Botulinum toxin in the treatment of outlet obstruction constipation caused by puborectalis syndrome

Effectiveness and safety of botulinum neurotoxin for treating dyssynergic defecation: A systematic review and meta-analysis

Dyssynergic defecation (DD) is a common cause of chronic constipation. Owing to the lack of a comprehensive synthesis of available data on the effectiveness of botulinum neurotoxin (BoNT) for treating DD, we performed a systematic review and meta-analysis. We searched the PubMed, Embase, and Cochrane databases from inception to May 9, 2023. The outcomes comprise short-term and long-term symptom improvement, various anorectal function measurements, complications of fecal incontinence, and symptom improvement after repeated BoNT injections. A meta-analysis comparing BoNT injection with either surgery or biofeedback (BFB) therapy in treating DD was also conducted. Subgroup analysis and meta-regression were performed to identify possible moderator effects. We included five randomized controlled trials, seven prospective studies, and two retrospective observational studies. Short-term potential improvement in symptoms (event rate [ER], 66.4%; 95% CI, 0.513 to 0.783) was identified, but in the long-term (>12 months), this effect was decreased (ER, 38.2%; 95% CI, 0.267 to 0.511). Short-term improvements in objective anorectal physiologic parameters were also observed. Repeated BoNT injection was effective for patients with symptom recurrence. Subgroup analysis revealed enhanced long-term symptom improvement with high-dose BoNT, but this treatment also increased the risk of complications and recurrence compared with low doses. The effectiveness, complications, and recurrence of symptoms associated with BoNT injection and surgery did not differ significantly. BoNT injection significantly provided short-term symptom improvement but also heightened the risk of incontinence compared with BFB therapy. Our systematic review and meta-analysis indicated that BoNT could be beneficial for short-term symptom improvement in patients with DD, but this effect tended to decline 12 months after injection. Standardized BoNT intervention protocols remain warranted. Among the several treatments for DD, we concluded that BoNT injection is not inferior to other options considering its effectiveness in relieving symptoms, the associated complication development, and the risk of symptom recurrence.

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.

Gastrointestinal Uses of Botulinum Toxin

Botulinum toxin (BT), one of the most powerful inhibitors that prevents the release of acetylcholine from nerve endings, represents an alternative therapeutic approach for "spastic" disorders of the gastrointestinal tract such as achalasia, gastroparesis, sphincter of Oddi dysfunction, chronic anal fissures, and pelvic floor dyssynergia.BT has proven to be safe and this allows it to be a valid alternative in patients at high risk of invasive procedures but long-term efficacy in many disorders has not been observed, primarily due to its relatively short duration of action. Administration of BT has a low rate of adverse reactions and complications. However, not all patients respond to BT therapy, and large randomized controlled trials are lacking for many conditions commonly treated with BT.The local injection of BT in some conditions becomes a useful tool to decide to switch to more invasive therapies. Since 1980, the toxin has rapidly transformed from lethal poison to a safe therapeutic agent, with a significant impact on the quality of life.

Management of constipation in patients with Parkinson's disease

A considerable body of research has recently emerged around nonmotor symptoms in Parkinson's disease (PD) and their substantial impact on patients' well-being. A prominent example is constipation which occurs in up to two thirds of all PD-patients thereby effecting psychological and social distress and consequently reducing quality of life. Despite the significant clinical relevance of constipation, unfortunately little knowledge exists on effective treatments. Therefore this systematic review aims at providing a synopsis on clinical effects and safety of available treatment options for constipation in PD. For this purpose, three electronic databases (MEDLINE, EMBASE, PsycINFO) were searched for experimental and quasi-experimental studies investigating the efficacy/effectiveness of interventions in the management of PD-associated constipation. Besides, adverse events were analyzed as secondary outcome. In total, 18 publications were identified involving 15 different interventions, of which none can be attributed sufficient evidence to derive strong recommendations. Nevertheless, some evidence indicates that dietetic interventions with probiotics and prebiotics may reduce symptom burden while providing a very favorable side-effects profile. Furthermore, the use of lubiprostone, macrogol and in the specific case of isolated or prominent outlet obstruction constipation injections of botulinum neurotoxin A into the puborectal muscles may as well be moderately supported. In summary, too little attention has been paid to treatment options for constipation in PD leaving abundant room for further research addressing this topic.

Review article: dyssynergic defaecation and biofeedback therapy in the pathophysiology and management of functional constipation

BACKGROUND

Functional constipation is a common clinical presentation in primary care. Functional defaecation disorders are defined as the paradoxical contraction or inadequate relaxation of the pelvic floor muscles during attempted defaecation (dyssynergic defaecation) and/or inadequate propulsive forces during attempted defaecation. Prompt diagnosis and management of dyssynergic defaecation is hindered by uncertainty regarding nomenclature, diagnostic criteria, pathophysiology and efficacy of management options such as biofeedback therapy.

AIM

To review the evidence pertaining to the pathophysiology of functional defaecation disorders and the efficacy of biofeedback therapy in the management of patients with dyssynergic defaecation and functional constipation.

METHODS

Relevant articles addressing functional defaecation disorders and the efficacy of biofeedback therapy in the management of dyssynergic defaecation and functional constipation were identified from a search of Pubmed, MEDLINE Ovid and the Cochrane Library.

RESULTS

The prevalence of dyssynergic defaecation in patients investigated for chronic constipation is as many as 40%. Randomised controlled trials have demonstrated major symptom improvement in 70%-80% of patients undergoing biofeedback therapy for chronic constipation resistant to standard medical therapy and have determined it to be superior to polyethylene glycol laxatives, diazepam or sham therapy. Long-term studies have shown 55%-82% of patients maintain symptom improvement.

CONCLUSIONS

Dyssynergic defaecation is a common clinical condition in patients with chronic constipation not responding to conservative management. Biofeedback therapy appears to be a safe, successful treatment with sustained results for patients with dyssynergic defaecation. Further studies are required to standardise the diagnosis of dyssynergic defaecation in addition to employing systematic protocols for biofeedback therapy.

Efficacy and safety of botulinum toxin in treatment of anismus: A systematic review

AIM: To evaluate the efficacy and safety of botulinum toxin type A (BTX-A) in the management of patients with anismus.

METHODS: An organized search of published literature was conducted using electronic databases including: PubMed/MEDLINE, and Cochrane Central Register of Controlled Trials, also an internet-based search using “Google Scholar” service was conducted. Both comparative and observational studies were included. We excluded irrelevant articles, editorials, case reports, reviews, and meta-analyses. The studies that followed the patients less than 6 mo were excluded. Variables collected were demographic data of the patients, technique of BTX-A injection and number of sessions, short-term and long-term clinical improvement, post-injection changes in electromyography (EMG), defecography, manometry, and balloon expulsion test, and complications recorded after BTX-A injection.

RESULTS: Seven studies comprising 189 patients were included in the review. The median age of the patients was 41.2 years and female-to-male ratio was 1.3:1. The median dose of BTX-A injected per procedure was 100 IU (range, 20-100 IU). Lateral injection was done in five trails and combined lateral and posterior injections in two trials. Three studies used endorectal ultrasonography-guided technique, one study used EMG-guided technique, whereas the remaining three studies used manual palpation with the index finger. The median percentage of patients who reported initial improvement of symptoms was 77.4% (range 37.5%-86.7%), this percentage declined to a median of 46% (range 25%-100%) at 4 mo after injection of BTX-A. Rates of improvement evaluated by balloon expulsion test, EMG, and defecography ranged between (37.5%-80%), (54%-86.7%), and (25%-86.6%), respectively. Fourteen (7.4%) patients developed complications after injection of BTX-A. Complication rates across the studies ranged from 0% to 22.6%.

CONCLUSION: Initial satisfactory improvement of symptoms after BTX-A injection remarkably deteriorated after 3 mo of the procedure. However, repeated injection may provide better sustained results with no additional morbidities. Further analysis of more patients is necessary to conclude the safety of BTX-A for the treatment of anismus.

Treatment of gastrointestinal sphincters spasms with botulinum toxin A

Botulinum toxin A inhibits neuromuscular transmission. It has become a drug with many indications. The range of clinical applications has grown to encompass several neurological and non-neurological conditions. One of the most recent achievements in the field is the observation that botulinum toxin A provides benefit in diseases of the gastrointestinal tract. Although toxin blocks cholinergic nerve endings in the autonomic nervous system, it has also been shown that it does not block non-adrenergic non-cholinergic responses mediated by nitric oxide. This has promoted further interest in using botulinum toxin A as a treatment for overactive smooth muscles and sphincters. The introduction of this therapy has made the treatment of several clinical conditions easier, in the outpatient setting, at a lower cost and without permanent complications. This review presents current data on the use of botulinum toxin A in the treatment of pathological conditions of the gastrointestinal tract.

Management of pelvic floor disorders: biofeedback and more

OPINION STATEMENT

Defecatory disorders (DD) and fecal incontinence (FI) are common conditions. DD are primarily attributable to impaired rectoanal function during defecation or structural defects. FI is caused by one or more disturbances of anorectal continence mechanisms. Altered stool consistency may be the primary cause or may unmask anorectal deficits in both conditions. Diagnosis and management requires a systematic approach beginning with a thorough clinical assessment. Symptoms do not reliably differentiate a DD from other causes of constipation such as slow or normal transit constipation. Therefore, all constipated patients who do not adequately respond to medical therapy should be considered for anorectal testing to identify a DD. Preferably, two tests indicating impaired defecation are required to diagnose a DD. Patients with DD, or those for whom testing is not available and the clinical suspicion is high, should be referred for biofeedback-based pelvic floor physical therapy. Patients with FI should be managed with lifestyle modifications, pharmacotherapy for bowel disturbances, and management of local anorectal problems (e.g., hemorrhoids). When these measures are not beneficial, anorectal testing and pelvic floor retraining with biofeedback therapy should be considered. Sacral nerve stimulation or perianal bulking could be considered in patients who have persistent symptoms despite optimal management of bowel disturbances and pelvic floor retraining.

Botulinum toxin type-A injection to treat patients with intractable anismus unresponsive to simple biofeedback training

AIM: To evaluate the efficacy of botulinum toxin type A injection to the puborectalis and external sphincter muscle in the treatment of patients with anismus unresponsive to simple biofeedback training.

METHODS: This retrospective study included 31 patients suffering from anismus who were unresponsive to simple biofeedback training. Diagnosis was made by anorectal manometry, balloon expulsion test, surface electromyography of the pelvic floor muscle, and defecography. Patients were given botulinum toxin type A (BTX-A) injection and pelvic floor biofeedback training. Follow-up was conducted before the paper was written. Improvement was evaluated using the chronic constipation scoring system.

RESULTS: BTX-A injection combined with pelvic floor biofeedback training achieved success in 24 patients, with 23 maintaining persistent satisfaction during a mean period of 8.4 mo.

CONCLUSION: BTX-A injection combined with pelvic floor biofeedback training seems to be successful for intractable anismus.

Improvement in pelvic pain with botulinum toxin type A - Single vs. repeat injections

The aim of this prospective study was to report the outcomes of pain and vaginal pressures of successive botulinum toxin type A injections for women with objective pelvic floor muscle overactivity and a two-year history of pelvic pain. Between 2005 and 2008, 37 women underwent injection of 100 IU of botulinum toxin type A into the puborectalis and pubococcygeous muscles with dysmenorrhoea, dyspareunia, dyschesia, and non-menstrual pelvic pain assessed using a visual analogue scale (VAS), and vaginal pressure measured by vaginal manometry, at 0, 4, 12 and 26 weeks from each injection. 26 women (70%) had one injection of botulinum toxin type A and 11 (30%) had 2 or more injections. The second injection was performed at the earliest at 26 weeks after the first, with subsequent injections having a median time to re-injection of 33.4 weeks (range 9.4-122.7 weeks). Single and repeated injections both demonstrated a statistically significant reduction in dyspareunia by VAS scores from 54 to 30 in the single injection group and from 51 to 23 in the multiple injection group (p = .001), non-menstrual pelvic pain VAS from 37 to 25 (p = .04), as well as vaginal pressures; 40 versus 34 cm H(2)O (p = .02). No statistically significant difference in dysmenorrhoea or dyschesia was observed for either group from their baseline scores. Multiple injections of botulinum toxin type A in women with pelvic floor muscle overactivity provide significant relief from dyspareunia and non-menstrual pelvic pain. The upper limit between re-injection is not yet determined, nor is the maximum number of treatments. Clinical outcomes for single and subsequent injection of botulinum toxin type A for recurrent pelvic pain are equivalent. Women who have had benefit from a single injection of botulinum toxin type A can be reassured that if symptoms reoccur, repeated injections can be expected to be equally efficacious.

Excellent response rate of anismus to botulinum toxin if rectal prolapse misdiagnosed as anismus ('pseudoanismus') is excluded

AIM

Anismus causes obstructed defecation as a result of inappropriate contraction of the puborectalis/external sphincter. Proctographic failure to empty after 30 s is used as a simple surrogate for simultaneous electromyography/proctography. Botulinum toxin is theoretically attractive but efficacy is variable. We aimed to evaluate the efficacy of botulinum toxin to treat obstructed defecation caused by anismus.

METHOD

Botulinum toxin was administered, under local anaesthetic, into the puborectalis/external sphincter of patients with proctographic anismus. Responders (resolution followed by recurrence of obstructed defecation over a 1- to 2-month period) underwent repeat injection. Nonresponders underwent rectal examination under anaesthetic (EUA). EUA-diagnosed rectal prolapse was graded using the Oxford Prolapse Grade 1-5.

RESULTS

Fifty-six patients were treated with botulinum toxin. Twenty-two (39%) responded initially and 21/22 (95%) underwent repeat treatment. At a median follow up of 19.2 (range, 7.0-30.4) months, 20/21 (95%) had a sustained response and required no further treatment. Isolated obstructed defecation symptoms (OR = 7.8, P = 0.008), but not proctographic or physiological factors, predicted response on logistic regression analysis. In 33 (97%) of 34 nonresponders, significant abnormalities were demonstrated at EUA: 31 (94%) had a grade 3-5 rectal prolapse, one had internal anal sphincter myopathy and one had a fissure. Exclusion of these alternative diagnoses revised the initial response rate to 96%.

CONCLUSION

Simple proctographic criteria overdiagnose anismus and underdiagnose rectal prolapse. This explains the published variable response to botulinum toxin. Failure to respond should prompt EUA seeking undiagnosed rectal prolapse. A response to an initial dose of botulinum toxin might be considered a more reliable diagnosis of anismus than proctography.

Comparative study between surgical and non-surgical treatment of anismus in patients with symptoms of obstructed defecation: a prospective randomized study

PURPOSE

This study came to compare the results of biofeedback retraining biofeedback (BFB), botulinum toxin botulinum type A (BTX-A) injection and partial division of puborectalis (PDPR) in the treatment of anismus patients.

PATIENTS AND METHODS

Consecutive patients treated for anismus fulfilled Rome II criteria for functional constipation at our institution were evaluated for inclusion. Participants were randomly allocated to receive BFB, BTX-A injection, and PDPR. All patients underwent anorectal manometry, balloon expulsion test, defecography, and electromyography activity of the anal sphincter. Follow up was conducted weekly in the first month then monthly for about 1 year. Study variables included clinical improvement, patient satisfaction, and objective improvement.

RESULTS

Sixty patients with anismus were randomized and completed the study. The groups differed significantly regarding clinical improvement at 1 month (50% for BFB, 75%BTX-A injection, and 95% for PDPR, P = 0.006) and differences persisted at 1 year (30% for BFB, 35%BTX-A injection, and 70% for PDPR, P = 0.02). Constipation score of the patients significantly improved postPDPR and BTX-A injection. Manometric relaxation was achieved significantly in the three groups.

CONCLUSION

Biofeedback retraining has a limited therapeutic effect, BTX-A injection seems to be successful for temporary treatment but PDPR is found to be an effective with lower morbidity in contrast to its higher success rate in treating anismus.

Paradoxical puborectalis contraction and increased perineal descent

Paradoxical puborectalis contraction and increased perineal descent are two forms of functional constipation presenting as challenging diagnostic and treatment dilemmas to the clinician. In the evaluation of these disorders, the clinician should take special care to exclude anatomic disorders leading to constipation. Physical examination is supplemented by additional diagnostic modalities such as cinedefecography, electromyography, manometry, and pudendal nerve tefninal motor latency. Generally, these investigations should be used in combination with the two playing the more relied upon techniques. Treatment is typically conservative with biofeedback playing a principal role with favorable results when patient compliance is emphasized. When considering paradoxical puborectalis contraction, failure of biofeedback is usually augmented with botulinum toxin injection. Increased perineal descent is generally treated with biofeedback and perineal support maneuvers. Surgery has little or no role in these conditions. The patient who insists on surgical intervention for either of these two conditions should be offered a stoma.

Transcutaneous needle-free injection of botulinum toxin: a novel treatment of childhood constipation and anal fissure

PURPOSE

Constipation is a common problem in children, and when it becomes chronic fecal impaction, overflow soiling and megarectum may develop. Children with chronic idiopathic constipation (IC) may not respond to conventional treatments of laxatives, enemas, and toilet training. The aims of the study were to evaluate the long-term outcome of transcutaneous needle-free injection of botulinum toxin (TNFBT) into the external anal sphincter (EAS) and to assess the extent of the toxin penetration into the sphincter.

METHOD

Children were recruited if symptomatic with chronic constipation, soiling, painful defecation, and withholding behavior requiring disimpaction of stool and rectal biopsy under general anesthesia. A total dose of 200 U of botulinum toxin (BT) (Dysport; Ipsen Limited, Slough, United Kingdom) was injected transcutaneously into the EAS at 3 and 9-o'clock positions using J-tip needle-free syringes (National Medical Products Inc, Irvine, Calif). The depth and width of toxin penetration was assessed by endosonography. Outcome was measured by a validated symptom severity (SS) score questionnaire. The total SS score ranged between 0 (best) and 65 (worst). The outcome was compared with 31 children in a comparable historical control group at 3 and 12-month follow-up.

RESULTS

Sixteen children were recruited with median age of 6.11 (range, 3-14.85) years and median duration of symptoms of 3.9 years (1.6-11.5). On endosonography, the median depth and width of BT penetration was 8 (7-10) mm and 8 (6-10) mm, respectively. At 3-month follow-up, the median SS score improved in all children after TNFBT from 32.50 (5-57) to 7.50 (0-26) (Wilcoxon's P < .0001). There were significant improvements in symptoms of constipation, soiling, painful defecation, general health and behavior, and fecal impaction of rectum (P < .05). Anal fissures healed in all 4 children. The SS score in the control group improved from 33 (12-49) to 15 (0-40) (P < .0001). At 12-month follow-up, the improvement of SS score in TNFBT group was significantly more than the control group as follows: 4 (0-25) vs 15 (0-51), respectively (Mann-Whitney U P < .002). Three patients had a second TNFBT injection for relapsed symptoms. There were no complications. The transcutaneous needle-free injection of botulinum toxin eliminates the risk of intravascular injection or needlestick injury. The transcutaneous needle-free injection of botulinum toxin also has other therapeutic applications including an alternative therapy to biofeedback training for dyssynergia of the EAS, treatment of muscle limb spasticity in cerebral palsy, and cosmetic treatment of overactive facial muscles and wrinkles and hyperhydrosis.

CONCLUSION

Transcutaneous needle-free injection of botulinum toxin into the external anal sphincter is a novel and safe new treatment of chronic idiopathic constipation and anal fissure in children. A second injection may be required in 20% of patients.

Comparative study between botulinum toxin injection and partial division of puborectalis for treating anismus

OBJECTIVES

The objective of this study was to compare the results of partial division of puborectalis (PDPR) versus local botulinum toxin type A (BTX-A) injection in treating patients with anismus.

PATIENTS AND METHODS

This prospective randomized study included 30 male patients suffering from anismus. Diagnosis was made by clinical examination, barium enema, colonoscopy, colonic transit time, anorectal manometry, balloon expulsion test, defecography, and electromyography. Patients were randomized into: group I which included 15 patients who were injected with BTX-A and group II which included 15 patients who underwent bilateral PDPR. Follow-up was conducted for about 1 year. Improvement was considered when patients returned to their normal habits.

RESULTS

BTX-A injection achieved initial success in 13 patients (86.7%). However, long-term success persisted only in six patients (40%). This was in contrast to PDPR which achieved initial success in all patients (100%) with a long-term success in ten patients (66.6%). Recurrence was observed in seven patients (53.8%) and five patients (33.4%) following BTX-A injection and PDPR, respectively. Minor degrees of incontinence were confronted in two patients (13.3%) following PDPR.

CONCLUSION

BTX-A injection seems to be successful for temporary treatment of anismus.

Comparative study between biofeedback retraining and botulinum neurotoxin in the treatment of anismus patients

PURPOSE

Anismus is a significant cause of chronic constipation. This study came to revive the results of BFB training and BTX-A injection in the treatment of anismus patients.

MATERIALS AND METHODS

Forty-eight patients with anismus (33 women; mean age 39.6 +/- 15.9) were included in this study. All patients fulfilled Rome II criteria for functional constipation. All patients underwent anorectal manometry, balloon expulsion test, defecography, and electromyography (EMG) activity of the EAS. All patients had non-relaxing puborectalis muscle. The patients were randomized into two groups. Group I patients received biofeedback therapy, two times per week for about 1 month. Group II patients were injected with BTX-A. Follow-up was conducted weekly in the first month then monthly for about 1 year.

RESULTS

In the BFB training group, three patients quit before the end of sessions with no improvement; initial improvement was recorded in 12 patients (50%) while long-term success was recorded in six patients (25%). In the BTX-A group, clinical improvement was recorded in 17 patients (70.83%), but the improvement persisted only in eight patients (33.3%). There is a significant difference between BTX-A group and BFB group regarding the initial success, but this significant difference disappeared at the end of follow-up. Manometric relaxation was achieved significantly post-BFB and post-BTX-A injection with no significant difference between the two groups.

CONCLUSIONS

Biofeedback training has a limited therapeutic effect on patients suffering from anismus. BTX-A injection seems to be successful for temporary treatment of anismus.

Systematic review of randomized controlled trials of the effectiveness of biofeedback for pelvic floor dysfunction

BACKGROUND

Pelvic floor dysfunction (PFD) is a type of functional constipation. The effectiveness of biofeedback as a treatment remains unclear.

METHODS

A systematic review of all randomized controlled trials evaluating the effectiveness of biofeedback in adults with PFD was carried out. All online databases from 1950 to 2007 were searched. This was supplemented by hand searching references of retrieved articles.

RESULTS

Seven trials fulfilled the inclusion criteria. Three compared biofeedback with non-biofeedback treatments and four compared different biofeedback modalities. Electromyography feedback was most widely utilized. The trials were heterogeneous with varied inclusion criteria, treatment protocols and definitions of success. Most had methodological limitations. Quality of life and psychological morbidity were assessed rarely. Meta-analysis of the studies involving any form of biofeedback compared with any other treatment suggested that biofeedback conferred a sixfold increase in the odds of treatment success (odds ratio 5.861 (95 per cent confidence interval 2.175 to 15.794); random-effects model).

CONCLUSION

Although biofeedback is the recommended treatment for PFD, high-quality evidence of effectiveness is lacking. Meta-analysis of the available evidence suggests that biofeedback is the best option, but well designed trials that take into account quality of life and psychological morbidity are needed.

Botulinum toxin: Clinical use

Since its development for the use of blepharospasm and strabismus more than 2.5 decades ago, botulinum neurotoxin (BoNT) has become a versatile drug in various fields of medicine. It is the standard of care in different disorders such as cervical dystonia, hemifacial spasm, focal spasticity, hyperhidrosis, ophthalmological and otolaryngeal disorders. It has also found widespread use in cosmetic applications. Many other indications are currently under investigation, including gastroenterologic and urologic indications, analgesic management and migraine. This paper is an extensive review of the spectrum of BoNT clinical applications.

Other indications of botulinum toxin therapy

The therapeutic possibilities of botulinum toxin are manifold and certainly not yet fully exhausted. Apart from the classical indications--focal dystonia and focal spasticity--its use in the management of wrinkles has become well known. Moreover, the toxin is now being administered in many medical fields, including many other kinetic disorders like rare dystonias and tremor. The toxin is also used in a great number of autonomic disorders such as focal hyperhidrosis and even rhinitis. Substantial advances have been made in the field of urology after injections into the sphincter and detrusor muscle. Studies for approval are meanwhile under way concerning the treatment of detrusor hyperreflexia. Gastroenterology is another important field for application of botulinum toxin--be it to the esophagus (e.g. achalasia), stomach, gallbladder, or anorectum. Anal fissure is considered a particularly common indication. Controlled studies for many indications are frequently lacking because of the limited incidence of some of these disorders and symptoms.

Management of bladder, prostatic and pelvic floor disorders

Since its introduction in the late 1970s for the treatment of strabismus and blepharospasm, botulinum toxin (BoNT) has been increasingly used in the interventional treatment of several other disorders characterized by excessive or inappropriate muscle contractions. Over the years, the number of primary clinical publications has grown exponentially, and still continues to increase. It has been shown that BoNT blocks cholinergic nerve endings in the autonomic nervous system but does not block non-adrenergic non-cholinergic responses mediated by nitric oxide (NO). The present paper reviews a number of recent clinical indications for urological and pelvic floor dysfunctions, such as overactive and neurogenic bladder, non-bacterial prostatitis, benign prostatic hyperplasia, chronic anal fissure, or conditions associated to hyperactivity of the puborectalis muscle during straining. These indications provide a new promising palette of indications for future usage of BoNT in clinical practice.

Defecación obstructiva. Métodos diagnósticos y tratamiento

Obstructive defecation is observed in approximately half of all patients with functional constipation. Functional constipation has been related to alterations in intestinal motility (slow transit constipation) and to pelvic floor disorders leading to obstructive defecation associated with anatomical alterations of the pelvic floor (rectocele, posterior perineal hernia, enterocele and sigmoidocele, internal rectal intussusception, occult mucosal prolapse, solitary rectal ulcer and descending perineum syndrome), or obstructive defecation without anatomical alterations (pelvic floor dyssynergy or anismus). The diagnostic methods used (history and physical examination, colonic transit time, balloon expulsion test, proctography, anorectal manometry and electromyography) are reviewed. Conservative medical treatment and the indications for surgical treatment and its results are also discussed.

Pelvic outlet obstruction

Despite the wide variety of definitions and descriptions of constipation, ideally, the diagnostic approach should be uniform. The evaluation process should begin with a careful and thorough patient history and physical exam; appropriate efforts should be made to exclude organic causes of constipation. Patients suffering from pelvic outlet obstruction often respond poorly to conservative treatment. Diagnostic tests include intestinal transit studies, anorectal manometry, defecography, balloon expulsion, and anal sphincter electromyography. For many patients constipation is multifactorial and accordingly, so is the treatment. In our opinion the first line of treatment should be based on conservative measures including adequate intake of fluids, dietary fiber supplementation, and laxatives. Biofeedback training should be offered, particularly to patients with paradoxical puborectalis contraction. Surgical management can, in very limited circumstances, be offered only to those patients with disabling symptoms who have failed other standard therapeutic measures.

Botulinum Toxin for the Treatment of Genital Pain Syndromes

Our purpose was to test the effect of botulinum toxin injections on hypertonic pelvic floor muscles of patients suffering from genital pain syndromes. We report two cases of women complaining of a genital pain syndrome resistant to pharmacological therapies and rehabilitation exercises associated with a documented involuntary tonic contraction of the levator ani muscle as a defense reaction triggered by vulvar pain. We performed botulinum toxin injections into the levator ani with the intent to relieve pelvic muscular spasms. Within a few days after the injections both the patients reported a complete resolution of the painful symptomatology, lasting for several months. Our experience suggests that botulinum injections are indicated in patients with genital pain syndrome with documented pelvic muscle hyperactivity, whose symptoms arise not only from genital inflammation and lesions, but also, and sometimes chiefly, from levator ani myalgia.

Noncosmetic uses of botulinum toxin

In conclusion, botulinum toxin usage over the past 2 to 3 decades has expanded exponentially. Almost every discipline in medicine has found some therapeutic use for this toxin. Botulinum toxin has been shown to be safe, effective, and relatively easy to administer with proper training.

Treatment with botulinum neurotoxin of gastrointestinal smooth muscles and sphincters spasms

Local injections of botulinum neurotoxin are now considered an efficacious treatment for neurological and non-neurological conditions. One of the most recent achievements in the field is the observation that botulinum neurotoxin provides benefit in diseases of the gastrointestinal tract. Botulinum neurotoxin inhibits contraction of gastrointestinal smooth muscles and sphincters; it has also been shown that the neurotoxin blocks cholinergic nerve endings in the autonomic nervous system, but it does not block nonadrenergic responses mediated by nitric oxide. This aspect has further promoted the interest to use botulinum neurotoxin as a treatment for overactive smooth muscles, such as the anal sphincters to treat anal fissure and outlet-type constipation, or the lower esophageal sphincter to treat esophageal achalasia. Knowledge of the anatomical and functional organization of innervation of the gastrointestinal tract is a prerequisite to understanding many features of botulinum neurotoxin action on the gut and the effects of injections placed into specific sphincters. This review presents current data on the use of botulinum neurotoxin to treat diseases of the gastrointestinal tract and summarizes recent knowledge on the pathogenesis of disorders of the gut due to a dysfunction of the enteric nervous system.

Pilot study of botulinum toxin type A in the treatment of chronic pelvic pain associated with spasm of the levator ani muscles

OBJECTIVE

To investigate whether botulinum toxin type A (BOTOX) injected into the levator ani muscles of women with objective pelvic floor muscle spasm decreases pain symptoms and improves quality of life.

DESIGN

A prospective cohort study.

SETTING

Outpatient clinic in a tertiary referral centre, Sydney, Australia.

SAMPLE

Twelve women, aged 18-55 years, with objective pelvic floor muscle hypertonicity and a minimum 2-year history of chronic pelvic pain were recruited.

METHODS

All women completed visual analog scale pain assessments; questionnaires relating to bladder and bowel symptoms and quality of life; and specific examinations. Forty units of BOTOX at three different dilutions were given bilaterally into the puborectalis and pubococcygeus muscles under conscious sedation.

RESULTS

Median visual analog scale scores were significantly improved for dyspareunia (80 vs 28; P=0.01) and dysmenorrhea (67 vs 28; P=0.03), with non-significant reductions in non-menstrual pelvic pain (64 vs 37) and dyschesia (47 vs 29). Pelvic floor muscles manometry showed a 37% reduction in resting pressure at week 4 and a 25% reduction was maintained at week 12 (P <0.0001). Quality of life scores (EQ-5D and SF-12) were improved from baseline at week 12, but did not reach statistical significance. Sexual activity scores were markedly improved, with a significant reduction in discomfort (4.8 vs 2.2; P=0.02) and improvement in habit (0.2 vs 1.9; P=0.03). These results were not influenced by dilution.

CONCLUSION

There is evidence from the present pilot study suggesting that women with pelvic floor muscles hypertonicity and pelvic pain may respond to BOTOX injections into the pelvic floor muscles. Further research into this novel treatment of chronic pelvic pain is strongly recommended.

Noncosmetic uses of botulinum toxin

Since the introduction of botulinum toxin (BTX) as a therapeutic tool in the 1970s, the number of uses for this substance has increased exponentially. BTX's mechanism of action involves degrading the SNARE proteins blockading the release of acetylcholine into the neuromuscular junction. In many body systems, decrease of contractility, strength, and tension of certain muscle groups result in improved clinical outcomes. Applications now include cosmetic, gastroenterologic, otolaryngologic, genitourinary, neurologic, and dermatologic uses. In fact, BTX can be considered as a potential treatment in any situation involving inappropriate or exaggerated muscle contraction. Currently, the FDA has approved BTX-A (Botox) for treating glabellar lines, blepharospasm, strabismus, hemifacial spasm, cervical dystonia, and spasticity. With the addition of cosmetic applications to the FDA's approval list, the use of BTX has increased dramatically.

Botulinum toxin in the management of bowel and bladder function in spinal cord injury and other neurologic disorders

Botulinum toxin inhibits release of acetylcholine and other neurotransmitters. It has been used successfully to treat pain and abnormal skeletal and smooth muscle activity in patients. This article discusses its use in patients with bladder and bowel disorders.

Constipation caused by functional outlet obstruction

Functional constipation is a very common problem in Western societies. Functional outlet obstruction, part of the spectrum of functional constipation, is suspected when patients present with select symptoms. Diagnosis is commonly made with anorectal manometry, electromyography, and rectal evacuation tests. Abnormal test patterns include poor relaxation and contraction of the anal sphincter in response to attempted defecation and difficult rectal evacuation. Several treatment approaches have been tested in these patients. Biofeedback training is considered the most specific therapeutic modality, and it is particularly attractive because of its safety. This review provides an assessment of the diagnostic tests for functional outlet obstruction and summarizes current options for therapy.

Review article: botulinum toxin in the therapy of gastrointestinal motility disorders

Since 1980, botulinum toxin has been employed for the treatment of various voluntary muscle spastic disorders in the fields of neurology and ophthalmology. More recently, botulinum toxin has been proved to be effective in the therapy of dyskinetic smooth muscle disorders of the gastrointestinal tract. Achalasia and anal fissure are the gastrointestinal disorders in which botulinum toxin therapy has been most extensively investigated. Botulinum toxin is the best treatment option for achalasia in patients whose condition makes them unfit for pneumatic dilation or surgery. In anal fissure, botulinum toxin is highly effective and may become the treatment of choice. In the future, botulinum toxin application in the gastrointestinal tract will be extended to many other gastrointestinal disorders, such as non-achalasic motor disorders of the oesophagus, dysfunction of Oddi's sphincter, achalasia of the internal anal sphincter and others. This article describes the mechanism of action, rationale of employment, indications and side-effects of botulinum toxin application in smooth muscle disorders of the gastrointestinal tract, and compares the results of different techniques of botulinum toxin therapeutic application.

Botulinum neurotoxin and other treatments for fissure-in-ano and pelvic floor disorders

BACKGROUND

The management of disorders of the lower gastrointestinal tract, such as chronic anal fissure and pelvic floor dysfunction, has undergone re-evaluation recently. To a large extent this is due to the advent of neurochemical treatments, such as botulinum neurotoxin injections and topical nitrate ointment.

METHODS AND RESULTS

This review presents, inter alia, current data on the use of botulinum neurotoxin to treat lower gastrointestinal tract diseases, such as chronic anal fissure for which it promotes healing and symptom relief in up to 70 per cent of cases. This agent has also been used selectively to weaken the external anal sphincter and puborectalis muscle in constipation and in Parkinson's disease. Symptomatic improvement can also be induced in anterior rectocele by botulinum neurotoxin injections.

CONCLUSION

Botulinum neurotoxin appears to be a safe therapy for anal fissure. It is more efficacious than nitrate application and does not require patient compliance to complete treatment. While it may also be a promising approach for the treatment of chronic constipation due to pelvic floor dysfunction, further investigation of its efficacy and safety in this role is needed before general usage can be advocated.

Other noncosmetic uses of BOTOX

Botulinum toxin A has a wide variety of clinical applications, which are related by blockade of acetylcholine and often are related to abnormal muscle contractures. These applications include ocular disorders, disorders of the upper aerodigestive tract, dystonia and hemifacial spasm, cosmetic, gastrointestinal disorders, genitourinary disorders, management of pain, and use in autonomic nervous system disorders. Many of these diseases will be discussed with regard to their treatment with botulinum toxin compared to conventional treatments. Advantages and disadvantages of botulinum toxin use are delineated. General guidelines for adult and pediatric dosing will also be discussed.

Study of the motile activity of the colon in rectal inertia constipation

BACKGROUND

We have recently demonstrated that rectal distension effected left colonic contraction, which probably acts to feed the rectum with fecal matter each time the rectum distends and evacuates its contents. This effect was postulated to occur through the recto-colic reflex. As the colonic status in rectal inertia constipation was scarcely addressed in the literature, we investigated this point.

METHODS

The response of the colonic pressure to rectal balloon distension in increments of 10 mL of water was studied in 38 patients with rectal inertia constipation (IC) (age 42.6 +/- 14.3 years, 29 women) and 12 healthy volunteers (40.9 +/- 12.2 years, nine women). The rectal and colonic pressures were measured by saline-perfused tubes connected to a pneumohydraulic infusion system. The rectum was distended by a condom applied to the end of a 10-F catheter.

RESULTS

The rectal and left colonic resting pressures were significantly lower in the patients than in the controls (P < 0.5, P < 0.05, respectively). In the healthy volunteers, rectal distension up to first rectal sensation produced no significant rectal or colonic pressure changes (P > 0.05, P > 0.05). At urge, rectal and left colonic pressures increased significantly (P < 0.001, P < 0.001, respectively), but there were no changes in the right colonic pressure (P > 0.05). The colonic response lasted as long as the rectum was distended. In IC, patients did not perceive the first rectal or urge sensation up to a rectal balloon filling of 300 mL; there was no rectal or colonic pressure response (P > 0.05, P > 0.05).

CONCLUSION

In normal subjects, left colonic contraction on rectal distension probably acts to feed the rectum with fecal material. In IC, the low left colonic resting pressure assumedly points to left colonic hypotonia which appears to aggravate the constipation produced by the inertic rectum. Furthermore, non-response of the left colon to rectal distension probably impedes rectal feeding with fecal matter and enhances constipation.

Botulinum toxin type-A in therapy of patients with anismus

INTRODUCTION

Anismus is a common cause of constipation and outlet obstruction. Standard therapy with laxatives or biofeedback has conflicting results. Surgical treatment gives poor results and has practically been abandoned.

PURPOSE

This study was designed to evaluate the efficacy of botulinum toxin type-A (Botox) injection to the puborectalis muscle in patients with anismus.

METHODS

Twenty-five patients (15 females; mean age, 23.2) with history of constipation and symptoms of outlet obstruction underwent anorectal perfusion manometry and video-proctography. All patients were found to have a nonrelaxing puborectalis muscle on both modalities. All have been unable to expel a rectal balloon. Each patient who participated in the study was randomly assigned to undergo local injection of Botox--10 units to each side of the puborectalis or 20 units to the posterior aspect of this muscle. Eight patients underwent further injections1-5 every 3 months in accordance with previous results. Follow-up was conducted 1, 4, 12, and 24 weeks after injection. Straining, anorectal pain, and overall satisfaction were assessed on a visual analog scale. Weekly evacuation, fecal incontinence, and complications were recorded. At the weekly meeting, each patient underwent anorectal manometry with a balloon expulsion test.

RESULTS

Manometric relaxation was achieved after the first injection in 18 patients (75 percent). Once relaxation was achieved, it lasted throughout the follow-up. Nine patients (37.5 percent) expelled the rectal balloon after the first injection. Seven of 16 patients who failed the first injection had an additional one. In 2 patients it was successful (28.6 percent). Symptom improvement of 29.2 percent in straining index was recorded during follow-up. In 3 patients (12.5 percent) pain developed after injection. No other complications were observed. Overall satisfaction with Botox injection results was observed in 58.3 percent.

CONCLUSIONS

Botox injection to the puborectalis muscle has been found to have a limited therapeutic effect on patients suffering from anismus. Our results justify the need for further double-blind placebo-controlled trials to determine the exact role of botulinum toxin type-A in anismus.

Other noncosmetic uses of BOTOX

Botulinum toxin A has a wide variety of clinical applications, which are related by blockade of acetylcholine and often are related to abnormal muscle contractures. These applications include ocular disorders, disorders of the upper aerodigestive tract, dystonia and hemifacial spasm, cosmetic, gastrointestinal disorders, genitourinary disorders, management of pain, and use in autonomic nervous system disorders. Many of these diseases will be discussed with regard to their treatment with botulinum toxin compared to conventional treatments. Advantages and disadvantages of botulinum toxin use are delineated. General guidelines for adult and pediatric dosing will also be discussed.

Review article: the therapy of constipation

Constipation is a common symptom that may be idiopathic or due to various identifiable disease processes. Laxatives are agents that add bulk to intestinal contents, that retain water within the bowel lumen by virtue of osmotic effects, or that stimulate intestinal secretion or motility, thereby increasing the frequency and ease of defecation. Drugs which improve constipation by stimulating gastrointestinal motility by direct actions on the enteric nervous system are under development. Other modalities used to treat constipation include biofeedback and surgery. Laxatives and lavage solutions are also used for colon preparation and evacuation of the bowels after toxic ingestions.

Anterior rectocele due to obstructed defecation relieved by botulinum toxin

Background. Surgical repair of rectocele does not always alleviate symptoms related to difficulty in defecation, and some patients have impaired fecal continence after surgical treatment. To avoid complications of surgical repair, we investigated the efficacy of botulinum toxin in treating patients with symptomatic rectocele. Methods. Fourteen female patients with anterior rectocele were included in the study. The patients were studied by using anorectal manometry and defecography, and then treated with a total of 30 units of type A botulinum toxin, injected into 3 sites, 2 on either side of the puborectalis muscle and the third anteriorly in the external anal sphincter, under ultrasonographic guidance. Results. After 2 months, symptomatic improvement was noted in 9 patients (P =.0003). At the same time, rectocele depth (mean +/- SD) was reduced from 4.3 +/- 0.6 cm to 1.8 +/- 0.5 cm (P =.0000001) and rectocele area from 9.2 +/- 1.3 cm(2) to 2.8 +/- 1.6 cm(2) (P =.0000001). Anorectal manometry demonstrated decreased tone during straining from 70 +/- 28 mm Hg at baseline to 41 +/- 19 mm Hg at 1 month (P =.003) and to 41 +/- 22 mm Hg at 2 months (P =.005). No permanent complications were observed in any patient for a mean follow-up period of 18 +/- 4 months. At 1 year evaluation, incomplete or digitally assisted rectal voiding was not reported by any patient, and a rectocele was not found at physical examination. Four recurrent, asymptomatic rectoceles were noted at defecography. Conclusions. Botulinum toxin injections should be considered as a simple therapeutic approach in patients with anterior rectocele. The treatment is safe and less expensive than surgical repair. A more precise method of toxin injections under transrectal ultrasonography accounts for the high success rate. Repeated injections may be necessary to maintain the clinical improvement.