Botulinum Toxin-A Injections Into Neurogenic Overactive Bladder-To Include or Exclude the Trigone? A Prospective, Randomized, Controlled Trial

Purpose: The short-term outcomes of initial detrusor injections vs combined detrusor-trigone botulinum toxin-A injections were determined in patients with spinal cord injury-neurogenic detrusor overactivity. Materials and Methods: Adults with refractory spinal cord injury-neurogenic detrusor overactivity who strictly discontinued anticholinergics were recruited for the study. At a 1: 1 ratio patients randomly received 300 U botulinum toxin-A intradetrusor injections excluding the trigone (detrusor arm) or 200 U intradetrusor plus 100 U intratrigonal injections (combined arm). Study end points were determination of the impact on incontinence episodes, complete dryness, quality of life, reusing anticholinergics, maximum detrusor pressure, reflex volume, maximum cystometric capacity, vesicoureteral reflux and adverse events. Patients were evaluated at baseline, and 2, 8, 12 and 18 weeks after injection. Statistical significance was considered at p<0.05. Results: Analysis included 18 patients per arm with no significant baseline differences. On within group analysis all parameters improved significantly compared to baseline. On between group analysis in the detrusor vs the combined arm at week 8 incontinence decreased by 52.4% vs 80.9% (number needed to treat 1.91 vs 1.23 patients, p<0.001), complete dryness was achieved in 33.3% vs 66.7% of patients (number needed to treat 3 vs 1.5, p<0.001) and quality of life score was decreased by 46.76% vs 48.13% (number needed to treat 2.14 vs 2.08, p<0.44). The absolute difference was 60% vs 82.5% for reflex volume (p<0.001), 66.2% vs 68.4% for maximum cystometric capacity (p<0.22) and -42.3% vs -41.9% for maximum detrusor pressure (p<0.21). At week 18 anticholinergics were needed again in 9 (50%) and 4 patients (22.2%) patients, respectively. No patient showed new or upgraded vesicoureteral reflux or reported significant adverse events. Conclusions: In the short term all parameters improved significantly in each arm. The superiority of including rather than excluding the trigone was significant.