Port site metastasis. An unresolved problem in laparoscopic surgery. A review

After the explosive success of laparoscopic cholecystectomy, great interest has been shown in the laparoscopic treatment of digestive malignancies. Laparoscopy has been proposed for diagnosis and staging, and as a technical option aiming to cure or palliate. But this optimism has been tempered by the doubt about the potential disseminatory role of laparoscopy after the observation of a large number of port site seeding tumors. Since the first laparoscopic cholecystectomy, more than 100 port site metastases have been reported, without a clear explanation for these findings. Port site recurrences have been observed after gynaecologic procedures, laparoscopic cholecystectomy in which an unsuspected gallbladder cancer was found and after laparoscopic operations indicated for oncological treatment of digestive tumors, mainly colorectal cancer. Other cases have been reported after thoracoscopic resection of oesophageal cancer or urologic cancer, even after staging laparoscopy associated with sampling. Possible mechanisms for port site cell implantation are direct implantation in the wound during unprotected and forced tissue retrieval or by contaminated instruments during tumor dissection, the effect of gas turbulence in long laparoscopic procedures and embolization of exfoliated cells during tumor dissection or hematogenous dissemination. Probably, a multifactorial mechanism may be responsible, in which the key factors could be a long operative procedure, the high pressure pneumoperitoneum, tumoral manipulation during dissection and forced extraction of unprotected specimens. Prophylactic measures proposed to avoid this disastrous complication are the use of protective bags for tissue retrieval, peritoneal lavage with heparin in order to avoid adhesion of free cells, or lavage with cytocidal solutions.