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MP44-11 URETEROSCOPY VS. SHOCKWAVE LITHOTRIPSY FOR LOWER POLE RENAL STONES: TREATMENT VARIATION AND OUTCOMES IN A SURGICAL COLLABORATIVE

INTRODUCTION AND OBJECTIVE: American Urological Association guidelines recommend ureteroscopy (URS) or shockwave lithotripsy (SWL) for lower pole (LP) renal stones 1cm, and URS for stones >1-2cm. However, data guiding these recommendations are from select centers. We examined treatment variation, unplanned healthcare utilization and stone-free rates (SFR) in the diverse practices comprising the Michigan Urological Surgery Improvement Collaborative (MUSIC). METHODS: Using the MUSIC registry we identified URS and SWL cases for LP stones 2cm from 2016-2021. We assessed practice and surgeon frequency of performing URS or SWL. A treatment modality was considered favored if the procedure rate was >50%. Emergency department (ED) visits, hospitalization and SFRs were assessed according to stone size ( 1, >1-2cm). RESULTS: 3,645 procedures were performed across 35 practices and 209 surgeons; 1358 (37.3%) URS and 2287 (62.7%) SWL. 80.2% of stones were 1cm. There was practice variation in performing URS (0 to 100%; p<0.001) and SWL (0 to 100%; p<0.001). 74.2% of surgeons favored SWL; 10% performed SWL, and 5.7% URS exclusively (Figure). For stones 1cm, ED visits (9.5% vs 2.5%, p<0.001) and hospitalizations (3.5% vs 0.4%, p<0.001) were higher after URS, as were SFRs (URS 56.4% vs SWL 38.8%; p<0.001). There were no significant differences between URS and SWL for ED visits, hospitalizations, or SFRs, for >1-2cm stones. Multivariable analysis revealed significantly increased odd of having an ED visit and being stone-free for all LP stones 2cm and 1cm treated with URS (Table). CONCLUSIONS: In Michigan, SWL is the favored treatment modality for LP stones 2cm. Over 15% of surgeons used one modality exclusively. URS provided better SFRs but with a 4-fold increase in ED visits and hospitalization for stones 1cm but no difference for >1-2cm stones. Our findings demonstrate the need for quality efforts to address treatment selection and improve outcomes. Source of Funding: Blue Cross Blue Shield of Michigan