[Differences in properties of interstitial procedures and their effect on clinical applications]

The effects of percutaneous ethanol injection (PEI) and cryosurgery (CS) on normal liver tissue are investigated in a mini-pig model. It was not possible to create a circumscribed, reproducible necrosis by PEI; there was a high incidence of thromboembolic complications. Due to the discrepancy between the temperatures necessary to induce freezing and to induce total cell destruction, the necroses were smaller than the ice balls induced by CS and contained vital cells in their periphery. In conclusion, PEI should not be used when ethanol spreading into normal parenchyma has to be assumed, and the difference in size between ice ball and complete necrosis has to be considered in tumor treatment by CS.