[Effect of CO2 pneumoperitoneum on intraperitoneal tumor growth in the animal model]

Clinical observations during recent years describe the increased occurrence of rapid intraperitoneal metastases and an impairment of prognosis if a malignant tumour was operated laparoscopically. It is not known whether the observed induction of intraabdominal metastases after laparoscopic surgery in the result of an inadequate surgical procedure with spillage of tumour cells into the abdominal cavity or whether pneumoperitoneum-induced changes of the peritoneal milieu promote tumour growth. An animal model was established to examine the effect of a CO2-pneumoperitoneum on the intraperitoneal growth of tumour cells. Six week old nude mice were divided into 4 groups of 15 animals each. A CO2-pneumoperitoneum was induced by a micro-hysteroflator with an intraperitoneal pressure of 6 mmHg for 90 minutes in groups 2 and 4. Two different tumour cell lines, suspended in 2 ml of Ringer's solution for homogeneous spread of the cells, were injected i.p.. The control groups 1 and 3 received the tumour cells without pneumoperitoneum induction of a CO2-pneumoperitoneum resulted in an increasing seeding rate of tumour cells and provoked a significant increase in the number and size of intraabdominal metastases. Laparoscopic surgery of malignancies is therefore contraindicated.