Rsearch Of Contralateral Renal Function Compensation With Severe Unilateral Hydronephrosis

Objective:To explore the clinically relevant indicators that can reflect the difference of renal compensatory functions after unilateral severe hydronephrosis,and to reflect the strength of compensatory function of the contralateral kidney and find out the related factors affecting the compensatory ability of the contralateral kidney,to determine the critical value of the best index that can predict whether the contralateral kidney plays a significant compensatory function after unilateral severe hydronephrosis and its prediction accuracy,thus provide theoretical basis for better and full play of renal compensatory ability.Methods:A total of 302 patients were selected with unilateral severe hydronephrosis and contralateral renal health who were admitted to the Department of Urology,Third Xiangya Hospital,Central South University from January 2013 to December 2019,all patients underwent complete blood routine,urine routine,liver and kidney function and other blood biochemical tests,as well as thoracoabdominal CT and nephrogram tests within one week after admission,the history of patients was reviewed and the relevant information was collected.The glomerular filtration rate（GFR）of bilateral kidneys was determined by ^99mTC-DTPA renal dynamic imaging,which reflected bilateral renal function and the percentage of GFR in the total GFR of the contralateral kidney（%GFR）was calculated.The all patients were divided into 4 groups according to age,namely（1）≤30 years old;（2）30 years old<age≤40 years old;（3）40years old<age≤50 years old;（4）>50 years old,according to the upper limit of unilateral normal kidney age of all ages in the"Diagnostic and Therapeutic Practices of Nuclear Medicine",the GFR of the contralateral kidney in different age groups was compared with this value,and whether the contralateral kidney compensatory ability was obvious or not was analyzed,and the contralateral kidney compensatory rate（%）was calculated according to the formula,renal compensation rate（%）=（renal GFR-normal upper limit GFR）/normal upper limit GFR×100%.All of the above indexes were recorded,the all patients were divided into two groups according to the value of renal compensation rate,namely,the compensatory function of the contralateral kidney was obvious（the compensatory rate was positive）and the compensatory function of the contralateral kidney was not obvious（the compensatory rate was negative）.The differences of clinical indicators between the two groups were analyzed.Univariate and multivariate logistic regression analysis were performed on the indicators with differences,the ROC curve analysis was drawn to reflect the independent predictors of kidney compensatory significance and the optimal threshold,and the accuracy and specificity of these indexes were analyzed to reflect the compensatory ability of the contralateral kidney.Results:A total of 302 patients were included in the study,including151 males and 151 females,age were（50.5±15.33）years,body mass index（BMI）was（23.54±3.44）kg/㎡,the contralateral renal compensation rate was（5.11±23.76）%,the contralateral renal function percentage was（76.91±12.12）%,95 patients with the history of hypertension,10 patients with the history of diabetes,41 patients with the history of smoking,22patients with the history of drinking,17 patients with the history of taking Chinese adult drugs,and CT showed vascular calcification in 154 patients,the contralateral kidney GFR was 57.53±14.1 m L/min,the affected kidney GFR was 18.68±13.17 m L/min.The PH value of urine was normal in 260 cases,acidic in 41 cases,alkaline in 1 case,hematuria in102 cases,proteinuria in 72 cases,hydronephritis（including renal calculi and ureteral calculi）in 234 cases and stricture（including UPJO and ureteral stricture）in 68 cases.All the above patients were divided into 2groups according to whether the value of the compensation rate was positive or not,and a statistical analysis was performed on the clinical indicators of the two groups.Univariate logistic regression analysis showed that the contralateral kidney GFR（OR=1.35,95%[CI]1.255-1.452,P<0.001）,percentage of the contralateral kidney function（OR=1.047,95%[CI]1.026-1.068,P<0.001）,serum creatinine（OR=0.981,95%[CI]0.971-0.991,P<0.001）,hemoglobin（OR=1.018,95%[CI]1.005-1.031,P<0.05）,red blood cell count（OR=1.643,95%[CI]1.074-2.514,P<0.05）,hematocrit（OR=1.055,95%[CI]1.007-1.105,P<0.05）,absolute value of neutrophil（OR=0.841,95%[CI]0.734-0.964,P<0.05）,white blood cell count（OR=0.849,95%[CI]0.753-0.958,P<0.05）,globulin（OR=0.942,95%[CI]0.901-0.985,P<0.05）,white ball ratio（OR=2.079,[CI]1.088-3.973,P<0.05）,proteinuria（OR=0.575,[CI]0.338-0.98,P<0.05）and renal compensation rate were statistically significant.Multivariate logistic regression analysis showed that the contralateral kidney GFR（OR=1.436,95%[CI]1.299-1.587,P<0.001）,the contralateral kidney percentage of kidney function（OR=1.051,95%[CI]1.011-1.093,P=0.013）and white blood cell count（OR=0.488,95%[CI]0.246-0.966,P=0.04）were independent predictors of the difference in renal compensatory function.Among them,GFR>50.305 m L/min,renal function percentage>84.95%,white blood cell count<6.665×10⁹/L were the best critical values for predicting the obvious compensatory function of the contralateral kidney,and AUC（area under ROC curve）were 0.94（95%[CI],respectively.0.917-0.964）,0.648（95%[CI],0.586-0.711）,0.592（95%[CI],0.526-0.657）,with sensitivity of98.9%,40.2%,43.8%,and specificity of 72.7%,80.5%,75.3%,respectively.Conclusion:Evaluation of the related factors that can reflect the difference of compensatory ability of the contralateral kidney after unilateral severe hydronephrosis,blood routine,urine routine,liver and kidney function and other related clinical indicators have certain reference value.Among them,serum creatinine,hemoglobin,red blood cell count,hematocrit,neutrophil absolute value,globulin,albuminuria and other clinical indicators were correlated with the difference of renal compensatory ability to a certain extent.The contralateral kidney GFR,percentage of the contralater kidney renal function（%GFR）and blood white blood cell count were independent predictors of the difference of the contralateral kidney compensatory ability,namely,when the contralateral kidney GFR>50.305ml/min,percentage of the contralateral kidney renal function>84.95%,and blood white blood cell count<6.665×10⁹/L,Compared with unilateral normal kidney GFR,the contralateral kidney showed a stronger compensatory capacity with hyperfiltration.However,in order to evaluate the compensatory ability of the contralateral kidney comprehensively,more aspects should be considered.