Increased Insufflation Pressure Enhances the Development of Liver Metastasis in a Mouse Laparoscopy Model

Abstract

Despite the widespread use of laparoscopic techniques for colorectal cancer surgery, little is known about the potential risk of liver metastasis following CO2 pneumoperitoneum. We investigated the effect of different insufflation pressures and durations of CO2 pneumoperitoneum on the growth of liver metastasis in a mouse model. Six- to 7-week old male BALB/C mice were intraportally inoculated with 2×104 Colon 26 cells and randomly allocated to receive either CO2 pneumoperitoneum at different pressures (5 mmHg, 10 mmHg, or 15 mmHg), xiphoid-pubic laparotomy, or no treatment other than tumor cell inoculation. Mice undergoing pneumoperitoneum or laparotomy were then subdivided by the duration of treatment (30 minutes or 60 minutes). Cancer nodules on the liver surface from a total of 122 mice were evaluated on the 14th postoperative day. Similar to full laparotomy, CO2 pneumoperitoneum at 10 mmHg and 15 mmHg for 60 minutes, and pneumoperitoneum at 15 mmHg for 30 minutes significantly promoted the growth of cancer nodules on the liver surface. Enhancement of tumor growth was influenced by increased insufflation pressures (p < 0.05) rather than the prolonged length of pneumoperitoneum (p = 0.53) without significant interaction (p = 0.49). These results suggest that an increased insufflation pressure promotes the growth of liver metastases as well as laparotomy in this animal model.