MP69-19 STONE SIZE ON ENDOSCOPIC VIEW AS A PREDICTOR OF SUCCESSFUL STONE RETRIEVAL DURING FLEXIBLE URETEROSCOPY

Abstract

You have accessJournal of UrologyStone Disease: Surgical Therapy VII (MP69)1 Apr 2020MP69-19 STONE SIZE ON ENDOSCOPIC VIEW AS A PREDICTOR OF SUCCESSFUL STONE RETRIEVAL DURING FLEXIBLE URETEROSCOPY Joseph Randall*, Raphael Carrera, David Duchene, Kerri Thurmon, Donald Neff, Wilson Molina, and Paul Fletcher Joseph Randall*Joseph Randall* More articles by this author , Raphael CarreraRaphael Carrera More articles by this author , David DucheneDavid Duchene More articles by this author , Kerri ThurmonKerri Thurmon More articles by this author , Donald NeffDonald Neff More articles by this author , Wilson MolinaWilson Molina More articles by this author , and Paul FletcherPaul Fletcher More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000000949.019AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Basketing plays an important role during flexible ureteroscopy. However, this step can be time consuming, especially when fragments are too large to pass through the ureteral access sheath and need to be replaced for further lithotripsy. To date there are no objective parameters for predicting successful stone removal through an access sheath. In this study we aim to present the optimal endoscopic stone size that predicts successful basketing through the access sheath during flexible ureteroscopy. METHODS: A tipless nitinol stone retrieval basket was placed through the ureteroscope’s working channel and maintained at a distance of 5 mm from its tip. The ureteroscope (Flex-Xc, Karl Storz; Flex-X2s, Karl Storz; LithoVue, Boston Scientific; or URF-P6R, Olympus) was advanced through access sheaths of different sizes (10-12 Fr, 11-13 Fr, 12-14 Fr, or 13-15 Fr) and an attempt was made to retrieve artificial stones of various sizes (2 mm³, 2.5 mm³, 3 mm³, 3.5 mm³, 4 mm³, or 5 mm³). Successful retrieval rates were documented, and both external and endoscopic views were recorded. Each stone’s maximum diameter on endoscopic view was measured on screen using a digital caliper and compared to the total screen diameter or width. RESULTS: Basketing of stones up to 2.5 mm3 was successful using all access sheaths. In those cases, the on-screen stone size divided by total screen size for each device was 0.38 (Flex-Xc), 0.30 (Flex-X2s), 0.32 (LithoVue), and 0.34 (URF-P6R). When 3 mm³ stones were used, only the 12-14 Fr and 13-15 Fr sheaths allowed for successful basketing. Stones that were 3.5 mm³ and larger did not successfully pass through any of the access sheaths. Karl Storz Flex-Xc presented the largest on-screen stone sizes: 0.38 (2.5 mm3) and 0.51 (3 mm3) relative to the total screen size. CONCLUSIONS: Successful stone retrieval can be predicted by estimating the stone’s size on the screen, and the choice of flexible ureteroscope or access sheath can influence this prediction. When maintaining the basket at 5 mm from the tip of the ureteroscope, stone fragments of approximately one third the size of the screen passed successfully in all cases. When a Flex-Xc is used, stones with a larger on-screen size, up to half of the screen, can pass successfully through 12-14 Fr and 13-15 Fr access sheaths. Source of Funding: None © 2020 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 203Issue Supplement 4April 2020Page: e1053-e1053 Advertisement Copyright & Permissions© 2020 by American Urological Association Education and Research, Inc.MetricsAuthor Information Joseph Randall* More articles by this author Raphael Carrera More articles by this author David Duchene More articles by this author Kerri Thurmon More articles by this author Donald Neff More articles by this author Wilson Molina More articles by this author Paul Fletcher More articles by this author Expand All Advertisement PDF downloadLoading ...