The variation of selective uNGAL levels after robot-assisted partial nephrectomy: Early results of a prospective single center study

Objectives: Acute kidney injury (AKI) secondary to nephron-sparing surgery represents a significant problem in order to preserve renal function. Since serum creatinine alone underestimates the early detection of AKI several biomarker have been investigated. Neutrophil Gelatinase-Associated Lipocalin (NGAL) is considered a good biomarker for AKI.
Materials and methods: We report our experience in 28 patients affected by localized renal cell carcinoma and submitted to robot-assisted partial nephrectomy (RAPN). In each patient selective urinary NGAL levels were dosed before surgery, then 2 and 48 hours after the procedure, through a ureteral catheter inserted into the excretory axis of the operated kidney. Moreover, we evaluated split renal function of the preserved renal parenchyma by a 99mTC-DTPA renal scintigraphy, performed before surgery and three months later.
Results: AKI was diagnosed, according to internationally criteria, in 3 patients (10.7%). The baseline selective urinary NGAL level was 20.02 ng/ml. This level significantly increased after surgery with a selective urinary NGAL level that reached 56.36 ng/ml (p < 0.0001). Moreover, a significant reduction in 99mTC-DTPA clearance of the operated kidneys after three months was detected (p < 0.0001).
Conclusions: Selective urinary NGAL assay represent a sensitive biomarker of acute kidney injury after robotic nephron sparing surgery, capable of predicting the functional outcome of the operated kidney.