important for perioperative management by the anesthesia team.

Variable Myocardial Response to Load Stresses in Infants with Single Left Ventricular Anatomy: Influence of Initial Physiology and Surgical Palliative Strategy

Initial surgical strategies in neonates with single left ventricular (LV) anatomy vary based on adequacy of pulmonary and systemic blood flow. Differing myocardial responses to these strategies, as reflected in indices of systolic function, ventricular size, and mass have not been well defined. We sought to evaluate single LV myocardial response to varied physiology and initial palliation and determine whether the response is consistent and predictable. Infants with single LV physiology were divided based on neonatal palliation: no palliation/PA band (NO); BT shunt only (BT); or Norwood procedure (NP). Echo measures were obtained at presentation, early post-bidirectional Glenn (BDG), late post-BDG follow-up, and post-Fontan procedure. Measures included ejection fraction, LV mass indexed to height^2.7 and end diastolic volume indexed to body surface area, and mass/volume ratio. The cohort included 38 children (13 NO, 13 BT, 12 NP). Ejection fraction was similar but depressed in all groups at all stages. LV mass was higher in the NP group than the BT group at early post-BDG (p = 0.03) and higher than both BT and NO groups (p < 0.01) at late post-BDG, but the difference was resolved by post-Fontan follow-up. The NP group had the most remarkable remodeling in LV size from BDG to Fontan, suggesting that volume unloading is most valuable in this subgroup. Ventricular remodeling can be identified by echocardiography in children with single LV physiology, despite variable initial surgical palliative strategies. Importantly, these initial surgical strategies do not result in significant differences after Fontan palliation during early childhood.

Surgical approach for systemic-pulmonary shunt in neonates with functionally univentricular heart: comparison between sternotomy and thoracotomy

OBJECTIVE

The preferred surgical approach for systemic-pulmonary shunts has changed from thoracotomy to sternotomy in our institution, to concomitantly manage the ductus arteriosus during surgery. The purpose of this study was to compare the outcomes of systemic-pulmonary shunts for neonates with functionally univentricular hearts based on surgical approach.

METHODS

Fifty-two neonates with functionally univentricular hearts underwent systemic-pulmonary shunt via sternotomy (n = 28) or thoracotomy (n = 24). Patient characteristics, achievement rates of right heart bypass, and survival rates were compared for the different approaches.

RESULTS

Prenatal diagnosis was made more common in the sternotomy group (p = 0.006). The shunt was placed more centrally in the sternotomy group. The ductus arteriosus was ligated or banded in most patients in the sternotomy group (26/28) and in a few patients in the thoracotomy group (6/24). Frequency of ductal management in the early postoperative phase was not different between the groups (21 vs 25 %), but three new incisions had to be made in the thoracotomy group. No differences were seen in the achievement rates of bidirectional cavopulmonary shunts (86 vs 87 % at 10 months of age) and total cavopulmonary connection (81 vs 81 % at 2 years of age), or in the survival rates (92 vs 96 % at 8 years).

CONCLUSIONS

There were no differences in short- and long-term outcomes between the groups. The sternotomy approach might be preferable in the current era of prenatal diagnosis, to allow simultaneous duct management during systemic-pulmonary shunt surgery, particularly in patients with large ducts associated with functionally univentricular hearts.

Clinical assessment of diastolic retrograde flow in the descending aorta for high-flow systemic-to-pulmonary artery shunting

OBJECTIVE

To investigate whether echocardiographic characteristics in the descending aorta of patients with cyanotic congenital heart disease who have received a systemic-to-pulmonary artery (SP) shunt can indicate shunt flow volume and predict postoperative adverse events related to high-flow shunting.

METHODS

Among the 73 consecutive patients who received an SP shunt between 2010 and 2014, data for 53 patients who underwent postoperative Doppler echocardiographic assessment of diastolic retrograde flow in the descending aorta (dAo-RF) were reviewed retrospectively.

RESULTS

The mean dAo-RF ratio was 0.50 ± 0.15 at intensive care unit admission and reached its peak level (0.56 ± 0.12) at 24 hours after surgery. All of the patients with a maximal dAo-RF ratio of ≥0.80 had experienced acute heart failure or cardiogenic shock due to postoperative high-flow shunting and required emergent surgical interventions to reduce pulmonary blood flow. Pulse oximetry-measured oxygen saturation and serum lactate level were significantly correlated with dAo-RF ratio, but they had some clinical dispersion to match the postoperative adverse events.

CONCLUSIONS

The dAo-RF ratio is a simple, repeatable, and noninvasive index for postoperative assessment of SP shunt flow volume. A high dAo-RF ratio is a significant predictor of postoperative adverse events of high-flow shunting.

The Effect of Noncardiac and Genetic Abnormalities on Outcomes Following Neonatal Congenital Heart Surgery

Significant noncardiac and genetic abnormalities (NC and GA) are common in neonates with congenital heart defects. We sought to examine current-era effect of those abnormalities on early and late outcomes following cardiac surgery. The method from 2002-2012, 1538 neonates underwent repair (n = 860, 56%) or palliation (n = 678, 44%) of congenital heart defects. Regression models examined the effect of NC and GA on operative results, resource utilization, and late outcomes. Neonates with NC and GA (n = 312, 20%) had higher incidence of prematurity (21% vs 13%; P < 0.001) and weight ≤2.5kg (24% vs 12%; P < 0.001) than neonates without NC and GA (n = 1226, 80%). Although the incidence of single ventricle was comparable (34% vs 31%; P = 0.37), neonates with NC and GA underwent more palliation (52% vs 42%; P = 0.001) and subsequently had higher percentage of STAT mortality categories (Society of Thoracic Surgeons (STS) and the European Association for Cardio-thoracic Surgery (EACTS) Congenital Heart Surgery Mortality Categories) 4 and 5 procedures (78% vs 66%; P < 0.001). Adjusted logistic regression models that included disparate patient and operative variables showed that the presence of NC and GA was associated with increased unplanned reoperation (odds ratio = 1.7; 95% CI: 1.1-2.7; P = 0.03) and hospital mortality (odds ratio = 2.2; 95% CI: 1.3-3.6; P = 0.002). Adjusted linear regression models showed significant association between NC and GA and increased postoperative mechanical ventilation duration, intensive care unit, and hospital stays (P < 0.001 each). Adjusted hazard analysis showed that the presence of NC and GA was associated with diminished late survival (hazard ratio = 2.4; 95% CI: 1.9-3.1; P < 0.001) and that was evident in all subgroups of patients (P < 0.001 each). Conclusion is neonates with NC and GA commonly have associated risk factors for morbidity and mortality such as prematurity and low weight. After adjusting for those factors, the presence of NC and GA continues to have significant association with increased unplanned reoperation, hospital mortality, and resource utilization after palliative and corrective cardiac surgery. Importantly, the hazard of death in those patients continues beyond the perioperative period for at least 1 year. Our findings show that the presence of NC and GA should be emphasized during parent counseling and decision making; and underscore the need to explore strategies to improve outcomes for this high-risk population that must address perioperative care, outpatient surveillance, and management.

Influence of Morphology and Initial Surgical Strategy on Survival of Infants With Tricuspid Atresia

BACKGROUND

Tricuspid atresia (TA) is a heterogeneous single-ventricle anomaly in which initial presentation and, consequently, timing and mode of palliation vary based on morphology and degree of pulmonary or systemic outflow obstruction. We report current era palliation outcomes and examine whether morphologic and, subsequently, surgical factors influence survival.

METHODS

From 2002 to 2012, 105 infants with TA underwent surgical palliation. Competing risks analyses modeled events after first-stage surgery (Glenn versus death) and after Glenn (Fontan versus death) and examined risk factors affecting outcomes.

RESULTS

Seventy-eight patients (74%) required neonatal first-stage palliation, including modified Blalock-Taussig shunt (n = 46, 44%), Norwood (n = 18, 17%), and pulmonary artery band (n = 14, 13%), whereas 27 (26%) received primary Glenn as their initial surgery. Hospital mortality was 5 patients (4.8%). Competing risks models showed that by 1 year after first-stage surgery, 15% of patients had died and 83% had undergone Glenn. By 5 years after Glenn, 2% of patients had died and 80% had undergone Fontan. Overall 8-year survival was 84%. On multivariable analysis, risk factors for mortality were genetic/extracardiac anomalies (hazard ratio 7.0, 95% confidence interval: 2.4 to 20.6, p < 0.001) and pulmonary atresia (hazard ratio 4.4, 95% confidence interval: 1.6 to 12.2, p = 0.004). Survival was not affected by initial palliation type (p = 0.36), ventriculoarterial discordance (p = 0.25), systemic outflow obstruction (p = 0.84), or arch obstruction (p = 0.62).

CONCLUSIONS

Despite morphologic and physiologic variations necessitating different palliative sequences, multistage palliation outcomes of various TA subtypes are comparable and generally good, with the exception of patients with associated genetic/extracardiac anomalies. The bulk of mortality is interstage, indicating continued opportunity for improvement in monitoring and managing patients during this critical period.