SVR is a trial in which infants with a single ventricle heart defect undergoing surgery, were randomly assigned to one of two commonly placed shunts: right ventricular to pulmonary artery shunt (RVPA) vs. Modified Blalock-Taussig Shunt (MBTS).
Babies born with a single ventricle heart, require a series of operations to correct. The first operation, the Norwood procedure, involves placing a shunt to carry blood from the heart to the lungs. The study began on May 1, 2005 and the last infant was enrolled in June 2008 with 555 babies randomized.
Were randomized in this study
Participants were enrolled in this study from 2005-2008
Continued follow-up of patients in the study is very important to see if one shunt is better than the other in the long term
Babies with a single ventricle (lower pumping chamber) heart were in the study if a Norwood procedure was planned.
Each baby was randomly assigned to one of two groups, either the MBT shunt or the RV-to-PA shunt. Babies were followed until they reached 14 months of age, had an echocardiogram and a neurodevelopmental examination with optional genetic evaluation.
Babies who received the right ventricle-to-pulmonary artery shunt had better survival, although they might have needed more unplanned heart treatments than did those who received the modified Blalock-Taussig shunt. However, when the babies were followed for longer periods of time, there was no difference between the two groups. Continued follow-up of patients in the study is very important to see if one shunt is better than the other in the long term.
What we learned may or may not apply to a specific child. These findings are based on all 555 children who were randomized, and an individual child’s result may be different. Please contact your cardiologist if you would like to discuss these findings in more detail.
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In children with a single heart ventricle undergoing the Norwood procedure, a trial was conducted to determine if one of two different shunts resulted in better survival after 12 months without the need for a heart transplant. Babies were randomly assigned to receive either the traditional modified Blalock-Taussig shunt (MBTS) or the right ventricle- pulmonary artery (RV-PA) conduit. The study showed that babies who received the RV-PA conduit had better survival without needing a heart transplant 12 months after entering the study. However, when the babies were followed for a longer period of time, there was no difference between the two groups. The results also revealed that babies who received the RV-PA conduit needed more procedures and had more complications than those receiving the MBTS.
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The first of the three surgeries (the Norwood procedure) for babies born with a single heart ventricle is one of the highest risk procedures in congenital heart surgery. Two types of shunts (tubes) may be used for the first surgery: the traditional modified Blalock-Taussig shunt (MBTS) and the right ventricle to pulmonary artery (RV-PA) shunt. Some research has shown one technique to be better than the other, but other research has shown no differences in the outcomes for each technique. This article describes a trial designed by the Pediatric Heart Network to compare the two types of shunts. In the study, babies were randomly assigned to receive either the MBTS or the RV-PA shunt, and they were followed over time to compare the outcomes.
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Babies born with a single heart ventricle require multiple surgeries in order to provide adequate blood flow to the body. The first of the three surgeries is one of the highest risk procedures in congenital heart surgery. Two types of shunts (tubes) may be used for the first surgery: the traditional modified Blalock-Taussig shunt (MBTS) and the right ventricle to pulmonary artery (RV-PA) shunt. This article explains the advantages and disadvantages of each shunt and the Pediatric Heart Network’s clinical trial to determine if one shunt type is better than another in this population (see results of the PHN trial).
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We assessed whether left ventricular size and function influence right ventricular function and clinical outcomes after staged palliation for single right ventricle anomalies. In the Single Ventricle Reconstruction (SVR) trial cohort, we studied left ventricle size and function compared to echocardiography-derived measures of right ventricular size and function as well as tricuspid regurgitation. We also assessed the impact of the left ventricle on outcome (death and/or heart transplantation). The hypoplastic left heart syndrome subtype of aortic atresia/mitral atresia was less likely to have a measurable left ventricle compared to other subtypes. Right ventricle end-diastolic and end-systolic volumes were significantly larger, while diastolic indices suggested better properties in those subjects with no measurable left ventricle compared to those with measurable ventricles. Right ventricular ejection fraction and tricuspid regurgitation were not different based on left ventricle size and function. There was no difference between groups in transplantation-free survival up to 14 months of age. In patients with single right ventricle anomalies, left ventricular size and function has a minimal short-term impact on survival and right ventricular performance.
K. R. Wolfe, Pediatr Pulmonol. 2019 Jun;54(6):922-927.