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.