Postoperative Peritoneal Dissemination of Ovarian Cancer Cells is not Promoted by Carbon-dioxide Pneumoperitoneum at Low Intraperitoneal Pressure in a Syngenic Mouse Laparoscopic Model with Controlled Respiratory Support: A Pilot Study

Abstract

Study Objective To investigate postoperative peritoneal dissemination of ovarian cancer cells in a syngenic mouse model with and without controlled respiratory support (CRS). Design Randomized controlled trial (Canadian Task Force classification I). Setting Academic facility. Subjects Sixty-four female C57BJ6 mice. Interventions Mice were randomly divided into 4 surgical groups: anesthesia alone group; 2 carbon-dioxide pneumoperitoneum groups, 1 with low (2 mm Hg) and 1 with high (8 mm Hg) intraperitoneal pressure (IPP); and finally the laparotomy group. Each of the 4 groups was then subdivided into one group with CRS and the other without. Mouse ovarian cancer cells were injected intraperitoneally just before surgery. Measurements and Main Results A laparotomy was performed to evaluate postoperative peritoneal dissemination of ovarian cancer cells on postoperative day 14. A computerized analysis system was then used to evaluate peritoneal dissemination. In the groups with CRS, the peritoneal dissemination score was significantly higher in the laparotomy and high IPP groups compared with anesthesia alone (p <.0001 vs laparotomy, p <.002 vs high IPP) and low IPP (p <.0002 vs laparotomy, p <.004 vs high IPP) groups. No significant difference was detected between the low IPP and anesthesia alone groups. Conclusion Postoperative peritoneal dissemination of ovarian cancer cells is not promoted by a carbon-dioxide pneumoperitoneum with a low IPP in a mouse model with CRS when assessed on postoperative day 14.