Introduction and hypothesis Intravesical onabotulinumtoxinA
(Botox®) is effective for idiopathic overactive bladder (OAB)
symptoms. Our primary objective was to compare the efficacy
of onabotulinumtoxinA for women with de novo OAB after
midurethral sling (MUS) surgery and women with idiopathic
OAB.
Methods Women enrolled in this prospective study had idiopathic
(n=53) or de novo (n=49) OAB symptoms after MUS,
with at least one episode of urgency urine incontinence per
day. OnabotulinumtoxinA (100 U) was administered in 20
intradetrusor injections. Postvoid residual volumes were
checked at 2, 4 and 12 weeks. Participants completed a 3-
day bladder diary and the King’s Health Questionnaire
(KHQ) before and 12 weeks after treatment.
Results After 12 weeks, 22 patients (41.5 %) in the idiopathic
OAB and 19 patients (38.8 %) in the de novo OAB groups
were completely dry. OnabotulinumtoxinA injections had a
significant benefit within both groups (p <0.001) to decrease
both the daily numbers of voids (−2.39 and −2.0) and incontinence
episodes (−1.38 and −1.44), with no significant
difference between groups. We observed an increase of mean
voided volume of >90 ml in both groups. Urinary retention
was observed in four patients.
Conclusions We observed similar improvement in OAB
symptoms after intravesical onabotulinumtoxinA injections
within both groups. The rates of retention and requirement
for catheterization even for women with a prior MUS were
acceptable. These observational data provide evidence that
onabotulinumtoxinA can effectively treat patients with OAB
following stress urinary incontinence surgery