Measurement Of Chest Cavity Volume In Acquired Pectus Excavatum Rats

Objective：On the basis of making rat model of Pectus Excavatum, by thoraxCT scanning measurement chest volume (chest volume, CV) and physical lung(including mediastinum) volume (pulmonary volume, PV) determination,explore the rat Pectus Excavatum chest volume change law and in the process ofevaluation measure of the chest cavity volume method.Methods：Four weeks SD rats only one-hundred and twenty，randomly dividedinto the experiment group and the control only sixty. Experimental groupthrough the sternum cut off the under observation of rib cartilage formationPectus Excavatum, the control do not make any intervention, ordinary breeding.In postoperative1,2,4,8and12weeks after rat measurement CV, chest CTscans after CT scan ligation neck period of trachea cut open chest lung(including mediastinum) PV determined by Archimedes’ principle, measuring12each time point. In control group and experimental group corresponding to thefive point CV and PV is measured with the same method, each time pointmeasuring10. Two groups of CV and PV corresponding time points betweengroups of the measurement results of t test analysis, the two groups of each point in time measured values plot of a comparative study on two groups of animalsCV and the change trend of PV, at the same time, make a scatter diagram toestablish two groups, the linear relationship between the measured value changethrough correlation analysis and regression equation to evaluate CT CVmeasurement results and the real value of PV.Results：Pectus Excavatum building surgery sixty rats, anesthesia, surgery, andno death breeding process, after two weeks are visible, Pectus Excavatummalformation, four weeks eight weeks to twelve weeks deformity has noobvious increase.120rats were successfully completed CV and thedetermination of PV.Both the control group and experimental group, the rats CV and PV grow alongwith the age of rats and increase, with rat ages8to16weeks significantlyincreased. Each point in time measured values CV were greater than the PV (P <0.05). By means of the experimental group the measured value of the CV andPV correlation analysis, the correlation between both is better, withpostoperative8weeks (r=0.832) and12weeks (r=0.894) is a highly positivecorrelation, while the control group at various time points of CV and PV ishighly correlated to the measured values are.CV and PV measured values between groups: CV value can be measured at eachtime point in the experimental group were less than the control group (P <0.01);PV corresponding time points in group comparison between measured valuesand only at4,8and12weeks after the test group were less than the control group (P <0.01), and the measured value of the postoperative1and2weeks incomparison between groups have no statistical significance (P>0.05).Based on the linear relationship of CV and PV, CV as independent variables, PVas dependent variable, to establish the regression equation for y=0.745+0.929x, R2is0.783, both highly correlated, the parallel relationship.Conclusion：Acquired in the course of Pectus Excavatum, with the increase ofrat rat age chest volume and lung volume are increased gradually, but comparedwith normal age animals, Pectus Excavatum rats chest volume and lung weresmaller, with Pectus Excavatum to chest and lung volume after the formation ofshrinkage is more obvious. Although CT measured chest volume than entitylung volume is big, but both show a good linear relationship, chest CT scanningmeasuring can objectively reflect the change of thoracic cavity volume.