Introduction:

Botulinum toxins is a neurotoxin produced by the anaerobic bacteria Clostridium botulinum, was first isolated by Van Ermengem (1). It has several types but type A the one with the best results regarding duration (1). The first usage of botulinum toxin A by Stohrer et al. was in 1999 and since that time it become one of the treatments for the neurogenic detrusor overactivity NDO (2’3). FDA approved one botulinum toxin A for the treatment of NDO in August 2011. 

Despite the efficacy of BTX injection, It is known that the most adverse effect post BTX injection are urinary tract infection UTI and urinary retention (1’4) and one randomized trial comparing different doses of BTX found the rate of post-procedural UTI to be 34–48%, with the highest being in the 200-U dose group (5).

The prevalence of UTI after Botox injection is well known, but it’s unknown the effect of Botox injection on recurrent UTI patient. The paucity of the outcomes of Botox injection on NDO patients with recurrent UTI in the literature make the need for the review of the outcomes.

 The aim of our study is to analyses the effect of intravesical Botox injection on recurrent UTIs patients either by increase or decrease.

Methods:
We conducted our prospective cohort  all patients who received 200 or 300 U Botox intravesical injection .We included patients with neurogenic bladder with detrusor overactivity, recurrent UTI . All patients received culture specific antibiotic and underwent Botox injection when urine is clean. Patients files were reviewed for  Diagnosis, VU reflux, hydronephrosis ,Urodynamic finding, dose of Botox used .Patients were followed for the incidence of UTI developed post Botox injection in the early 6 months post injection .

Results:
Total of 93 patients were diagnosed as neurogenic detrusor overactivity and symptomatic recurrent UTI. Diagnosis included spina bifida in 53 patients, Henman’s syndrome in 35.Median Patients age was 22y ( 8y -55y). Dose used was 300IU in 58% of patients while 41% received 200IU.After  receiving Botox injection  75% of patient (70) had no more symptomatic UTI. Urodynamic test post injection showed increase in bladder volume at 1st uninhibited bladder contraction  in 65% and increased bladder capacity in 79% . Correlation analysis showed significant correlation between resolved  UTI post Botox Injection and Pt diagnosis, presence of hydonephrosis and post injection  bladder filling pressure with P value of  p=0.019, p=0.003,p=0.014 respectively.

incidence of urinary tract infection decreased after botox injection in neurogenic overactive bladder patients  with recurrent UTI, with improvement in urodynamic parameters.

Conclusion 
Intravesical Botox injection may decrease incidence of symptomatic urinary infections in neurogenic detrusor overactivety. This  effects seemed to be related to maintaining low pressure  reservoir.

S. Mouttalib, S. Khan, E. Castel-Lacanal, et al. Risk of urinary tract infection after detrusor botulinum toxin A injections for refractory neurogenic detrusor overactivity in patients with no antibiotic treatment BJU Int, 106 (2010), pp. 1677-1680
Siroky MB. Pathogenesis of bacteriuria and infection in the spinal cord injured patient. Am J Med 2002;113(Suppl. 1A):67S–79S.
Cruz F, Herschorn S, Aliotta P, Brin M, Thompson C, Lam W et al Efficacy and safety of onabotulinumtoxinA in patients with urinary incontinence due to neurogenic detrusor overactivity: a randomised, double-blind, placebo-controlled trial. Eur Urol 2011; 60: 742–750.