Therapeutic Effects of Botulinum Toxin A, via Urethral Sphincter Injection on Voiding Dysfunction Due to Different Bladder and Urethral Sphincter Dysfunctions

Role of Urological Botulinum Toxin-A Injection for Overactive Bladder and Voiding Dysfunction in Patients with Parkinson's Disease or Post-Stroke

Botulinum toxin A (BoNT-A) paralyzes muscle by blocking acetylcholine release at the synaptic junction. BoNT-A has shown its therapeutic effects in neurological disorders such as Parkinson's disease (PD) and post-stroke spasticity. A high proportion of patients with PD and post-stroke develop neurogenic detrusor overactivity (nDO) and then develop urinary incontinence and overactive bladder (OAB) symptoms. This study aimed to disclose the safety and efficacy of BoNT-A injection in treating bladder and voiding dysfunction in PD and post-stroke patients by reviewing the current evidence. At present, intradetrusor injection of BoNT-A is a Food and Drug Administration (FDA)-approved third-line therapy for nDO and idiopathic OAB. Although intradetrusor injection of onaBoNT-A 200 U is already approved for nDO treatment, most researchers would like to manage PD and post-stroke patients by using onaBoNT-A 100 U intradetrusor injection to achieve long-term efficacy and reduce adverse effects. However, in contrast to its inclusion in the International Continence Society guidelines for PD treatment, the clinical use of BoNT-A for post-stroke patients is limited to experimental use due to the development of urinary retention in about one-fifth of patients. For treating urethral pseudodyssynergia, half of patients may respond to onaBoNT-A 100 U urethral injection. However, refinement is needed to reduce unwanted urinary incontinence.

Botulinum Toxin A Injection for Autonomic Dysreflexia-Detrusor Injection or Urethral Sphincter Injection?

Spinal cord injuries (SCI) have a profound impact on autonomic systems, sometimes resulting in multi-organ dysfunction, including of the neurogenic bladder. Autonomic dysreflexia (AD) is commonly seen in patients with SCI above T6 when the injured cord develops a deregulated sympathetic reflex, which can be induced by bladder sensation and can cause hypertensive crisis. While intravesical injection of botulinum toxin A (Botox) is a standard therapy for neurogenic detrusor overactivity, the role of Botox for AD has rarely been described. This study reviewed the medical records of SCI patients who reported AD and received either detrusor or urethral sphincter injection with Botox. The primary endpoint is the subjective improvement of AD. The secondary endpoint is a change in videourodynamic parameters before and after Botox injection. A total of 200 patients were enrolled for analysis. There were 125 (62.5%) patients in the detrusor injection group, and 75 (37.5%) in the urethral sphincter injection group. There were 79 (63.2%) patients in the detrusor injection group and 43 (57.3%) in the urethral sphincter injection group reporting moderate or marked improvement. Detrusor injection leads to a greater improvement in AD, probably because of decreased detrusor pressure and increased compliance after Botox injection. Urethral sphincter injection appears to have a modest effect on AD, despite general improvements in the voiding parameters of videourodynamic study.

Urethral Sphincter Botulinum Toxin A Injection for Non-Spinal Cord Injured Patients with Voiding Dysfunction without Anatomical Obstructions: Which Patients Benefit Most?

OBJECTIVE

Treating voiding dysfunction without anatomical obstructions is challenging. Urethral onabotulinum toxin A (BoNT-A) is used in treating voiding dysfunction; however, the success rate varies widely, and patients may not be satisfied with the treatment outcome. This study compared the efficacy of the urethral BoNT-A injection between patients with different non-spinal cord injury (SCI) voiding dysfunctions.

MATERIALS AND METHODS

This study retrospectively analyzed patients with refractory voiding dysfunction, including detrusor underactivity (DU), dysfunctional voiding (DV), and poor relaxation of the external sphincter (PRES) who received the urethral sphincter 100 U BoNT-A injection. The treatment outcomes were assessed via a global response assessment (GRA) one month after treatment. Baseline and follow-up videourodynamic study (VUDS) parameters were also compared.

RESULTS

Totally, 161 patients (60 with DU, 77 with DV, and 24 with PRES) with a mean age of 58.8 ± 20.2 were enrolled, of which 62.1% had a good response (GRA ≥ 2) after urethral BoNT-A injection. DV patients had a higher success rate (76.6%) than DU (50%) and PRES (45.8%) patients (p = 0.002). A diagnosis of DV, higher voided volume and recurrent urinary tract infection were predictors of a good treatment response, while the cervical cancer status post-radical surgery predicted a poor response. Receiver operating characteristic (ROC) curve analyses identified PVR > 250 mL as a negative predictor (p = 0.008) in DU patients.

CONCLUSIONS

The urethral BoNT-A injection provides a satisfactory success rate for non-SCI voiding dysfunction. Patients with DV benefit most from both subjective and objective parameters. Approximately 50% of patients with DU and PRES also had a fair response. PVR > 250 mL was a negative predictor in DU patients.

Predictive Factors for a Successful Treatment Outcome in Patients with Different Voiding Dysfunction Subtypes Who Received Urethral Sphincter Botulinum Injection

Voiding dysfunction is a common but bothersome problem in both men and women. Urethral sphincter botulinum toxin A (BoNT-A) injections could serve as an option in refractory cases. This study analyzed the efficacy and outcome predictors of the injections in patients with functional, non-neurogenic voiding dysfunction. Patients who received urethral sphincter BoNT-A injection for refractory voiding dysfunction due to detrusor underactivity (DU) or urethral sphincter dysfunction were retrospectively reviewed. A successful outcome was defined as a marked improvement as reported in the global response assessment. The study evaluated the therapeutic efficacy of urethral sphincter BoNT-A injections and measured the changes in urodynamic parameters after the procedure in the patients. A total of 181 patients including 138 women and 43 men were included. The overall success rate was 64%. A lower success rate was noted in patients with DU compared to those with urethral sphincter dysfunction in both genders. In the multivariable analysis, recurrent urinary tract infection (UTI) and bladder voiding efficiency (BVE) were positive predictors for a successful outcome, while DU was a negative predictor. Urethral sphincter BoNT-A injection is an effective treatment for refractory non-neurogenic voiding dysfunction. Baseline BVE and history of recurrent UTI positively predict a successful outcome. DU is a negative outcome predictor.

Satisfaction with Surgical Procedures and Bladder Management of Chronic Spinal Cord Injured Patients with Voiding Dysfunction Who Desire Spontaneous Voiding

We aimed to investigate treatment outcome and satisfaction with bladder outlet surgeries and bladder management in patients with spinal cord injury (SCI), voiding dysfunction, and to seek a spontaneous voiding or reflex voiding program. A total of 261 patients were included in this retrospective study. The mean age at surgical procedure was 49.2 ± 15.9 years; the median follow-up period was 11 (IQR 6, 17) years; 119 received a urethral Botox injection, 41 underwent transurethral incision of the bladder neck (TUI-BN), 77 underwent transurethral incision or resection of the prostate (TUI-P or TUR-P), and 24 had an external sphincterotomy. Satisfactory surgical outcome was reported by 80.5% of patients undergoing TUI-BN, 70.8% undergoing external sphincterotomy, 64.9% receiving TUI-P or TUR-P, and 59.7% receiving the urethral Botox injection. Persistent dysuria was the most common reason for dissatisfaction after the urethral Botox injection (73.1%) and TUI-BN (58.5%). Recurrent urinary tract infection continued in most patients after any type of surgery (all >75%). Most patients with SCI were satisfied with their initial bladder outlet operation in facilitating spontaneous voiding. However, repeat, or multiple surgical interventions were needed in 65.5% of SCI patients to achieve satisfactory voiding. A correct diagnosis is very important before every intervention and bladder management to reach the best satisfaction. VUDS is suggested before surgical procedures to ensure efficacy, even in patients with the same level of SCI.

Botulinum toxin A injection to the external urethral sphincter for voiding dysfunction in females: A tertiary center experience

AIM

The aim of this study is to examine the functional outcomes of ona-botulinum toxin A (BTX-A) injection into the external urethral sphincter (EUS) for female patients with nonneurogenic nonrelaxing sphincter as the underlying cause of voiding dysfunction (VD).

METHOD

A retrospective analysis was performed for all the patients with the urodynamic findings of higher than expected maximum urethral closure pressure (MUCP) who received their first injection during the study period. All patients were evaluated with preoperative videourodynamic study and urethral pressure profilometry and received 100 U of EUS BTX-A. Patients aged less than 18 years and those with neurogenic bladder were excluded. All patients were followed up with the free flow, postvoid residuals (PVR), and patient global impression of improvement (PGI-I) scale at 6 weeks and then at 3 monthly intervals.

RESULT

We identified 35 female patients with a mean age of 37.5 ± 15 years (range 18-72 years) with a mean follow-up of 20 months. More than 50% of patients had a history of prior surgical intervention and 28 (80%) patients were catheter dependent, a suprapubic catheterization, or clean intermittent self-catheterization. Mean MUCP was 97.1 ± 22 cm of water. After treatment with BTX-A, 21 (60%) patients were able to void per urethral (p = 0.02). The mean maximum flow rate (Qmax) improved from 8.8 to 11 mls/s and the mean PVR decreased from 200 to 149 mls (p < 0.05). On multivariate analysis, we identified high preoperative PVR, high preoperative actual MUCP, and previous surgical intervention (urethral dilatation, sacral neuromodulation, and pelvic surgery) as predictors of successful voiding restoration. The mean duration of response was 4.7 months, 46% of patients requested repeat injection, and 29% were established on maintenance injections. On the 5-point PGI-I score, 13 (37%), 12 (34%), and 10 (29%) patients reported good, some, and no improvement, respectively. Quality of life was also improved in 60% of patients. Two patients had transient stress urinary incontinence (for <6 weeks) and there were no significant long-lasting adverse events.

CONCLUSION

EUS BTX-A is a valid treatment option for VD considering therapeutic options are limited. The patient must be made aware of the need for repeat treatments.

Clinical Application of Botulinum Neurotoxin in Lower-Urinary-Tract Diseases and Dysfunctions: Where Are We Now and What More Can We Do?

Botulinum toxin A (Botox) had been considered a promising drug that has an effect on functional disorders of the lower urinary tract. Because Botox exhibits anti-inflammatory and antispasmodic effects, Botox injection into the bladder can decrease detrusor contractility, reduce bladder hypersensitivity, and eliminate painful sensations. Injecting Botox into the bladder outlet can relax the hyperactivity of the bladder neck, and of the urethral smooth and striated muscles. Based on these therapeutic effects, Botox has been widely applied to treat lower-urinary-tract dysfunctions (LUTDs) such as overactive bladder and neurogenic detrusor overactivity. However, this treatment has not been licensed for use in other LUTDs such as interstitial cystitis, voiding dysfunction due to benign prostatic hyperplasia in men, and dysfunctional voiding in women. Botox has also not been approved for the treatment of children with overactive bladder and dysfunctional voiding; in patients with spinal cord injuries with detrusor sphincter dyssynergia and autonomic dysreflexia; or for poorly relaxed external sphincter in non-neurogenic patients. This article reviews the current knowledge regarding Botox treatment for LUTDs and discusses the potential clinical applications of Botox, as well as work that can be conducted in the future.

Therapeutic Efficacy of Urethral Sphincteric Botulinum Toxin Injections for Female Sphincter Dysfunctions and a Search for Predictive Factors

External urethral sphincter (EUS) dysfunction is a common, bothersome female voiding dysfunction. This study aims to analyze the characteristics of different types of female EUS dysfunction, as well as to determine the outcome predictors of sphincteric botulinum toxin A (BoNT-A) injection. Women receiving sphincteric BoNT-A injections for refractory EUS dysfunction were retrospectively reviewed. A comparison of the baseline clinical, urodynamic parameters and the treatment responses were made for patients with different EUS dysfunctions. A total of 106 females were included. Significantly increased detrusor overactivity, detrusor contracting pressure and the bladder outlet obstruction index with decreased urge sensation were noted in patients diagnosed with dysfunctional voiding or detrusor sphincter dyssynergia comparing to those diagnosed with poor relaxation of the external urethral sphincter. The average subjective improvement rate was 67% for the injection. The therapeutic effect was not affected by the type of EUS dysfunction. The multivariate analysis revealed that bladder neck narrowing and catheterization history were predictive of negative outcomes. There is a distinct urodynamic presentation for each type of female EUS dysfunction. Sphincteric BoNT-A injection provides a good therapeutic outcome for refractory EUS dysfunction. A narrowing bladder neck and a history of catheterization suggest poor therapeutic outcomes.

Dysfunctional voiding: update on evaluation and treatment

PURPOSE OF REVIEW

This review will be covering dysfunctional voiding, its diagnosis, and treatment options. This will focus primarily on dysfunctional voiding rather than all lower urinary tract dysfunction and we will focus on some of the newer findings and progress within this disease.

RECENT FINDINGS

Dysfunctional voiding is the inappropriate sphincter and pelvic floor constriction during voiding in an otherwise neurologically normal child. This has a wide spectrum of symptoms and can lead to a number of complications such as chronic kidney disease and poor quality of life if not appropriately addressed. Dysfunctional voiding is diagnosed with a careful examination and history with further imaging including a renal ultrasound and uroflowmetry to confirm the diagnosis. Urotherapy and biofeedback are the first and second-line treatments respectively and lead to significant improvement or cure in the majority of patients. For refractory patients, additional therapy options include use of α-blockers, botulinum injection, and electroneurostimulation, though the majority of the literature surrounding the use of these therapies consists of small studies with heterogenous causes of voiding dysfunction.

SUMMARY

Dysfunctional voiding is a common urologic complaint that has many excellent options for improving the patient's voiding issues and should be considered in patients with voiding dysfunction.

Botulinum toxin A injection in the treatment of chronic pelvic pain with hypertonic pelvic floor in women: Treatment techniques and results

Chronic pelvic pain (CPP) is an extremely bothersome condition which leads to major effects in women's everyday life. In addition to visceral sources of pain, pelvic floor dysfunction including myofascial pain and spasm on the pelvic floor muscles causing hypertonicity are causes often overlooked. Injecting botulinum toxin type A (BoNT-A) into hypertonic pelvic floor muscles may aid the relaxation of pelvic floor musculature. The muscles that are injected in CPP treatment include the obturator internus, levator ani (pubococcygeus, iliococcygeus, and puborectalis), and coccygeus. Generally, injections can be performed tolerably with safety under conscious sedation combined with local anesthesia. Most practitioners perform BoNT-A injection of pelvic floor muscles using anatomical landmarks identified by manual palpation only. For the precise location of injection sites, some needle guidance techniques were proposed, including electromyography, electrical stimulation, ultrasound, fluoroscopy, and/or computed tomography. Side effects of BoNT-A injection in CPP are rare and self-limiting. Because of the reversible nature of BoNT-A, reinjection appears to be necessary. Increasing proof points out that BoNT-A is a promising treatment option for CPP in women. We conducted a review of published literature in Pubmed, using chronic pelvic pain in women, hypertonic pelvic floor, and botulinum toxin as the keywords. This article aims to summarize the treatment techniques and results of BoNT-A injection for hypertonic pelvic floor in women with chronic pelvic pain.

The Therapeutic Effects and Pathophysiology of Botulinum Toxin A on Voiding Dysfunction Due to Urethral Sphincter Dysfunction

Neurogenic and non-neurogenic urethral sphincter dysfunction are common causes of voiding dysfunction. Injections of botulinum toxin A (BoNT-A) into the urethral sphincter have been used to treat urethral sphincter dysfunction (USD) refractory to conventional treatment. Since its first use for patients with detrusor sphincter dyssynergia in 1988, BoNT-A has been applied to various causes of USD, including dysfunctional voiding, Fowler’s syndrome, and poor relaxation of the external urethral sphincter. BoNT-A is believed to decrease urethral resistance via paralysis of the striated sphincter muscle through inhibition of acetylcholine release in the neuromuscular junction. Recovery of detrusor function in patients with detrusor underactivity combined with a hyperactive sphincter also suggested the potential neuromodulation effect of sphincteric BoNT-A injection. A large proportion of patients with different causes of USD report significant improvement in voiding after sphincteric BoNT-A injections. However, patient satisfaction might not increase with an improvement in the symptoms because of concomitant side effects including exacerbated incontinence, urinary urgency, and over-expectation. Nonetheless, in terms of efficacy and safety, BoNT-A is still a reasonable option for refractory voiding function. To date, studies focusing on urethral sphincter BoNT-A injections have been limited to the heterogeneous etiologies of USD. Further well-designed studies are thus needed.