The behavior of residual pulmonary artery gradient after arterial switch operation: A longitudinal data analysis.

OBJECTIVE: The arterial switch operation (ASO) is the standard treatment for the transposition of the great arteries. The timely variation in the residual pressure gradient across the pulmonary arteries is ill-defined. This study is aimed to study the progressive changes in the pressure gradient across the pulmonary valve and pulmonary arteries after ASO. METHODS: All eligible patients for this study who underwent ASO between 2000 and 2019 were reviewed. Transthoracic echocardiography was used to estimate the peak pressure gradient across the pulmonary artery and its branches. The primary outcome was the total peak pressure gradient (TPG) which is the sum of peak pressure gradients across the main pulmonary artery and pulmonary artery branches. Furthermore, longitudinal data analyses with mixed-effect modeling were used to determine the independent predictors for the changes in the pressure gradient. RESULTS: Three hundred and nine patients were included in the study. Over a 17-year follow-up, the freedom from pulmonary stenosis reintervention was 95% (16 out of the 309 patients underwent reintervention = 5%). The longitudinal data analyses of serial 1844 echocardiographic studies for the included patients revealed that the TPG recorded in the first postoperative echocardiogram across pulmonary valve, right and left pulmonary artery branches was the most significant predictor for reintervention. CONCLUSION: The total peak gradient measured in the first postoperative echocardiogram is the most important predictor for reintervention. We propose that a total peak gradient in the first postoperative echocardiography of 55 mm Hg or more is a predictor for reintervention.

Effects of pulmonary artery banding in doxorubicin-induced left ventricular cardiomyopathy.

OBJECTIVE: Central pulmonary banding has been proposed as a novel alternative for the treatment of left ventricular dilated cardiomyopathy in children. We sought to investigate the effects of central pulmonary banding in an experimental model of doxorubicin-induced left ventricular dilated cardiomyopathy. METHODS: Four-month-old sheep (n = 28) were treated with intermittent intracoronary injections of doxorubicin (0.75 mg/kg/dose) into the left main coronary artery. A total dose of up to 2.15 mg/kg of doxorubicin was administered until signs of left ventricular dilation with functional impairment occurred by transthoracic echocardiography evaluation. Animals that survived were treated with surgical central pulmonary banding through a left anterior thoracotomy or sham surgery. Transthoracic echocardiography and pressure-volume loop measurements were used to compare left ventricular function preoperatively and 3 months later. Macroscopic and microscopic histologic examinations followed after hearts were harvested. RESULTS: Nine animals from the central pulmonary banding group and 8 animals from the sham group survived and were included in the final analysis. Both groups showed similar inflammation and fibrosis upon histologic examination consistent with the toxic myocardial effects of doxorubicin. There were no differences in the echocardiographic measurements before central pulmonary banding or sham operation. Baseline measurements before the central pulmonary banding/sham operation were considered as 100%. The central pulmonary banding group had better left ventricular ejection fraction (102.5% ± 21.6% vs 76.7% ± 11.7%, P = .01), with a tendency for smaller left ventricular end-diastolic (101.2% ± 7.4% vs 120.4% ± 10.8%, P = .18) and significantly smaller end-systolic (100.3% ± 12.9% vs 116.5 ± 9.6%, P = .02) diameter of the left ventricle in comparison with the sham animals at 3 months. The end-systolic volume (101.4% ± 31.6% vs 143.4% ± 28.6%, P = .02) was significantly lower in the central pulmonary banding group 3 months postoperatively. Fractional shortening in the long axis (118.5% ± 21.5% vs 85.2% ± 22.8%, P = .016) and short axis (122.5% ± 18% vs 80.9% ± 13.6%, P = .0005) revealed significantly higher values in the central pulmonary banding group. In the conductance catheter measurements, no significant differences were seen between the groups for the parameters of systolic and diastolic function. CONCLUSIONS: Central pulmonary artery banding in the setting of experimental toxic left ventricular dilated cardiomyopathy improved left ventricular echocardiographic function and dimensions.

Hybrid therapy for hypoplastic left heart syndrome: Myth, alternative, or standard?

OBJECTIVE: This retrospective study presents our operative results, mortality, and morbidity with regard to pulmonary artery growth and reinterventions on the pulmonary artery and aortic arch, including key features of our institutional standards for the 3-stage hybrid palliation of patients with hypoplastic left heart syndrome. METHODS: Between June 1998 and February 2015, 182 patients with hypoplastic left heart structures underwent the Giessen hybrid stage I procedure. Among these, 126 patients with hypoplastic left heart syndrome who received a univentricular palliation or heart transplantation were included in the main analysis. Median age and body weight of patients at hybrid stage I were 6 days (0-237) and 3.2 kg (1.2-7), respectively. Comprehensive stage II operation was performed at 4.5 months (2.9-39.5), and Fontan completion was established at 33.7 months (21.1-108.2). Operative and interstage mortality, morbidity, growth and reinterventions on the pulmonary arteries, and long-term operative results of the aortic arch reconstruction were assessed. RESULTS: Median follow-up time after Giessen hybrid stage I palliation was 4.6 years (0-16.8). Operative mortality at hybrid stage I, comprehensive stage II, and Fontan completion was 2.5%, 4.9%, and 0%, respectively. Cumulative interstage mortality was 14.2%. At 10 years, the probability of survival is 77.8%. Body weight (<2.5 kg) and aortic atresia had no significant impact on survival. McGoon ratio did not differ at comprehensive stage II and Fontan completion (P = .991). Freedom from pulmonary artery intervention was estimated to be 32.2% at 10 years. Aortic arch reinterventions were needed in 16.7% of patients; 2 reoperations on the aortic arch were necessary. CONCLUSIONS: In view of the early results and long-term outcome, the hybrid approach has become an alternative to the conventional strategy to treat neonates with hypoplastic left heart syndrome and variants. Further refinements are warranted to decrease patient morbidity.

Long-term results of biventricular repair after initial Giessen hybrid approach for hypoplastic left heart variants.

OBJECTIVE: This article presents the long-term results of our patients with a diagnosis of hypoplastic left heart syndrome (HLHS), hypoplastic left heart complex (HLHC), and variants who received a biventricular repair following hybrid stage I with ductal stenting and bilateral pulmonary artery banding. METHODS: Between June 1998 and June 2013, a total of 154 patients with hypoplastic left heart structures underwent a hybrid stage I procedure. Forty patients were definitely treated by creating a biventricular circulation. Median age and body weight of patients before hybrid stage I were 8.5 days (2-40) and 3.0 kg (1.6-3.8), respectively. The diagnoses were HLHS with mitral and aortic stenosis (n = 7), HLHC (n = 15), HLHC with interrupted aortic arch (n = 9), critical aortic stenosis with hypoplastic aortic arch (n = 4), imbalanced atrioventricular septal defect with hypoplastic aortic arch (n = 2), double-outlet right ventricle with hypoplastic aortic arch (n = 2), and d-transposition of the great arteries with interrupted aortic arch (n = 1). Median age at the time of biventricular correction was 6.7 months (1.6-13.8). The patients were treated with direct biventricular correction, including repair of intracardiac defects (n = 32), Norwood/Rastelli or Yasui (n = 4), arterial switch (n = 2), Rastelli (n = 1), and Ross-Konno (n = 1) operations with ascending aortic/aortic arch reconstruction. RESULTS: All patients survived hybrid stage I. Median survival after biventricular correction is 7.9 years (0.9-14.9). Overall mortality was 10% (4 patients) at 4 weeks, 5 weeks, 6 weeks, and 4 months after biventricular correction, respectively. One patient had to be switched to univentricular circulation and another patient underwent orthotopic heart transplantation 3 and 4 months after biventricular correction, respectively. CONCLUSIONS: The Giessen hybrid approach is an alternative to the conventional strategy to treat neonates with HLHS, HLHC, and variants. Biventricular repair after hybrid stage I is feasible and can be performed with satisfactory long-term survival.