Lines between center points of Voronoi 3D cells

Hi all!

I want to create tetrahedrons based on Voronoi 3D cells. So the idea is to connect the center points of Voronoi 3D cells which have an area in common. I got the surfaces which two Voronoi cells have in common, but does somebody know how to connect the center points of the cells which share an area?

Thanks a lot in advance!

Simone