Effect of povidone-iodine on anastomotic tumor growth in an experimental model of colorectal cancer surgery.

Implantation of viable exfoliated tumor cells may be responsible for the local recurrence of colorectal cancer. Intraluminal colon cancer cells derived from chemically induced colon cancer in syngenic F344 rats, were introduced 2 cm proximally to a colonic anastomosis and anastomotic tumor growth was observed. Anastomotic tumor growth was found in about 30% of the animals, when sacrificed on the 3rd postoperative week. The cytotoxic efficacy of povidone-iodine (PVP-I) was tested with the same model. The administration of 10% PVP-I solution significantly reduced the incidence of tumor growth. Viable intraluminal tumor cells cause anastomotic tumor growth by becoming implanted on an anastomosis and PVP-I had effective cytotoxicity.