[Preservation of venous grafts]

The objective of the work was to find an optimal preservation medium for short-term preservation of venous grafts which could be subsequently used to line metal stents. The external jugular vein of dogs (n = 15) was removed surgically, divided into portions and immersed into preservation media. For hypothermic preservation (+4 degrees C) solutions of Optisol (Chiron, USA), University of Wisconsin (Baxter, USA), Eurocollins (Fresenius, GFR) and saline (Bieffe Medital, Italy) were used. For normothermic preservation (+37 degrees C) in an atmosphere with 5% CO2 Dulbecc's medium for tissue cultures (Sigma, USA) was used. During hypothermic preservation the specimens were kept for 24 hours, 3 and 7 days, during normothermic preservation in Dulbecc s medium also for 24 hours, 3 and 7 days. The specimens were evaluated by light microscopy and raster electron microscopy. The results revealed that minimal changes on the endothelia of venous grafts occurred during normothermic preservation in Dulbecc's medium where after 7 days the endothelium did not become detached and the vitality of cells did not change. During hypothermic preservation the solution of Wisconsin University proved most suitable. By addition of 5% human albumin to this solution it proved possible moreover to reduce pyknosis of the endothelial cell nuclei. The specimens kept in saline displayed deformities of the nuclei, oedema and loss of endothelia incl. incipient oedema of the cellular wall already after 24 hours of hypothermic preservation. The authors consider the use of this solution unsuitable for preservation.