Chronographic microscopic study of healing processes after cryosurgery on rabbit’s liver

Cryosurgery is an accepted method for treatment of various lesions. Cryoablation produces rapid freezing of tissues, which leads to cell death due to ice crystallization, desiccation, ischemia, and reperfusion injury during thawing. The beneficial effect of cryocycling, however, has not been universally accepted. In the present study, which was conducted on rabbits, we investigated healing processes after inducing injury by pulse cryocycling on normal liver tissue in vivo. The study was performed on 12 male Dutch rabbits (Oryctolagus cuniculus). A 20-mm diameter contacting probe was used to freeze parietal surface of the liver until the extending of ice ball was visible at the opposite visceral surface. After thawing, the probe was put on the same place and frozen again with equal duration of time as the first. The liver was returned to its normal location in the body and the abdominal and skin incisions were sutured. To evaluate liver injury and regeneration, injured and adjacent healthy tissues were harvested 1, 6 and 24 h, and 3,7,14 days after operation. Pieces of liver tissue were prepared for light microscopy. Connective tissue had completely separated the injured and healthy areas. Abundant capillaries and some new generated basophilic hepatocytes were seen around the central vein after 14 days post operation. Creation of granulation tissue and some regenerated hepatocytes with basophilic cytoplasm, in the 14th day of post operation period, shows ability of the surrounding cells to regenerate the normal tissue. © 2014, Springer-Verlag London.