Single Ventricle Reconstruction (SVR)

(RV-PA Shunt vs MBT Shunt Trial)

Study Summary

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.

555 Children

Were randomized in this study

3 Years

Participants were enrolled in this study from 2005-2008

Long-term follow-up

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

Who was in the study?

Babies with a single ventricle (lower pumping chamber) heart were in the study if a Norwood procedure was planned.

What happened during the study?

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.

What were the results of the study?

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.

Study Publications

  • Comparison of Shunt Types in the Norwood Procedure for Single-Ventricle Lesions

    R. Ohye, N Engl J Med 2010; 362(21):1980-1992.

    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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  • Design and Rationale of a Randomized Trial Comparing the Blalock-Taussig and Right Ventricle-Pulmonary Artery Shunts in the Norwood Procedure

    R. Ohye, J Thorac Cardiovasc Surg 2008; 136:968-975.

    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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  • The Modified Blalock-Taussig Shunt Versus the Right Ventricle-to-Pulmonary Artery Conduit for the Norwood Procedure

    R. Ohye, Pediatr Cardiol 2007; 28:122-125.

    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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  • Prenatal Diagnosis and Risk Factors for Preoperative Death in Neonates with Single Right Ventricle and Systemic Outflow Obstruction: Screening Data from the Pediatric Heart Network Single Ventricle Reconstruction Trial

    A. Atz, J Thorac Cardiovasc Surg 2010; 140:1245-1250.

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  • Celiac Artery Flow Pattern in Infants with Single Right Ventricle Following the Norwood Procedure with a Modified Blalock-Taussig or Right Ventricle to Pulmonary Artery Shunt

    J. Johnson, Pediatr Cardiol 2011; 32:479-486.

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  • Reporting adverse events in a surgical trial for complex congenital heart disease: The Pediatric Heart Network Experience

    L. Virzi, J Thorac Cardiovasc Surg 2011; 142(3): 531-537.

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  • Early neurodevelopmental outcome in hypoplastic left heart syndrome and related anomalies: The Single Ventricle Reconstruction Trial

    J. Newburger, Circulation 2012; 125:2081-2091.

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  • Intermediate-term mortality and cardiac transplantation in infants with single-ventricle lesions: Risk factors and their interaction with shunt type

    J. Tweddell, J Thorac Cardiovasc Surg 2012; 144(1):152-159.e2.

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  • Does initial shunt type for the Norwood procedure affect echocardiographic measures of cardiac size and function during infancy? The Single Ventricle Reconstruction Trial

    P. Frommelt, Circulation 2012; 125:2630-2638.

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  • Variation in perioperative care across centers for infants undergoing the Norwood procedure

    S. Pasquali, J Thorac Cardiovasc Surg 2012; 144:915-21.

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  • Risk factors for hospital morbidity and mortality after the Norwood procedure: A report from the Pediatric Heart Network Single Ventricle Reconstruction Trial

    S. Tabbutt, J Thorac Cardiovasc Surg 2012; 144:882-95.

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  • Interstage mortality after the Norwood Procedure: Results of the multicenter Single Ventricle Reconstruction Trial

    N. Ghanayem, J Thorac Cardiovasc Surg 2012; 144:896-906.

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  • Cause, timing and location of death in the Single Ventricle Reconstruction trial

    R. Ohye, J Thorac Cardiovasc Surg 2012; 144:907-14.

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  • Introduction to the Single Ventricle Reconstruction trial

    E. Bacha, J Thorac Cardiovasc Surg 2012; 144(4): 880-1.

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  • A Predictive Model for Neurodevelopmental Outcome Following the Norwood Procedure

    W. Mahle, Pediatr Cardiol 2013; 34(2):327-333.

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  • Doppler flow patterns in the right ventricle-to-pulmonary artery shunt and neo-aorta in infants with single right ventricle anomalies – Impact on outcome after initial staged palliations

    P. Frommelt, J Am Soc Echocardiogr 2013; 26:521-9.

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  • Intervention for re-coarctation in the Single Ventricle Reconstruction Trial: Incidence, risk and outcomes

    K. Hill, Circulation 2013; 128(9): 10.1161/CIRCULATIONAHA.112.000488.

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  • A multi-center study comparing shunt type in the Norwood procedure for single-ventricle lesions: 3-Dimensional echocardiographic analysis

    G. Marx, Circ Cardiovasc Imaging 2013; 6(6): 934–942.

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  • Risk factors for prolonged length of stay following stage 2 procedure in the Single-Ventricle Reconstruction Trial

    S. Schwartz, J Thorac Cardiovasc Surg 2014; 147(6):1791-8, 1798.e1-4.

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  • Variation in Feeding Practices Following the Norwood Procedure

    L. Lambert, J Pediatr 2014; 164(2): 237–242.e1.

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  • Technical performance score is associated with outcomes after the Norwood procedure

    M. Nathan, J Thorac Cardiovasc Surg. 2014 Nov;148(5):2208-13, 2214.e1-6.

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  • Impact of pre-stage II hemodynamics and pulmonary artery anatomy on 12-month outcome in the Single Ventricle Reconstruction Trial

    R. Aiyagari, J Thorac Cardiovasc Surg 2014; 148(4):1467-74

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  • Associations Between Day of Admission and Day of Surgery on Outcome and Resource Utilization in Infants With Hypoplastic Left Heart Syndrome Who Underwent Stage I Palliation (from the Single Ventricle Reconstruction Trial)

    J. Johnson, Am J Cardiol 2015; 116(8):1263-9.

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  • Impact of Initial Norwood Shunt Type on Right Ventricular Deformation: The Single Ventricle Reconstruction Trial

    G. D. Hill, J Am Soc Echocardiogr. 2015 May; 28(5): 517–521.

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  • The Single Ventricle Reconstruction Trial: The data goes public

    S. Bradley, J Thorac Cardiovasc Surg 2016; 152(1):195-6.

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  • Heart block following stage 1 palliation of hypoplastic left heart syndrome

    D. Mah, J Thorac Cardiovasc Surg 2016; 152(1):189-94.

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  • Intraoperative Steroid Use and Outcomes Following the Norwood Procedure: An Analysis of the Pediatric Heart Network’s Public Database

    J. Elhoff, Pediatr. Crit. Care Med 2016; 17(1):30-5.

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  • Association of Digoxin With Interstage Mortality: Results From the Pediatric Heart Network Single Ventricle Reconstruction Trial Public Use Dataset

    M. Oster, J Am Heart Assoc 2016; 13;5(1). pii: e002566.

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  • Impact of Operative and Postoperative Factors on Neurodevelopmental Outcomes After Cardiac Operations

    International Cardiac Collaborative on Neurodevelopmental (ICCON) Investigators. Ann Thorac Surg. 2016; 102(3):843-849.

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  • Outcomes and risk factors for listing for heart transplantation after the Norwood procedure: An analysis of the Single Ventricle Reconstruction Trial

    A. Kulkarni. J Heart Lung Transplant. 2016 Mar;35(3):306-311.

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  • Impact of postoperative complications on hospital costs following the Norwood operation

    K. E. McHugh. Cardiol Young. 2016 Oct;26(7):1303-9.

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  • Adrenergic receptor genotypes influence postoperative outcomes in infants in the Single-Ventricle Reconstruction Trial

    R. Ramroop, J Thorac Cardiovasc Surg. 2017; 154(5):1703-1710.e3.

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  • Development and impact of arrhythmias after the Norwood procedure: A report from the Pediatric Heart Network

    M.E. Oster, J Thorac Cardiovasc Surg 2017 Mar;153(3):638-645.e2.

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  • Encrypted prediction: A hacker’s perspective

    T. Karamlou, J Thorac Cardiovasc Surg 2017 Dec;154(6): 2038-2040.

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  • A prognostic tool to predict outcomes in children undergoing the Norwood operation

    P. Gupta, J Thorac Cardiovasc Surg 2017 Dec;154(6):2030-2037.e2.

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  • The optimal timing of Stage-2-Palliation for Hypoplastic Left Heart Syndrome: An analysis of the Pediatric Heart Network Single Ventricle Reconstruction Trial public dataset

    J. M. Meza, Circulation. 2017 Oct 31; 136(18): 1737–1748.

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  • Cost Variation Across Centers for the Norwood Operation

    K. E. McHugh, Ann Thorac Surg. 2018 Mar; 105(3): 851–856.

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  • Survival to Stage II with Ventricular Dysfunction: Secondary Analysis of the Single Ventricle Reconstruction Trial

    E. Jean-St-Michel, Pediatr Cardiol 2018 Jun;39(5):955-966.

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  • The Impact of the Left Ventricle on Right Ventricular Function and Clinical Outcomes in Infants with Single-Right Ventricle Anomalies up to 14 Months of Age

    M.S. Cohen, J Am Soc Echocardiogr. 2018 Jul 3. pii: S0894-7317(18)30249-9.

    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.

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  • Oxygen saturations and neurodevelopmental outcomes in single ventricle heart disease

    K. R. Wolfe, Pediatr Pulmonol. 2019 Jun;54(6):922-927.

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