Botulinum toxin in patients at‐risk for bladder augmentation: Durable impact or kicking the can?

Abstract

Deferring bladder augmentation (BA) may be desirable in a pediatric neurogenic bladder (NGB) with worsening compliance, but prior studies have questioned whether onabotulinum toxin A (BTX) demonstrates durable improvement in compliance. We present our overall experience with BTX and its role in mitigating the "at-risk" NGB, as determined by urodynamic characteristics.Methods: A retrospective single-institution review of all BTX procedures performed during January 2010 to October 2018 was conducted. Patients with <12 months follow-up after first BTX injection were excluded. Urodynamic studies (UDS) were reviewed to assign National Spina Bifida Patient Registry (NSBPR) as well as institutionally developed (LCH) risk classification groups.Patients were considered "at-risk" for BA if they had any of the following: NSBPR risk grade of intermediate or hostile; LCH risk grades indicating endfill pressure >25 cmH 2 O or detrusor sphincter dyssynergia (DSD); upper tract changes including new hydronephrosis; new or worsening vesicoureteral reflux; or other signs of a hostile urinary tract (i.e., febrile UTIs). UDS risk grades pre and post-first BTX injection were compared in this "at-risk" group, when available.Results: Thirty-nine patients underwent 162 injection procedures over a median follow-up of 65 months interquartile range . Median age at first BTX was 10 years and the median number of BTX injections per patient was 4 (IQR 2-7; range 1-12) with a median time of 6 months between injections (IQR 4-10). Twenty-six patients were deemed "at-risk" at the time of first BTX injection, and of those, 16 (61.5%) proceeded to BA at a median of 36 months . A small number (four) had BA due to upper tract changes or worsening pressures on BTX, while nine patients (five with CKD) proceeded to BA given a lack of sufficient improvement to consider BTX a long-term viable option. Post-first BTX UDS demonstrated downgrading of risk group in 38% and 63% using NSBPR and LCH classifications, respectively.

Understanding factors influencing primary treatment with intradetrusor onabotulinumtoxinA versus augmentation cystoplasty in patients with spina bifida

“…Notably, only one patient of the 17 was treated with Botox before AC. Prior literature has described intravesical Botox as a means to delay or potentially avert the need for AC, [14][15][16] with similar indications to reconstructive surgery including poor efficacy or poor tolerance of oral antimuscarinics with CIC alone. 17,18 In a recent systematic review, clinical outcomes of intravesical Botox include improvements in incontinence, maximum detrusor pressure, cystometric capacity, and bladder compliance.…”

“…17,18 In a recent systematic review, clinical outcomes of intravesical Botox include improvements in incontinence, maximum detrusor pressure, cystometric capacity, and bladder compliance. 18 A recent retrospective study of 39 patients by Bowen 16 and colleagues demonstrated downgrading of risk classification in nearly 40% of patients following primary Botox. Finally, the joint European Association of Urology (EAU) and European Society for Pediatric Urology (ESPU) guidelines for the surgical treatment of neurogenic bladder in children now suggests that bladder augmentation be considered only after failure of Botox to achieve adequate bladder capacity and compliance.…”

Editorial Comments

“…3 Future studies may combine urodynamic, biochemical and radiological parameters (eg, bladder wall thickness) to delineate children who eventually will need bladder augmentation. 4 Tufan Tarcan This is an important study that gives further support to the use of botulinum toxin for the management of pediatric neurogenic bladder dysfunction. Since the initial reports in children, this strategy has gained popularity, particularly to address intolerance to oral medications or as an adjunct to improve hostile bladder dynamics in order to avoid (or delay) the need for augmentation cystoplasty.…”

OnabotulinumtoxinA is now an important tool for managing pediatric neurogenic lower urinary tract dysfunction

“…While early reports characterizing the efficacy of BTX-A in pediatric patients with NLUTD have been encouraging, the majority of studies are single institution series with no control group and variable primary endpoints and definitions of treatment success (9,(15)(16)(17)(18)(19)(20). Therefore, conclusions regarding the utility of BTX-A must be made in this context.…”