Intra-vesical injections of Botulinum Toxin A have proven to be an effective and safe third-line therapy option in management of neurogenic detrusor overactivity (NDO). Previous prospective studies have suggested that pre-operative urodynamic parameters could be used to predict the response to intra-vesical Botulinum Toxin A [1]. We have reviewed the records of 140 consecutive patients with neurogenic-mediated overactive bladder symptoms (nOAB) who have been treated with intra-vesical injections of Botulinum Toxin A, and assessed whether there were any correlations between patient-reported treatment outcomes (PROMS) and pre-operative urodynamic findings.

We conducted a retrospective review of all 140 patients (93 women, mean age 57; 47 men, mean age 54) who have received intra-vesical Botulinum Toxin A injections at our tertiary referral centre for refractory nOAB symptoms between 1st January 2006 and 31st December 2018. To evaluate treatment outcomes we used the 5-point Patient Global Impression of Improvement (PGII) score at last review (all within 6 months of this study) . The PROMS were correlated with pre-operative urodynamic findings. Statistical analysis was done by Students T-Test and Chi Square Test with significance determined at p< .05.

A total of 116 patients had pre-operative urodynamic results available for review; of these 95 had urodynamically confirmed neurogenic detrusor overactivity (NDO) and 14 demonstrated loss of compliance (LoC). Meaningful voiding studies were only obtained in 8 patients, which limited our assessment of the impact of the voiding phase parameters. The full results are listed in Table 1.

A large proportion of our patients had complex past medical history – 60% had previous abdominal surgery, 22% reported concurrent SUI symptoms, 11% had urodynamically confirmed bladder outlet obstruction and 65% were intermittent or indwelling catheter-dependent prior to receiving intra-vesical injections of Botulinum Toxin A, which increased to 88% after receiving the treatment. 
At the last follow-up, 73% of women and 81% of men reported good or partially good effect (PGII scores of 1 and 2) following Botox A injections. We noted that successful outcomes of the Botulinum toxin A injections in men were more likely with nOAB dry (p=0.032 comparing to nOAB wet). We also noted that larger voided volumes in men correlated with reduction in treatment benefit (p=0.042), however our assessment was limited by a small proportion of valid voiding studies during pre-treatment urodynamic investigations. We have not identified any correlation between pre-operative urodynamic findings and treatment outcomes in women.

In our real-world neurogenic patients with refractory nOAB symptoms successful outcomes of the Botulinum toxin A injections in men were more likely with nOAB dry (p=0.032 comparing to nOAB wet). We have not identified any correlation between pre-operative urodynamic findings and treatment outcomes in women.

Álvares, R. A., Araújo, I. D., & Sanches, M. D. (2014). A pilot prospective study to evaluate whether the bladder morphology in cystography and/or urodynamic may help predict the response to botulinum toxin a injection in neurogenic bladder refractory to anticholinergics. BMC urology, 14, 66. https://doi.org/10.1186/1471-2490-14-66