EFFICACY OF CYTOTOXIC AGENTS FOR THE PREVENTION OF LAPAROSCOPIC PORT-SITE METASTASES

Background: Recent experimental studies support initial clinical impre ssions that laparoscopic surgery for malignant neoplasms may be associ ated with an increased incidence of metastases to port sites. This stu dy investigated in an experimental model the influence of cytotoxic ag ents (administered intraperitoneally or intramuscularly) on the develo pment of port-site metastases following laparoscopic surgery. Methods: Seven days after the implantation of an adenocarcinoma in the left ab dominal flank, 72 Dark Agouti rats underwent laparoscopy with carbon d ioxide insufflation, instillation of an intraperitoneal agent, and int raperitoneal tumor laceration within the following study groups (12 ra ts in each group): (1) control (no intraperitoneal instillation); (2) intraperitoneal instillation of isotonic sodium chloride solution (0.9 %); (3) intraperitoneal instillation of povodine-iodine (1:10 dilution of povidine-iodine and isotonic sodium chloride solution); (4) intrap eritoneal instillation of methotrexate (0.125 mg of methotrexate in 3 mt of isotonic sodium chloride solution); and (5) intraperitoneal inst illation of aqueous chlorhexidine acetate. Twelve additional rats unde rwent laparoscopic tumor laceration following intramuscular injection of 0.125 mg of methotrexate (no intraperitoneal agent). Rats were kill ed 7 days after the procedure, and the wounds were examined histologic ally by a blinded histopathologist for the presence of tumor metastase s. Results: No tumor was found in any port site following the intraper itoneal administration of povidine-iodine (P =.04). In contrast, port- site metastases developed in the control group (5 [41.7%] of 12), the isotonic sodium chloride solution group (4 [33.3%] of 12), the chlorhe xdine group (4 [33.3%] of 12), the intraperitoneal methotrexate group (2 [16.7%] of 12), and the parenteral methotrexate group (5 [41.7%] of 12). Conclusions: The results of this study suggest that the developm ent of metastases to port sites following laparoscopic surgery may be prevented by the intraperitoneal instillation of diluted povodine-iodi ne. Other agents failed to influence the incidence of port-site metast ases. Further studies are needed to determine if these findings can be applied to humans.