Comparative Of Abdominal Capacity In Adult And Nude Mouse And CO₂Pneumoperitoneum Impact On The Quantity Of Intraperitoneal Free Cancer Cells And It’s Capacity Of Forming Tumor In Vivo

Objects:1) Through measure the body abdominal capacity of adult anddiscussion on it’s influencing factors and measure the intraperitoneal volumeof nude mice,and draw a comparison between them. Then provides the basisfor animal model of nude mouse of free intraperitoneal tumor cells. Discussdifferent Conditions of CO2pneumoperitoneum impact on quantity ofintraperitoneal free cancer cells and it’s capacity of forming tumor in vivo.Methods:1)The intraperitoneal volume was studied in387patientsundergoing a variety of laparoscopy. The insufflated CO2volume was seriallyrecorded at intraperitoneal insufflation pressures of15mm Hg duringlaparoscopic access and it’s influence factor were learned. And theintraperitoneal volume was studied in20nude mice. The insufflated CO2volume was recorded at intraperitoneal insufflation pressures of5mm Hgduring laparoscopic access. A comparison of the insufflated CO2volume wasdraw between human beings and nude mice.2)2×105labeled tumor cells(SGC7901) were injected into the abdominalcavity of every nude mice respectively.Then30nude mice with cancer cellwere randomly divided into5groups to accept different conditions of CO2pneumoperitoneum processing. No CO2pneumoperitoneum for control group,established3mmHg and1h,2h of CO2pneumoperitoneum for S3-1, S3-2;and5mmHg and1h,2h of CO2pneumoperitoneum for S5-1, S5-2 respectively. After the procedure, the abdominal cavity was irrigated with5ml0.9%saline, the lavage fluid was collected, and the labeled living cancercells in the lavage fluid were detection by flow cytometry. After Peritoneallavage,the nude mice were raised for4weeks before killed, and theintraperitoneal tumor nodules was evaluated ultimately.Results:1) The mean±SD of insufflated CO2volumes at15mmHg ofhumans was3.02±0.41L. Using multivariate analysis, we known that at15mm Hg the insufflated CO2volume was correlated with the gender, heightand reproductive number(female). There was no correlation withage,weight,BMI and histories of abdominal surgery or trauma.The mean±SDof insufflated CO2volumes at5mmHg of nude mice was10.6±1.44ml. Thehuman body abdominal capacity is about300times of nude mice. Hence,toestablish a reasonable animal model, about1.3×105of injected cancer cells isneeded in terms of known data in humans.2) The number of tumor cells in peritoneal lavage fluid was no differencebetween control group and S3-（1p>0.05）; but there was significant differencebetween control group and S3-2(p<0.05), and S5-1(p<0.05), andS5-2(p<0.05); also between S3-1and S3-2(p<0.05), and S5-1(p<0.05), andS5-2(p<0.05). Moreover,there was no difference between S3-2and S5-1（p>0.05）；And the number of tumor cells in S5-2was significantly smallerthan S3-2and S5-1（p<0.05）.Every only nude mouse has intraperitonealtumor nodules,But there was no difference between groups(p>0.05).Conclusion:1) The mean±SD of insufflated CO2volumes at15mmHgof humans was3.02±0.41L. And the insufflated CO2volume was correlatedwith the gender, height and reproductive number(female),but does notcorrelated with age,weight,BMI and histories of abdominal surgery or trauma. The mean±SD of insufflated CO2volumes at5mmHg of nude mice was10.6±1.44ml. Accordingly, to establish an animal model,1.3×105of injectedtumor cells is needed in terms of known data in humans.2) With the pressure and time of CO2pneumoperitoneum increased, theintraperitoneal free cancer cells was reduced significantly. After Peritoneallavage, the intraperitoneal tumor nodules was no difference between groups.