Experimental Study On Relationship Between Renal Pelvic Pressure And Endotoxemia During Minimally Invasive Percutaneous Nephrolithotomy

Objective:To construct the animal model of endotoxemia caused by high renal pelvicpressure so as to research and analyses infection detection indicators, to investigatethe safe range of high renal pelvic pressure and its duration during minimally invasivepercutaneous nephrolithotomy(MPCNL), and to look for the early warning indicatorsof postoperative infection undergoing MPCNL.Methods:Forty rabbits were randomly divided into A,B,C,D four groups, with10rabbitsin each group. Four groups’ renal pelvic pressure was constant at0cmH2O (controlgroup A),20cmH2O (experimental group B),40cmH2O (experimental group C),60cmH2O (experimental group D). To establish the external jugular vein blood channeland MPCNL rabbit model, the renal pelvis of each group was injected withconcentration of1×10~8cfu/ml5mg/kg standard Escherichia coli strains when eachgroup’s pressure was constant, then, start timing. Drew0.5mL of blood respectivelythrough the blood channel in perfusion0s (T0),60s (T1),120s (T2),180s (T3),240s(T4).Then, measured serum endotoxin by ELISA. And detected the serumprocalcitonin (PCT), tumor necrosis factor (TNF-alpha), C-reactive protein (CRP)and creatinine (Cr) level respectively at preoperative and postoperative2h,4h,6h,12h. Analysised the rabbits’ mortality of the control group and the experimentalgroups after postoperative12h and postoperative24h.After then, analysis theexperimental results by statistical methods: T test was used within a group, one-wayanalysis of variance(ANOVA) was used between different groups.Results:First, in the animal model, there was no significant differences in serumendotoxin of the group A and the group B at each time point (P>0.05).But in thegroup C, there was statistically significant difference in serum endotoxin at each timepoint (P<0.05), wherein the group multiple comparison showed that the endotoxin ofT1,T2,T3,T4increased more significantly than T0’s (P <0.01), the endotoxin of T2, T3, T4increased more significantly than T1’s(P＜0.05）,the endotoxin of T3,T4increased more significantly than T2’s (P＜0.05). In the group D, wherein the groupmultiple comparison showed that the endotoxin of T1,T2,T3,T4increased moresignificantly than T0’s (P <0.01), the endotoxin of T2, T3, T4increased moresignificantly than T1’s (P＜0.05), there was statistical significance in the pairwisecomparison among T2,T3,T4.Multiple comparison within groups (A,B,C,D) at T0showed that the level of serum endotoxin of group D was higher than other groups’(P<0.05). Multiple comparisons within the groups respectively at T1,T2,T3,T4showedthat there was no significant difference in the serum endotoxin level of the group Aand the group B (P>0.05), the endotoxin levels of the group C and the group D weresignificantly higher than A group’s and B group’s(P <0.05), there were statisticallysignificant differences in the serum endotoxin level of C group and D group (P <0.05).Second, the fourth postoperative hour, the PCT’s increase of C group and Dgroup showed an acute ladder-type. the second postoperative hour, except the controlgroup, all experimental groups’s TNF-a fell gradually after a sharp increase. Eachgroups’ CRP in postoperative12h increased significantly, but there was nostatistically significant differences among groups. The sixth postoperative hour,acutekidney injury appeared in D group, in postoperative12h, serum creatinine increasedgradually, what were no found in the other groups.Third, Postoperative12h natural mortality rate:20%in A group (2/10),10%in Bgroup (1/10),30%in C group (3/10),40%in D group (4/10);Postoperative24hnatural mortality rate:20%in A group (2/10),30%in B group (3/10),50%in C group(5/10),70%in D group (7/10).Conclusions:First, when the renal pelvis was injected5ml/kg, concentration of1.0xl08cfu/standard Escherichia coli, we can get a relatively stable animal model of acute refluxendotoxemia caused by the renal pelvic pressure through different perfusion pressure,the animal model can be used for the simulation of the pathological process afterPNCL postoperative infection.Second, when the pelvis perfusion pressure≥40cmH2O,perfusion time≥60s, it is easy to form the renal pelvis reflux endotoxemia. and high renal pelvic pressure aremore likely to cause endotoxemia than the long times perfusion.Third, PCT has important significance for the prediction of the clinical MPCNLsevere postoperative infection. TNF-α has some restrictions for the diagnosis of earlyinfection after MPCNL, while CRP has no obvious significance. When the greater therenal pelvic pressure, the longer after surgery, the higher the serum creatinine level,the greater the tendency of acute kidney injury is.Fourth, Renal pelvic pressure exceeds the limit of reflux, the greater thepressure, natural mortality increased significantly24h after postoperation.