Travis J. Wilder

Survival and right ventricular performance for matched children after stage-1 Norwood: Modified Blalock-Taussig shunt versus right-ventricle-to-pulmonary-artery conduit

OBJECTIVE Early survival advantages after Norwood with right-ventricle-(RV)-to-pulmonary-artery conduit (NW-RVPA) over Norwood-operation with a Blalock-Taussig shunt (NW-BT) are offset by concerns regarding delayed RV dysfunction. We compared trends in survival, RV dysfunction, and tricuspid valve regurgitation (TR) between NW-RVPA and NW-BT for propensity-matched neonates with critical left ventricular outflow tract obstruction (LVOTO). METHODS In an inception cohort (2005-2014; 21 institutions), 454 neonates with critical LVOTO underwent Norwood stage 1. Propensity-score matching paired 169 NW-RVPA patients with 169 NW-BT patients. End-states were compared between NW-RVPA and NW-BT using competing-risks, multiphase, parametric, hazard analysis. Post-Norwood echocardiogram reports (n = 2993) were used to grade RV dysfunction and TR. Time-related prevalence of ≥moderate RV dysfunction and TR were characterized using nonlinear mixed-model regression, and compared between groups via multiphase, parametric models. RESULTS Overall 6-year survival was better after NW-RVPA (70%) versus NW-BT (55%; P < .001). Additionally, transplant-free survival during this time was better after NW-RVPA (64%) versus NW-BT (53%; P = .004). Overall prevalence of ≥moderate RV dysfunction reached 11% within 3 months post-Norwood. During this time, RV dysfunction after NW-BT was 16% versus 6% after NW-RVPA (P = .02), and coincided temporally with an increased early hazard for death. For survivors, late RV dysfunction was <5% and was not different between groups (P = .36). Overall prevalence of ≥moderate TR reached 13% at 2 years post-Norwood and was increased after NW-BT (16%) versus NW-RVPA (11%; P = .003). Late TR was similar between groups. CONCLUSIONS Among propensity-score-matched neonates with critical LVOTO, NW-RVPA offers superior 6-year survival with no greater prevalence of RV dysfunction or TR than conventional NW-BT operations.

Pulmonary vein stenosis: Severity and location predict survival after surgical repair

OBJECTIVES Pulmonary vein characteristics that influence survival after repair of stenosis have not been defined. We sought to develop a predictive model relating postrepair survival to preoperative pulmonary vein characteristics on computed tomography and magnetic resonance imaging. METHODS Patients who underwent pulmonary vein stenosis repair (1990-2012) with preoperative computed tomography and magnetic resonance imaging were reviewed. We measured pulmonary vein short and long cross-sectional diameters at the left atrial junction (downstream), vein bifurcation (upstream), and narrowest point, and calculated the total cross-sectional area indexed for body surface area. The relationship between pulmonary vein dimensions and survival was related via risk-adjusted parametric hazard analyses. RESULTS Of 145 patients who underwent surgical repair, 31 had preoperative computed tomography and magnetic resonance imaging and were analyzed. Surgical repairs were sutureless (n = 30) or pericardial patch reconstruction (n = 1). Mean follow-up was 4.28 ± 4.2 years. In-hospital mortality was 9.7%; unadjusted survival was 75% ± 7%, 69% ± 8%, and 64% ± 7% at 1, 3, and 5 years, respectively. Median downstream total cross-sectional area indexed for body surface area was 163 mm(2)/m(2), upstream total cross-sectional area indexed for body surface area was 263 mm(2)/m(2), and total cross-sectional area indexed for body surface area at maximal stenosis, localized at the left atrial junction in approximately two thirds of patients, was 163 mm(2)/m(2). Smaller upstream total cross-sectional area indexed for body surface area (P = .030) and greater number of stenotic pulmonary veins (P = .0069) were associated with increased early (<1 year) risk of death. Smaller downstream total cross-sectional area indexed for body surface area tended to be associated with a late risk of death (P = .059). CONCLUSIONS Smaller upstream or downstream total cross-sectional area indexed for body surface area negatively influenced survival. Early survival seemed especially poor for patients with a greater number of stenotic veins and upstream pulmonary vein involvement. The total cross-sectional area indexed for body surface area measurements can help to inform prognosis and stratify patients for enrollment in clinical trials of agents directed at pulmonary vein pathology.

Is a hybrid strategy a lower-risk alternative to stage 1 Norwood operation?

Background: For neonates with critical left ventricular outflow tract obstruction (LVOTO), hybrid procedures are an alternative to the Norwood stage 1 procedure. Despite perceived advantages, however, outcomes are not well defined. Therefore, we compared outcomes after stage 1 hybrid and Norwood procedures. Methods: In a critical LVOTO inception cohort (2005‐2014; 20 institutions), a total of 564 neonates underwent stage 1 palliation with the Norwood operation with a modified Blalock‐Taussig shunt (NW‐BT; n = 232; 41%), Norwood operation with a right ventricle–to–pulmonary artery conduit (NW‐RVPA; n = 222; 39%), or a hybrid procedure (n = 110; 20%). Post–stage 1 outcomes were analyzed via competing‐risks and parametric hazard analyses and compared among all 564 patients and between patients who underwent propensity‐matched hybrid and those who underwent NW‐BT/NW‐RVPA. Results: By 6 years after the stage 1 operation, 50% ± 3%, 7% ± 2%, and 4% ± 1% of patients transitioned to Fontan, transplantation, and biventricular repair, respectively, whereas 7% ± 2% were alive without transition and 32% ± 2% died. Risk factors for death without transition included procedure type, smaller ascending aorta, aortic valve atresia, and lower birth weight. Risk‐adjusted 4‐year survival was better after NW‐RVPA than after NW‐BT or hybrid (76% vs 60% vs 61%; P < .001). Furthermore, for neonates with lower birth weight (<˜2 kg), an interaction between birth weight and hybrid resulted in a trend toward better survival after hybrid compared with NW‐BT or NW‐RVPA. For propensity‐matched neonates between hybrid and NW‐BT (88 pairs), 4‐year survival was similar (62% vs 57%; P = .58). For propensity‐matched neonates between hybrid and NW‐RVPA (81 pairs), 4‐year survival was better after NW‐RVPA (59% vs 75%; P = .008). Conclusions: For neonates with critical LVOTO undergoing single‐ventricle palliation, NW‐RVPA was associated with the best overall survival. Hybrid strategies are not a lower‐risk alternative to Norwood operations overall; however, the impact of lower birth weight on survival may be mitigated after hybrid procedures compared with Norwood operations.

Aortic valve repair for insufficiency in older children offers unpredictable durability that may not be advantageous over a primary Ross operation

OBJECTIVES To evaluate the durability of aortic valve (AoV) repair relative to other strategies for children with significant aortic insufficiency (AI). METHODS From 2001 to 2012, 90 children with greater than or equal to moderate AI underwent surgery. Resulting procedures were classified according to final operative outcome: AoV repair (repair; n = 46, 51%), Ross procedure (Ross; n = 21, 23%) or replacement with mechanical or tissue prosthesis [aortic valve replacement (AVR); n = 23, 26%]. Repeated measures (n = 1081 echocardiograms) mixed-model analysis and parametric multiphase risk-adjusted hazard analysis were used to evaluate haemodynamic parameters and durability of operations. RESULTS Mean age at operation was similar for repair and Ross groups, but slightly higher for the AVR group (10.6, 11 and 13.2, respectively; P = 0.04). Baseline annular dimensions were similar among groups. Of 46 repairs, 85% involved pericardial leaflet extensions (commonly with leaflet shaving and/or commisuroplasty). The remaining repairs were commissuroplasties. On multivariable analysis, repair was associated with increased early (∼1-2 years) AI and increased outflow tract peak pressure gradients relative to Ross and AVR procedures. On univariate analysis, repairs tended to have a larger annulus size compared with Ross or AVR; however, this was not significant on multivariable analysis. There were 25 reinterventions (surgical reoperation = 16; transcatheter intervention = 9) for 22 children. Freedom from surgical reoperation was 64, 100 and 51% at 6 years for repairs, Ross and AVR, respectively (P = 0.05); however, three of five reoperations after AVR were for failed bioprosthetic devices. The freedom from reintervention was not significantly influenced by the type of AoV operation (P = 0.43). CONCLUSIONS Durability of aortic valve repair for children is limited by recurrence of AI and/or stenosis, often within the first few years. After repair, reoperation should be anticipated within ∼7 years.

Young Infants with Severe Tetralogy of Fallot: Early Primary Surgery versus Transcatheter Palliation

Background: Infants with severe tetralogy of Fallot may undergo (1) early primary surgical repair (EARLY) or (2) early transcatheter palliation (CATH) before delayed surgical repair. We compared these strategies with (3) elective single‐stage tetralogy of Fallot repair (IDEAL). Methods: From 2000 to 2012, 453 children underwent tetralogy of Fallot repair (excluding systemic‐pulmonary shunts), including 383 in the IDEAL (75%), 42 in the EARLY (9%), and 28 in the CATH (6%) groups. IDEAL repair at The Hospital for Sick Children occurs after 3 months. Risk‐adjusted hazard analysis compared freedom from surgical or catheter reintervention. Somatic size, branch pulmonary artery size, and right ventricle systolic pressure were modeled using 2780 echocardiogram reports via mixed‐model regression. Results: CATH involved right ventricular outflow tract stent in 18 patients, right ventricular outflow tract balloon in 9 patients, and ductal‐stent in 1 patient. Three patients died (1 per group). Risk‐adjusted freedom from surgical reoperation was 89% ± 4%, 88% ± 5%, and 85% ± 6% for the IDEAL, EARLY, and CATH groups, respectively, at 10 years. Patients in the EARLY and CATH groups had similar reoperation rates, except for neonates (<1 month), for whom EARLY repair conferred an increased risk of reoperation. Risk‐adjusted freedom from catheter reintervention was lower in the EARLY group (76%) and especially for the CATH group (53%) at 10 years versus the IDEAL group (83%). Somatic growth and progression of right ventricle systolic pressure were similar among groups at 8 years. Although those undergoing EARLY (P = .02) and CATH (P = .09) tend to have smaller branch pulmonary arteries initially, late pulmonary artery size was not significantly different among groups. Conclusions: Early primary repair for neonates may increase surgical reoperation, whereas transcatheter palliation comes at a cost of increased catheter reintervention. However, overall outcomes between groups, in terms of survival, growth, and hemodynamic parameters, were comparable, suggesting that both strategies are a reasonable option for children with severe tetralogy of Fallot.

Aggressive Patch Augmentation May Reduce Growth Potential of Hypoplastic Branch Pulmonary Arteries After Tetralogy of Fallot Repair

BACKGROUND Potential surgical strategies for hypoplastic branch pulmonary arteries (BPAs) during tetralogy of Fallot repair include (1) extensive patch augmentation to the hilum (PATCH), (2) limited extension arterioplasty to the proximal pulmonary artery (EXTENSION), or (3) leaving the native vessels unaugmented (NATIVE). We explored the effect of these strategies on reintervention and BPA growth. METHODS From 2000 to 2012, 434 children underwent complete tetralogy of Fallot repair. Risk-adjusted parametric models were used to analyze the risk of BPA reintervention for (1) all children, (2) children with BPAs of 4 mm or smaller, and (3) children with BPAs of 3 mm or smaller. Repeated-measures analysis of more than 2,000 echocardiograms was used to characterize postoperative BPA growth and right ventricular pressure by using nonlinear mixed models. RESULTS Overall survival (99% [3 deaths]) was excellent. The 10-year freedom from BPA reintervention was 84%. In risk-adjusted models (including baseline BPA z-score), PATCH had a decreased freedom from reintervention (73%; p < 0.01) vs EXTENSION (87%) or NATIVE (91%). For children with BPAs of 4 mm or smaller (28 PATCH, 60 EXTENSION, 75 NATIVE), baseline characteristics were similar. The risk-adjusted 5-year freedom from reintervention was 68% for PATCH, 76% for EXTENSION, and 85% for NATIVE. PATCH trended toward an increased risk of reintervention (p = 0.07). For children with BPAs of 4 mm or smaller left in their NATIVE state, only ∼15% required reintervention. After adjustment for baseline BPA z-score, the time-related BPA growth was decreased (p < 0.014) and right ventricular pressure was increased (p = 0.03) for the PATCH group. CONCLUSIONS Aggressive PATCH augmentation of hypoplastic BPAs improves the short-term geometry but may lead to late stenosis and higher rates of reintervention. Hypoplastic BPAs in tetralogy of Fallot tend (∼85%) to grow well without instrumentation.

Survival and right ventricular performance for matched children after stage-1 Norwood: Modified Blalock-Taussig shunt versus right-ventricle-to-pulmonary-artery conduit Read at the 95th Annual Meeting of the American Association for Thoracic Surgery, Seattle, Washington, April 25-29, 2015.

OBJECTIVE Early survival advantages after Norwood with right-ventricle-(RV)-to-pulmonary-artery conduit (NW-RVPA) over Norwood-operation with a Blalock-Taussig shunt (NW-BT) are offset by concerns regarding delayed RV dysfunction. We compared trends in survival, RV dysfunction, and tricuspid valve regurgitation (TR) between NW-RVPA and NW-BT for propensity-matched neonates with critical left ventricular outflow tract obstruction (LVOTO). METHODS In an inception cohort (2005-2014; 21 institutions), 454 neonates with critical LVOTO underwent Norwood stage 1. Propensity-score matching paired 169 NW-RVPA patients with 169 NW-BT patients. End-states were compared between NW-RVPA and NW-BT using competing-risks, multiphase, parametric, hazard analysis. Post-Norwood echocardiogram reports (n = 2993) were used to grade RV dysfunction and TR. Time-related prevalence of ≥moderate RV dysfunction and TR were characterized using nonlinear mixed-model regression, and compared between groups via multiphase, parametric models. RESULTS Overall 6-year survival was better after NW-RVPA (70%) versus NW-BT (55%; P < .001). Additionally, transplant-free survival during this time was better after NW-RVPA (64%) versus NW-BT (53%; P = .004). Overall prevalence of ≥moderate RV dysfunction reached 11% within 3 months post-Norwood. During this time, RV dysfunction after NW-BT was 16% versus 6% after NW-RVPA (P = .02), and coincided temporally with an increased early hazard for death. For survivors, late RV dysfunction was <5% and was not different between groups (P = .36). Overall prevalence of ≥moderate TR reached 13% at 2 years post-Norwood and was increased after NW-BT (16%) versus NW-RVPA (11%; P = .003). Late TR was similar between groups. CONCLUSIONS Among propensity-score-matched neonates with critical LVOTO, NW-RVPA offers superior 6-year survival with no greater prevalence of RV dysfunction or TR than conventional NW-BT operations.

Exercise restriction is not associated with increasing body mass index over time in patients with anomalous aortic origin of the coronary arteries

Anomalous aortic origin of the coronary arteries is associated with exercise-induced ischaemia, leading some physicians to restrict exercise in patients with this condition. We sought to determine whether exercise restriction was associated with increasing body mass index over time. From 1998 to 2015, 440 patients ⩽30 years old were enrolled into an inception cohort. Exercise-restriction status was documented in 143 patients. Using linear mixed model repeated-measures regression, factors associated with increasing body mass index z-score over time, including exercise restriction and surgical intervention as time-varying covariates, were investigated. The 143 patients attended 558 clinic visits for which exercise-restriction status was recorded. The mean number of clinic visits per patient was 4, and the median duration of follow-up was 1.7 years (interquartile range (IQR) 0.5-4.4). The median age at first clinic visit was 10.3 years (IQR 7.1-13.9), and 71% (101/143) were males. All patients were alive at their most recent follow-up. At the first clinic visit, 54% (78/143) were exercise restricted, and restriction status changed in 34% (48/143) during follow-up. The median baseline body mass index z-score was 0.2 (IQR 0.3-0.9). In repeated-measures analysis, neither time-related exercise restriction nor its interaction with time was associated with increasing body mass index z-score. Surgical intervention and its interaction with time were associated with decreasing body mass index z-score. Although exercise restriction was not associated with increasing body mass index over time, surgical intervention was associated with decreasing body mass index z-score over time in patients with anomalous aortic origin of the coronary arteries.

Survival and right ventricular performance for matched children after stage-1 Norwood

OBJECTIVE Early survival advantages after Norwood with right-ventricle-(RV)-to-pulmonary-artery conduit (NW-RVPA) over Norwood-operation with a Blalock-Taussig shunt (NW-BT) are offset by concerns regarding delayed RV dysfunction. We compared trends in survival, RV dysfunction, and tricuspid valve regurgitation (TR) between NW-RVPA and NW-BT for propensity-matched neonates with critical left ventricular outflow tract obstruction (LVOTO). METHODS In an inception cohort (2005-2014; 21 institutions), 454 neonates with critical LVOTO underwent Norwood stage 1. Propensity-score matching paired 169 NW-RVPA patients with 169 NW-BT patients. End-states were compared between NW-RVPA and NW-BT using competing-risks, multiphase, parametric, hazard analysis. Post-Norwood echocardiogram reports (n = 2993) were used to grade RV dysfunction and TR. Time-related prevalence of ≥moderate RV dysfunction and TR were characterized using nonlinear mixed-model regression, and compared between groups via multiphase, parametric models. RESULTS Overall 6-year survival was better after NW-RVPA (70%) versus NW-BT (55%; P < .001). Additionally, transplant-free survival during this time was better after NW-RVPA (64%) versus NW-BT (53%; P = .004). Overall prevalence of ≥moderate RV dysfunction reached 11% within 3 months post-Norwood. During this time, RV dysfunction after NW-BT was 16% versus 6% after NW-RVPA (P = .02), and coincided temporally with an increased early hazard for death. For survivors, late RV dysfunction was <5% and was not different between groups (P = .36). Overall prevalence of ≥moderate TR reached 13% at 2 years post-Norwood and was increased after NW-BT (16%) versus NW-RVPA (11%; P = .003). Late TR was similar between groups. CONCLUSIONS Among propensity-score-matched neonates with critical LVOTO, NW-RVPA offers superior 6-year survival with no greater prevalence of RV dysfunction or TR than conventional NW-BT operations.