Short Communication
Botulinum toxin A submucosal injection for refractory
non-neurogenic overactive bladder: Early outcomes
Kikuo Okamura,
1
Yoshikatsu Nojiri,
1
Kaname Ameda,
3
Takashige Namima,
4
Masahito Suzuki,
5
Katsumi Inoue,
6
Takatoshi Ogawa,
7
Momokazu Gotoh
2
and Yukio Homma
8
1
Division of Urology, Department of Surgery and Intensive Care, National Center for Geriatrics and Gerontology, Obu,
2
Department
of Urology, Nagoya University, Graduate School of Medicine, Nagoya,Aichi,
3
Department of Urology, Hokkaido Urology Memorial
Hospital, Sapporo, Hokkaido,
4
Department of Urology, Tohoku Rosai Hospital, Sendai, Miyagi,
5
Department of Urology, Kashiwa
City Hospital, Kashiwa, Chiba,
6
Department of Urology, Showa Northern Yokohama Hospital, Yokohama, Kanagawa,
7
Department of
Urology, Kainan Municipal Hospital, Kainan, Wakayama, and
8
Department of Urology, Graduate School of Medicine, The University
of Tokyo, Tokyo, Japan
Abstract: The objective of the present study was to assess the short-term effects of botulinum toxin A (BTX-A) injection
for refractory non-neurogenic overactive bladder (OAB) in the setting of a prospective multicenter clinical trial. Refractory
OAB was defined as persistent urgency urinary incontinence (UUI) once a week despite taking anticholinergic agents, or
the incapability to continue the agents because of the adverse effects. A total of 100 U of BTX-A were reconstituted in
15 mL of normal saline and an aliquot of 0.5 mL was injected at 30 submucosal sites of the bladder wall. Nine men and
eight women aged 67 12 years were included. Subjective daytime frequency, urgency and UUI significantly decreased
after treatment. On a 3-day frequency-volume chart, the daytime and night-time frequency of UUI significantly decreased
from 5.5 and 0.5 pre-injection to 2.0 and 0.3 postinjection, respectively. Daytime urinary incontinence completely disap-
peared in six subjects. A urodynamic study showed the disappearance of detrusor overactivity in eight patients and a
decrease in five patients. Maximum bladder capacity significantly increased from 179.9 to 267.3 mL. Difficulty on mictu-
rition or feeling of incomplete emptying was reported by 23.5% and 43.8% of patients at weeks 2 and 4, respectively.
Postvoid residual urine increased to >100 mL in seven patients and >200 mL in one patient after injection; however, none
of the patients required clean intermittent catheterization. These findings suggest promising efficacy of BTX-A in Japanese
OAB patients.
Key words: botulinum toxin A, non-neurogenic overactive bladder, short-term outcome.
Introduction
With aging, the proportion of people with overactive bladder
(OAB) is increasing.
1
It is reported that urgency urinary
incontinence (UUI) severely impairs quality of life (QoL).
2
Although anticholinergic agents are effective for most
patients with OAB, some patients are refractory or cannot
continue them because of adverse reactions, such as dry
mouth, constipation and blurred vision.
3,4
Deterioration of
cognitive function can also be problematic among the
elderly.
5
Since Schurch et al. reported the effectiveness of botuli-
num toxin A (BTX-A) for neurogenic detrusor overactivity
(DO), BTX-A injection into the bladder wall is also being
considered as a promising treatment for non-neurogenic
OAB.
6–12
Although the use of BTX-A has not yet been
approved for urinary tracts in Japan, Watanabe et al.
reported the initial experience with intradetrusor BTX-A
injection for Japanese patients with OAB.
13,14
In the present
report, we describe the short-term efficacy of BTX-A for
Japanese individuals with non-neurogenic OAB.
Methods
Study design
The patients who met the following inclusion criteria were
recruited into this prospective multicenter study: (i) subjects
aged 20 years with non-neurogenic OAB; and (ii) com-
plaining of UUI once a week despite taking anticholin-
ergic agents, or incapable of continuing the agents because
of adverse effects. Exclusion criteria were: (i) postvoid
residual (PVR) 100 mL; (ii) apparent lower urinary tract
obstruction or detrusor underactivity by urodynamic study
(UDS); (iii) average voided volume on a 3-day frequency-
volume chart (FVC) 200 mL; (iv) coexistence of stress or
functional urinary incontinence; (v) urinary tract infection,
Correspondence: Kikuo Okamura M.D., Ph.D., Division of
Urology, Department of Surgery and Intensive care, National
Center for Geriatrics and Gerontology, 35, Gengo, Morioka-cho,
Obu 474-8511, Japan. Email: kokamura@ncgg.go.jp
Received 17 January 2011; accepted 18 March 2011.
Online publication 13 April 2011
International Journal of Urology (2011) 18, 483–487 doi: 10.1111/j.1442-2042.2011.02768.x
© 2011 The Japanese Urological Association 483