Conservation of veins with preservation of viable endothelium.

The influence of cryoprotective agents on the endothelium of jugular veins of dogs was examined after silver staining on en face preparations. Comparatively low concentrations of Glycerol or DMSO caused distinct morphological changes. Quick-freezing of air-filled vessels by liquid nitrogen permitted reservation of vessels with vital endothelium and comparatively mild morphological changes. Such vessels could be replanted after quick thawing. 2-4 days thereafter the endothelium of the grafts contained nuclei stainable with hematoxilin. The area covered by this endothelium remained devoid of parietal thrombi 2-4 days after replantation. However, lyophilized vessels grafted under the same conditions, were covered by large mural thrombi 2-4 days after the grafting procedure and no endothelial cells were found histologically.