Pathological changes of vascular tissue after rabbit limb replantation with different methods of cryopreservation / 中国组织工程研究

ABSTRACT

BACKGROUND:The cryopreservation of single tissue has achieved great advancement and is gradual y applied in clinics. However, the cryopreservation of complex tissue is rarely reported. OBJECTIVE:To investigate the morphological change in rabbit limb tissue after replantation through different rewarming methods, find the best rewarming methods of compound textured blood vessels, and provide theoretical basis for the feasibility of limb replantation after long-term cryopreservation. METHODS:Thirty New Zealand white rabbits were randomly divided into control group, slow freezing-slow thawing group, and slow freezing-rapid thawing group. The right posterior limbs of al the rabbits were cut off 1 cm above the knee joint. Except control group, the latter two groups were given limb replantation after thawing, and then the right posterior limb was again cut off after the replanted limbs were survived for 6 hours. For al groups, the histological changes and gross observation in aorta tissue were observed by light microscopy and transmission electron microscope, and the results were analyzed with statistical methods. RESULTS AND CONCLUSION:In the slow freezing-slow thawing, slow freezing-rapid thawing groups, the pathological changes (gross specimen, light microscope, electron microscope) of rabbit limbs 6 hours after replantation were worse than those in control group. Compared with slow freezing-rapid thawing group, better integrity of endothelial cells and less damage of the organel es were found in slow freezing-slow thawing group. Through deep cryogenic freezing-thawing process, rabbit limb blood vessels can maintain the structural integrity after replantation and survived at 6 hours. Slow freezing-slow thawing is better than slow freezing-rapid thawing for the preservation of severed limbs, providing evidences for the long-term survival fol owing a deep cry ogenic treatment after the severed limb replantation.