An experimental study on transannular patching of the right ventricular outflow tract with and without a pulmonary valve monocusp mechanism.

The efficacy of a pericardial patch in the right ventricular outflow tract (RVOT) with a monocusp valve mechanism was investigated experimentally. Hemodynamic performance of the right ventricle and angiographic competence of the valve were compared in animals after patching of the RVOT and removal of the pulmonary valve (group I), patching of the RVOT, removal of the pulmonary valve and implantation of a monocusp valve (group II), patching of the RVOT, partial removal of the pulmonary valve and implantation of a monocusp valve (group III) and a control group (IV). Postoperative effective right ventricular cardiac index, stroke volume and stroke work improved significantly from group I to III, but did not reach the control values of group IV. Angiographically the monocusp valve allowed some early diastolic regurgitation due to late closure (group II) if it was not supported by remnants of the animal's own pulmonary valve (group III).