title: Experimental assessment of tumor growth and dissemination of a microscopic peritoneal carcinomatosis after CO2 peritoneal insufflation or laparotomy.
abstract: BACKGROUND
  Based on clinical observations and previous animal studies, laparoscopic surgery for malignant disease is regarded as controversial. We used a rat model to measure and compare the tumor growth, proliferation, and dissemination of a microscopic peritoneal carcinomatosis after CO(2) intraperitoneal insufflation or laparotomy.
  
  
  METHODS
  Peritoneal carcinomatosis was induced in three groups of 27 BD IX rats each with intraperitoneal injections of 106 DHD/K12 cells, an aneuploid tumor cell line. At 48 h after tumor cell injection, the animals were randomly divided into three groups to undergo different types of intervention. All animals were anesthetized for 20 min (Halothane). The control group had no surgical intervention (group C), group I had CO(2) insufflation (7 mmHg),and group L had a midline laparotomy (5-cm). Neither bowel manipulation nor any other traumatic action was performed. Two weeks later, the rats were killed and the incidence, type, and dissemination of carcinomatosis were evaluated. We also measured the tumor's weight. Malignant omentum was sampled for flow cytometry analysis (DNA ploidy, S-phase fraction).
  
  
  RESULTS
  The incidence of carcinomatosis did not differ among the groups. The mean score of macroscopic characteristics of the carcinomatosis was 2.8 +/- 1.9 in group L, 2.9 +/- 1.9 in group I, and 3 +/- 1.9 in group C (NS). The location of the implants did not differ, except for parietal peritoneum location, which was more frequent in group L (p < 0.01). The tumor weight was 4.96 g +/- 3.2 in group L, 5.55 g +/- 3.2 in group C, and 5.75 g +/- 3.4 in group I (NS). The percentage of aneuploid cells and S-phase fraction did not differ statistically among the groups.
  
  
  CONCLUSIONS
  These results indicate that CO(2) insufflation does not cause more effects than laparotomy when tumors cells are present before the beginning of the surgery. Further studies are needed to determine the influence of other steps in laparoscopic surgery on tumor growth and dissemination.
authors.affiliation: Department of Surgery, Centre Régional de Lutte Contre le Cancer Paul Papin, 2, rue Moll, 49033, Angers, France. e.fondrinier@unimedia.fr
authors.forename: E
authors.initials: E
authors.lastname: Fondrinier
authors.forename: M
authors.initials: M
authors.lastname: Boisdron-Celle
authors.forename: A
authors.initials: A
authors.lastname: Chassevent
authors.forename: G
authors.initials: G
authors.lastname: Lorimier
authors.forename: E
authors.initials: E
authors.lastname: Gamelin
mesh_terms: D000818:Animals; D002245:Carbon Dioxide; D004195:Disease Models, Animal; D007327:Insufflation / Q000009:adverse effects*; D007813:Laparotomy / Q000009:adverse effects*; D008297:Male; D009366:Neoplasm Seeding; D010534:Peritoneal Neoplasms / Q000601:surgery*; D051381:Rats
chemical_list: D002245:Carbon Dioxide