TUMOR-GROWTH AND DISSEMINATION AFTER LAPAROTOMY AND CO2 PNEUMOPERITONEUM - A RAT OVARIAN-CANCER MODEL

Objective: To compare tumor growth, intraperitoneal implantation, and abdominal wall metastasis after laparotomy and CO2 pneumoperitoneum in a rat ovarian cancer model. Methods: To mimic intraoperative rupture of an ovarian tumor in a syngenic rat ovarian carcinoma model, 10(5) m alignant cells were injected intraperitoneally after a 5-cm vertical m idline laparotomy or after the insufflation of a CO2 pneumoperitoneum achieved with 4 mmHg or 10 mmHg intra-abdominal pressure. Two weeks la ter, the intraperitoneal tumor growth and the tumor dissemination were evaluated semiquantitatively with a scoring system. The scores attrib uted to each organ were added to calculate the dissemination score of each animal. Results: The mean (+/- SD) dissemination score was 83.4 a 12 in the laparotomy group and 67.3 +/- 16 and 71.9 +/- 17 in the 4 a nd 10 mmHg CO2 pneumoperitoneum groups, respectively (P < .01). The sc ores for the peritoneum were 21.8 +/- 3.8 in the 10 mmHg pneumoperiton eum group and 18 +/- 2.4 in the laparotomy group (P < .01). In the lap arotomy group, the implant found along the midline scar accounted for a mean of 62.6 +/- 15% of the peritoneal, score, whereas the trocar si te metastases did not influence the peritoneal score in the pneumoperi toneum groups. The incidence of wound metastasis was 96% in the laparo tomy group and 55% and 54% in the 4 mmHg and 10 mmHg pneumoperitoneum groups, respectively. Conclusion: In this model, tumor growth was grea ter after laparotomy than after laparoscopy, but peritoneal tumor diss emination was more severe after CO2 pneumoperitoneum. (Obstet Gynecol 1998;92:104-8. (C) 1998 by The American College of Obstetricians and G ynecologists.).