Systemic effects and side effects of interstitial techniques used in livertissue

Background: Percutaneous ethanol injection (PEI) and cryosurgery are increa singly used for the treatment of liver malignancies. To create a safety mar gin and to destroy completely diffusely growing tumors, the precise destruc tion of healthy liver tissue is necessary. Little is known about the effect s of operating on this type of tissue. This study evaluated the effects and side effects of PEI and cryosurgery when applied to normal parenchyma of t he liver. Study Design: Two groups of six minipigs each were treated with either PEI or cryosurgery to create necrosis in the liver. During and after the proced ures, vital signs were monitored and necrotic areas were observed by ultras onography. Standard and immunohistochemistry stains were made from samples of the necrosis, the liver, and the lung. Results: In the PEI group, thromboembolic complications occurred in all ani mals (fatality rate 50%). Hematogenous spread of hepatocytes was demonstrat ed by immunohistochemistry and was a cause of pulmonary embolism. In the cr yosurgery group, neither specific complications nor signs of cell spillage occurred. Because of an isolating effect of blood perfusion, hepatocytes cl ose to the portal triads were less damaged, vital cells were present in the periphery, and the necroses were smaller than the induced lesions. Conclusions: The effect of PEI in healthy liver tissue is unpredictable. Th is makes the creation of a safety margin or the treatment of a diffusely in filtrating tumor impossible. PEI always introduces the risk of hematogenous cell spread. Effects of cryosurgery are less dependent on tissue qualities . In both techniques, the real extent of complete tissue destruction cannot be visualized by ultrasonography. (J Am Coil Surg 1999;188: 636-642. (C) 1 999 by the American College of Surgeons).