Hypoxia does not occur during temporary storage of vein grafts in air-equilibrated solutions

Vein autografts are commonly stored temporarily in heparinized blood or electrolyte solution with contact to air. As O2 and CO2 may not diffuse freely through the vein wall, and the vein itself may consume O2 and produce CO2, the gas tensions may be different inside a closed vein, and might be expected to be different depending on whether blood or electrolyte solution is used as a storage medium. Closed segments of human saphenous vein, containing saline or blood were used to study whether hypoxia and/or hypercapnia develops during one hour of storage. Neither hypoxia nor hypercapnia was found and it could be calculated that neither would be expected even in collapsed veins. The highest number of endothelial cells with protrusion or craters (an expression of injury) were found in blood-stored veins. Our findings show that hypoxia is not a cause of endothelial cell injury during vein storage, and indicate that endothelial damage is more pronounced in blood-stored veins than in saline-stored veins.