Implant integration as seen in polished MMA microsections and scanning electron microscopy. Left panel from reference CE animal 16 weeks after implantation, right images from MAR animal. The coating meshes of both annuloplasty rings are fully penetrated by cells and connective tissue. The thicknesses of the layer seem to be larger in the reference. In b, the atrial ring is to the right, the ventricular part is not completely covered with newly formed tissue. d shows details of the sleeve integration. The insets in e and f show the complete endothelial coverage. Bars in a-d = 500 μm.