Selective Use of the Blalock-Taussig Shunt and Right Ventricle-to-Pulmonary Artery Conduit During the Norwood Procedure

BACKGROUND: The single ventricle reconstruction trial showed better one-year transplant-free survival for the right ventricle-to-pulmonary artery (RV-to-PA) conduit over the modified Blalock-Taussig shunt (mBTS) at Norwood operation. However, concerns remain about the long-term effects of a neonatal ventriculotomy. In our institution, we have used specific selection criteria for the use of mBTS in the Norwood operation.

METHODS: We reviewed 122 consecutive neonates undergoing the Norwood procedure from December 2006 to December 2013. We used the following criteria to select our source of pulmonary blood flow: (1) presence of a dominant morphologic left ventricle; (2) presence of antegrade blood in an ascending aorta that is greater than 3 mm; and (3) presence of significant large "crossing coronaries" on ventricle. All patients who met any of the above 3 criteria underwent an mBTS while the remaining patients underwent an RV-to-PA conduit.

RESULTS: Seventy-five (61.5%) patients had the RV-to-PA conduit and 47 (38.5%) patients had an mBTS. The overall surgical mortality was 9%. Mean follow-up interval was 23.5 months. Actuarial transplant-free survival was similar at 12, 24, 36, and 48 months in both the mBTS group and the RV-to-PA conduit group. In the RV-to-PA conduit group, actuarial transplant-free survival was 73% at 12 months, 71% at 24 months, 71% at 36 months, and 67% at 48 months, while in the mBTS group, actuarial transplant-free survival was 82% at 12 months, 75% at 24 months, 75% at 36 months, and 75% at 48 months.

CONCLUSION: Our selection criteria for mBTS have allowed us to obtain equivalent transplant-free survival at 12, 24, 36, and 48 months when compared to the RV-to-PA conduit group.