["In situ" anesthetics and experimental cryotumorectomy]

Some similarities have been found between the actions of anesthetics and freezing on biological membranes. Therefore, it has been thought that these agents could potentiate the destructive effect of cryosurgery. Experiments on cryopreservation of HeLa cells in vitro using three anesthetics--thiopental sodium, lignocaïne and CT 1341--indicate enhancement of "cryosensitivity". When using in vivo the same anesthetics injected in an experimental carcinoma (KDMC) of the Sprague-Dawley rat, cryosurgically treated, the results are: --no tumoricidal effect nor antitumoral activity of these agents when used alone,--the simultaneous use of anesthetics and cryosurgery gives better (but no significant results than cryosurgery alone,--the best agent in regard to this possible adjuvant effect seems to be thiopental sodium, it also facilitates tumoral dissemination. The authors conclude from these preliminary results that they need further experiments to assess this findings with smaller tumors, more numerous animals, same and others anesthetics at different concentrations. They attempt to define some caracteristics of potentiative agents during physical phase of cryodestruction.