Impact of laparoscopic colonic resection on tumour growth and spread in an experimental model

Background: The influence of surgical manipulation and carbon dioxide pneumoperitoneum on intraperitoneal tumour growth and port‐site metastasis during laparoscopic colon resection is still unknown. Methods: Some 33 male WAG/Rij rats were randomized into three experimental groups: a laparoscopy group with carbon dioxide pneumoperitoneum (n = 11), a gasless laparoscopy group (n = 11) and a laparotomy group (n = 11). After transanal injection of a tumour cell suspension (1 × 106 CC 531 cells) into the distal colon, a colon segment resection and an end‐to‐end anastomosis (laparoscopy; intra‐abdominal technique) were performed. Tumour growth was scored semiquantitatively 24 days after the operation. Data were analysed by the Kruskal–Wallis test. Results: The tumour indices from the four locations with the greatest tumour growth were significantly decreased in the laparoscopy group with carbon dioxide pneumoperitoneum compared with the gasless laparoscopy and laparotomy groups (P < 0·01). Port‐site metastases were significantly decreased in the carbon dioxide pneumoperitoneum group compared with the gasless laparoscopy group (P = 0·05). Conclusion: A full laparotomy incision promotes greater tumour growth than does carbon dioxide pneumoperitoneum. Surgical manipulation stimulates local tumour spread more than the establishment of a carbon dioxide pneumoperitoneum. © 1999 British Journal of Surgery Society Ltd