Combined detrusor-trigone BTX-A injections for urinary incontinence secondary to neurogenic detrusor overactivity.

Objectives: The objective of this study was to evaluate the effect and safety of trigonal injection of botulinum toxin A (BTX-A) for patients with neurological detrusor overactivity (NDO) with incontinence.

Methods: A prospective, multicenter, single-blind and randomized controlled trial was conducted between June 2011 and June 2014. Spinal cord injury patients with urinary incontinence secondary to NDO overactivity were recruited. At a 1:1 ratio, patients randomly received 200 U BTX-A intradetrusor injections excluding the trigone (the control group) or 160 U intradetrusor and 40 U intratrigonal injections (the experimental group). Patients were evaluated at baseline and at 4 and 12 weeks after injection. The efficacy and safety outcomes included Incontinence-Specific-Quality-of-Life Instrument (I-QoL), voiding volume, urinary incontinence episodes, complete dryness, maximum detrusor pressure (P(detmax)) and volume at first involuntary detrusor contraction (V(FIDC)). Vesicoureteral reflux (VUR) and other adverse events were recorded.

Results: Ninety-six patients were recruited and 91 of them completed the trial. Among the 91 patients, 47 were randomized to the experimental group and 44 to the control group. There were no significant differences in baseline evaluation items (gender, age, duration of spinal cord injury, level of neurological injury, AIS (the American Social Injury Association) scores) between the two groups. At 12 weeks, the improvement was significantly better in the experimental group compared with that in the control group for I-QoL (26.01 vs 18.75, P=0.01), mean urinary incontinence episodes (-5.22 vs -4.68 per day, P=0.01), complete dryness (13 vs 5, P=0.03), mean voiding volume (159.72 vs 139.07 ml, P=0.02), P(detmax) (-33.34 vs -28.02 cmH(2)O, P=0.04) and VFIDC (106.81 vs 97.86 ml, P=0.02), duration of first detrusor contraction (-41.54 vs -18.65 s, P=0.03) and the number of patients with detrusor contraction (-20 vs -9, P=0.02). In both the groups, no patients developed VUR.

Conclusions: BTX-A intradetrusor and intratrigonal injections are more effective compared with those excluding the trigone for patients with NDO with incontinence. Intratrigonal injections do not induce VUR.