THE INFLUENCE OF A PNEUMOPERITONEUM ON THE PERITONEAL IMPLANTATION OFFREE INTRAPERITONEAL COLON-CANCER CELLS

Background: In order to test the influence of a pneumoperitoneum on th e peritoneal implantation of free intraperitoneal colon cancer cells, 40 male syngeneic WAG rats were at random divided into four groups. Me thods: Group 1 (n = 10) animals underwent a midline laparotomy and 10( 4) CC531 colon cancer cells were injected intraperitoneally (IF); in g roup 2 (n = 10) 10(4) CC531 cells were injected TP without further man ipulation; in group 3 (n = 10) a pneumoperitoneum up to 10 mmHg was cr eated after the IP injection of the same amount of CC531 cells, The pn eumoperitoneum was maintained for 15 min, Finally in group 4 (n = 10) after the IP injection of 10(4) CC531 cells and after the creation of a pneumoperitoneum, two 14-G IV catheters simulating trocars were intr oduced in each flank. A follow-up period of 8 weeks was used, Tumor im plantation was scored according to the peritoneal cancer index of Egge rmont and the index of Chauffert. Results: Tumor nodules were found va rying from 60% in groups 1-3 to 50% in group 4, There was no statistic al difference between the implantation rate in the four groups, A port -site recurrence was seen in group 4; all the other tumor implants wer e located in the mesenterium, omentum, internal genitals, or parietal peritoneum. Conclusions: The presence of a pneumoperitoneum does not e nhance the implantation of free intraperitoneal malignant colon cancer cells in the rat, but the presence of a ''port'' may lead to abdomina l-wall metastases.