Fractures in Cryopreserved Arteries

The common carotid artery of the rabbit, a typical small elastic artery, can be cryopreserved using dimethyl sulfoxide, slow cooling, storage at less than -160°C, and rapid warming. This technique provides satisfactory preservation of muscle and endothelial cells, but in about 75% of cases, gross circumferential fractures occur in the vessel wall. This paper investigates the influence of vehicle solution composition, cryoprotectant concentration, cooling rate, and storage temperature on the occurrence of cracks. When cooling was halted at -80°C and the arteries were stored at this temperature, fractures no longer occurred. Possible mechanisms are discussed and it is proposed that mechanical stresses develop in the vitreous material that separates the ice crystals and lead to structural failure.