Comparison of the effects of gasless procedure, CO2-pneumoperitoneum, and laparotomy on splenic and hepatic natural killer activity in a rat model.
BACKGROUND
Natural killer (NK) activity plays an important role in the prevention of tumor metastasis. However, few studies compared changes in NK activities between gas(less) laparoscopy and open surgery.


METHODS
Donryu rats were randomized to 4 groups ( n = 6-9, for each lime point in each group): gasless group, pneumoperitoneum group, laparotomy group, and control group. The surgical treatment groups received additional cecal resection at the end of the procedures. Spleen cells and hepatic nonparenchymal cells were harvested at 6, 24, or 96 h, to determine the splenic and hepatic NK activities against YAC-1 cells.


RESULTS
Compared with the anesthesia control, laparotomy and pneumoperitoneum depressed splenic NK activity at 24 h ( p < 0.01 for laparotomy and p < 0.05, for pneumoperitoneum) and 96 h ( p < 0.05). Laparotomy also depressed hepatic NK activity at 24 h ( p < 0.05). In contrast, the gasless procedure did not show any deterioration in the splenic and hepatic NK activities.


CONCLUSIONS
These results suggest that gasless laparoscopic surgery would be a favorable approach in terms of the preservation of NK activities.
Takeuchi
I
I
Department of Surgery, Saitama Medical Center and School, 1981 Kamoda, Kawagoe, Saitama, 350-8550, Japan. ikuya@sj8.so-net.ne.jp
Ishida
H
H
Mori
T
T
Hashimoto
D
D
D000818:Animals; D002245:Carbon Dioxide; D002432:Cecum / Q000601:surgery*; D045744:Cell Line, Tumor; D003602:Cytotoxicity, Immunologic; D007165:Immunosuppression Therapy; D007694:Killer Cells, Natural / Q000276:immunology*; D010535:Laparoscopy / Q000009:adverse effects*; D007813:Laparotomy / Q000009:adverse effects*; D008099:Liver / Q000276:immunology*; D008297:Male; D011028:Pneumoperitoneum, Artificial / Q000009:adverse effects*; D011897:Random Allocation; D051381:Rats; D013154:Spleen / Q000276:immunology*
D002245:Carbon Dioxide