Influence of different gases and intraperitoneal instillation of antiadherent or cytotoxic agents on peritoneal tumor cell growth and implantation with laparoscopic surgery in a rat model

Background: A generally accepted approach to prevent tumor implantation with laparoscopic surgery does not exist. Alternative gases in combination with intraperitoneal instillation of different antiadherent or cytotoxic agents have not been evaluated. Methods: The effect of taurolidine, heparin, and povidone-iodine on the growth of colon adenocarcinoma DHD/K12/TRb was measured in rats undergoing laparoscopy with carbon dioxide (n = 40), helium (n = 40), or xenon(n 40). In the procedure, 10(4) tumor cells were administered intraperitoneally, and pneumoperitoneum was established over 30 min at 8 mmHg with the different gases. The rats additionally received intraperitoneal instillation with one of the following: 1 ml of Ringer's solution, 1 ml of 0.5% taurolidine, 1 ml 0.5% taurolidine with heparin (10 U/ml), or 1 ml 0.25% of povidone-iodine. Tumor growth was mea sured after 4 weeks. Results: Median intraperitoneal tumor weight was lower in rats receiving taurolidine (CO2: 10 mg; helium: 50 mg; xenon: 39.5 mg) or taurolidine with heparin (CO2: 41 mg; helium: 4.5 mg; xenon: 46.5 mg) in all gas groups than in the control groups (CO2: 427 mg; helium: 268 mg; xenon: 345 mg) (p < 0.001). Whereas povidone-iodine caused sig nificantly lower tumor growth in the CO2 group (56.5 mg) (p < 0.01), the combination of helium (145 mg) and xenon (457 mg) with povidone-iodine produced no reduction of tumor growth as compared with the control groups (helium: 268 mg; xenon: 345 mg). Conclusions: Taurolidine and taurolidine with heparin significantly inhibit intraperitoneal tumor growth, with different gases used for pneumoperitoneum. Only povidone-iodine caused significant decrease of tumor growth in combination with CO2. The combination of xenon and povidone-iodine should not be used in patients with cancer because of increased tumor growth.