Risk factors for steinstrasse formation after extracorporeal shock wave lithotripsy for renal pelvic stones

BACKGROUND: This study aimed to identify predictive factors for the formation of steinstrasse following extracorporeal shock wave lithotripsy (SWL) in patients with medium-sized (10-20 mm) renal pelvic stones. METHODS: This retrospective cohort study, data of 718 patients who underwent SWL for urinary tract stones were analyzed and single, unilateral, radio-opaque renal pelvic stones were included in the study. Patient age, sex, stone side, shape (round/non-round), size, surface area (SA), and presence of hydronephrosis were recorded. Patients were divided into two groups depending on the presence of steinstrasse: Group 1 (with steinstrasse) and Group 2 (without). Demographic, clinical, and radiological parameters were compared between the groups. RESULTS: ; p = 0.044). Round stones were more frequently observed in Group 1, whereas non-round stones predominated in Group 2 (83.3% vs. 62.5%, respectively; p = 0.008). The overall SWL success rate was determined as 76.9%. Logistic regression analysis revealed that round stones increased the risk of steinstrasse by 8.333 times (OR = 8.333, 95% CI = 1.604-43.288, p = 0.012). CONCLUSIONS: SA was higher in patients who developed steinstrasse. Since the likelihood of steinstrasse formation is elevated in medium-sized round renal pelvic stones, pre-stenting may be appropriate.