Albino rats, in which an implanted abdominal cancer was lacerated during laparotomy or laparoscopy, were used to evaluate the rate of tumour spreading following both techniques. The postmortem examination revealed that infiltration of the primary tumour was higher in rats exposed to laparoscopy than laparotomy. Microscopically, the incidence of secondary implantation was greater after laparoscopic laceration than after tumour laceration by laparotomy, particularly at the wound from which laparoscopic lacerating instruments were introduced. However,
both treated groups showed neither macroscopic nor microscopic evidence of metastasis in any organ beyond the laparotomy or laparoscopy wounds.