Risk factors for acute kidney injury after radical nephrectomy and inferior vena cava thrombectomy for renal cell carcinoma.

OBJECTIVE: The objectives of the present study are to estimate the incidence of postoperative acute kidney injury (AKI) after radical nephrectomy with inferior vena cava (IVC) thrombectomy for renal cell carcinoma (RCC) based on the Acute Kidney Injury Network (AKIN) criteria, to investigate the risk factors for postoperative AKI, and to define the association between postoperative AKI and clinical outcome in patients undergoing such a surgery.

METHODS: We retrospectively analyzed 76 patients (22 women; mean age, 56.9 years; range, 29-83 years) with RCC and IVC thrombus who underwent radical nephrectomy and IVC thrombectomy at our institute between January 2003 and December 2011. Postoperative AKI was diagnosed after surgery based on the AKIN criteria. Logistic regression was used to model the association between preoperative factors and the risk of AKI after surgery. The relationship between postoperative AKI and clinical outcomes, including chronic kidney disease (CKD), mortality, and days in hospital, was investigated.

RESULTS: Postoperative AKI was diagnosed in 41 patients (53.9%) based on the AKIN criteria (stage 1, n = 34; stage 2, n = 2; and stage 3, n = 5). Multivariate analysis demonstrated an independent association between postoperative AKI and male gender (odds ratio 4.79, 95% confidence interval: 1.13-20.39; P = .034), and IVC clamping time lasting more than 20 minutes (odds ratio 6.60, 95% confidence interval: 1.48-29.42; P = .013). Development of AKI was associated with an increased rate of postoperative CKD (43.9% vs 20.0%; P = .031) and prolonged hospitalization (17.7 vs 12.2 days; P = .047). Only one patient who had postoperative AKI required renal replacement therapy. There was no 30-day mortality during the study period and no difference in mortality between AKI and non-AKI patients (4.9% vs 5.7%; P = .859).

CONCLUSIONS: The incidence of postoperative AKI in patients with RCC and IVC thrombus was considerable. Intraoperative management seems to influence the risk of AKI after surgery; particularly, the longer the IVC clamping time, the higher the risk of postoperative AKI. Postoperative AKI was associated with postoperative CKD (P = .031), prolonged hospitalization (P = .047), and increased long-term mortality (1 year after surgery).