Assessment of urodynamic and detrusor contractility variables in patients with overactive bladder syndrome treated with botulinum toxin-A: is incomplete bladder emptying predictable?
OBJECTIVE
To assess whether incomplete bladder emptying and the need for clean intermittent self-catheterization (CISC) is predictable, by analysing urodynamic and detrusor contractility variables in patients treated with botulinum toxin-A (BTX-A) for refractory idiopathic detrusor overactivity (IDO).


METHODS
Sixty-seven patients (mean age 50.3) with IDO, from two centres, had bladder injections of 200 U BTX-A. Patients with difficulty in emptying their bladder and/or persistent overactive bladder symptoms, with postvoid residual volumes (PVR) of >150 mL after treatment were started on CISC. Urodynamics were conducted at baseline, 4 and 12-16 weeks after injection with BTX-A. Detrusor contractility was assessed using the projected isovolumetric pressure (PIP1) in women and bladder contractility index (BCI) in men.


RESULTS
There were improvements in the mean maximum cystometric capacity, bladder compliance and maximum detrusor pressures during filling cystometry after BTX-A injections. The PVR was significantly increased at 4 but not at 12 weeks. Nineteen patients required CISC and when compared with those not needing CISC their pretreatment maximum flow rate (15 vs 22 mL/s, P = 0.003), PIP1 (43 vs 58, P = 0.02) and BCI (113 vs 180, P = 0.001) were lower. Receiver operator characteristic curve analysis suggested that a PIP1 of < or =50 in women (sensitivity 0.83; specificity 0.70; area under the curve 0.822) and BCI < or =120 (sensitivity 0.7; specificity 0.79; area 0.879) might predict the need for CISC.


CONCLUSIONS
The maximum flow rate, PIP1 and BCI were significantly lower in patients who required CISC after BTX-A treatment than in those who did not. A PIP1 of < or =50 in women and a BCI of < or =120 might be predictive of a need for CISC in this setting, and might help when counselling patients.
Sahai
Arun
A
Department of Urology, Guy's Hospital & KCL School of Medicine, London, UK.
Sangster
Philippa
P
Kalsi
Vinay
V
Khan
Mohammad S
MS
Fowler
Clare J
CJ
Dasgupta
Prokar
P
D000293:Adolescent; D000328:Adult; D000368:Aged; D019274:Botulinum Toxins, Type A / Q000009:adverse effects / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009119:Muscle Contraction / Q000187:drug effects; D009130:Muscle, Smooth / Q000187:drug effects; D009465:Neuromuscular Agents / Q000009:adverse effects / Q000627:therapeutic use*; D012680:Sensitivity and Specificity; D016896:Treatment Outcome; D001743:Urinary Bladder / Q000187:drug effects / Q000503:physiopathology*; D053201:Urinary Bladder, Overactive / Q000188:drug therapy* / Q000503:physiopathology; D014546:Urinary Catheterization; D014563:Urodynamics / Q000502:physiology*; D055815:Young Adult
D009465:Neuromuscular Agents; D019274:Botulinum Toxins, Type A