title: Enhanced tumour growth and impaired cellular antitumoural defense in hepatic colorectal carcinoma metastasis in rats after laparoscopy compared to open surgery.
abstract: BACKGROUND
  This study aims to assess postoperative hepatic growth of colorectal adenocarcinoma metastasis and peritumoural macrophage counts after laparoscopy in an experimental animal model.
  
  
  METHODS
  Thirty male syngenic WAG/Rij rats were randomised into two surgical groups: laparoscopy (LS; n = 15) using CO(2) at 12 mmHg and laparotomy (LT; n = 15; negative control) during an operating time of 90 min. At 45 min after setup, CC531s colon adenocarcinoma cells were injected into two liver lobes. Postoperative tumour volumes were determined by abdominal magnetic resonance imaging (MRI) and computed three-dimensional volumetry. Peritumoural macrophages were counted by local stereology using a confocal laser-scanning fluorescence microscope.
  
  
  RESULTS
  The median postoperative tumour volume was significantly higher after LS in both lobes (L): after 10, 15 and 20 days in L2 and L5: 24/12, 54/38, 275/62 mm(3) and 0/0, 15/11, 55/24 mm(3) (LS/LT). Significantly fewer peritumoural macrophages were found after LS at all postoperative time points (Mann-Whitney: p < 0.05).
  
  
  CONCLUSIONS
  Increased hepatic growth of colorectal adenocarcinoma metastasis and impaired cellular antitumoural defence after LS cast doubt on the use of LS in colorectal cancer and needs further clinical investigation.
authors.affiliation: Department of General Surgery, Hôpital Cantonal Fribourg, CH-1708, Fribourg, Switzerland.
authors.forename: D Th
authors.initials: DT
authors.lastname: Inderbitzin
authors.forename: G R
authors.initials: GR
authors.lastname: Marti
authors.forename: S
authors.initials: S
authors.lastname: Eichenberger
authors.forename: H- M
authors.initials: H
authors.lastname: Hoogewoud
authors.forename: L
authors.initials: L
authors.lastname: Kraehenbuehl
mesh_terms: D000230:Adenocarcinoma / Q000503:physiopathology* / Q000556:secondary / Q000601:surgery; D000818:Animals; D002452:Cell Count; D045744:Cell Line, Tumor; D015179:Colorectal Neoplasms / Q000473:pathology*; D004195:Disease Models, Animal; D006498:Hepatectomy; D008113:Liver Neoplasms / Q000503:physiopathology* / Q000556:secondary / Q000601:surgery; D008264:Macrophages; D008297:Male; D051381:Rats