Trends of acute kidney injury after radical or partial nephrectomy for renal cell carcinoma

OBJECTIVES: To investigate the prevalence, temporal trends, and predictors of postoperative acute kidney injury (AKI) in a large cohort of patients with renal cell carcinoma treated with radical or partial nephrectomy.

METHODS: Between January 1998 and December 2010, patients who underwent radical or partial tumor nephrectomy were identified within the Nationwide Inpatient Sample. First, prevalence and temporal trends of AKI were analyzed. Second, predictors of AKI were identified using multivariable regression analyses. Third, associations between AKI and in-hospital complications, length of stay, hospital costs, and in-hospital mortality were evaluated using logistic regression models adjusted for clustering.

RESULTS: Of total 253,046 patients, 5.5% (14,303 in radical and 3,525 in partial nephrectomy) experienced AKI. Rates of AKI significantly increased from 2.0% in 1998 to 10.4% in 2010 (P<0.001). Predictors of AKI included male sex, radical nephrectomy, more contemporary years (2004-2010), older age, black race, higher comorbidities, higher preoperative chronic kidney disease stage, Medicare insurance status, and nephrectomy at urban hospitals (all P<0.01). Postoperative AKI during hospitalization was associated with an increased rate of in-hospital mortality, any complications, transfusion, prolonged length of stay, and higher hospital costs (all P<0.001).

CONCLUSIONS: Rising rates of in-hospital AKI after radical and partial nephrectomy were observed. Increasing awareness of AKI, identification of patients at risk before surgery, early postoperative AKI diagnosis, collaboration with nephrologists, implementation of renoprotective strategies, long-term renal functional follow-up, and a well-designed prospective study, may be warranted.