Background
Observational studies on the association of endourological procedures with renal parenchymal damage are lacking. This randomized trial examined the effect of standard-percutaneous-nephrolithotomy (sPCNL) in comparison to miniaturized-PCNL (mini-PCNL) and retrograde-intrarenal-surgery (RIRS) for nephrolithiasis treatment on novel biomarkers of renal injury.
Methods
Seventy-five patients were randomized in 1:1:1 ratio to receive sPCNL, mini-PCNL and RIRS for nephrolithiasis. The ratios of neutrophil-gelatinase-associated-lipocalin (NGAL), kidney injury molecule-1 (KIM-1), and interleukin-18 (IL-18) normalized for urinary creatinine (Cr) were calculated from urine samples collected at baseline (2-hours-preoperatively) and at 2, 6, 24 and 48-hours postoperatively. Two-way mixed ANOVA for repeated measurements was used to evaluate the effects of type of procedure and time on studied biomarkers.
Results
Between baseline and 2-hours postoperatively, no significant differences were observed in NGAL/Cr changes between sPCNL [9.46(4.82-14.9)], mini-PCNL [12.78(1.69-25.24)] and RIRS [6.42(2.61-23.90)](p = 0.902). Similarly, no between-group differences were observed of KIM-1/Cr (p = 0.853) and IL-18(p = 0.980) at 2-hours, and all biomarkers at any time-point postoperatively. Within-groups, significant increases from baseline were noted for NGAL/Cr (sPCNL p<0.001; mini-PCNL p<0.001; RIRS, p = 0.001), KIM-1/Cr and IL-18/Cr at 2-hours; progressively lower increases from baseline were noted in all groups for KIM-1/Cr and IL-18/Cr at 6-, 24- and 48-hours postoperatively. As such a significant effect of time but not of type of procedure was evidenced with two-way mixed ANOVA. No significant between-group differences were observed in acute-kidney-injury incidence and complications.
Conclusions
The endourological procedures under study are associated with similar patterns of early tubular injury, detected by novel biomarkers, that is largely reduced within 48 hours and no changes in glomerular function.
