Modulation of tumor‐induced lethality after pneumoperitoneum in a mouse model

BACKGROUND To the authors' knowledge, a generally accepted approach to prevent increased intraabdominal tumor implantation after laparoscopic cancer surgery does not exist. METHODS One week after establishing an ovarian carcinoma cell line in black mice intraabdominally (n = 156), a carbon dioxide pneumoperitoneum (Group 1: n = 78) was administered. The effect of this procedure on tumor‐induced lethality and the therapeutic effect of mitoxantrone and taurolidin mixed with heparin and sodium chloride was investigated. The different drugs were added immediately after the release of the pneumoperitoneum and after 48 hours. The 78 control animals received the drugs at the same time without preexisting pneumoperitoneum. Survival time was registered. RESULTS The survival time was reduced significantly in all pneumoperitoneum groups compared with the corresponding control group without pneumoperitoneum. The effect of mitoxantrone on survival time (mean, 62.08 days) was diminished significantly by the application of a pneumoperitoneum (mean, 34.27 days). Taurolidine/heparin appeared to have a positive effect on survival time only in the case of a previous pneumoperitoneum (mean of 21.12 days vs. mean of 16.04 days in the pneumoperitoneum control group; P < 0.001). CONCLUSIONS The induction of a pneumoperitoneum appears to decrease survival time by increasing tumor cell growth and decreases the efficacy of intraperitoneal chemotherapy. The effects of pneumoperitoneum appear to be reduced by the use of heparin/taurolidine, which theoretically blocks extracellular matrix binding domains and inhibits the production of interleukin‐1. Cancer 2000;89:262–6. © 2000 American Cancer Society. The induction of a pneumoperitoneum decreases survival time by increasing tumor cell growth and decreases the efficacy of intraperitoneal chemotherapy. This effect appears to be reduced by the intraperitoneal use of heparin/taurolidine.