Morphometric study of the pulmonary trunk: implications for a new approach of the Ross procedure.

A pulmonary valve autograft may be proposed to replace diseased aortic valves. The explanted pulmonary valve is replaced with a pulmonary homograft with the inherent risk of calcified degeneration. A monocusp valve using the anterior pulmonary trunk has been proposed to reconstruct the right ventricular outflow tract. The aim of this study was to determine the feasibility of this technique. In hearts from 17 adult cadavers, we measured: pulmonary trunk diameter at the leaflet tops (D1). H1 and H2 were respectively from leaflet top to lower and upper levels of the pulmonary trunk bifurcation. D2 = 1.4 D1 was calculated as the monocusp size allowing a 45 degrees opening of the valve and thus permitting good valvular efficacy. G = H1 - D2 determined the feasibility of the technique: G greater than 10 mm, appeared the most favorable, G between 0 and 10 mm, appeared possible, and G less than 0, appeared to be impossible. Mean values of D1, H1 and H2 were respectively: 20.19 mm, 37 mm and 57 mm. The technique was possible in 16 cases (94%) and impossible in 1 case (6%). Preoperative determination of these parameters, by echocardiography or magnetic resonance imaging, appears necessary before applying this new surgical technique.