Role of biomarkers of acute kidney damage during lithotripsy of high-density stones

Aim. To obtain the information about functional state of kidneys in patients with urolithiasis before and after treatment, as well as to study the damaging effect of different types of energy used for fragmentation of high-density stones. Materials and methods. A total of 105 patients aged from 25 to 62 years with high-density stones were undergone to lithotripsy. In Group 1 (n=38), Group 2 (n=32) and Group 3 (n=35) contact laser lithotripsy, contact ultrasound lithotripsy and extracorporeal shock-wave lithotripsy was used, respectively. In all cases the clinical and biochemical blood and urine tests were performed as well as leukocyte migration inhibition test, selective proteinuria, a urine level of inteleukin-18 (IL-18) and urine NGAL (lipocalin-2) were assessed. The first examination was done the day before lithotripsy and the next ones were performed after 3 hours, on the 1st and 5th day after the intervention. Results. In all cases dense unilateral kidney stones of size 0.8-2 cm were detected. The stone-free rate after contact lithotripsy was 92.8%. After ESWL, the stone-free rate after two weeks was 94.9%. The average duration of lithotripsy in the Group 1, 2 and 3 was 40±3.8 min, 35±2.3 min and 32±3.6 min, respectively. Based on the level of biomarkers of AKI, laser lithotripsy allows to achieve stone fragmentation with the least damage. Conclusion. Our study proves that IL-18, NGAL, leukocyte migration inhibition test and selective proteinuria allows to diagnose AKI at early stages, as well as to objectively assess the functional state of the kidneys after lithotripsy. The obtained data proves that laser lithotripsy is the safest method as assessed by damaging effects on the kidney parenchyma.

urolithiasis, urinary stone disease, lithotripsy, kidney injury, biomarkers