Is carbon dioxide insufflation safe for laparoscopic surgery? A model to assess the effects of carbon dioxide on transitional-cell carcinoma growth, apoptosis, and necrosis.

Purpose: To study the effects of carbon dioxide insufflation pressure and concentration on the adhesion, growth, apoptosis, and necrosis of transitional-cell carcinoma (TCC).

Materials And Methods: Adhesion and growth of the AY-27 rat TCC cell line was measured after CO2 insufflation in vitro at different pressures ranging from 0 to 15 mm Hg and after incubation in CO2-air mixtures at 5%, 10%, and 15% CO2 by volume.

Results: Tumor adhesion decreased significantly after CO2 insufflation. For all insufflation pressures, there was an increase in cell growth, apoptosis, and necrosis for the first 24 hours followed by a steady decline. High concentrations of CO2 (>5%) inhibited cell growth for only the first 48 hours. The effects of CO2 pneumoperitoneum on tumor-cell adhesion, growth inhibition, apoptosis, and necrosis were more prominent at high CO2 pressure (> or =15 mm Hg) and concentration (>5% CO2). However, insufflation pressure had a greater inhibitory effect on tumor growth than did CO2 concentration. High insufflation pressures and CO2 concentrations significantly decreased extracellular pH.

Conclusion: The short-term effect of CO2 on TCC growth and apoptosis is complex. Overall, CO2 has a toxic effect on TCC and inhibits cell adhesion and growth. High CO2 concentrations (>5%) and high insufflation pressures (> or =15 mm Hg) are most effective in decreasing tumor-cell adhesion and growth.