NGAL as a Renai Injury Marker: A Prospective Randomized Trial using Wolf Piezolith 3000

Abstract

Background Shock wave lithotripsy (SWL) has proven to be safe and effective for renal stone treatment. The shock wave rate used during the SWL procedure causes cavitation, which is the phenomenon responsible for stone fragmentation and may be responsible for tissue and vascular damages ascribed to lithotripsy. Neutrophil Gelatinase-Associated Lipocalin (NGAL) has been shown to be one of the earliest and most overexpressed markers in case of cellular damage in the kidney. Objective Using a new generation piezoelectric lithotripter, we evaluated the relation between renal damage, stone fragmentation rate, pain and shock wave rate delivered during SWL. Materials and Methods 80 patients suffering from a single renal stone were included in our clinical trial and underwent SWL with Wolf PiezoLith 300 lithotripter. A urine sample was collected in 54 patients (30 belonging to Group A, 24 to Group B) before treatment, within 2 hours and 72 hours after SWL, for NGAL measurement. Results The stone fragmentation rate obtained in the 2 groups was practically the same 30 days after SWL, with an efficacy rate of 72.7% in Group A and of 73.3% in Group B. NGAL increased after treatment, but was not statistically different in the two groups, and returned to the baseline value after 72 h. Furthermore, NGAL was always well below the threshold value of 350 ng/mL, indicative of acute renal failure. Conclusions The best stone fragmentation rate achievable with a piezoelectric lithotripter can be reached with a higher shock wave rate without significant renal damage, thus optimizing the treatment time.