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 influen ce of surgical technique on tumour implantation needs further assessment. S mall animals such as rodents are inappropriate for such laparoscopic surgic al studies. There is a requirement for another animal tumour model with ani mals greater in size. Methods: Accordingly we developed an intraperitoneal tumour xenograft survi val model using the domesticated pig. After creating a 12 mmHg pneumoperito neum, 10(7) human HeLa cells were injected into the peritoneal cavity of ni ne non-syngeneic animals to induce tumour xenograft. Resection of the sigmo id colon using four trocars and a transanal double-stapling technique was p erformed. The mean operating time was 69 min. No signs of post-operative pa in symptoms were observed, and all the animals survived the procedure and g ained weight. After 4 weeks, the animals were sacrified and all incision si tes and anastomoses were excised. Results: Immunohistochemical staining with antihuman pancytokeratin antibod ies confirmed tumour implants in 25 out of 36 port-sites (63.8%). No perito neal carcinosis nor tumour implants at anastomosis sites were observed. Conclusion: This intraperitoneal xenograft tumour model in the pig can be a pplied in survival studies to check the quality of surgical techniques and its influence on tumour implantation following laparoscopy for cancer. (C) 2000 Harcourt Publishers Ltd.