title: Preliminary Evidence Suggests Periureteral Botulinum Toxin Type A Injection Improves Ureteral Stone Passage in the Porcine Model.
abstract: OBJECTIVE
  We evaluated the use of periureteral injection of botulinum toxin type A (Botox(®), BTX-A) to facilitate passage of ureteral stones in a porcine model. We believe that reducing detrusor muscle tone around the intramural ureter may facilitate passage of ureteral stones through the ureterovesical junction.
  
  
  METHODS
  With complete Institutional Animal Care and Use Committee approval, artificial stones (BegoStone plus) were placed by retrograde ureteroscopy into the proximal ureter using fluoroscopic guidance using an in-vivo porcine model. Six animals underwent periureteral BTX-A injection 30 U/mL to three locations around the ureteral orifice, and six animals were in the control group undergoing periureteral injection of physiologic saline.
  
  
  RESULTS
  There was a significant decrease in time to stone passage in the BTX-A group compared with the control group, 2.6 ± 1.3 vs 6.8 ± 2.9 days, respectively (p = 0.018). None of the animals had evidence of vesicoureteral reflux postprocedure (N = 0/12).
  
  
  CONCLUSIONS
  Preliminary results suggest that periureteral injection of BTX-A facilitates ureteral stone passage in this model. BTX-A may provide a simple, office-based endoscopic treatment option for ureteral stones. Further studies would be necessary to evaluate its efficacy in humans compared with traditional medical expulsive therapy.
authors.affiliation: Department of Urology, University of Wisconsin School of Medicine and Public Health , Madison, Wisconsin.
authors.forename: Necole M
authors.initials: NM
authors.lastname: Streeper
authors.affiliation: Department of Urology, University of Wisconsin School of Medicine and Public Health , Madison, Wisconsin.
authors.forename: Stephen Y
authors.initials: SY
authors.lastname: Nakada
authors.affiliation: Department of Urology, University of Wisconsin School of Medicine and Public Health , Madison, Wisconsin.
authors.forename: Margaret L
authors.initials: ML
authors.lastname: Wertheim
authors.affiliation: Department of Urology, University of Wisconsin School of Medicine and Public Health , Madison, Wisconsin.
authors.forename: Sara L
authors.initials: SL
authors.lastname: Best
mesh_terms: D000818:Animals; D019274:Botulinum Toxins, Type A / Q000494:pharmacology* / Q000627:therapeutic use; D004195:Disease Models, Animal; D005260:Female; D007267:Injections; D009130:Muscle, Smooth / Q000187:drug effects*; D009465:Neuromuscular Agents / Q000494:pharmacology* / Q000627:therapeutic use; D013552:Swine; D013997:Time Factors; D014513:Ureter / Q000187:drug effects*; D014514:Ureteral Calculi / Q000188:drug therapy*; D018666:Ureteroscopy; D014718:Vesico-Ureteral Reflux
chemical_list: D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A