A proposed model for the movement of cells within the abdominal cavity during CO2 insufflation and laparoscopy.

Background: The application of laparoscopic-assisted surgery to gastrointestinal malignancy has lead to the recurrence of malignancy in wounds created during these procedures by laparoscopic ports.

Methods: Possible mechanisms of this complication have been studied in an in vitro model. Using filter systems, we have examined the expelled carbon dioxide used during laparoscopy and the laparoscopic ports and instruments for the presence of malignant cells.

Results: No malignant cells were identified in the exhaust CO2 examined, whereas all instruments and laparoscopic ports were contaminated by malignant cells.

Conclusions: These findings suggest that direct contamination by the instruments and ports and not dispersion of malignant cells by CO2 is the route by which port seeding of tumour cells occurs.