Intravesical Botulinum Toxin for Neurogenic Bladder—Can We Just Irrigate the Bladder with Botulinumtoxin?

Historically, patients failing treatment with anti-muscarinic medications were subjected to bladder augmentation or urinary diversion, invasive procedures with significant complications. The approval of botulinum toxin A (BTX-A) intravesical injections revolutionized the treatment of neurogenic bladder (NGB). Ongoing research efforts to find even less invasive methods of treatments are exploring the possibility of intravesical botulinum toxin instillations for the treatment of neurogenic bladder. This paper reviews BTX-A in the treatment of neurogenic bladder, intravesical instillation of other medications in the treatment of this disease, available research on intravesical instillation of BTX-A for neurogenic bladder, and other forms of voiding dysfunction.

Initial research has been done on rodents and human subjects. Some studies on BTX-A intravesical instillations have shown preliminary success and others have shown no improvement compared to placebo. Research groups have used a variety of mechanisms to overcome the low permeability of the bladder wall, including protamine sulfate, DMSO, and liposomes. While studies have shown improvements in markers of bladder pain response, a variety of urodynamic study (UDS) parameters, and patient satisfaction scores, none have shown a decrease in contraction amplitude. The most recent development is the use of liposomes as a delivery system for intravesical instillation of BTX. They have seen some preliminary success as some endpoints were met, others not.

There is limited research on intravesical instillation of BTX-A for neurogenic detrusor overactivity. While available data suggests some degree of success in modulating symptoms, the data does not show an increase in bladder capacity or decreased voiding pressure. Further research is needed on the impact of BTX-A intravesical instillations in the NGB patient population.