Botulinum toxin injection in the pediatric population with medically refractory neuropathic bladder

Summary Introduction Botulinum toxin injection (BTI) has been advocated as a second line therapy in management of neuropathic bladder in pediatric population for refractory patients to conventional medical management such as anticholinergics. The purpose was to review the safety and efficacy of BTI in children with neuropathic bladder refractory to conservative non-surgical measures. We hypothesized that BTI would be an effective alternative to bladder augmentation in certain patients but not all. Methods We retrospectively identified 22 patients with neuropathic bladder due to any condition who underwent urologic BTI at our hospital since 2010. Multiple clinicopathologic variables were examined including the following: demographics, use of anticholinergics, the presence of anticholinergic refractoriness or intolerance, dosage of BTI, urodynamic variables, and continence status. Results The mean patient age at time of BTI was 10 years with a follow up of 12 months. Indications for BTI were anti-cholinergic refractory (AR) urodynamic parameters and/or incontinence and anticholinergic intolerance (AI). Nearly all patients received 300 Units at BTI into detrusor. No complications occurred from BTI. Overall 54% had improved continence after the initial BTI whereas 45% had achieved complete continence between catheterizations. Cystometric capacity increased by 46% and maximum detrusor pressure decreased by 43% following initial BTI (See Table). 75% of AI patients were continent between CIC after BTI compared to 50% of AR patients (P = 0.002). The observed mean duration of clinical improvement after initial BTI was 4.6 months and four patients underwent repeat BTI. Pre BTI % of age expected bladder capacity Post BTI % of age expected bladder capacity % Improvement in Urodynamic Parameter P value Cystometric Capacity (mL) 227 60 331 87 46 0.008 Maximum Detrusor Pressure (cm H2O) 63 44 43 0.002 Compliance (mL/cm H2O) 4.3 8.8 104 0.001. Discussion Our results are comparable to existing literature with respect to urodynamic parameters. The observed differences may be due to heterogenous patient population of various etiologies of neuropathic bladder and no uniform criteria to proceed with bladder augmentation. The AR patients in our cohort may have had a higher degree of bladder fibrosis which BTI would be less likely to impact and explain the differences in clinical response between AR and AI patients. Conclusions BTI is a safe and effective treatment option for pediatric patients with neuropathic bladder refractory to standard therapy. The degree of continence observed after BTI in our series was higher for AI rather than AR patients. Table . Urodynamic changes following Botulinum toxin injection. Pre-Botulinum toxin injection % of age-expected bladder capacity Post Botulinum toxin injection % of age-expected bladder capacity % improvement in urodynamic parameters P-value Cystometric capacity (ml) 227 60 331 87 46 0.008 Maximum detrusor pressure (cm H2O) 63 44 43 0.002 Compliance (ml/cm H2O) 4.3 8.8 104 0.001 Uninhibited detrusor contractions (UDC) 14/22 (63% of total patients) 4/14 (29% of patients with UDC pre-BTI)