Table 4.

Possible mechanisms which lead to port site metastasis

Mechanical
Direct contamination
Seeding during extraction of tumor through a small wound
Seeding by contact with instruments contaminated with tumor cells
Indirect contamination
Seeding into the wound during episodes of desufflation of the pneumoperitoneum
Cells exist in an aerosol and are transferred to wounds and ports without direct contamination (chimney effect)
Metabolic / immunological
Seeding occurs in both open and laparoscopic wounds, but metastases are more likely after laparoscopy because of locally acting immunological and / or metabolic factors
Hematogenous
Seeding by hematogenous spread during surgery