Abstract: PD20-11
Sources of Funding: None

Introduction

Acute kidney injury (AKI) is associated with increased risk of developing chronic kidney disease (CKD) in the general population. AKI is frequently observed after partial nephrectomy (PN), however the long-term functional impact of AKI in this setting has not been adequately studied.

Methods

From 2004-2014, 90 solitary kidneys managed with PN had necessary studies for analysis of percent function and renal parenchyma preserved before and after surgery. Functional data including serum creatinine (SCr) and glomerular filtration rate (GFR) was required at all of the following time points: pre-operative (<3 months prior to PN), peak post-operative, new baseline (3-12 months post-operative), and long-term (>12 months post-operative). AKI was classified by RIFLE (Risk/Injury/Failure/Loss/End?stage) defined by either standard criteria (comparison of peak SCr to preoperative SCr) or proposed criteria (comparison to projected postoperative SCr based on parenchymal mass reduction). Long-term functional deterioration was defined as decline in GFR >20% between new baseline and long-term follow-up, or need for dialysis >12 months post-operatively. Relationship between AKI grade and long-term functional outcomes was assessed by multivariable logistic regression, controlling for pertinent patient, tumor, and perioperative characteristics.

Results

Median age was 64 years. Median duration of follow-up was 45 (IQR=29-90) months. Warm ischemia was used in 47% of patients, and overall median ischemia time was 29 minutes. Median parenchymal mass preservation was 80% and median GFR preserved was 79%. Based on standard criteria, AKI grade 1/2/3 occurred in 31%, 19%, and 18%, respectively, and analogous findings for the proposed criteria were 22%, 13%, and 7%. Fourteen (16%) patients experienced long-term functional decline. On multivariable analysis, presence of AKI and degree of AKI did not associated with long-term functional decline after PN, whether defined by standard or proposed criteria (all p>0.5). Limitations include retrospective design.

Conclusions

AKI related to surgery (AKI-S) may not have the same adverse functional implications as AKI due to medical causes (AKI-M). AKI-M is typically due to longstanding medical comorbidities, such as CHF, while AKI-S is primarily due to a transient ischemia insult that will not be repeated. Additional study, with larger sample sizes and longer follow-up will be required to further elucidate the relationship between AKI and CKD after PN.

Funding

None