Preliminary Evidence Suggests Periureteral Botulinum Toxin Type A Injection Improves Ureteral Stone Passage in the Porcine Model

Purpose: 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. Materials and 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.