Four-dimensional ultrasound guidance for pelvic floor Botulinum toxin-A injection in chronic pelvic pain: a novel technique

Botulinum toxin type A injection combined with biofeedback in the treatment of spastic pelvic floor syndrome

BACKGROUND

Spastic pelvic floor syndrome (SPFS) is a refractory pelvic floor disease characterized by abnormal (uncoordinated) contractions of the external anal sphincter and puborectalis muscle during defecation, resulting in rectal emptation and obstructive constipation. The clinical manifestations of SPFS are mainly characterized by difficult defecation, often accompanied by a sense of anal blockage and drooping. Manual defecation is usually needed during defecation. From physical examination, it is commonly observed that the patient's anal muscle tension is high, and it is difficult or even impossible to enter with his fingers.

AIM

To investigate the characteristics of anorectal pressure and botulinum toxin A injection combined with biofeedback in treating pelvic floor muscle spasm syndrome.

METHODS

Retrospective analysis of 50 patients diagnosed with pelvic floor spasm syndrome. All patients underwent pelvic floor surface electromyography assessment, anorectal dynamics examination, botulinum toxin type A injection 100 U intramuscular injection, and two cycles of biofeedback therapy.

RESULTS

After the botulinum toxin A injection combined with two cycles of biofeedback therapy, the patient's postoperative resting and systolic blood pressure were significantly lower than before surgery (P < 0.05). Moreover, the electromyography index of the patients in the resting stage and post-resting stages was significantly lower than before surgery (P < 0.05).

CONCLUSION

Botulinum toxin A injection combined with biofeedback can significantly reduce pelvic floor muscle tension in treating pelvic floor muscle spasm syndrome. Anorectal manometry is an effective method to evaluate the efficacy of treatment objectively. However, randomized controlled trials are needed.

Four-dimensional ultrasound biometry following botulinum toxin type A injection to the pelvic floor

AIMS

The objective of this study was to provide follow-up data on four-dimensional ultrasound (4DUS) morphometry for women having botulinum toxin type A (BoNT-A) treatment of pelvic floor tension myalgia (PFTM).

MATERIALS AND METHODS

A prospective cohort study was performed from October 2013 to June 2018, recruiting women scheduled for BoNT-A injection in the pelvic floor musculature. Translabial 4DUS, vaginal pressure assessment by manometry and pain visual analog scales (VAS) were performed on all women before injection and again at 4, 12, and 26 weeks. The BoNT-A injection was performed under 4DUS guidance.

RESULTS

Twenty-nine women had 44 injections over the course of the study. Although improvements were seen in VAS scores for dysmenorrhea, nonmenstrual pelvic pain, and dyspareunia, there were no significant differences in ultrasound biometry at either rest, Valsalva, or on contraction when comparing postinjection measurements at 4, 12, and 26 weeks with pre-injection baseline. Similarly, vaginal pressure readings at rest demonstrated a significant improvement throughout the 4, 12, and 26 week follow-up, with a reduction in maximal contraction at 4 and 12 but not 26 weeks.

CONCLUSIONS

This study demonstrates that 4DUS biometry of the pelvic floor does not correlate with clinical pain and vaginal pressure outcomes for BoNT-A injection in the context of PFTM.

Improving Botulinum Toxin Efficiency in Treating Post-Stroke Spasticity Using 3D Innervation Zone Imaging

Spasticity is a common post-stroke syndrome that imposes significant adverse impacts on patients and caregivers. This study aims to improve the efficiency of botulinum toxin (BoNT) in managing spasticity, by utilizing a three-dimensional innervation zone imaging (3DIZI) technique based on high-density surface electromyography (HD-sEMG) recordings. Stroke subjects were randomly assigned to two groups: the control group ([Formula: see text]) which received standard ultrasound-guided injections, and the experimental group ([Formula: see text]) which received 3DIZI-guided injections. The amount of BoNT given was consistent for all subjects. The Modified Ashworth Scale (MAS), compound muscle action potential (CMAP) and muscle activation volume (MAV) from bilateral biceps brachii muscles were obtained at the baseline, 3 weeks, and 3 months after injection. Intra-group and inter-group comparisons of MAS, CMAP amplitude and MAV were performed. An overall improvement in MAS of spastic elbow flexors was observed during the 3-week visit ([Formula: see text]), yet no statistically significant difference found with intra-group or inter-group analysis. Compared to the baseline, a significant reduction of CMAP amplitude and MAV were observed in the spastic biceps muscles of both groups at 3-week post-injection, and returned to approximate baseline value at 12-week post injection. A significantly higher reduction was found in CMAP amplitude ([Formula: see text]% versus [Formula: see text]%, [Formula: see text]) and MAV ([Formula: see text]% versus [Formula: see text]%, [Formula: see text]) in the experimental group compared to the control group. The study has demonstrated preliminary evidence that precisely directing BoNT to the innervation zones (IZs) localized by 3DIZI leads to a significantly higher treatment efficiency improvement in spasticity management. Results have also shown the feasibility of developing a personalized BoNT injection technique for the optimization of clinical treatment for post-stroke spasticity using proposed 3DIZI technique.

Botulinum Toxin A: A Review of Potential Uses in Treatment of Female Urogenital and Pelvic Floor Disorders

Background: Botulinum toxin is an injectable neuromodulator that inhibits transmission between peripheral nerve endings and muscle fibers, resulting in muscle paralysis. Botulinum toxin type A is the most common form of botulinum toxin used in clinical practice.

Methods: In this review, we examine the mechanism of action, formulations, common clinical use in the genital-urinary tract, and potential clinical use in pelvic floor disorders of botulinum toxin type A.

Results: Several aspects of botulinum toxin A make it a favorable therapeutic tool, including its accessibility, its longevity, and its impermanence and reversibility of resultant chemodenervation in a relatively short and safe manner. Although botulinum toxin A has well-established efficacy in treating refractory overactive bladder and neurogenic detrusor overactivity, its use in pelvic floor disorders is still in its infancy.

Conclusion: The efficacy of botulinum toxin A for treating pelvic pain, voiding dysfunction, muscle pain and dysfunction, and certain colorectal-related pain issues shows promise but requires additional rigorous evaluation.

Botulinum toxin type A for the treatment of dyssynergic defaecation in adults: a systematic review

AIM

Dyssynergic defaecation (DD) is characterized by inappropriate coordination of the pelvic floor muscles during defaecation, resulting in impaired stool expulsion. The mainstay of treatment is biofeedback and alternative therapies are limited in those who do not respond. This systematic review evaluated botulinum toxin type A injection (BTXA) as a treatment option for dyssynergia.

METHODS

PubMed, Embase and Cochrane Central Register of Controlled Trials were searched for studies evaluating adult patients with DD treated with BTXA injection into the puborectalis and/or external anal sphincter. All study designs, except case reports, were included in the review with no language restriction. Studies limited to patients with specific neurological diagnoses or with a follow-up period under 1 month were excluded. Study selection, assessment and data extraction were performed by two reviewers and results were synthesized narratively.

RESULTS

Eleven studies (three randomized control trials) involving 248 participants were included. All studies used the transanal approach to deliver the injection, most commonly at the 3 and 9 o'clock positions using digital palpation for guidance. The most commonly used patient position was left lateral, and most studies did not use any anaesthesia. The dose of BTXA varied (Botox 12-100 units, Dysport 100-500 units), and outcomes measured were heterogeneous (global rating ± up to five investigations). Symptomatic improvement varied between 29.2% and 100% and adverse effects occurred in 0% to 70%.

CONCLUSION

The evidence to support using BTXA for DD is poor and only covers a transanal approach. Future studies should redress these limitations: heterogeneity of design, dose and outcome measures.

High-density surface electromyographic assessment of pelvic floor hypertonicity in IC/BPS patients: a pilot study

INTRODUCTION AND HYPOTHESIS

To assess the feasibility of objectively assessing pelvic floor hypertonicity (PFH) in women with interstitial cystitis/bladder pain syndrome (IC/BPS) using an intra-vaginal high-density surface electromyography (HD-sEMG) probe.

METHODS

Seven female subjects (mean age 44 ± 13 years) with a prior diagnosis of IC/BPS were recruited. A full digital pelvic examination was administered to identify hypertonic muscles. Intra-vaginal HD-sEMG was acquired during rest. Root-mean-squared (RMS) amplitude during rest was calculated for each channel to define a hypertonicity index and hypertonic zone. Innervation zones (IZs) were identified from the bipolar mapping of decomposed HD-sEMG signals and summarized into an IZ distribution mapping.

RESULTS

Of the seven subjects recruited, five had normal pelvic floor muscle tone and two exhibited hypertonicity upon muscle palpation. Subjects with PFH demonstrated a higher hypertonicity index (12.6 ± 3.5 vs. 4.5 ± 1.2) in sessions 1 and 2. The hypertonic zone defined by the 64-channel RMS mapping coincided with the digital pelvic examination findings. The corresponding IZs were localized for each motor unit. The hypertonicity indices between two consecutive sessions were well correlated (CC = 0.95).

CONCLUSIONS

This study represents the first effort to employ intra-vaginal HD-sEMG to assess PFH in women with IC/BPS. Our results demonstrate the feasibility of HD-sEMG to provide a quantitative diagnosis of PFH and the precise localization of hypertonic muscles and IZs. The proposed HD-sEMG-based techniques provide promising tools for clinical diagnosis and treatment of PFH, such as the personalized guidance of BoNT injections.

Botulinum injections for myofascial pelvic pain

INTRODUCTION AND HYPOTHESIS

The aim of this study was to assess the impact of botulinum toxin injection in women with myofascial pelvic pain (MFPP) syndrome of the pelvic floor who had failed conservative treatment.

METHODS

This was a retrospective descriptive observational study of 48 consecutive patients receiving botulinum toxin to the pelvic floor for MFPP syndrome in a tertiary teaching hospital over an 8-year period. Trigger points were identified, and botulinum toxin was injected into the pelvic floor at the trigger points in doses ranging from 50 to 200 units. The patient-reported global impression of improvement scale was used to evaluate the success at follow-up, and adverse effects were recorded.

RESULTS

Forty-six women attended for follow-up at 3-6 months. Of these, 34 (74%) reported an improvement in their symptoms (slightly better, much better, very much better), 12 (26%) had no change, and no patients reported worsening of symptoms. One patient (2%) reported transient postoperative faecal incontinence, which resolved after 2 weeks. There appeared to be no difference in outcome between the doses.

CONCLUSIONS

Botulinum toxin injection into the pelvic floor of women with MFPP appears to be beneficial in those who have failed conservative treatment. Prospective studies, including dose-finding studies, are now required.

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.

MRI of the Male Pelvic Floor

The pelvic floor is a complex structure that supports the pelvic organs and provides resting tone and voluntary control of the urethral and anal sphincters. Dysfunction of or injury to the pelvic floor can lead to gastrointestinal, urinary, and sexual dysfunction. The prevalence of pelvic floor disorders is much lower in men than in women, and because of this, the majority of the published literature pertaining to MRI of the pelvic floor is oriented toward evaluation of the female pelvic floor. The male pelvic floor has sex-specific differences in anatomy and pathophysiologic disorders. Despite these differences, static and dynamic MRI features of these disorders, specifically gastrointestinal disorders, are similar in both sexes. MRI and MR defecography can be used to evaluate anorectal disorders related to the pelvic floor. MRI can also be used after prostatectomy to help predict the risk of postsurgical incontinence, to evaluate postsurgical function by using dynamic voiding MR cystourethrography, and subsequently, to assess causes of incontinence treatment failure. Increased tone of the pelvic musculature in men secondary to chronic pain can lead to sexual dysfunction. This article reviews normal male pelvic floor anatomy and how it differs from the female pelvis; MRI techniques for imaging the male pelvis; and urinary, gastrointestinal, and sexual conditions related to abnormalities of pelvic floor structures in men.Online supplemental material is available for this article.^©RSNA, 2019.