Intravesical Electromotive Botulinum Toxin Type A (Dysport) Administration in Children With Myelomeningocele

[A review of intravesical treatment options in neuro-urology]

Neurogenic lower urinary tract dysfunction is caused by various disorders of the central and peripheral nervous system. This can result in several malfunctions of the storage and voiding phase, which are reflected in symptoms such as urgency, urinary incontinence, recurrent urinary tract infections and post-void residual urine. Reduced quality of life, impairment of the upper urinary tract, reduced employment opportunities and worsening of the symptoms of the underlying condition can be the consequences. Therefore, the primary goals of neuro-urology are to protect the upper urinary tract, maintain continence and improve the quality of life of those affected. To achieve these goals, different intravesical drug and electrophysical therapy options are available. These article addresses these intravesical therapy options as well as their indication and relevance in neuro-urology.

Beyond botulinum neurotoxin A for chemodenervation of the bladder

PURPOSE OF REVIEW

Botulinum neurotoxin A (BoNT/A), or Botox, is a popular option for overactive bladder (OAB) and neurogenic bladder (NGB) with or without incontinence. This review aims to discuss the clinical outcomes of BoNT in adult and pediatric bladder conditions, and introduces the potential benefit of novel, engineered neurotoxins beyond BoNT/A.

RECENT FINDINGS

A large volume of evidence supports the use of Botox for OAB (to reduce urgency, frequency and incontinence episodes), and for NGB (to decrease incontinence and improve bladder capacity and detrusor pressures). Botox is now also Food & Drug Administration (FDA)-approved for pediatric neurogenic detrusor overactivity. However, urinary retention, diminished response over time and treatment failures are prevalent issues with Botox. Modifying natural BoNTs or forming chimeric toxins are alternatives to BoNT/A that may have higher efficacy and lower side-effect profile. One example is BoNT/BMY-WW. This novel engineered toxin binds to a more commonly expressed synaptotagmin receptor, with potentially more potent paralytic effect and less capacity for systemic diffusion.

SUMMARY

Novel engineered neurotoxins may be the next frontier in OAB and NGB therapy.

Chronic in vivo exposure to Helicobacter pylori VacA: Assessing the efficacy of automated and long-term intragastric toxin infusion

Helicobacter pylori (Hp) secrete VacA, a diffusible pore-forming exotoxin that is epidemiologically linked to gastric disease in humans. In vitro studies indicate that VacA modulates gastric epithelial and immune cells, but the in vivo contributions of VacA as an important determinant of Hp colonization and chronic infection remain poorly understood. To identify perturbations in the stomachs of C57BL/6 or BALB/C mice that result specifically from extended VacA exposure, we evaluated the efficacy of administering purified toxin using automated infusion via surgically-implanted, intragastric catheters. At 3 and 30 days of interrupted infusion, VacA was detected in association with gastric glands. In contrast to previously-reported tissue damage resulting from short term exposure to Hp extracts administered by oral gavage, extended infusion of VacA did not damage stomach, esophageal, intestinal, or liver tissue. However, several alterations previously reported during Hp infection were detected in animals infused with VacA, including reduction of the gastric mucus layer, and increased vacuolation of parietal cells. VacA infusion invoked an immune response, as indicated by the detection of circulating VacA antibodies. These foundational studies support the use of VacA infusion for identifying gastric alterations that are unambiguously attributable to long-term exposure to toxin.

Botulinum Toxin Type A Therapy: Intravesical Injection or Electromotive Drug Administration

OBJECTIVES

To compare the outcomes of intravesical injection of botulinum toxin A (BoNTA) with intravesical electromotive drug administration (EMDA) of BoNTA on urinary incontinence secondary to neuropathic detrusor overactivity (NDO) in children with myelomeningocele (MMC).

MATERIALS AND METHODS

A total of 26 children with MMC (11 boys, 15 girls) who had urinary incontinence secondary to NDO were retrospectively enrolled in the study. Patients in EMDA group (n = 14), using an electrode-catheter, 10 IU/kg of BoNTA were inserted into the bladder for EMDA without anesthesia and on an outpatient basis. The EMDA equipment was connected to the electrode of indwelling catheter and 2 dispersive electrodes, a pulsed current generator delivered 10-20 mA for 20 minutes. Patients in injection group (n = 12) were received interavesical injection of 10 IU/kg of BoNTA via rigid cystoscope on an inpatient basis. All patients had been evaluated by a voiding diary, urodynamic study, renal, and bladder ultrasounds before, 6 months and 1 year after the treatment.

RESULTS

Six months after the treatment, 12 of 14 (85.7 %) and 8 of 12 (66.6%) patients in EMDA and injection groups respectively became completely dry between 2 consecutive clean intermittent catheterizations, which maintained in 11 of 14 (78.5%) of patients in EMDA group compared to 6 of 12 (50%) of patients in injection group, 1 year after the treatment.

CONCLUSION

Patients in both groups improved after the treatment; however improvement in EMDA group was more prominent with better sustained effects. BoNTA/EMDA is a feasible, reproducible, cost benefit, and pain free method as an outpatient basis and no need for anesthesia.