Midterm ventricular performance after Norwood procedure with right ventricular-pulmonary artery conduit

Abstract

Background: Midterm and long-term results of patients who underwent a Norwood procedure with a right ventricular-pulmonary artery conduit remain unclear. This study aimed to compare the midterm ventricular performance of the Norwood procedure with right ventricular-pulmonary artery conduit and the Norwood procedure with systemic-pulmonary shunt.

Methods: Twenty-one patients who underwent both a bidirectional Glenn procedure and a total cavopulmonary connection after Norwood palliation at Fukuoka Children's Hospital Medical Center were divided into two groups: the systemic-pulmonary shunt group (n = 11) and the right ventricular-pulmonary artery conduit group (n = 10). End-systolic elastance (contractility), effective arterial elastance (afterload), and ventriculoarterial coupling and the ratio of stroke work and pressure-volume area (ventricular efficiency) were measured on the basis of cardiac catheterization data before the bidirectional Glenn procedure, before and after the total cavopulmonary connection, and at approximately 1 year after total cavopulmonary connection.

Results: After bidirectional Glenn procedure and total cavopulmonary connection, end-systolic elastance of the right ventricular-pulmonary artery conduit group was lower than that of the systemic-pulmonary shunt group, whereas effective arterial elastance of the right ventricular-pulmonary artery conduit group was lower than that of the systemic-pulmonary shunt group. Consequently, there was no difference in ventricular efficiency in both groups 1 year after total cavopulmonary connection.

Conclusions: The midterm ventricular performance of the right ventricular-pulmonary artery conduit group was comparable with the systemic-pulmonary shunt group in terms of ventricular efficiency. However, after bidirectional Glenn procedure and total cavopulmonary connection, contractility in patients who underwent a Norwood procedure with a right ventricular-pulmonary artery conduit was inferior to that of patients who underwent a Norwood procedure with a systemic-pulmonary shunt.