Post-operative acute kidney injury in patients with renal cell carcinoma is a potent risk factor for new-onset chronic kidney disease after radical nephrectomy

Abstract

Background: Radical nephrectomy is a significant risk factor for chronic kidney disease (CKD). There are few reports on the renal outcome of acute kidney injury (AKI) after radical nephrectomy. The aim of this study was to determine the incidence of AKI and whether post-operative AKI is associated with new-onset CKD after radical nephrectomy for renal cell cancer (RCC).

Methods: We conducted a retrospective study of 519 adult patients (>40 years old) with normal renal function who underwent unilateral radical nephrectomy for a solitary renal cortical tumour and were pathologically diagnosed with RCC between January 2000 and February 2007. Post-operative AKI was classed using risk, injury, failure, loss and end-stage kidney disease (RIFLE) criteria. CKD was defined as a decrease in estimated glomerular filtration rate (GFR) to <60 mL/min/1.73 m(2).

Results: According to the RIFLE criteria, 165 of 175 patients fell into the AKI risk category, 8 patients fell into the AKI injury category and 2 patients fell into the AKI failure category. Multivariate analysis revealed that older age [odds ratio (OR) 1.02, 95% confidence interval (CI) 1.00-1.05], male gender (OR 3.13, 95% CI 1.91-5.12), higher body mass index (OR 1.08, 95% CI 1.01-1.15), smaller RCC size (OR 0.87, 95% CI 0.81-0.93) and higher preoperative GFR (OR 1.04, 95% CI 1.03-1.06) were independent risk factors for post-operative AKI. CKD was more prevalent in the AKI risk group than in patients without AKI 1 year after surgery (54.7% versus 43.9%, respectively; P = 0.006) and 3 years after surgery (50% versus 32%, respectively; P = 0.003). Patients who experienced post-operative AKI had a 4.24-fold higher risk of new-onset CKD after multiple adjustments were made to the data (95% CI 2.28-7.89, P < 0.001).

Conclusion: AKI after radical nephrectomy in patients with RCC is a potent risk factor for new-onset CKD. Prevention of post-operative AKI is essential for reducing the incidence of CKD after nephrectomy.