The Factors That Affecting Shockwave Lithotripsy Treatment Outcome of Kidney Stones

Objective: We analyzed the relation of shockwave lithotripsy (SWL) success and the combination of success predictors. Materials and Methods: In this retrospective study, the outcomes of 1.880 patients with kidney stones treated with SWL were analyzed. A total of 124 adult patients with complete records with non-contrast computed tomography, stone analysis, laboratory data were involved in the study. Patients who were with urinary system anomalies, who were receiving alpha-blocker and/or calcium channel blockers and whom with impaired kidney function were excluded. The effect of stone density, skin-to-stone distance (SSD), perirenal tissue density (PTD), subcutaneous tissue density (STD), stone size, stone burden, stone localization, infundibulopelvic angle (IA), body mass index (BMI) and stone analysis results on the success of the treatment was evaluated. Results: SSD, PTD, STD, stone localization, IA and BMI did not have any significant effect on SWL success. Stone size and stone burden had a significant association with treatment success (p=0.0001), and the cut-off values determined for stone size and stone burden were 12.95 mm (p=0.0006) and 121.38 [mm.sup.2] (p=0.004) respectively. Stone density also had a significant association with treatment success (p=0.0001), and the cut-off value determined for stone density was 739 Hounsfield Unit (p=0.001). Treatment success was significantly lower in cystine and calcium oxalate monohydrate stones compared to other stone types (p=0.019). Conclusion: Significant markers that determine SWL effectiveness are stone size, stone burden, stone density and stone type. Keywords: Shockwave lithotripsy, kidney stone, stone type