Endourology & Stone Disease(구연) (E-171) Predictors of successful oral dissolution therapy for urolithiasis 경북대학교 의과대학 비뇨의학과교실 Jeong Seok Oh, Kyungchan Min, Kyeong-Hyeon Byeon, Seung Yun Yi, Eun Sang Yoo, Jun Nyung Lee, Jae-Wook Chung, Bum Soo Kim Background and purpose: With the development of technology, most of urolithiasis can be managed by minimal-invasive therapy, such as extracorporeal shock wave lithotripsy (ESWL) and endoscopic surgery. However, there are still some cases, which are hard to be managed by these minimal-invasive therapy depending on the patients’ comorbidity. Chemolysis using oral agents, such as potassium citrate or sodium bicarbonate can be an alternate in these cases. Since this oral chemolysis is not always successful to dissolute the urolithiasis, we tried to analyze the predictive factors of successful oral dissolution in patients with urolithiasis. Materials and Methods: We retrospectively reviewed the medical records of 69 patients who received oral dissolution therapy at least 2 months using potassium citrate or sodium bicarbonate for urolithiasis from January 2010 to December 2019. Treatment outcome was assessed at 6 months after starting medication and success was defined as complete dissolution and disappearance of stones at non-contrast CT. All patients were divided into 2 groups according to the success of oral dissolution therapy and characteristics of patients and stones, laboratory findings and medication duration were compared. Multivariate analysis was performed to identify the predictors of successful oral dissolution therapy. Results: Of the 69 patients, complete dissolution was observed in 35 patients (50.7%). Comorbid hypertension rate was lower in dissolution group compared to non-dissolution group (37.1% vs 64.7%, p=0.022). The mean stone attenuation value (hounsfield unit, HU) was significantly lower in dissolution group compared to non-dissolution group (471.14±161.00 vs 644.41±440.79, p=0.033). Multivariate analysis revealed that HU and comorbid HTN were predictive factors of successful dissolution of urolithiasis in patients who underwent oral dissolution therapy. The cut-off value of HU using ROC curve was 475 (Sensitivity 61.8% Specificity 51.4%). Conclusions: Although it is not always successful, oral dissolution therapy can be effectively tried in patients with urolithiasis who are not good candidates for minimal-invasive therapy. This study demonstrated that absence of comorbid HTN and low HU can be predictors of successful oral dissolution therapy in patients with urolithiasis. keywords : rolithiasis, chemolysis, predictive factors