The facilitation of peritoneal dissemination of a tumor by laparotomy in a rabbit model

The effects of conventional laparotomy and laparoscopic surgery on the peritoneal dissemination of VX2 tumors were evaluated in a rabbit model. Either 5 x 10(3) or 5 x 10(4) of VX2 tumor cells were inoculated into the peritoneal cavities of rabbits which were divided into three groups according to the procedure performed, namely, a conventional laparotomy group (group 1), a laparoscopy group (group 2), and a control group (group 3). All the animals were killed 2 weeks after the treatment to examine the spread of the VX2 tumor in the omentum. In the experiment in which 5 x 10(3) tumor cells were inoculated, no significant difference was found in the number of metastases among the three groups. Conversely, after inoculating 5 x 10(4) tumor cells, the mean numbers of metastatic colonies greater than 1 mm in diameter in the greater omentum were 14.4+/-4.7 in group 1, 9.9+/-2.4 in group 2, and 3.3+/-1.1 in group 3, with a significant difference between groups 1 and 3, and between groups 2 and 3, but not between groups 1 and 2. In conclusion, conventional laparotomy facilitated the greatest peritoneal dissemination of a VX2 tumor in this animal model when 5 x 10(4) tumor cells were inoculated. Furthermore, laparoscopic surgery influences tumor growth to almost the same degree as conventional laparotomy.