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 supported by a burgeoning experimental literature which suggests that laparoscopy promotes tumour metastasis to wounds. This study investigated the effect of intraperitoneal blood and heparin on the incidence of tumour cell implantation and port site metastasis. Methods: Twenty‐four Dark Agouti rats underwent laparoscopy with carbon dioxide insufflation and the instillation of a tumour cell suspension and/or blood into the peritoneal cavity. Rats were allocated randomly to one of the following study groups (six rats per group): (1) controls; (2) intraperitoneal blood (2 ml blood introduced from a syngeneic donor rat); (3) intraperitoneal heparin; (4) intraperitoneal blood and heparin. Rats were killed 7 days after the procedure, and the peritoneal cavity and port sites were examined for the presence of tumour. Results: Tumour implantation and port site metastases were reduced by the intraperitoneal administration of heparin, but increased by the presence of intraperitoneal blood. Conclusion: The results of this study suggest that tumour implantation following laparoscopy is promoted by the presence of intraperitoneal blood and that this effect may be reduced by the use of intraperitoneal heparin. © 1999 British Journal of Surgery Society Ltd