The Experimental Study Of The Efficacy Of Heparin And Povidone-iodine On Preventing Port-sites Metastases

Ground and objective: Port-sites raetastases (PSM)is a major cause of morbidity and mortality following cancer laparoscopy, the question arises to as to weather it is a safe ontological procedure . Several previous experimental studies shown that heparin or Povidone-iodine (PVP-I) can significantly inhibit the growth and implantation of tumor cells in conventional open surgery, the purpose of this study was to evaluate the efficacy of local application of heparin or Povidone-iodine or the combination of both substances on tumor growth and port-sites metastases in rats laparoscopic tumor model.Material and method: The effect of heparin and PVP-I on tumor growth and implantation was measured in vitro and in vivo. In vivo, under intraperitoneal pentobarbital anaesthesia, 1ml RH-35 hepatic cancer cells suspension was injected into the peritoneum of SD rats via a direct upper abdomen puncture. Gas was insufflated at a rate of IL/min and a pressure of 3mmHg for 20 minutes. During this period simple laparoscopic procedures were performed. Total 60 rats were allocated randomly to groups I , II, IIIor IV, to receive either intraperitoneal normal saline or intraperitoneal heparin or intraperitoneal povidone-iodine or intraperitoneal heparin plus povidone-iodine, and besmear the port-sitebefore the end of surgical procedure.The rats were killed and microscopic tumor implants was examined by an independent observer at two trocar sites five weeks later.In vitro 1ml 0.9% normal saline or heparin or PVP-I or heparin plus PVP-I was added to 1ml tumor cell suspension respectively, and exposed for five minutes, the viability of tumor cell suspension was counted by trypan blue exclusion.Result: Total four rats were dead and were excluded from this study. In the remaining 56 rats, port-site metastases were detected in 8 of 14 rats in group I , 2 of 13 in group II , 1 of 14 in group III, 0 of 15 in group IV. Compared with the control group, all experimental groups can significantly reduce the rate of port-site metastases (P<0.05). In vitro, the trypan blue exclusion test showed that: compared with the control group, PVP-I was effective at killing all most tumor cells (mortality: 91%-96%, P<0.05), but heparin has no significant tumor cell toxicity, the viability of tumor cells was 86%-91%.Conclusion: These results suggest that the local application of Povidone-iodine or/and heparin can reduce the incidence of PSM in rats laparoscopy model, PVP-I has significant tumor cell toxicity, heparin cannot kill tumor cells, but which can inhibit the adherent of tumor cell with injured tissue to reduce the incidence of PSM. Further dose-effect curve study would be required to define the optimum amount of theseagents to which was applied locally to prevent implantation of tumor.