What is the optimum dose of type A botulinum toxin for treating neurogenic bladder overactivity?

[Bladder augmentation in the era of botulinum toxin: Indications and results]

AIM

To determine the surgical indication and results of bladder augmentation (BA) during the last decade in a neurourology center in the era of intradetrusor botulinum toxin injection.

MATERIAL

We conducted a retrospective study that included patients with BA between January 1, 2012 and December 31, 2022 in our centre. We collected pre-operative demographic, clinical, and urodynamic data, BA indication, and associated procedures. We analyzed early and late complications as well as continence and postoperative voiding mode in patients with first BA in a neurological pathology context.

RESULTS

We performed 77 BA over the study period. The main indication was neurogenic overactive bladder, which was secondarily resistant to botulinum toxin. The main associated procedure was continent cutaneous diversion (n=31, 57.4%). Among patients who had a first BA for neurogenic bladder, 34 patients had early complications (50%) including 12 patients with≥Clavien 3 complications (17.6%). After a median follow-up of 33 [14; 55] months, 23 patients had late complications (33.8%) and 59 patients had complete continence (86.8%).

CONCLUSION

In the era of botulinum toxin, the main indication of BA is the secondary failure of botulinum toxin for overactive neurogenic bladder. The BA provided continence in 86.8% of patients. It remains however an intervention with a significant rate of severe complications whose indication must be discussed by a multidisciplinary team.

LEVEL OF EVIDENCE

Weak.

AbobotulinumtoxinA is effective in patients with urinary incontinence due to neurogenic detrusor overactivity regardless of spinal cord injury or multiple sclerosis etiology: Pooled analysis of two phase III randomized studies (CONTENT1 and CONTENT2)

BACKGROUND

Neurogenic detrusor overactivity incontinence (NDOI) is often inadequately managed with oral therapy.

OBJECTIVE

To assess efficacy and safety of abobotulinumtoxinA (aboBoNT-A; Dysport®; Ipsen Ltd.) according to etiology of NDOI.

DESIGN, SETTING, AND PARTICIPANTS

Two phase III, randomized, double-blind studies (CONTENT1 [NCT02660138] conducted in Asia, Europe and North America; CONTENT2 [NCT02660359] conducted in the Americas, Asia, Europe and Oceania) both included patients with spinal cord injury (SCI) or multiple sclerosis (MS), with inadequately managed NDOI, regularly performing clean intermittent catheterization (CIC).

INTERVENTION

Patients in CONTENT1 and CONTENT2 received aboBoNT-A injections 600 U (n = 162)/800 U (n = 161), or placebo (n = 162) into the detrusor muscle.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Primary endpoint: mean change from baseline in number of NDOI episodes/week at Week 6. Secondary endpoints: proportion of patients with no NDOI episodes; incontinence-related quality of life (I-QoL); urodynamic parameters; and time-to-retreatment. Safety was also assessed. Statistical analyses were conducted for pooled populations by etiology (aboBoNT-A doses vs. placebo).

RESULTS AND LIMITATIONS

Of 485 randomized patients, 341 (70%) and 144 (30%) had SCI and MS etiologies, respectively. A significant reduction was observed in mean NDOI episodes/week at Week 6 with both aboBoNT-A doses versus placebo in the SCI (all p < 0.001) and MS (all p < 0.01) groups, as well as significant improvements in I-QoL and urodynamic parameters. Median time-to-retreatment was longer in patients with MS (48-62 weeks across doses) than those with SCI (39-44 weeks). Safety data were similar between etiologies. Urinary tract infection was the most frequent adverse event; similar numbers were reported across treatment groups.

CONCLUSIONS

AboBoNT-A was well tolerated and significantly improved continence and bladder function, and QoL, in patients with SCI or MS with NDOI performing regular CIC.

PATIENT SUMMARY

AboBoNT-A injections improved QoL, symptoms, and bladder function in patients with SCI or MS with bladder muscle overactivity that causes incontinence.

Learning Curve of Botulinum Toxin Bladder Injection for the Treatment of Refractory Overactive Bladder

PURPOSE

Intradetrusor botulinum toxin injections is an established second-line treatment for patients with refractory overactive bladder syndrome (OAB). We aimed to evaluate the learning curve of intradetrusor injections with botulinum toxin for the treatment of refractory OAB.

PATIENTS AND METHODS

This retrospective study analyzed all women with idiopathic and refractory OAB who underwent botulinum toxin bladder injections performed by residents with no previous experience with operative cystoscopy under consultant supervision. Baseline International Consultation on Incontinence Questionnaire-Short Form questionnaire (ICIQ-SF) and Euroqol (EQ-5D) questionnaires were collected. Procedural data (operative time, number of valid injections, complications, subjective easiness, perceived tolerability) and patients' outcomes (Patients Global Impression of Improvement (PGI-I), ΔICIQ-SF, ΔEQ-5D, need for self intermittent catheterization, duration of efficacy) were considered as markers to evaluate learning curves for each resident.

RESULTS

Twenty-seven patients underwent intravesical injection of botulinum toxin performed by residents. Only a grade 1 Clavien-Dindo complication occurred, and none of the patients had urinary retention. PGI-I was very satisfactory, scoring 1.4 ± 0.9. Both ICIQ-SF and EQ-5D 2-2 were statistically improved (p < 0.00001 and p = 0.04, respectively). The mean duration of efficacy resulted to be 8.0±4.3 months. A positive effect of the learning curve was observed only for operative time, subjective easiness, and perceived tolerability.

CONCLUSION

Intradetrusor botulinum toxin injection for the treatment of refractory OAB is characterized by high efficacy and very low complications even at the very beginning of the learning curve when performed under proper mentorship.

Generalised muscle weakness after bladder wall injection of Abobotulinum Toxin A: experience of a woman with tetraplegia who required increased caregiver support: importance of doctor-patient communication: duty of candour for spinal cord physician and responsibilities of a patient

INTRODUCTION

Generalised muscle weakness can occur after bladder wall injection of Abobotulinum toxin and the patient may require additional caregiver support.

CASE PRESENTATION

A woman with C-8 AIS A tetraplegia received bladder wall injection of Abobotulinum toxin A 1000 units for detrusor over-activity. After 2.5 weeks, she developed weakness of arms; could not lift herself for pressure relief; could not transfer using sliding board; she regained the original muscle strength in 6 weeks. After 13 months, Abobotulinum toxin A 1000 units were injected into detrusor. Ten days after the second Abobotulinum toxin A injection, she developed generalised muscle weakness. She had not regained full function in her arms and hands 8 months later.Prior to bladder wall injection of Abobotulinum toxin A, this patient was not aware that she could develop muscle weakness albeit very rarely. Therefore, the patient made no association of the muscle weakness, which occurred after the first injection, to Abobotulinum toxin A. For this reason, she did not inform the clinicians that she developed weakness of upper limbs following Abobotulinum toxin A injection. As she was not informed of this side effect before the second bladder wall injection of Abobotulinum toxin A, she consented to undergo the repeat procedure and developed generalised muscle weakness.

DISCUSSION

Patients should inform doctors the adverse effects of medical therapy so that future treatment is amended to ensure patient safety. Professional duty of candour states that doctors should discuss risks which occur often, those that are serious even if very unlikely, and those that are important to the patient.

Botulinum Toxin Use in Neurourology

The use of botulinum toxin A (BTX-A) has revolutionized the treatment of neurogenic lower urinary tract dysfunction (NLUTD) over the past three decades. Initially, it was used as a sphincteric injection for detrusor sphincter dyssynergia but now is used mostly as intradetrusor injection to treat neurogenic detrusor overactivity (NDO). Its use is supported by high-level-of-evidence studies and it has become the gold-standard treatment for patients with NDO refractory to anticholinergics. Several novelties have emerged in the use of BTX-A in neurourology over the past few years. Although onabotulinumtoxinA (BOTOX^®, Allergan, Inc., Irvine, CA) remains the only BTX-A for which use is supported by large, multicenter, randomized, controlled trials (RCT), and is therefore the only one to be licensed in the United States and Europe, a second BTX-A, abobotulinumtoxinA (Dysport^®, Ipsen Biopharmaceuticals, Basking Ridge, NJ), is also supported by high-level-of-evidence studies. Other innovations in the use of BTX-A in neurourology during the past few years include the BTX switch (from abobotulinumtoxinA to onabotulinumtoxinA or the opposite) as a rescue option for primary or secondary failures of intradetrusor BTX-A injection and refinements in intradetrusor injection techniques (number of injection sites, injection into the trigone). There is also a growing interest in long-term failure of BTX-A for NDO and their management, and a possible new indication for urethral sphincter injections.

Botulinum toxin in the treatment of overactive bladder

Clinical effectiveness of botulinum toxin (BTX) in the treatment of both neurogenic and idiopathic detrusor overactivity has been demonstrated in several studies. However, different protocols and techniques have been used by authors.

Methods.

Literature review on intradetrusor injection of BTX for detrusor overactivity.

Results.

The greatest clinical experience reports the use of 200 and 300 U Botox®. Available data suggest that clinical efficacy, duration, and the side effect profile is similar at these doses. Very few data, on the other hand, are available regarding the clinical outcomes using the Dysport® preparation; isolated reports support that efficacy is similar when using a dosing range of 500 to 1000 SU with increased risk of systemic side effects using 1000 SU. A variety of injection volumes was used, demonstrating similar efficacy and tolerability profile. Clinical effect duration extends six to ten months in the majority of studies. Data suggest that a repeated injection scheme proves successful in the vast majority of initial responders.

Conclusions.

Safety, effectiveness, specificity and reversibility make BTX a new attractive treatment modality for overactive bladder syndrome. However, more experience is needed to standardize the injection protocol with respect to therapeutic outcomes and adverse effects.

Switch to Abobotulinum toxin A may be useful in the treatment of neurogenic detrusor overactivity when intradetrusor injections of Onabotulinum toxin A failed

AIMS

To assess the outcomes of switching to a different brand of botulinum toxin A (BTA, from Botox® to Dysport®) in case of failure of intradetrusor injections (IDI) of Botox® in the treatment of neurogenic detrusor overactivity (NDO).

METHODS

The charts of all patients who underwent a switch to IDI of Dysport® after failure of an IDI of Botox® at six departments of neurourology were retrospectively reviewed. The main outcomes of interest were the bladder diary data and four urodynamic parameters: maximum cystometric capacity (MCC), maximum detrusor pressure (PDET max), and volume at first uninhibited detrusor contraction (UDC).

RESULTS

Fifty-seven patients were included. After the first injection of Dysport®, no adverse events were reported. A significant decrease in number of urinary incontinence episodes per day was observed in 52.63% of patients (P < 0.001) and all patients experienced a reduction in PDET Max (-8.1 cmH20 on average; P = 0.003). MCC significantly increased by a mean of 41.2 (P = 0.02). The proportion of patients with no UDC increased significantly at week 6 after ATA injections (from 15.79% to 43.9%; P = 0.0002). Hence, 32 patients draw clinical and/or urodynamic benefits from the botulinum toxin switch from (56.14%). After a median follow up of 21 months, 87% of responders to BTA switch were still treated successfully with BTA.

CONCLUSION

Most patients refractory to Botox® (56.14%) draw benefits from the switch to Dysport®.

Efficacy and safety of the first and repeated intradetrusor injections of abobotulinum toxin A 750 U for treating neurological detrusor overactivity

PURPOSE

To assess clinical and urodynamic efficacy of the first and repeated intradetrusor injections of abobotulinum toxin A (Dysport(®), Ipsen(®), France) in patients with neurogenic detrusor overactivity (NDO) refractory to anticholinergic treatment.

METHODS

A single-center retrospective study was conducted in 81 consecutive patients who had never received any botulinum toxin intradetrusor injections. They were treated with at least one 750 U intradetrusor injection of abobotulinum toxin A. All patients performed clean intermittent self-catheterization (CIC) before injections. Success was defined as a combination of no incontinence episode, a number of catheterization <8 reported in a 3-day bladder diary and the lack of detrusor overactivity.

RESULTS

Six weeks after the first injection, the success rate was 64.2 %. The proportion of continent patients was 80.2 %, the mean number of CIC per 24 h reduced (-3.55, p < 0.0001) and the mean catheterization volume increased (+237.3 ml, p < 0.0001). Regarding urodynamics, mean maximum cystometric capacity and mean volume at the first uninhibited contraction increased (+132.7 ml, p < 0.0001 and +180 ml, p < 0.0001, respectively) and mean maximum bladder pressure decreased significantly (-21.5 cm H2O, p < 0.0001). Mean reinjection number was 3.9 and mean interval between reinjection was 8.8 ± 3 months. The clinical efficacy rate after each reinjection (up to fourteen) was at least 86.7 %. Out of 55 patients who underwent repeated injections, secondary resistance was noted in 2 (3.6 %).

CONCLUSION

The results of the present study are in favor of a long-term safety and efficacy of abobotulinum toxin A 750 U for NDO.

Efficacy and duration of response to botulinum neurotoxin A (onabotulinumA) as a treatment for detrusor overactivity in women

INTRODUCTION AND HYPOTHESIS

Overactive bladder syndrome with urinary incontinence has a number of treatment options. The National Institute for Health and Care Excellence (NICE) in the UK, the American Urological Association (AUA) and the European Association of Urology (EAU) recommend intradetrusor botulinum neurotoxin A (onabotulinumA) injections in women with proven detrusor overactivity (DO) in whom conservative therapies have failed to improve symptoms. However, the effects of individual onabotulinumA treatments are of short duration and patients usually require further treatments. There is little evidence to inform long-term management strategies using onabotulinumA for DO.

METHODS

A retrospective review of patients receiving intradetrusor onabotulinumA injections for DO over a 7-year period was conducted. The primary outcome measures included patient's subjective reports of symptom change following injections (efficacy) and the duration of symptomatic relief following each treatment.

RESULTS

The analysis included 136 patients. The mean time between patients receiving intradetrusor onabotulinumA and being added to the surgical waiting list for re-treatment varied between 8.5 and 10.4 months for the first five cycles of treatment with the longest time between the third and fourth cycles. This decreased to 5.5 and 5.25 (ANOVA p = 0.015) between the fifth and sixth cycles and between the sixth and seventh cycles of treatment, respectively. Only 19.9% of patients continued treatment beyond this, with four patients receiving a seventh treatment.

CONCLUSIONS

Our results suggest that in patients who respond to onabotulinumA treatment, the duration of response declines after the fifth treatment, suggesting a possible tolerance effect and a subsequent decline in efficacy.

Advances in the management of neurogenic detrusor overactivity in multiple sclerosis

Bladder dysfunction in multiple sclerosis (MS) can be socially disabling, have negative psychological and economic consequences, and impair patients' quality of life. Knowledge of the functional anatomy and physiology of the urinary tract is essential to understand the symptoms associated with central nervous system lesions and the pharmacotherapies used to treat them. Treatments for neurogenic detrusor overactivity (NDO) have consisted mainly of administration of anticholinergic drugs, which have been shown to provide suboptimal clinical benefits and be poorly tolerated. The US Food and Drug Administration (FDA) approval of intravesicular botulinum toxin therapy provides a second-line option for MS patients with NDO not responsive to anticholinergic drugs. We performed a review of key literature pertaining to the intravesicular application of botulinum toxin. In the management of NDO, administration of intravesicular botulinum toxin using clean intermittent catheterization decreases the incidence of urinary tract infections, promotes urinary continence, and improves quality of life for 9 months after a single injection; moreover, those benefits are maintained with repeated injections over time.

Botulinum A toxin as a treatment for overactive rectum with associated faecal incontinence

AIM

Rectal hypercontractility can lead to faecal incontinence (FI). Botulinum toxin (BT) has been used successfully for the treatment of bladder overactivity. This study aimed to evaluate the therapeutic value of intrarectal injections of BT in inhibiting colorectal contractions and relieving FI in patients suffering from FI as a result of overactive rectal contractions.

METHOD

A prospective open study was carried out in Rouen University Hospital. Six patients (four men and two women) with severe FI related to overactive rectal contractions underwent intrarectal submucosal injections of BT placed in three rows of 10, 1-ml injections (50 U/1 ml; Dysport(®)) starting 1 cm above the dentate line and repeated twice, at intervals of 5 cm proximally. The end-points included improvement in the FI score, in faecal incontinence quality of life (FIQL) and of manometric abnormality.

RESULTS

All patients reported improvement in the FI score [18.2±1.1 at baseline vs 9.0±1.7 at 3 months (P=0.04)] and in FIQL. Rectal contractile activity was reduced. The frequency of contractions remained unaffected (28.1±6.6/h; P=0.46 vs baseline). High-amplitude contractions of >50 cmH(2)O were significantly decreased in all patients (16.6±3.9 vs 6.6±4.1/h; P=0.03).

CONCLUSION

Patients with an 'overactive rectum' are a heterogeneous group, with varying causes of dysfunction. The dose of BT used was arbitrarily selected. Nevertheless, the study introduces a further therapeutic option in the treatment of FI caused by rectal overactivity.

Risk of urinary tract infection after detrusor botulinum toxin A injections for refractory neurogenic detrusor overactivity in patients with no antibiotic treatment

OBJECTIVE

To determine if antibiotic prophylaxis is required for intradetrusor botulinum toxin A (BoNT-A) injections.

PATIENTS AND METHODS

This was a prospective non-randomized study. Inclusion criteria were adult patients with neurogenic detrusor overactivity who failed anticholinergic-based first-line treatment and had sterile urine culture 7 days before injections, a negative dipstick test on the day of the injections, and were performing clean intermittent self-catheterization. Injections were performed using a rigid cystoscope, under local anaesthetic. Patients received BoNT-A as either Botox® (Allergan Inc., Irvine, CA, USA) 300 U in 30 sites or Dysport® (Ipsen Ltd, Ipsen, Paris, France) 750 U in 20 sites. Urine culture was done 6 days and 6 weeks after the injections. If urinary tract infection (UTI) was suspected, a physician performed a complete physical examination. The primary outcome criterion was the occurrence of UTI during the first week after injections.

RESULTS

In all, 42 patients (22 women, 20 men) with a mean (sd) age 45.3 (16.4) years were included. A symptomatic UTI occurred during the first week after the injections in three patients (7.1%). The urinary colonization rate was 31% and 26% at 6 days and 6 weeks after injection, respectively. The most common bacterium was Escherichia coli (62.5%). There were no differences between 20 and 30 injection sites or between the sexes.

CONCLUSION

The rate of UTI after intradetrusor injections of BoNT-A was 7.1%. The most frequent bacterium involved was Escherichia coli. These results indicate that antibiotic prophylaxis for intradetrusor BoNT-A injections seems necessary.

Efficacy and tolerability of botulinum toxin type A in patients with neurogenic detrusor overactivity and without concomitant anticholinergic therapy: comparison of two doses

BACKGROUND

Botulinum toxin type A (BoNTA) has been reported to be effective for treatment of patients with neurogenic detrusor overactivity (NDO) refractory to anticholinergic agents. However, in most of the studies, the efficacy was associated with concomitant use of anticholinergics.

OBJECTIVE

To evaluate the efficacy and tolerability of BoNTA and compare two different doses in patients with NDO without concomitant anticholinergics.

DESIGN, SETTING, AND PARTICIPANTS

Between 2004 and 2006, adults with NDO refractory to anticholinergics or discontinued anticholinergics due to adverse events or contraindications from four different French clinical centres were included in a prospective, randomised, double-blind, comparative trial. Inclusion criteria were urinary incontinence (UI) resulting from NDO that could not be managed with anticholinergics. Patients with bladder cancer, lithiasis, or urinary infection were excluded.

INTERVENTION

Patients were randomised to receive an intradetrusor injection of 500 U or 750 U of BoNTA.

MEASUREMENTS

The initial evaluation (ie, clinical and urodynamic variables and quality of life [QoL]) was repeated at days 30, 90, 180, and 360. Primary outcome was complete continence rate at day 30. Secondary outcomes were cumulative incontinence rate, reappearance of leakages, pad usage, urodynamics, and QoL.

RESULTS AND LIMITATIONS

Seventy-seven patients received 500 U (n=39) or 750 U (n=38) of BoNTA and were included in the full analysis set for efficacy analysis. Complete continence at day 30 was observed in 22 patients (56.4%) and 28 patients (73.7%) receiving 500 U or 750 U of BoNTA, respectively (p=0.056; one-sided χ(2) test to compare to α=0.025). The median delay in the reappearance of leakages was 168 d. Monotherapy of BoNTA significantly improved UI in patients with NDO. Although there was a trend towards a greater improvement with 750 U of BoNTA, no statistically significant differences in terms of clinical and urodynamic variables and QoL were found between the treatment groups. Tolerability was excellent and equivalent for both doses.

CONCLUSIONS

Monotherapy of BoNTA at Dysport (Ipsen, Brisbane, CA, USA) doses of 500 U or 750 U seems to be effective and well tolerated in patients with NDO.

The use of botulinum neurotoxin type A (BoNTA) in urology

The use of Botulinum neurotoxin type A (BoNT/A) in the lower urinary tract was pioneered as early as 20 years ago with injections into the urethral sphincter reducing bladder voiding pressures, urethral pressures, and post-void residual urine. Over the past 9 years, the use of BoNT/A has revolutionised the treatment of intractable symptoms associated with the neurogenic or idiopathic overactive bladder, both in adults and children. The duration of clinical improvement is 6-11 months, is accompanied by significant amelioration of patients' quality of life and repeat bladder treatments appear to have sustained effects. Despite evidence for an effect on the afferent pathways, its mode of action in the human bladder remains largely unknown. The use of BoNT/A has also expanded into the painful bladder syndrome and in benign prostatic diseases, with promising preliminary results. This review aims to provide an insight of the use of BoNT/A in the lower urinary tract, addressing issues such as treatment outcomes and safety, mechanisms of action and potential for future research.

Neurogenic detrusor overactivity treated with english botulinum toxin a: 8-year experience of one single centre

OBJECTIVE

Determine long-term effect of English botulinum neurotoxin type A (BoNTA; Dysport) for refractory neurogenic detrusor overactivity (NDO) for possible reduction of BoNTA efficacy after repeated injections.

METHODS

Between 1999 and 2005, 199 patients with spinal cord lesions with refractory NDO were treated with Dysport. All patients underwent a clinical examination, urinalysis, and videourodynamic study at baseline and at 3, 6, and 12 mo after each treatment, as well as a visual analogue scale (VAS) assessment and a bladder diary checked for 1 wk before each visit. We used 1000, 750, 500 IU BoNTA at the beginning of our experience, and thereafter we mainly used 750 IU. Outcome measures included frequency of urge urinary incontinence (Incontinence Episode Frequency [IEF] test); urodynamic parameters including maximum cystometric bladder capacity (MCBC), reflex volume (RV), bladder compliance (BC); number of pads/condoms; antimuscarinic drug consumption; short- and long-term side-effects; and quality of life measured with VAS.

RESULTS

No statistically significant differences were found in efficacy duration with the three Dysport doses (p=0.5274). The difference between the intervals of injections was not statistically significant (p=0.2659). MCBC, RV, and BC improved significantly after treatment compared with baseline values (p<0.001) and there were no statistically significant differences after each retreatment or regarding Dysport dose (p>0.05). There was a significant improvement in patient satisfaction after each retreatment as expressed on the VAS (p<0.001). There was a significant reduction in IEF score and pads/condoms use in the first 4 wk after each treatment (p<0.0001).

CONCLUSION

After repeated injections the effect of BoNTA remained constant.

Developments in the pharmacotherapy of the overactive bladder

PURPOSE OF REVIEW

The overactive bladder is a common and distressing condition that has a significant impact on the quality of life of many people worldwide. Anticholinergics remain the first line in pharmacotherapy, however the use of these agents is hindered by adverse effects and limited efficacy. Thus there is a need for more effective treatments. Recently, there has been a move towards targeting novel pathways thought to play a role in overactivity. This review aims to provide an insight into the recent developments in pharmacotherapy of the overactive bladder.

RECENT FINDINGS

With recent advances in our understanding of the basic science of the overactive bladder it is becoming clear that the control of bladder functioning is far more complex than previously believed. Peripherally, a prominent role has emerged for the urothelium and the underlying suburothelium in mechanosensory control, and the role of afferent pathways in pathophysiology is increasingly recognized.

SUMMARY

Recent research has highlighted several potential targets for treatment of the overactive bladder, particularly within the mechanosensory pathways. With the exception of botulinum toxin, however, few new therapies have emerged showing clinical benefits. A clearer understanding of the pathophysiology of the bladder will hopefully lead to more effective and tolerated treatments.

Botulinum toxin for detrusor overactivity and symptoms of overactive bladder: where we are now and where we are going

Botulinum toxin (BTX) treatment for overactive bladder and detrusor overactivity is becoming increasingly recognized as an excellent therapeutic option for treating patients refractory to anticholinergic agents. Results from open-label studies have suggested that this therapy is effective in neurogenic and idiopathic detrusor overactivity, yet validating evidence from randomized, placebo-controlled trials has been unavailable. The exact mechanism of action of BTX in the bladder is controversial, although evidence suggests that apart from preventing the presynaptic release of acetylcholine from the parasympathetic innervation to the bladder, it might have an effect on sensory mechanisms. The latter hypothesis could in part explain its effect on symptoms such as urgency. The purpose of this Review is to present the results of randomized, placebo-controlled trials in which BTX treatment for detrusor overactivity was investigated. Also the evidence supporting its potential dual mechanism of action in the bladder will be considered. In addition, the various techniques of administration of BTX are discussed and avenues for further research suggested.

Chapitre C-l C - Traitement pharmacologique de l’hyperactivité détrusorienne neurologique : injections intra-détrusoriennes de toxine botulique A

Botulinum toxins are among the most powerful of all natural poisons. They are responsible for human botulism and constitute potential chemical weapons, but are nevertheless used as therapeutic agents in an increasing number of indications and medical specialties. Botulinum toxins were used for the first time in urology by intrasphincteric injection by Dykstra in 1988 to treat detrusor-sphincter dyssynergia in spinal cord injury patients. Schurch performed the first intradetrusor injections in 2000 to treat incontinence due to overactive bladder in adult spinal cord injury or multiple sclerosis patients. This review of the literature presents the results and level of proof for the use of botulinum toxin intradetrusor injection to treat neurogenic voiding disorders. Botulinum toxin A intradetrusor injections constitute a safe, conservative, reversible and short-term effective (6-12 months) alternative after failure of anticholinergic therapy for overactive bladder and its clinical consequences in adult spinal cord injury or multiple sclerosis patients (level 1b) and in children with neural tube defects (level 4). The efficacy of the first injection appears to be maintained at subsequent injections (up to 10 cycles) (level 4). Convergent and longer-term data are necessary to document and more clearly define the medium- and long-term efficacy profile of this approach, currently considered to be a major progress in neurourology.

Botulinum toxin injection: a review of injection principles and protocols

Despite the favorable outcomes seen using botulinum toxin (BTX) for voiding dysfunction using BTX, a standardized technique and protocol for toxin injection is not defined. We reviewed the current literature on intravesical BTX injection for DO (detrusor overactivity). Specific attention was placed on defining optimal injection protocol, including dose, volume, and injection sites. In addition, we sought to describe a standard technique to BTX injection.

Botulinum Toxin Type A for Refractory Neurogenic Detrusor Overactivity in Spinal Cord Injured Patients in Singapore

Introduction: Managing neurogenic detrusor overactivity (NDO) successfully in spinal cord-injured patients is a challenge. The aims of preserving kidney function by achieving safe bladder pressures with anticholinergic medication often leave a significant proportion of patients with side effects. Botulinum toxin type A has been shown to be a promising alternative. Materials and Methods: Spinal cord injury patients who had NDO, on clean intermittent self-catheterisation, and were refractory to oral medications, were recruited. Three hundred units of botulinum toxin type A (Botox) in 30 mL NaCl solution were injected under cystoscopic guidance into the bladder. Results: Fifteen patients were recruited of whom 9 were tetraplegic and 6 were paraplegic. Eleven (73.3%) had complete injuries. There was a significant reduction in the mean number of leakages from 3.75 ± 1.79 pre-injection to 0.67 ± 1.31 and 1.5 ± 1.5 at 6 and 26 weeks post-injection, respectively (P <0.05). Seventy-five per cent, 37.5% and 50% were completely dry at 6, 26 and 39 weeks post-injection, respectively. The mean maximal catheterisable volume increased from 312.3 ± 145.6 mL pre-injection to 484.6 ± 190 mL, 422.3 ± 157.3 mL and 490.0 ± 230.4 mL at 6, 26 and 39 weeks post-injection, respectively (P <0.005). Maximum detrusor pressure decreased significantly from 66.3 ± 22.6 cmH2O to 21.2 ± 23.1 cmH2O and 33.6 ± 30.2 cmH2O at 6 and 26 weeks post-injection, respectively (P <0.05). The volume at which reflex detrusor contractions first occurred increased from 127.8 ± 57.5 mL pre-injury to 305.7 ± 130.8 mL at 6 weeks and 288.3 ± 13.0 mL at 26 weeks post-injection (P <0.05). Mean cysometric bladder capacity increased from 187.8 ± 69.2 mL to 305 ± 136.4 mL and 288.3 ± 13.0 mL at 6 and 26 weeks post- injury, respectively (P <0.05). Sixty per cent of patients were completely off medications at 6 and 26 weeks post-injection. One patient had urinary tract infection and 1 experienced autonomic dysreflexia during cystoscopy. Satisfaction levels increased from 4.3 ± 2.3 pre-injury to 7.2 ± 1.9 and 7.3 ± 2.3 at 6 weeks and 26 weeks, respectively. This also correlated with fewer leakages. Conclusion: Botulinum toxin type A injected into the detrusor is safe and efficacious for spinal cord injured patients with refractory detrusor overactivity. This effect is maintained at 26 weeks post-injection. Key words: Anticholinergics, Spinal cord injury, Urodynamics, Voiding