How to manage urinary incontinence after intravesical Botox (onabotulinumtoxinA) injection for NLUTD (Neurogenic Lower Urinary Tract Dysfunction) in patients with SCI (Spinal Cord Injury)?

Management of Urinary Incontinence After Intravesical Botox in NLUTD of SCI

The primary management of persistent urinary incontinence after intravesical Botox injection in SCI patients with NLUTD requires first determining the type of incontinence (overflow from retention versus persistent detrusor overactivity), then implementing clean intermittent catheterization for retention-related incontinence or considering additional interventions for stress incontinence if storage parameters are acceptable. 1

Initial Assessment Algorithm

Determine the Mechanism of Post-Botox Incontinence

If patients do not improve symptomatically after Botox injection, obtain post-void residual (PVR), urinalysis, and urine culture, as UTI or incomplete emptying may be the cause rather than treatment failure. 2

• Overflow incontinence from urinary retention occurs in 20.49% of NLUTD patients receiving onabotulinumtoxinA versus 3.67% with placebo, with rates ranging from 2.6-54% in treatment groups 1, 2
• Persistent detrusor overactivity incontinence despite treatment may indicate inadequate dosing or need for alternative interventions 1
• Stress urinary incontinence may emerge or persist as a separate issue requiring outlet procedures 1

Critical Urodynamic Evaluation

Urodynamic investigation is mandatory for outcome assessment, as urinary continence alone is insufficient—18% of continent patients after Botox have maximum storage detrusor pressures >40 cmH₂O that threaten the upper urinary tract. 3

• Assess maximum cystometric capacity, maximum detrusor pressure during first involuntary detrusor contraction, and bladder compliance 4, 3
• High intravesical pressures may be missed in continent patients without urodynamic testing 3
• Gender, underlying neurological disorder, and high baseline detrusor pressures increase risk of poor urodynamic outcomes despite continence 3

Management Based on Incontinence Type

For Overflow Incontinence from Urinary Retention

Clean intermittent catheterization (CIC) is the standard treatment for urinary retention after Botox injection. 2

• Initiate CIC for symptomatic incomplete emptying 2
• In the pivotal trial, 12% of placebo patients, 30% of 200U patients, and 42% of 300U patients initiated CIC post-treatment 4
• This is an expected adverse event that should have been discussed pre-treatment per AUA/SUFU guidelines 1

For Persistent Detrusor Overactivity Incontinence

Consider repeat Botox injection, as the median time to patient request for retreatment is 42.1 weeks with onabotulinumtoxinA versus 13.1 weeks with placebo. 4

• OnabotulinumtoxinA 200U significantly reduced UI episodes by -21.8 per week versus -13.2 with placebo at week 6 4
• Long-term data shows 88.2% of SCI patients achieved complete continence with repeat injections over 6-year follow-up 5
• The 200U dose provides optimal balance between efficacy and retention risk compared to 300U 4, 6

For Stress Urinary Incontinence After Botox

Slings should be offered to select NLUTD patients with stress urinary incontinence and acceptable bladder storage parameters, with mandatory urodynamic assessment prior to any outlet procedure. 1

• Assessment of bladder storage parameters with urodynamics must be performed before any SUI procedure, as bladder compliance could be worsened by an outlet procedure, resulting in elevated storage pressures and risk to the upper urinary tracts 1
• If future need for CIC is anticipated, consider autologous fascia or other biologic grafts 1
• Urethral bulking agents may be offered but efficacy is modest and cure is rare 1
• Artificial urinary sphincter may be offered but carries risk of voiding dysfunction and possible need for CIC 1

For Male Patients Unable or Unwilling to Perform CIC

Sphincterotomy may be offered to facilitate emptying in appropriately selected male patients with NLUTD, but counsel them of the high risk of failure or potential need for additional treatment. 1

• Appropriate candidates include those with reflex voiding who can maintain urinary drainage with condom catheter and have poor hand function or unwillingness to perform CIC 1
• Sphincterotomy is irreversible but can increase effectiveness of bladder emptying, decrease UTIs, and preserve upper urinary tract function 1

Common Pitfalls to Avoid

• Never assume continence equals treatment success—always perform urodynamics to detect dangerous high storage pressures 3
• Do not overlook UTI as cause of persistent incontinence—obtain urinalysis and culture before declaring treatment failure 2
• Avoid outlet procedures without urodynamic confirmation of acceptable storage parameters—this can worsen bladder compliance and threaten upper tracts 1
• Do not perform repeat Botox injections without addressing retention—ensure patient is willing and able to perform CIC if needed 1