Early Biohumoral Detection of Acute Kidney Injury After Robotic Renal Surgery and Its Impact on Medium-Term Renal Function

Renal surgery for localized renal cell carcinoma carries substantial risk of acute kidney injury (AKI) regardless of surgical approach. This prospective study evaluated early biohumoral markers for AKI detection after robotic renal surgery and assessed their prognostic value for 12-month functional outcomes. Adults undergoing robotic renal tumor surgery with a healthy contralateral kidney were enrolled; AKI followed KDIGO 2012 criteria. Biomarkers measured at baseline and 2/24/72 h were serum β2-microglobulin (sβ2) serum IL-6, as well as urinary β2-microglobulin (uβ2), cystatin C (uC), and α2-macroglobulin (uα2M). Kidney function at 12 months was staged according to KDOQI criteria. Among 170 patients (35 radical nephrectomy, RN; 135 partial nephrectomy, PN), 33 developed AKI, more frequently after RN (p < 0.001); baseline biomarkers levels were similar. sβ2 was significantly higher at 2/24/72 h, and at 2 h, it achieved an AUC of 0.78 (cut-off 0.17: sensitivity 82%, specificity 60%), remaining the earliest independent predictor of AKI (p = 0.015). IL-6 differed at 24 h (AUC 0.80), uC at 72 h (AUC 0.73) and uβ2 at 72 h (AUC 0.66). Clinical AKI predicted KDOQI stage progression at 12 months (p < 0.001). Bulldog clamps (mean ischemia time 17.2 ± 6.9 min) were not associated with AKI (p = 0.99) or with KDOQI stage progression (p = 0.54). RN confers a higher AKI risk than PN. sβ2 at 2 h is the earliest actionable marker, complemented by IL-6 (24 h) and uC (72 h); short warm ischemia during robotic PN appears safe. Sequential multimarker assessment may improve recognition of AKI and support timely nephroprotective strategies.