Functional biventricular repair using left ventricle-pulmonary artery conduit in patients with discordant atrioventricular connections and pulmonary outflow tract obstruction-does conduit obstruction maintain tricuspid valve function?

Abstract

The aim of the study is to determine whether function of the tricuspid valve placed for the systemic circulation is related to left ventricular pressure supporting the pulmonary circulation after functional repair for atrioventricular discordance. Right ventricular volume and tricuspid regurgitation (TR) were investigated, in relation to left ventricular pressure, in 15 patients with this malformation who underwent functional biventricular repair with left ventricle-pulmonary artery conduit. After the functional biventricular repair, ratio of systolic left ventricular pressure to right ventricular one (LVP/RVP) was 0.58+/-0.24 and right ventricular end-diastolic pressure (RVEDV) significantly increased from 104+/-24 to 137+/-39% of normal predicted value (P = 0.015). Five patients with LVP/RVP>0.6 were free from TR, however, six of seven with LVP/RVP<0.6 developed TR. Three patients required eventual tricupid valve replacement. Conduit replacement was required in seven patients and five were assessed similarly. After the conduit replacement, LVP/RVP decreased from 1.08+/-0.34 to 0.58+/-0.14 and RVEDV increased significantly from 87+/-24 to 129+/-19% (P = 0.011). One patient with postoperative LVP/RVP of 0.36 developed moderate TR. Mild obstruction at the pulmonary channel is not necessarily an evil after functional biventricular repair for this malformation, in terms of TR and right ventricular dilatation.