The Use of Tissue Markers of Kidney Injury KIM1 and NAG to Compare between Effect of Extra Corporeal Shock Wave Lithotripsy and Retrograde Intrarenal Surgery on Renal Tissue for Early Detection of Kidney Injury in Managing Renal Stone ≤ 2 cm

Abstract Background Retrograde Intrarenal surgery (RIRS) and Extracorporeal shock wave lithotripsy (ESWL) are well-established treatment options for treatment of kidney stones. Kidney injury molecule 1 (KIM-1) and N-acetyl-β-D-glucosaminidase (NAG) are two proteins secreted by the kidney into the urine and have been found to be sensitive markers of acute kidney injury. The aim of this study is to compare between RIRS and ESWL effect on renal tissue and detect early signs of kidney injury by measuring urinary levels of KIM-1and NAG in patients with kidney stone who were treated by ESWL and RIRS. Objective To compare between effect of ESWL and RIRS on renal tissue and detect early signs of AKI through using new biomarkers for AKI (KIM-1, NAG) in managing renal stone ≤ 2 cm Patients and Methods This prospective randomized study was conducted in urology department Ain Shams university hospitals and in urology department of Theodor Bilharz Research Institute hospital during the period from 4/2022 till 4/2023 after obtaining Ain Shams university ethics committee approval (No. FWA 000017585). Results This study revealed highly statistically significant increased 24-hour post-operative KIM-1/Cr and NAG/Cr in group A (ESWL) (4.59 ± 0.94) and (0.22 ± 0.04) when compared with group B (RIRS) (2.22 ± 0.65) and (0.13 ± 0.03). In group A (ESWL) there was high statistically significant increase in 24-hour post-operative KIM-1/Cr (4.59 ± 0.94) and NAG/Cr (0.22 ± 0.04) when compared with pre-operative KIM-1/Cr (2.26 ± 0.45) and NAG/Cr (0.12 ± 0.04), while in group B (RIRS) there was only statistically significant increased 24-hour post-operative NAG/Cr (0.13 ± 0.03) when compared with pre-operative NAG/Cr (0.11 ± 0.03) with no statistical significant difference between pre-operative KIM-1/Cr (2.22 ± 0.51) and 24-hour post-operative KIM-1/Cr (2.22 ± 0.65). Conclusion Patients with known renal impairment or decreased renal functions suffering from renal stone ≤ 2 cm we recommend management of stone using RIRS over ESWL and in case of ESWL being the only option we recommend use of lower number of shock waves per setting.