Laparoscopic surgery: the effects of insufflation gas on tumor-induced lethality in nude mice.
OBJECTIVE: The aim of the study was to examine the effect of helium (group 2), carbon dioxide (group 3), and heated carbon dioxide (group 4) pneumoperitoneum on survival in case of intraabdominal spread of tumor cells in nude mice. STUDY DESIGN: The pneumoperitoneum was induced by a microhysteroflator with an intraperitoneal pressure of 8 mm Hg for 30 minutes. A washed tumor solution (0.4 ml) of a mesothelioma was injected intraperitoneally. RESULTS: The survival rate of group 3 was significantly reduced compared with the controls (group 1) and group 4. The latter groups showed similar survival rates. In groups 2 and 3 no significant differences in survival rate were observed. CONCLUSION: Clinical observations and the results of this animal study warn against the use of standard unheated carbon dioxide pneumoperitoneum in case of malignant tumors. Heated carbon dioxide seems to be advantageous.