RELATIONSHIPS BETWEEN THE DIMENSIONS OF THE HUMAN AORTIC AND PULMONARY VALVE LEAFLETS - IMPLICATIONS ON ROSS OPERATION

The technique of replacing the aortic valve with the patient's pulmona ry valve and the implantation of a homograft in the pulmonary position was first introduced by D. Ross in 1967. Despite the many advantages and successes of this procedure, it frequently results in some degree of valve insufficiency. In order to optimize the results of Ross' oper ation, we carried out a comparative study (n=22) of the relative dimen sions of the human aortic and pulmonary valve leaflets using a digitiz er, The digitizer supplies the spatial coordinates of a given point (i n a pre-chosen reference frame), by the positioning of its sensor on t hat point. By digitizing relevant points marked on the arterial wall w e were able to calculate the distance between the commissures and the perimeter of each leaflet. Analysing the values thus obtained, we foun d that in 17 of the 22 cases studied (77.3%) there was one orientation (out of the three anatomically possible orientations) of the pulmonar y valve, relative to the configuration of the recipient aortic root, t hat was clearly better than the other two. This study led to the formu lation of a ''rule'' that, in most of the cases studied (86.4%), led t o the best fitting orientation of the autograft using the knowledge of the intercommissural distances.