Clinical Feature And Metabolic Global Profiling Of Post-surgery Acute Kidney Injury In Kidney Stone Patients

Part 1 A monocentric epidemiological survey of acute kidney injury after urolithiasis surgeryObjective To investigate the incidence of acute kidney injury(AKI)after urolithiasis surgery.Methods Clinical data of the patients who developed AKI after urolithiasis surgery from January 2011to November 2013 in Changhai Hospital were analyzed.The patientsunderwent percutaneous nephrolithotomy(PCNL),ureteroscopic nephrolithotomy and ureteros-cope flexible ureteroscope(FURL),respectively.The incidence of postoperative AKI was detected.Results A total of 526patients were enrolled in this study.There were 364 males and 162females with an average age of(50±13)years(range,18to 78 years).The incidence of AKI after PCNL and ureteroscopic nephrolithotomy was 13.0%(16/123)and 9.4%(13/139,P>0.05),respectively.The incidence of AKI after FURL was 3.4%(9/264),which was significantly lower than that after PCNL and ureteroscopic nephrolithotomy(both P<0.05).Multivariate logistic regression analysis revealed that preoperative serum creatinine concentration(OR =1.006,95%CI:1.001-1.012,P =0.012)and operative methods(PCNL vs.FURL,OR=4.774,95%CI:1.999-11.399,P<0.000 l;ureteroscope vs.FURL,OR= 2.923,95%CI:1.181-7.234,P<0.000 1)were the main risk factors for predicting postoperative AKI.Conclusion Surgical treatment for urolithiasis can cause renal damage.Preoperative serum creatinine concentration and operation method are independent risk factors of postoperative AKI.(Shanghai Med J,2014,37:386-388)Part 2 Analysis of urine metabolic profiles after ureteroscopy lithotripsyin patients with renal calculiObjective To seek urine specimen-based potential biomarkers of acute kidney injury(AKI)after ureteroscopy lithotripsy(URSL)and explore possible metabolic pathways.Methods Urine specimens were collected in patients with renal calculi 12hbefore and after URSL and analyzed using ultra-high performance liquid chromatography-quadruped time-of-flight mass spectrometry(UHPLC-Q-TOF/MS).Data schemas were identified by principal component analysis(PCA)and partial least squares discriminant analysis(PLS-DA).Finally,potential biomarkers were screened to construct possible metabolic pathways.Results Endogenous metabolites underwent significant changes after URSL as compared with those before the procedure.Of the 25 potential biomarkers identified by preliminary screening,10substances(mainly including carnitines and unsaturated fatty acids)were up-regulated,and the other 15substances(mainly including amino acids and their metabolites)were down-regulated postoperatively group.Conclusion The main potential biomarkers of AKI after URSL are amino acids and their metabolites,carnitines,and unsaturated fatty acids.The possible mechanisms may be related to cellular and mitochondrial injuries arising from renal oxidative stress or free radicals or inflammatory mediators released during the inflammatory response after URSL.