Bravi CA, Vertosick E, Benfante N, et al. - The data of 1,893 patients treated by partial nephrectomy for a single cT1 N0 M0 renal mass was investigated by experts to examine the correlation between acute kidney injury (AKI) and renal function 1 year following partial nephrectomy, and whether this association was impacted by the term of AKI. A total of 388 patients experienced AKI following surgery. The rate of patients recovering 90% of baseline function was lower in the AKI group, while the proportion of patients who had chronic kidney disease (CKD) upstaging was significantly greater. AKI was correlated with worse renal function 1 year following partial nephrectomy, despite the outcome of interest. Longer AKI increased the risk of functional decline, principally following the third day of injury. For an average patient who had 1–3 vs ≥ 4 days of AKI, the risk of CKD upstaging was 46%. Therefore, AKI negatively impacted long-term functional recovery following partial nephrectomy, and hence, modifiable factors related to AKI should be recognized and fixed preoperatively. The investigators concluded that the duration of injury is informative, and should be included in AKI evaluation and in future trials studying this topic.