Analysis Of Changes In Renal Function After Radical Nephrectomy And Risk Factors For Secondary Acute Kidney Injury And Chronic Kidney Disease

Objective:To observe the changes of renal function in patients undergoing unilateral radical nephrectomy for kidney cancer in our hospital,and to explore the risk factors for perioperative AKI and long-term CKD.Methods:A retrospective analysis was performed for the clinical data of 102 patients with kidney cancer who received unilateral RN in China-Japan Union Hospital of Jilin University,including age,sex,BMI,SCR and UA,tumor pathological type,tumor location and surgical method（open/laparoscopic）,whether there was a history of diabetes,hypertension and smoking,and rGFR and renalGFR were obtained by⁹⁹m Tc-DTPA renal dynamic imaging,and the longest diameter of the tumor measured in the pathology report was used as the tumor size.The highest serum creatinine level within 7 days of radical nephrectomy was compared with the preoperative serum creatinine level,and patients were assessed and grouped according to KDIGO clinical practice guideline criteria.Based on the 1-year postoperative eGFR estimated by the MDRD formula,combined with the criteria for diagnosing CKD,reference K/DOQI guidelines:GFR<60 ml/min/1.73m²,and should last for 3 months or longer,patients who meet the criteria are divided into CKD group and non-CKD group.SPSS 27.0was used to statistically analyze the clinical data,and the measurement data were expressed as mean±standard deviation,and the t-test and one-way ANOVA were used for the comparison of the measurement data that conformed to the normal distribution,and vice versa.The counting data is expressed in frequency（rate）,and the（2 test）is used for comparison between groups.Pearson was used to analyze the correlation between rGFR and eGFR,and the relationship between clinical data and eGFR at 1 year postoperative was evaluated.Univariate comparison and multivariate logistic regression were used to analyze the risk factors for postoperative perioperative AKI and long-term CKD.P<0.05 was statistically significant.Results:A total of 102 patients were included in this study,60 males and 42 females,with a male to female ratio of 1.4:1.the mean BMI was 25.0±3.8（17.6-35.6）kg/m2and the mean age was 60.6±10.6（35-82）years.30.3%of the patients had a history of smoking,and chronic comorbidities included hypertension（30.3%）,diabetes mellitus（17.6%）).Postoperative pathology confirmed 90 cases（88%）of renal clear cell carcinoma,which was the predominant type.The non-clear cell carcinoma included 9cases of suspicious cell carcinoma,2 cases of papillary renal cell carcinoma,and 1case of TFE3 chromosomal ectopic renal cell carcinoma.The mean tumor size was4.8±1.9 cm,89（87.3%）cases were T1 stage and 13（12.7%）cases were T2 stage,and93.1%of patients underwent laparoscopic surgery.The mean preoperative eGFR was 89.9±21.0 ml/（min·1.73m2）in 102 patients,and the contralateral meanGFR was 44.5±10.2 ml/（min·1.73m2）higher than the affected meanGFR 40.8±13.3 ml/（min·1.73m2）.The overall meanGFR at 7 days postoperatively was 60.5±18.3 ml/（min·1.73m2）,a 32.7%decrease from the preoperative level,which was significantly different from the preoperative level（P<0.001）.The meanGFR at 3 months and 1 year postoperatively were 61.6±15.6ml/（min·1.73m2）and 64.8±16.2 ml/（min·1.73m2）,respectively,which were significantly different from each other（P<0.001）,but the comparison betweenGFR at7 days postoperatively andGFR at 3 months postoperatively was not statistically significant.Pearson’s concordance correlation analysis between preoperative rGFR assessed by 99m Tc-DTPA renal dynamic imaging method and preoperative eGFR measured by MDRD formula showed r=0.7454（95%CI:0.6443-0.8209）,P<0.001,indicating a significant correlation between the two.Sixty（58.8%）patients had postoperative AKI,and 58 of the 60 patients had stage1 AKI according to the KDIGO clinical practice guideline criteria,and the remaining2 patients had stage 2 and 3 AKI,respectively.They were divided into two groups according to the presence or absence of postoperative AKI,and a univariate analysis of variance was performed,which revealed statistically significant differences in gender,contralateralGFR,and smoking history between the two groups（P<0.05）.Multi-factor logistic regression analysis of the above statistically significant factors showed that low preoperative contralateralGFR（P<0.001）,male（P=0.047）and combined smoking history（P=0.024）were independent risk factors for the development of AKI after surgery.The risk of AKI after RN was 2.681 times higher in male patients than in female patients,and the risk of AKI after surgery was 3.79times higher in patients with a preoperative history of combined smoking than in patients with a non-smoking history.For serial changes inGFR and creatinine values within groups,in the non-AKI group（n=42）,the meanGFR decreased from 93.8±23.2 ml/（min·1.73m2）preoperatively to 74.4±16.6 ml/（min·1.73m2）postoperatively（P<0.001）,with no significant change thereafter（70.1±13.7 ml/（min·1.73m2）at 3 months after single nephrectomy）.13.7 ml/（min·1.73m2）3 months after single nephrectomy and71.4±15.2 ml/（min·1.73m2）1 year after single nephrectomy.in the AKI group（n=60）,the meanGFR decreased from 87.1±19.1 ml/（min·1.73m2）preoperatively to50.8±12.2 ml/（min·1.73m2）postoperatively（P<0.001）,and thereafter rebounded to60.2±15.4 ml/（min·1.73m2）1 year after surgery（P=0.0092）.In the comparison of creatinine values within groups,in the AKI group,the mean creatinine value increased from 81.0±19.4 umol/L to 131.4±37.9 umol/L postoperatively（P<0.001）,and no statistically significant comparison was seen between the means of the remaining time points.A total of 96 patients with preoperative eGFR>60 ml/min/1.73m2 were screened.Among them,35 cases had CKD after surgery,and the incidence of CKD was 36.5%.Statistical analysis revealed statistically significant differences in age,cystatin C,UA,eGFR,affectedGFR,contralateralGFR,and AKI in both groups（P<0.05）.Dichotomous multifactorial logistic regression analysis of the above statistically significant variables showed that AKI（P=0.007）was an independent risk factor for the development of CKD after radical nephrectomy,and the risk of new CKD was increased 5.248-fold in patients with postoperative AKI compared with those without AKI.Conclusion:After radical nephrectomy patients experience a significant decline in renal function,with early compensation of contralateral renal function occurring.Changes in postoperative renal function are influenced by a number of factors and preoperative99m Tc-DTPA renal dynamic imaging is recommended.Low preoperative contralateralGFR,being male and smoking are independent risk factors for postoperative AKI.Postoperative AKI is an independent risk factor for new onset of radical nephrectomy after The risk factor for new-onset CKD after radical nephrectomy is independent.