Introduction
Significant atrioventricular valve (AVV) insufficiency, which has been reported in up to 37% of patients with single-ventricle [1,2], is one of the major drawbacks of the completion of Fontan circulation. Congestion in the atrium resulting from atrioventricular regurgitation should be reduced before and after completion of single-ventricle circulation. Valve repair is preferable for surgical intervention to the lesion, because valve and ventricle function can be preserved, and the risk of complications related to anticoagulant therapy after mechanical valve implantation might be reduced. Furthermore, an artificial valve frame fixes the AVV annulus without expected annulus growth after implantation, which results in the need for repeat artificial valve replacement depending on the body growth of the patient. Valve replacement is frequently associated with a moderately high mortality and various complications, including the need for permanent pacemaker implantation and repeat valve replacement [3]. However, valve replacement is often used as treatment for irreparable valve lesions.