Acute kidney injury after nephrectomy: a new nomogram to predict postoperative renal function

BACKGROUND: We aimed to develop a nomogram based on preprocedural features for early prediction of acute kidney injury (AKI) and to assess the prognosis in patients after radical and partial nephrectomy. METHODS: The study included a development cohort of 1111 patients who were treated between June 2012 and June 2017 and an additional validation cohort of 356 patients who were treated between July 2017 and June 2018. Stepwise regression and logistic regression analyses were used to evaluate the association between predictors and AKI. Incorporating all independent predictors, a nomogram for postoperative AKI was developed and externally validated. Patients were followed up for 5 years to assess renal function, acute kidney disease (AKD), chronic kidney disease (CKD), hospital readmission and mortality were key prognosis we focused on. RESULTS: After multivariate logistic regression, radical nephrectomy (odds ratio (OR) = 3.57, p < 0.001), aspirin (OR = 1.79, p = 0.008), systolic blood pressure (OR = 1.41, p = 0.004), triglyceride (OR = 1.26, p = 0.024), and alkaline phosphatase (OR = 1.75, p = 0.034) were independent risk factors for postoperative AKI, while albumin (OR = 0.72, p = 0.031) was a protective factor for postoperative AKI. Patients with a higher estimated glomerular filtration rate (eGFR) (60–90 ml/min/1.73 m(2), OR = 0.41, p = 0.004; ≥ 90 ml/min/1.73 m(2), OR = 0.37, p < 0.001) were less prone to AKI than those with a lower eGFR (< 15 ml/min/1.73 m(2)). These predictors were all included in the final nomogram. The area under the receiver operating characteristics curve for the model were 0.77 (p < 0.001) in the development cohort and 0.72 (p < 0.001) in the validation cohort. The incidence of AKD and CKD were 27.12 and 18.64% in AKI group, which were much higher than those in no AKI group (p < 0.001). CONCLUSIONS: The nomogram had excellent predictive ability and might have significant clinical implications for the early detection of AKI in patients undergoing nephrectomy.