First-stage Palliation Research Articles

Single Ventricle With Atrioventricular Valve Regurgitation—Ongoing Challenges

In this issue of The Annals of Thoracic Surgery, the article by Sinha and colleagues1 determined risk factors for death after repair of atrioventricular valve regurgitation in patients with single-ventricle circulation treated at a single institution. Risk factors that emerged included earlier age at atrioventricular valve repair, heterotaxy, and unbalanced atrioventricular septal defect. Transplant-free survival was lowest in patients who underwent repair at the first-stage palliation. In addition, patients with severe dysfunction of the dominant ventricle had lower transplant-free survival.

Dead space fractions in neonates following first-stage palliation for hypoplastic left heart syndrome.

(1) To characterise changes in dead space fraction during the first 120 post-operative hours in neonates undergoing stage 1 palliation for hypoplastic left heart syndrome, including hybrid procedure; (2) to document whether dead space fraction varied by shunt type (Blalock-Taussig shunt and Sano) and hybrid procedure; and (3) to determine the association between dead space fraction and outcomes. Retrospective chart review in neonates undergoing stage 1 palliation for hypoplastic left heart syndrome in a cardiac intensive care unit over a consecutive 30-month period. A linear mixed model was used to determine the differences in dead space over time. Multivariable linear regression and a multivariable linear mixed model were used to assess the association between dead space and outcomes at different time points and over time, respectively. Thirty-four neonates received either a Blalock-Taussig shunt (20.5%), Sano shunt (59%), or hybrid procedure (20.5%). Hospital mortality was 8.8%. Dead space fractions in patients undergoing the hybrid procedure were significantly lower on day 1 (p = 0.01) and day 2 (p = 0.02) and increased over time. A dead space fraction >0.6 on post-operative days 3-5 was significantly associated with decreased duration of mechanical ventilation in all surgical groups (p 0.6 on post-operative days 3-5 was associated with lower duration of mechanical ventilation in all surgical groups. A more comprehensive, prospective assessment of dead space in this delicate patient population would likely be beneficial in improving outcomes.

Outcomes of Single Ventricle Patients Undergoing the Kawashima Procedure: Can We Do Better?

Current technology advances in virtual surgery modeling and computational flow dynamics allow preoperative individualized computer-based design of Fontan operation. To determine potential role of those innovations in patients undergoing hepatic vein incorporation (HVI) following Kawashima operation, we retrospectively examined historic cohort of patients who underwent HVI following Kawashima with focus on regression of pulmonary arteriovenous malformations (PAVMs). Twenty-two children with single ventricle and interrupted inferior vena cava underwent Kawashima operation (2002-12). Twenty-one (96%) patients had left atrial isomerism and 21 (96%) had undergone prior first-stage palliation. Clinical outcomes were examined. Mean O2 saturation (SaO2) increased from 77% ± 8% to 85% ± 6% ( P = .002) after Kawashima. Fifteen (68%) patients developed PAVMs. Eighteen patients underwent HVI (median age and interval from Kawashima: 4.4 and 3.7 years, respectively). Mean SaO2 prior to HVI was 77% ± 8% and increased to 81% ± 10% at the time of hospital discharge ( P = .250), with five patients requiring home oxygen. On follow-up, mean SaO2 increased to 95% ± 4% ( P < .001). Overall ten-year survival following Kawashima was 94%. A large number of patients develop PAVMs and subsequent cyanosis after Kawashima operation. Early following HVI, SaO2 is commonly low and insignificantly different from that prior to HVI. Although SaO2 will improve on follow-up in most patients, a number of patients continue to have low saturations, indicating incomplete resolution of PAVMs. Given the heterogeneity of those patients and lack of preoperative predictors for complete PAVM regression, our findings suggest a role for virtual surgery to determine optimal individual procedure design that would provide even distribution of hepatic blood flow to both pulmonary arteries.

Patient-Specific Multiscale Modeling of the Assisted Bidirectional Glenn

First-stage palliation of neonates with single-ventricle physiology is associated with poor outcomes and challenging clinical management. Prior computational modeling and invitro experiments introduced the assisted bidirectional Glenn (ABG), which increased pulmonary flow and oxygenation over the bidirectional Glenn (BDG) and the systemic-to-pulmonary shunt in idealized models. In this study, we demonstrate that the ABG achieves similar performance in patient-specific models and assess the influence of varying shunt geometry. In a small cohort of single-ventricle prestage 2 patients, we constructed three-dimensional in silico models and tuned lumped parameter networks to match clinical measurements. Each model was modified to produce virtual BDG and ABG surgeries. We simulated the hemodynamics of the stage 1 procedure, BDG, and ABG by using multiscale computational modeling, coupling a finite-element flow solver to the lumped parameter network. Two levels of pulmonary vascular resistances (PVRs) were investigated: baseline (low) PVR of the patients and doubled (high) PVR. The shunt nozzle diameter, anastomosis location, and shape were also manipulated. The ABG increased the pulmonary flow rate and pressure by 15% to 20%, which was accompanied by a rise in superior vena caval pressure (2 to 3 mm Hg) at both PVR values. Pulmonary flow rate and superior vena caval pressures were most sensitive to the shunt nozzle diameter. Patient-specific ABG performance was similar to prior idealized simulations and experiments, with good performance at lower PVR values in the range of measured clinical data. Larger shunt outlet diameters and lower PVR led to improved ABG performance.

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.

Genetic and Extracardiac Anomalies Are Associated With Inferior Single Ventricle Palliation Outcomes

We examined the effect of genetic syndromes and extracardiac (GS/EC) anomalies on single-ventricle (SV) palliation with focus on hospital and interstage death and progression toward subsequent palliation stages. First-stage palliation was performed in 530 neonates with SV: Norwood in 284 (53%), shunt in 173 (33%), and band in 73 (14%). Outcomes were compared between those with GS/EC anomalies (121 [23%]) and without GS/EC anomalies (409 [77%]). Regression analyses were adjusted for other risk factors (age, sex, prematurity, weight, SV anomaly, and first-stage palliation operation). GS/EC anomalies varied among SV defects (range, 3% for double-inlet left ventricle to 100% for atrial isomerism). Patients with GS/EC anomalies required significantly longer durations of mechanical ventilation and intensive care unit and hospital stay. Although patients had comparable rates of extracorporeal membrane oxygenation (13% vs 11%, p= 0.552) and unplanned reoperation (16% vs 11%, p= 0.189), hospital mortality was higher in patients with GS/EC anomalies (24% vs 12%, p= 0.0008). After discharge, patients with GS/EC anomalies had higher interstage death, with lower progression to Glenn (60% vs 77%, p= 0.002) and lower 10-year survival (56% vs 76%, p < 0.001). After adjustment for other risk factors, GS/EC anomalies significantly affected survival in almost all subgroups of patients. The presence of GS/EC anomalies varies among SV anomalies and is associated with additional risk factors such as prematurity and low weight. After adjusting for other risk factors, GS/EC anomalies are associated with prolonged recovery after first-stage palliation and increased hospital and interstage death, with subsequently fewer patients progressing toward Glenn shunt. The increased death risk in those patients is highest in the first 6 months and persists for 2 to 3 years after first-stage palliation, suggesting the need for more vigilant monitoring and outpatient care in these high-risk patients.

Blalock-Taussig Shunt Size: Should it be Based on Body Weight or Target Branch Pulmonary Artery Size?

The study aimed to revisit the in-hospital predictors of shunt thrombosis (ST) in the foreground of the pulmonary artery size in patients who received modified Blalock-Taussig shunt (mBTS) as the first-stage palliation. Data from 80 patients who received mBTS as their initial palliative procedure between February 2012 and January 2017 was retrospectively collected. The median age and weight of the patients at the time of their mBTS procedure was 4days (IQR 2-22days) and 3.2kg (IQR 2.8-3.7kg), respectively. Of the 80 patients in the study, 11 (13.8%) developed ST. The diameter and corresponding z scores of the pulmonary arteries were significantly lower in patients with ST. The median shunt size/shunted pulmonary artery size (S/PA) ratio was considerably higher in patients with ST. In logistic regression analysis, pulmonary artery hypoplasia (PAH) [odds ratio (OR) = 13.7 (0.06-0.21), p < 0.001], S/PA ratio ≥ 0.9 [OR = 8.1 (0.03-0.53), p = 0.03], prematurity [OR = 9.5 (0.05-0.33), p = 0.003], and shunt size/weight (S/W) ratio ≥ 1.3 [OR = 6.4 (0.04-0.67), p = 0.012] were found to have a significant impact on ST. The best combination of sensitivity and specificity of the S/W (0.73 and 0.75) and the S/PA ratio (0.73 and 0.80) were achieved at the cut-off value of 1.3 and 0.9, respectively. The Youden index of S/PA was 0.52. While the area under the curve (AUC) of the S/W ratio was 0.686 ± 0.12 (p = 0.049), the AUC of the S/PA ratio was 0.791 ± 0.08 (p = 0.002). In conclusion, instead of weight, considering the size of the target pulmonary artery and thereby, the S/PA ratio would be more instructive in determining shunt size. There were a high number of patients in our study who showed PAH having received a shunt size based on their body weight. By contrast, our results showed that the S/PA ratio of ≥ 0.9 would be a good predictor of in-hospital ST.

Right Ventricular Longitudinal Shortening Before and After Stage I Surgical Palliation Correlates with Outcomes.

Quantification of right ventricular function is difficult, but important, in patients with single ventricles. Tissue motion annular displacement (TMAD) is an echocardiographic tool that measures displacement of the tricuspid valve relative to the apex. We evaluated TMAD, lateral annular displacement (LAD), and fractional area change (FAC) for correlation with outcomes. We measured TMAD, LAD, FAC, and other variables that may affect prognosis in patients with single right ventricle physiology pre- and post-Stage I palliation and correlated them with outcomes up to the Glenn procedure. Intra- and inter-observer variability for TMAD measurements were 2.7% (1.2-3.5%) and 6.1% (3.3-8.1%), respectively. Sixty-six subjects met the inclusion criteria. Pre-Stage I TMAD was 13.7% (SD 3.9%). TMAD had a linear relationship with FAC (r2 = 0.76). There was a correlation between TMAD and hospital stay (p = 0.044) and ECMO/arrest (p = 0.024). LAD correlated with ECMO/arrest (p = 0.045) and mortality/transplant (p = 0.049). FAC correlated with in-hospital mortality (p = 0.028). Post-Stage I TMAD was 11.8% (SD 3.7%). TMAD, LAD, and FAC all correlated with in-hospital mortality and mortality/transplant. In multivariate models, TMAD was independently predictive of weight for age Z score pre-Glenn. TMAD, FAC, and LAD correlate with clinically significant outcomes after the first-stage palliation. TMAD correlated with more outcomes than FAC and was the only measure that was independently predictive of any outcome. TMAD is a reproducible measure of RV function in this population. TMAD has prognostic value before and after first-stage palliation and may outperform more traditional measures.

Nurse-driven analgesia and sedation in pediatric patients with univentricular hearts requiring extracorporeal life support after first-stage palliation surgery: A pilot study.

Few data are available regarding requirements of sedation and analgesia in children during extracorporeal life support. The aim of this study was to evaluate if children with functionally univentricular hearts on extracorporeal life support after first-stage palliation surgery have higher requirement of analgesics and sedatives compared with children without extracorporeal life support using a goal-directed nurse-driven analgesia and sedation protocol. This prospective observational matched case-control pilot study was conducted at a cardiac pediatric intensive care unit of a tertiary referral center. Seventeen patients with functionally univentricular hearts including hypoplastic left heart syndrome who were on extracorporeal life support after first-stage palliation surgery were enrolled from July 2012 to January 2017. Seventeen matched patients served as controls. Doses of morphine, midazolam, clonidine, and muscle relaxants as well as sedation scores (COMFORT behavior scale and the nurse interpretation of sedation scale) were assessed according to a nurse-driven protocol every 8 hours up to 120 hours after first-stage palliation surgery. Sedation scores were equal in the extracorporeal life support group and in the control group at most points in time. There was no significant difference in cumulative doses of morphine and midazolam. However, children of the extracorporeal life support group received higher doses of midazolam and morphine at some points in time. A nurse-driven protocol for analgesia and sedation of children with extracorporeal life support is feasible. Patients with extracorporeal life support do not need deeper sedation levels and have not higher cumulative sedation requirements than children without extracorporeal life support.

Acute kidney injury following first-stage palliation in hypoplastic left heart syndrome: hybrid versus Norwood palliation.

The aim of this study was to evaluate the prevalence of acute kidney injury after first-stage surgical palliation in patients with a single ventricle and to explore associated risk factors and outcomes. Design and patients This single-centre retrospective study included neonates who underwent either Norwood or Hybrid procedure from 2008 to 2015 for a single ventricle. Postoperative acute kidney injury was defined using the paediatric risk, injury, failure, loss, end-stage renal disease (pRIFLE), criteria within 72 hours of the procedure. Main results Our cohort (n=48) underwent surgical palliation at a mean (SD) age of 12 (11) days. Postoperative acute kidney injury was diagnosed in 14 (29%) patients. The prevalence of acute kidney injury in the Hybrid group was 16% and 53% in the Norwood group. Infants who developed acute kidney injury underwent surgery at younger ages [6 (5-10) versus 10 (8-16) days, p=0.016], and had a higher peak lactate level in the initial 24 hours [5.9 (4.2-9.1) versus 3.4 (2.4-6.7), p=0.007]. Norwood procedure was significantly associated with acute kidney injury [odds ratio 11.7 (95% confidence interval 1.3-101.9), p=0.03]. ICU stay [38 (21-84) versus 16 (6-45) days, p=0.038] and time to extubation [204 (120-606) versus 72 (26-234) hours, p=0.014] were longer in those with acute kidney injury. The two patients who developed early postoperative renal failure as per pRIFLE died before discharge from associated comorbidities. Acute kidney injury occurs in a third of the patients with single ventricle after surgical palliation but is mostly transient. Norwood, compared with Hybrid procedure, is a risk factor for postoperative acute kidney injury, which, in turn, is associated with longer ICU stay and time to extubation.

First-stage palliation strategy for univentricular heart disease may impact risk for acute kidney injury.

Norwood palliation for patients with single ventricle heart disease is associated with a significant risk for acute kidney injury, which portends a worse prognosis. We sought to investigate the impact of hybrid stage I palliation (Hybrid) on acute kidney injury risk. This study is a single-centre prospective case-control study of seven consecutive neonates with single ventricle undergoing Hybrid palliation. Levels of serum creatinine and four novel urinary biomarkers, namely neutrophil gelatinase-associated lipocalin, interleukin-18, liver fatty acid-binding protein, and kidney injury molecule-1, were obtained before and after palliation. Acute kidney injury was defined as a ⩾50% increase in serum creatinine within 48 hours after the procedure. Data were compared with a contemporary cohort of 12 neonates with single ventricle who underwent Norwood palliation. Patients who underwent Hybrid were more likely to be high-risk candidates (86 versus 25%, p=0.01) compared with those who underwent Norwood. Despite similar preoperative serum creatinine levels, there was a trend towards higher levels of postoperative peak serum creatinine (0.7 [0.63, 0.94] versus 0.56 [0.47, 0.74], p=0.06) and rate of acute kidney injury (67 versus 29%, p=0.17) in the Norwood cohort. Preoperative neutrophil gelatinase-associated lipocalin (58.4 [11, 86.3] versus 6.3 [5, 16.2], p=0.07) and interleukin-18 (30.6 [9.6, 167.2] versus 6.3 [6.3, 16.4], p=0.03) levels were higher in the Hybrid cohort. Nevertheless, longitudinal mixed-effect models demonstrated Hybrid palliation to be a protective factor against increased postoperative levels of neutrophil gelatinase-associated lipocalin (estimate -1.8 [-3.0, -9.0], p<0.001) and liver fatty acid-binding protein (-49.3 [-89.7, -8.8], p=0.018). In this single-centre case-control study, postoperative acute kidney injury risk did not differ significantly by single ventricle stage I treatment strategy; however, postoperative elevation in novel urinary biomarkers, consistent with subclinical kidney injury, was encountered in the Norwood cohort but not in the Hybrid cohort.

Current Results of Single Ventricle Palliation of Patients With Double Inlet Left Ventricle

Double inlet left ventricle (DILV) is a heterogeneous single ventricle anomaly in which initial presentation, and consequently, timing and palliation mode vary based on morphology and degree of pulmonary or systemic outflow obstruction. Very few reports, mostly old, focused on palliation outcomes of DILV. We report current-era results and examine whether morphologic and subsequently surgical factors influence survival. Fifty-eight infants with DILV underwent single ventricle palliation. Echocardiographic examination showed pulmonary (n= 29, 50%), systemic outflow tract (n= 11, 19%), and arch (n= 17, 29%) obstruction. Factors associated with death or transplantation were examined. Forty-four patients (76%) required neonatal first-stage palliation: modified Blalock-Taussig shunt (n= 15, 26%), Norwood (n= 15, 26%), or pulmonary artery band (n= 14, 24%), whereas 14 (24%) received primary Glenn. There was 1 hospital death (2%) and 2 interstage deaths before Glenn, in addition to 1 late death that was noncardiac. Overall 10-year survival was 94% and was comparable for different palliative surgeries (p= 0.49). Three patients (6%) underwent heart transplantation after first-stage palliation (n= 1) or after Glenn (n= 2) for ventricular noncompaction (n= 1), ventricular and atrioventricular valve dysfunction (n= 1), and pacemaker-induced cardiomyopathy (n= 1). Overall 10-year freedom from death or transplantation was 87% and was comparable for different palliative surgeries (p= 0.58). On regression risk analysis, none of the tested morphologic or surgical variables was associated with the risk of death or transplantation. Current outcomes of multistage palliation of DILV are relatively good compared with published reports of other single ventricle anomalies. Survival is not greatly affected by cardiac morphology or initial palliative surgery type.

Hybrid Palliation for Interrupted Aortic Arch With Small Aortic Valve.

Open heart surgery for interrupted aortic arch in the neonatal period is still a high-risk procedure related in part to patient factors such as low birth weight, other morphologic anomalies, and, especially, small aortic valve size. Recently, we performed hybrid palliation with bilateral pulmonary artery banding and ductal stenting as the first-stage palliation for such cases. In this study, the outcomes of this procedure were examined. Six cases of interrupted aortic arch with a small aortic valve underwent the hybrid procedure in the neonatal period in our institute from 2010 to 2015 (mean age: 6.8 days, mean body weight: 3.2 kg, mean z score of the aortic valve annulus: -8.3). Their postoperative clinical courses and results of the second-stage surgery were evaluated. No mortality or severe morbidity was seen in association with initial hybrid palliation. Five of six patients were discharged from the hospital; the one exception had a significant urinary tract anomaly. None needed an additional catheter intervention or surgical procedure postoperatively. All surviving patients underwent second-stage surgery; three had biventricular repair by the conventional method or Damus-Kaye-Stansel anastomosis with the Rastelli procedure and the other three proceeded toward staged Fontan reconstruction. Growth of the aortic valve was seen in four patients, and increased indexed left ventricle volume was recognized in one after the palliation. Hybrid palliation could be useful not only to avoid high-risk neonatal surgery but also to allow for eventual selection of the second-stage surgery based on the observations of potential interval development of left ventricular structures.

Interstage Home Monitoring After Newborn First-Stage Palliation for Hypoplastic Left Heart Syndrome: Family Education Strategies

Children born with hypoplastic left heart syndrome are at high risk for serious morbidity, growth failure, and mortality during the interstage period, which is the time from discharge home after first-stage hypoplastic left heart syndrome palliation until the second-stage surgical intervention. The single-ventricle circulatory physiology is complex, fragile, and potentially unstable. Multicenter initiatives have been successfully implemented to improve outcomes and optimize growth and survival during the interstage period. A crucial focus of care is the comprehensive family training in the use of home surveillance monitoring of oxygen saturation, enteral intake, weight, and the early recognition of "red flag" symptoms indicating potential cardiopulmonary or nutritional decompensation. Beginning with admission to the intensive care unit of the newborn with hypoplastic left heart syndrome, nurses provide critical care and education to prepare the family for interstage home care. This article presents detailed nursing guidelines for educating families on the home care of their medically fragile infant with single-ventricle circulation.

Usefulness of Percutaneous Transluminal Pulmonary Artery Balloon Angioplasty after Bilateral Pulmonary Artery Banding: Prevention against Additional Surgical Interventions

Objectives: We evaluated the efficacy of balloon dilatation after bilateral pulmonary artery banding for the treatment of severe congenital heart disease that depends on patent ductus arteriosus for systemic circulation. Background: Neonatal cardiopulmonary bypass can cause brain injury, which may result in a severely impaired neurodevelopmental outcome. Hence, we perform bilateral pulmonary artery banding combined with postoperative percutaneous trans catheter angioplasty with balloon dilatation as first-stage palliation. Methods: From October 2007 to December 2013, 27 consecutive patients underwent bilateral pulmonary artery banding at our institution. We retrospectively obtained their diagnostic, clinical, and catheter examination data from the medical records. Results: Bilateral pulmonary artery banding was performed at a median of 7 days. Among the 27 patients, 16 underwent expansive angioplasty using a balloon catheter at each banding site to increase pulmonary blood flow. The mean age at dilatation was 53.4 ± 25.9 days, and the mean pulmonary artery index significantly increased from 130.6 mm2/m2 ± 51.1 mm2/m2 before dilatation to 243.6 mm2/ m2 ± 93.5 mm2/m2 after dilatation (p<0.01). All patients underwent a secondstage operation at a mean age of 126 ± 14.8 days. Of the 11 patients who did not undergo balloon dilatation, five required additional surgical interventions. However, of the 16 patients who underwent balloon dilatation, only one required an additional surgical intervention (p<0.01). Conclusions: Our strategy of balloon dilatation after bilateral pulmonary artery banding can improve the outcome of clinical treatment for severe congenital heart disease in infants. However, further studies are warranted.

The Impact of Dominant Ventricle Morphology on Palliation Outcomes of Single Ventricle Anomalies

Differences in right ventricle and tricuspid valve structure compared with left ventricle and mitral valve structure make them less equipped to support the systemic circulation long term, with subsequent systemic right ventricle failure. We examined the effect of dominant ventricle morphology on single ventricle palliation outcomes. We grouped 530 neonates who underwent first-stage palliation into two groups based on dominant ventricle morphology: right dominant ventricle (RV group; n= 302, 57%) and left dominant ventricle or functional single ventricle with two well-formed ventricles (LV group; n= 228, 43%). Comparisons of hospital outcomes, interstage mortality, progression to subsequent palliation stages, and late survival was performed, and factors affecting outcomes were examined. After first-stage palliation, the RV group and LV group, respectively, had comparable extracorporeal membrane oxygenation requirements (12% versus 11%,p= 0.648), unplanned reoperation (12% versus 13%, p= 0.586), and hospital death (16% versus 13%, p=0.437). Among hospital survivors, interstage mortality (11% versus 9%, p= 0.509) and progression to Glenn operation (89% versus 84%, p= 0.182) were comparable; however, death after Glenn was higher in the RV group (10%, versus LV group 4%, p= 0.020) with a trend for lower 8-year survival (66% versus 73%, p= 0.081). On multivariable analysis, dominant RV was not associated with mortality (hazard ratio 0.75, 95% confidence interval: 0.6 to 1.0, p= 0.081), whereas factors such as genetic syndromes, weight 2.5 kg or less, underlying cardiac anomaly, and first-stage palliation type affected survival. At midterm follow-up, underlying cardiac anomaly and patient characteristics affect single ventricle palliation outcomes more than dominant ventricular morphology. As right ventricle and associated tricuspid valve failure might occur at late stages, the impact of dominant ventricular morphology on long-term outcomes requires further assessment.

Outcomes of multistage palliation of infants with functional single ventricle and heterotaxy syndrome

BackgroundManagement of infants with heterotaxy syndrome and functional single ventricle is complicated due to associated cardiac and extracardiac anomalies. We report current era palliation results. MethodsBetween 2002 and 2012, 67 infants with heterotaxy syndrome underwent multistage palliation. Competing risks analyses modeled events after surgery (death vs Glenn procedure) and examined factors associated with survival. In addition, early and late outcomes following first-stage palliation surgery were compared with a matched contemporaneous control group of patients with nonheterotaxy single ventricle anomalies. ResultsFifty-eight patients (87%) required neonatal palliation, including a modified Blalock-Taussig shunt (n = 34; 51%), Norwood operation (n = 12; 18%) or pulmonary artery band (n = 12; 18%), whereas 9 patients (13%) underwent a primary Glenn procedure. Competing risks analysis showed that at 1 year after first-stage palliation surgery, 29% of the patients had died or undergone transplantation and 63% had undergone a Glenn procedure. By 5 years after the Glenn procedure, 64% of patients had undergone a Fontan procedure. The overall 8-year survival rate was 66%. On multivariable analysis, factors associated with mortality were unplanned reoperation (hazard ratio [HR], 2.9; 95% confidence interval [CI], 1.1-7.3; P = .005) and total anomalous pulmonary venous connection repair (HR, 2.3; 95% CI, 1.0-5.6; P = .056). Comparison with the contemporaneous matched patients with nonheterotaxy single ventricle anomalies showed that first-stage palliation in the patients with heterotaxy was associated with a higher rate of in-hospital death (27% vs 10%; P = .022), and significantly longer durations of ventilation and intensive care unit stay. Interstage mortality, survival after the Glenn procedure, and progression to the Fontan procedure were comparable in the 2 groups. ConclusionsThe management of infants with heterotaxy and a functional single ventricle remains challenging. First-stage palliation is associated with high operative mortality and increased resource utilization owing to surgical morbidity. Nonetheless, outcomes beyond hospital discharge are comparable to those for patients with other single ventricle anomalies. Efforts to improve survival in those patients should focus on perioperative care.

Benefits of Balloon‐Dilatable Bilateral Pulmonary Artery Banding in Patients With Hypoplastic Left Heart Syndrome and Other Complex Cardiac Anomalies

The purpose of this study was to evaluate the potential of balloon-dilatable bilateral pulmonary artery banding (b-PAB) and its impact on the configuration of the pulmonary artery (PA). We have previously used balloon-dilatable b-PAB as first-stage palliation for patients with hypoplastic left heart syndrome (HLHS) and other complex cardiac anomalies. Two pliable tapes were placed around each branch of the PA and tightened with 7-0 polypropylene sutures in a manner that allowed for the subsequent adjustment of PA diameters. We retrospectively examined the adjustability of PA diameters by balloon dilation and the need for surgical PA angioplasty at later stages. From January 2010 to October 2013, we performed b-PAB in 8 patients, including 3 borderline cases between biventricular repair (BVR) and univentricular repair (UVR). The b-PAB procedures were performed at a median age of 6.5 days (range, 2-10 days). Balloon dilations were performed in 10 lesions in 4 patients. All of the procedures were performed safely. Two patients reached definite BVR. The remaining 6 patients underwent open palliative procedures with univentricular physiologies that resulted in 2 deaths unrelated to the initial b-PAB. In all but 1 of the patients, the PA configuration was properly maintained and did not require surgical pulmonary angioplasty. Balloon-dilatable b-PAB can be performed safely and prevents PA distortion at later stages. This technique should be considered for patients with complex cardiac anomalies if uncertainty exists regarding the optimal surgical strategy (BVR or UVR) in early infancy.

Pharmacological Manipulation of Peripheral Vascular Resistance in Single Ventricle Patients (Stages I, II, and III of Palliation).

Pharmacological manipulation of afterload is often used in the management of single ventricle patients, both in the acute post-operative setting and more chronically. After the first stage of palliation the pulmonary and systemic circulations are in parallel and afterload reduction is often used to increase total cardiac output and systemic oxygen delivery. The effectiveness of this approach is likely to be dependent on the intrinsic contractile state of the myocardium as well as the post-operative vascular tone. A variety of clinical studies and theoretical models support this approach. The use of afterload reduction in this context must be balanced with the need to maintain a critical systemic blood pressure for organ perfusion and to promote pulmonary blood flow. After the second and third stages of palliation the use of acute afterload reduction is less complex and primarily directed at promoting cardiac output when it is low and/or controlling high blood pressure. Second stage palliation is particularly unique in that the cerebral and pulmonary circulations are in series and respond differently to many manipulations designed to control vascular resistance. The incidence of long-term circulatory failure in single ventricle patients has led to frequent use of afterload reducing agents in this population but data to suggest that this improves overall outcomes is lacking. Newer studies suggest there may be a role for drugs that reduce pulmonary vascular resistance. This chapter will discuss the principles of manipulation of systemic vascular resistance, or afterload, following each of the three stages of single ventricle reconstruction. This article addresses the seventh of eight topics comprising the special issue entitled "Pharmacologic strategies with afterload reduction in low cardiac output syndrome after pediatric cardiac surgery".

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

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. 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. 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). 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.