Experimental study of the effect of intraperitoneal heparin on tumour implantation following laparoscopy

Background: Conclusions drawn from clinical reports of port site metastases following laparoscopic resection of intra-abdominal malignancy are now sup ported by a burgeoning experimental literature which suggests that laparosc opy promotes tumour metastasis to wounds. This study investigated the effec t of intraperitoneal blood and heparin on the incidence of tumour cell impl antation and port site metastasis. Methods: Twenty-four Dark Agouti rats underwent laparoscopy with carbon dio xide insufflation and the instillation of a tumour cell suspension and/or b lood into the peritoneal cavity. Rats were allocated randomly to one of the following study groups (six rats per group): (1) controls; (2) intraperito neal blood (2 mi blood introduced from a syngeneic donor rat); (3) intraper itoneal heparin; (4) intraperitoneal blood and heparin. Rats were killed 7 days after the procedure, and the peritoneal cavity and port sites were exa mined for the presence of tumour. Results: Tumour implantation and port site metastases were reduced by the i ntraperitoneal administration of heparin, but increased by the presence of intraperitoneal blood. Conclusion: The results of this study suggest that tumour implantation foll owing laparoscopy is promoted by the presence of intraperitoneal blood and that this effect may be reduced by the use of intraperitoneal heparin.