Six-Year Follow-Up of Botulinum Toxin A Intradetrusorial Injections in Patients with Refractory Neurogenic Detrusor Overactivity: Clinical and Urodynamic Results

BACKGROUND: Most reports in the literature on botulinum toxin A (BoNTA) therapy for neurogenic detrusor overactivity (NDO) are based on the results of a single injection. Because most patients may require retreatment, the efficacy and safety of multiple injections must be addressed clearly. OBJECTIVE: To investigate the effectiveness and safety of BoNTA intradetrusorial injections in a group of spinal cord-injured (SCI) patients with refractory detrusor overactivity (DO). DESIGN, SETTING, AND PARTICIPANTS: Seventeen SCI patients were prospectively included in the study and followed up to 6 yr. INTERVENTION: All patients received repeat intradetrusorial injections of BoNTA 300 units (Botox, Allergan, Irvine, CA) under cystoscopic control on an inpatient basis. MEASUREMENTS: The preliminary assessment included voiding diary, urodynamics, kidney and bladder ultrasound, and cystourethrography. Patients also completed a standardised quality-of-life (QoL) questionnaire. Clinical evaluation, urodynamics, urinary tract imaging, and QoL assessment were repeated every year throughout the follow-up. RESULTS AND LIMITATIONS: Before treatment, all patients complained of urinary incontinence and had DO. Bilateral and monolateral renal pelvis dilatation were detected in six and five patients, respectively, and a monolateral and third-grade vesicoureteral reflux was observed in three. At 6-yr follow-up, a significant decrease in the frequency of daily incontinence episodes (p<0.01), a significant increase in first uninhibited detrusor contraction and in maximum bladder capacity (p<0.001 for both), and a significant decrease in maximum pressure of these contractions (p<0.01) were observed. Fifteen patients (88.2%) were completely continent. Renal pelvis dilatation and vesicoureteral reflux resolved in all cases, and the QoL index significantly increased. Limitations of the study are related to the small number of included patients. CONCLUSIONS: In SCI patients with refractory NDO who do not want or are unfit for invasive reconstructive surgery, BoNTA intravesical treatment represents a valid alternative to control DO and urinary incontinence and to preserve upper urinary tract function over a long-term follow-up.