A model of port-site metastases of gallbladder cancer: The influence of peritoneal injury and its repair on abdominal wall metastases

Background. Recent surgical literature contains several reports of wound metastases of unexpected gallbladder cancer after laparoscopic cholecystectomy. We hypothesized that peritoneal injury caused by trocar insertion potentiates wound metastases. This study was designed to determine the effect of peritoneal injury on tumor implantation. Methods. Cultured human gallbladder cancer cells were injected into the peritoneal cavity of mice immediately after surgical procedures. In a peritoneal injury group muscle and the peritoneum were perforated; in a peritoneal injury and repair group each muscle and peritoneal wound was sutured carefully; in a laparoscopic model group animals underwent peritoneal insufflation with carbon dioxide gas and tumor cell injection and then the abdominal wall was perforated. Some mice (controls) were not subjected to any surgical procedure. All mice (n = 178) were killed 2 weeks after tumor cell injection and were examined for tumor implantation. Results. Although no control mice showed intraperitoneal tumor, all mice in the peritoneal injury group showed tumors at the injured sites. In the laparoscopic model group, 90% of injured sites had tumors. The traumatized site-specific implantation rate in the peritoneal injury and repair group was only 40%, whereas it was 100% in the peritoneal injury group (P < .001). Conclusions. Peritoneal injury enhances peritoneal implantation of carcinoma cells. Repair of injured peritoneum at trocar sites may reduce the frequency of wound metastases in laparoscopic surgery for unexpected gallbladder carcinoma.