Description of an intraperitoneal tumour xenograft survival model in the pig

Aims: Experimental animal studies are necessary if the results of minimally invasive oncological surgery are to be improved. In particular the influence of surgical technique on tumour implantation needs further assessment. Small animals such as rodents are inappropriate for such laparoscopic surgical studies. There is a requirement for another animal tumour model with animals greater in size. Methods: Accordingly we developed an intraperitoneal tumour xenograft survival model using the domesticated pig. After creating a 12 mmHg pneumoperitoneum, 107human HeLa cells were injected into the peritoneal cavity of nine non-syngeneic animals to induce tumour xenograft. Resection of the sigmoid colon using four trocars and a transanal double-stapling technique was performed. The mean operating time was 69 min. No signs of post-operative pain symptoms were observed, and all the animals survived the procedure and gained weight. After 4 weeks, the animals were sacrified and all incision sites and anastomoses were excised. Results: Immunohistochemical staining with antihuman pancytokeratin antibodies confirmed tumour implants in 25 out of 36 port-sites (63.8%). No peritoneal carcinosis nor tumour implants at anastomosis sites were observed. Conclusion: This intraperitoneal xenograft tumour model in the pig can be applied in survival studies to check the quality of surgical techniques and its influence on tumour implantation following laparoscopy for cancer.