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From: Proceedings 10th World Congress of Cryosurgery
Hepatic cryosurgery: experimental studies, Part I

November 1998
NN Korpan, LV Keysevich, JV Zharkov, G Hochwarter Vienna International Institute for Cryosurgery, Vienna, Austria; Scientific Research Institute of Experimental and Clinical Surgery, Kiev, Ukraine; Technological Research Company Puls, Kiev, Ukraine; Department of Surgery, SMZ-Ost Hospital, Vienna, Austria

Background: To achieve local destruction, fast freezing using liquid nitrogen is efficient.

Objective: To determine the morphologic changes in the animal liver parenchyma after applicability of different cryosurgical methods.

Study Design: In 54 mongrel dogs, the application of cryogenic probes to the liver was performed, with the use of cryosurgical unit, Cryoelectronic-2 and Cryoelectronic-4. Hepatic cryodestruction was performed by means of probes of roughly different disk design (5-mm - 55-mm) by volume of frozen zone of 40 cm3 to 180 cm3 approximately 5 to 30 minutes. Various temperatures from -50C to - I 90C were used. The thawing of freeze-thaw cycle took automatically approximately 2 to 3 minutes.

Results: It is detected, that immediately after cryodestruction, the intracellular and extracellular edema and diffuse hemorrhages were observed. In the vessels, the formation of erythrocytic thromboses takes place. The borderline between the hepatocytes was not detected. At Day 1, after the cryogenic destruction, multiple hemorrhages and hepatocytes with the phenomena of necrosis were seen in the specimens. At Day 7, the lesion represented fibrous cellular tissue containing a great number of fibroblasts which were at the different stages of maturation. The borderline between the connective tissue and liver parenchyma was clear enough. At Day 2 1, the site of cryodestruction was separated from the surrounding liver tissue by a layer of fibrous tissue, and between the granular tissue and the destructed tissue which was found in the center of the lesion, there was a clear borderline. The mentioned changes and areas in the site of cryodestruction were being formed independently of the temperature for freezing of tissue. Conclusion: Such a procedure provides a sufficient destruction of tissue with a good demarcation and almost no bloodloss. The size and depth of the cryonecrosis and the time of first formation depended on the different temperatures.

 


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