Open versus laparoscopic surgery: a comparison of natural antitumoral cellular immunity in a small animal model.

The scope of laparoscopic surgery has extended to the treatment of cancer. The immunological impact of laparoscopic surgery as compared with open surgery has not been well characterized. A paucity of information is available about differences or similarities of these two methods regarding natural antitumoral cellular immunity, namely, natural killer cell cytotoxicity. This study compared the activity of natural killer cells in rats subjected to pneumoperitoneum, open dissection of the retroperitoneum, and laparoscopic dissection of the retroperitoneum. When compared to control animals, rats subjected to pneumoperitoneum did not show any change in natural killer cell activity. Conversely, the groups of open surgery and laparoscopic surgery revealed significantly decreased natural killer cell cytotoxicity compared with controls (P < 0.0167). When the laparoscopic and the open surgical groups were compared to each other, no difference was found. In this study, both open and laparoscopic surgery had a suppressive effect upon the natural antitumoral cellular immunity. Pneumoperitoneum did not have an immune suppressive effect on natural killer cell activity. In this model, the advantages of laparoscopic surgery do not apply to natural antitumoral cellular immunity.