You have accessJournal of UrologyStone Disease: Surgical Therapy III (MP15)1 Apr 2020MP15-09 DISPLACING STONES FROM THE LOWER POLE DURING RETROGRADE INTRARENAL SURGERY (RIRS): IMPROVED STONE FREE RATES OR A WASTE OF TIME? A PROSPECTIVE RANDOMIZED STUDY Blair Gallante*, Jacob N. Bamberger, William Atallah, Anna Zampini, and Mantu Gupta Blair Gallante*Blair Gallante* More articles by this author , Jacob N. BambergerJacob N. Bamberger More articles by this author , William AtallahWilliam Atallah More articles by this author , Anna ZampiniAnna Zampini More articles by this author , and Mantu GuptaMantu Gupta More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000840.09AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Renal stones located in the lower pole (LP) are more difficult to access, fragment, and are more likely to cause ureteroscope damage and result in residual fragments (RF). To improve the stone free rate and decrease damage to the ureteroscope, some urologists will displace a LP stone to a more accessible part of the kidney. Although some have advocated using this technique, its benefit has not been definitively demonstrated on stone clearance and other treatment parameters. Retrospective work has shown that a higher stone free rate can be obtained by using this technique when treating lower pole calculi 1 to 2cm. We sought to prospectively compare the effect of stone fragmentation in situ versus fragmentation after displacing the stone on stone clearance in patients with LP stones. Our primary outcome was stone free rates. METHODS: In this prospective, randomized study, patients were included if they had stones only in the LP, total stone burden was 7-15 mm, and did not have anatomic kidney abnormalities, pre-existing ureteral stents, or ureteral stones. Patients were randomized into the in situ or displacement group prior to URS. Demographics, comorbidities, and operative parameters were documented. We determined stone free rates using renal ultrasound and abdominal x-ray (KUB) at 1-month follow-up. Mann-Whitney U and Chi-Square tests were conducted to assess differences between the groups. RESULTS: Our data includes 68 patients. 29 in situ patients and 39 displaced patients have completed the study with imaging. Displaced stone patients had higher stone free rates when compared to in situ patients (97% vs. 83%, p=.035). In addition, both total surgery time and total laser energy were higher in the displaced group (p=.005 and p=.049). CONCLUSIONS: Displacing LP stones may require more OR time, but does improve stone free rates when compared to patients who are treated in situ. Increased OR time and laser energy may be due to the time it takes to displace the stone and time spent to achieve complete stone fragmentation and removal. Source of Funding: None © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 203Issue Supplement 4April 2020Page: e207-e208 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.MetricsAuthor Information Blair Gallante* More articles by this author Jacob N. Bamberger More articles by this author William Atallah More articles by this author Anna Zampini More articles by this author Mantu Gupta More articles by this author Expand All Advertisement PDF downloadLoading ...