Comparison of two different formulations of botulinum toxin A for the treatment of oesophageal achalasia. The Gismad Achalasia Study Group

From Toxin to Treatment: A Narrative Review on the Use of Botulinum Toxin for Autonomic Dysfunction

Since its regulatory approval over a half-century ago, botulinum toxin has evolved from one of the most potent neurotoxins known to becoming routinely adopted in clinical practice. Botulinum toxin, a highly potent neurotoxin produced by Clostridium botulinum, can cause botulism illness, characterized by widespread muscle weakness due to inhibition of acetylcholine transmission at neuromuscular junctions. The observation of botulinum toxin's anticholinergic properties led to the investigation of its potential benefits for conditions with an underlying etiology of cholinergic transmission, including autonomic nervous system dysfunction. These conditions range from disorders of the integument to gastrointestinal and urinary systems. Several formulations of botulinum toxin have been developed and tested over time, significantly increasing the availability of this treatment for appropriate clinical use. Despite the accelerated and expanded use of botulinum toxin, there lacks an updated comprehensive review on its therapeutic use, particularly to treat autonomic dysfunction. This narrative review provides an overview of the effect of botulinum toxin in the treatment of autonomic dysfunction and summarizes the different formulations and dosages most widely studied, while highlighting reported outcomes and the occurrence of any adverse events.

An overview of the efficacy, safety, and predictors of achalasia treatments

INTRODUCTION

Achalasia is a rare esophageal motility disorder characterized by abnormal esophageal peristalsis and the inability of the lower esophageal sphincter to relax, resulting in poor esophageal emptying. This can be relieved by endoscopic and surgical treatments; each comes with certain advantages and disadvantages.

AREAS COVERED

This review aims to guide the clinician in clinical decision making on the different treatment options for achalasia regarding the efficacy, safety, and important predictors.

EXPERT OPINION

Botulinum toxin injection is only recommended for a selective group of achalasia patients because of the short term effect. Pneumatic dilation improves achalasia symptoms, but this effect diminishes over time and requiring repeated dilations to maintain clinical effect. Heller myotomy combined with fundoplication and peroral endoscopic myotomy are highly effective on the long term but are more invasive than dilations. Gastro-esophageal reflux complaints are more often encountered after peroral endoscopic myotomy. Patient factors such as age, comorbidities, and type of achalasia must be taken into account when choosing a treatment. The preference of the patient is also of great importance and therefore shared decision making has to play a fundamental role in deciding about treatment.

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.

ASGE guideline on the management of achalasia

Achalasia is a primary esophageal motor disorder of unknown etiology characterized by degeneration of the myenteric plexus, which results in impaired relaxation of the esophagogastric junction (EGJ), along with the loss of organized peristalsis in the esophageal body. The criterion standard for diagnosing achalasia is high-resolution esophageal manometry showing incomplete relaxation of the EGJ coupled with the absence of organized peristalsis. Three achalasia subtypes have been defined based on high-resolution manometry findings in the esophageal body. Treatment of patients with achalasia has evolved in recent years with the introduction of peroral endoscopic myotomy. Other treatment options include botulinum toxin injection, pneumatic dilation, and Heller myotomy. This American Society for Gastrointestinal Endoscopy Standards of Practice Guideline provides evidence-based recommendations for the treatment of achalasia, based on an updated assessment of the individual and comparative effectiveness, adverse effects, and cost of the 4 aforementioned achalasia therapies.

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.

Comparison between botulinum injection and removable covered self-expanding metal stents for the treatment of achalasia

BACKGROUND

Intrasphincteric injection of botulinum toxin (BTX) and removable self-expanding metal stents (SEMS) have both been used for the treatment of achalasia.

AIM

To compare the effectiveness and long-term outcome of SEMS placement and BTX injection in patients with achalasia.

METHODS

A total of 110 patients with newly diagnosed achalasia were enrolled in the study between July 2003 and December 2009. The patients received either BTX injection (n = 51) or SEMS placement (n = 59). Clinical symptoms, objective parameters, and long-term clinical outcomes were evaluated after 7 and 30 days and then every 6 months until withdrawal from the study. The mean duration of follow-up was 28 months (range 10-36 months).

RESULTS

Improvements in global symptom and dysphagia scores and in basal lower esophageal sphincter pressure were significantly more marked in the SEMS group than in the BTX group (all P < 0.05). After 12 months, the remission rate in the SEMS group (81.28 %) was statistically significantly higher than that in the BTX group (64.58; P < 0.05). At 36 months, the remission rates in the two groups were 49.1 and. 4.2 %, respectively (P < 0.01). The symptom-free interval was 831 ± 46 days in the SEMS group and 522 ± 42 days in the BTX group (P < 0.01). No side effects were reported with BTX treatment. In the SEMS group there were 13 episodes of chest pain, nine cases of regurgitation, and four stent migrations. No serious complications occurred.

CONCLUSION

Removable SEMS was associated with better long-term outcomes than BTX injection in patients with achalasia.

Achalasia

This article reviews the diagnosis and treatment of achalasia, a rare esophageal motility disorder characterized by absent peristalsis and failure of the lower esophageal sphincter (LES) to relax. Various treatment options including management with sublingual nitrates or calcium channel blockers, injection of the LES with botulism toxin, pneumatic dilation of the LES, and pneumatic dilation are discussed. Laparoscopic Heller myotomy is minimally invasive with incumbent low morbidity and mortality rates, and combined with a partial fundoplication is a durable, safe, and effective treatment option for patients with achalasia.

Retrospective evaluation of the dose equivalence of Botox(®) and Dysport (®) in the management of blepharospasm and hemifacial spasm: a novel paradigm for a never ending story

Botox(®) and Dysport(®) are the preparations of botulinum neurotoxin most widely used for therapeutic purposes. Several studies have addressed the topic of the equivalency ratio (D/B ratio) to be used in clinical practice and whether a reliable value exists is still a matter of debate. To this purpose, we ideated a novel paradigm by retrospectively examining the patients affected by hemifacial spasm and blepharospasm. We compared the pairs of treatments with a switch from one brand to the other undergone by the same patient in consecutive sessions with overlapping clinical outcome. Out of 2006 treatments, we found 51 treatment pairs. D/B ratio was extremely variable (range 1.2-13.3) and in most cases (65%) it was between 1:3 and 1:5. In conclusion, even if the 1:4 ratio might be reliable for clinical purpose, a true bioequivalence between Dysport(®) and Botox(®) might not exist due to the intrinsic difference in their pharmacokinetic properties.

Updated perspectives on neurogenic thoracic outlet syndrome

Pain represents a foremost feature of neurogenic thoracic outlet syndrome (NTOS). Similar to other persistent pain conditions, the physical discomfort associated with NTOS can cause severe and often debilitating symptoms. In fact, those suffering from the syndrome report a quality of life impacted as significantly as those with chronic heart failure. This evidence-based literature review focuses on the classification, etiology, clinical presentation, diagnostic measures, and surgical treatment of NTOS, with a focus on nonoperative therapies such as physical modalities, pharmacological therapies, and more contemporary minimally invasive intramuscular treatments with botulinum toxin.

Single CT-guided chemodenervation of the anterior scalene muscle with botulinum toxin for neurogenic thoracic outlet syndrome

OBJECTIVE

To examine pain relief in patients with neurogenic thoracic outlet syndrome (NTOS) after a single, low dose injection of botulinum toxin A (Botox) into the anterior scalene muscle (ASM) under computed tomographic (CT) guidance.

DESIGN

Prospective longitudinal study.

SETTING

Academic medical institution.

PATIENTS

Patients 18 years of age and older were evaluated for potential scalenectomy and first rib resection using the transaxillary approach at the study institution between 2005 and 2008. All patients had failed physical therapy. A total of 29 procedures on 27 participants were studied.

INTERVENTIONS

A single, 20-unit injection of Botox into the ASM under CT-guidance.

OUTCOME MEASURES

Short-form McGill Pain Questionnaire (SF-MPQ) prior to and at 1, 2, and 3 months post-Botox toxin injection.

RESULTS

There was a decline in pain during the 3 months subsequent to Botox injection as noted by the following components of the SF-MPQ: sensory (P = 0.02), total (P = 0.05), visual analog scale (VAS [P = 0.04]), and present pain intensity (PPI) score (P = 0.06). The proportion of patients reporting more intense pain scores did not return to the pre-intervention level at 3 months post-Botox injection.

CONCLUSION

Patients experienced substantial pain relief in months 1 and 2 following a single Botox injection into the ASM under CT guidance. Significant pain reduction was noted for 3 months after Botox injection with respect to both sensory and VAS scores, and the total and PPI scores approximated statistical significance. After 3 months, patients experienced a 29% decrease in the sensory component of their pain as well as an approximate 15% reduction in their VAS score. A single, CT-guided Botox injection into the ASM may offer an effective, minimally invasive treatment for NTOS.

Combined treatment of achalasia - botulinum toxin injection followed by pneumatic dilatation: long-term results

Injection of botulinum toxin (BT) and pneumatic dilatation are available methods in nonsurgical treatment of achalasia. Authors anticipate beneficial effect of prior BT injection on the success of pneumatic dilatation and duration of its effect. There are no long-term data available to assess efficacy of combined treatment. From 1998 to 2007, 51 consecutive patients (20 men and 31 women, age 24-83) with achalasia were included and prospectively followed up. Each patient received injection of 200 IU of BT into the lower esophageal sphincter (LES) during endoscopy and 8 days later pneumatic dilatation (PD) under X-ray control was performed. The follow-up was established every 3 months first year and then annually. The efficacy was evaluated by a questionnaire concerning patient's symptoms and manometry. Results were compared with 40 historical controls (16 men and 24 women, age 26-80) treated by PD alone using the same method and follow-up. Fifty-one patients underwent combined treatment. Four patients failed in follow-up and were not included for analysis. The mean duration of follow-up was 48 months with range 12-96 months. Thirty-four of forty-seven (72%) patients were satisfied with results with none or very rare and mild troubles at the time of the last visit. Forty-one patients were followed up more than 2 years. Effect of therapy lasted in 75% (31/41) of them. In 17 patients, more than 5 years after treatment, effect lasted in 12 (70%). Mean tonus of LES before therapy was 29 mm Hg (10-80), 3 months after therapy decreased to 14 mmHg (5-26). The cumulative 5 years remission rate (+/-95% CI) in combined treated patients 69% +/- 8% was higher than in controls 50% +/- 9%; however it, was not statistically significant (P= 0.07). In control group 1, case of perforation (2.5%) occurred. Eight patients (17%) with relapse of dysphagia were referred to laparoscopic Heller myotomy with no surgical complication. The main adverse effect was heartburn that appeared in 17 patients (36%). Initial injection of BT followed by PD seems to be effective for long-term results with fewer complications. But the combined therapy is not significantly superior to PD alone.

Current clinical approach to achalasia

Idiopathic achalasia is a rare primary motility disorder of the esophagus. The classical features are incomplete relaxation of a frequently hypertensive lower esophageal sphincter (LES) and a lack of peristalsis in the tubular esophagus. These motor abnormalities lead to dysphagia, stasis, regurgitation, weight loss, or secondary respiratory complications. Although major strides have been made in understanding the pathogenesis of this rare disorder, including a probable autoimmune mediated destruction of inhibitory neurons in response to an unknown insult in genetically susceptible individuals, a definite trigger has not been identified. The diagnosis of achalasia is suggested by clinical features and confirmed by further diagnostic tests, such as esophagogastroduodenoscopy (EGD), manometry or barium swallow. These studies are not only used to exclude pseudoachalasia, but also might help to categorize the disease by severity or clinical subtype. Recent advances in diagnostic methods, including high resolution manometry (HRM), might allow prediction of treatment responses. The primary treatments for achieving long-term symptom relief are surgery and endoscopic methods. Although limited high-quality data exist, it appears that laparoscopic Heller myotomy with partial fundoplication is superior to endoscopic methods in achieving long-term relief of symptoms in the majority of patients. However, the current clinical approach to achalasia will depend not only on patients’ characteristics and clinical subtypes of the disease, but also on local expertise and patient preferences.

Using translational medicine to understand clinical differences between botulinum toxin formulations

When using botulinum toxin-based products, the physician must decide the optimal location and dose required to alleviate symptoms and improve the patient's quality of life. To deliver effective treatment, the physician needs to understand the importance of accurate target muscle selection and localization and the implications of each product's migration properties when diluted in different volumes. Pre-clinical mouse models of efficacy and safety have been utilized to compare local and distal muscle relaxation effects following defined intramuscular administration. Data from the model allow the products to be ranked based on their propensity for local efficacy versus their distal migration properties. Using standardized dilutions, the non-parallel dose-response curves for the various formulations demonstrate that they have different efficacy profiles. Distal effects were also noted at different treatment doses, which are reflected in the different safety and/or therapeutic margins. Based on these pre-clinical data, the safety and therapeutic margin rankings are ordered, largest to smallest, as BOTOX, Dysport and Myobloc. The results of subsequent clinical trials are variable and dose comparisons are inconclusive, thus supporting the regulatory position that the dose units of the individual preparations are unique and cannot be simply converted between products.

Non-surgical treatment of esophageal achalasia

Esophageal achalasia is an infrequent motility disorder characterized by a progressive stasis and dilation of the oesophagus; with subsequent risk of aspiration, weight loss, and malnutrition. Although the treatment of achalasia has been traditionally based on a surgical approach, especially with the introduction of laparoscopic techniques, there is still some space for a medical approach. The present article reviews the non-surgical therapeutic options for achalasia.

Review article: the management of achalasia - a comparison of different treatment modalities

BACKGROUND

Achalasia is an uncommon primary oesophageal motor disorder with an unknown aetiology. Therapeutic options for achalasia are aimed at decreasing the lower oesophageal sphincter pressure, improving the oesophageal empting, and most importantly, relieving the symptoms of achalasia. Modalities for treatment include pharmacologic, endoscopic, pneumatic dilatation and surgical. The decision of which modality to use involves the consideration of multiple clinical and economic factors.

AIM

To review the management strategies currently available for achalasia.

METHODS

A Medline search identified the original articles and reviews the published in the English language literature between 1966 and 2006.

RESULTS

The results reveal that pharmacotherapy, injection of botulinum toxin, pneumatic dilatation and minimally invasive surgical oesophagomyotomy are variably effective at controlling the symptoms of achalasia but that each modality has specific strengths and weaknesses which make them each suitable in certain populations. Overall, pharmacologic therapy results in the shortest lived, least durable response followed by botulinum toxin injection, pneumatic dilatation and surgery, respectively.

CONCLUSION

The optimal treatment for achalasia remains an area of controversy given our lack of complete understanding about the pathophysiology of the disease as well as the high numbers of clinical relapse after treatment. Further research focusing on optimal dosing of botulinum toxin injection and optimal timing of repeated graduated pneumatic dilatations could add to our knowledge regarding long-term therapy.

Botulinum toxin for gastrointestinal disorders: therapy and mechanisms

Botulinum toxin has gained widespread acceptance as a treatment option for various spastic gastrointestinal disorders such as achalasia, gastroparesis, sphincter of Oddi dysfunction, chronic anal fissures, and pelvic floor dyssnergia, despite the lack of strong evidence supporting its use in many of these diseases. This review summarizes the trials investigating the use of BoNT since it was first utilized as a treatment in achalasia. BoNT has proven to be safe, but long-term efficacy in many disorders has not been observed, primarily due to is relatively short duration of action. BoNT may be most useful in confirming a diagnosis which can lead to a more definitive treatment modality. Furthermore, its safety profile allows it to be a useful alternative in patients who are at high risk for invasive procedures.

Botulinum toxin therapy of hemifacial spasm: comparing different therapeutic preparations

Hemifacial spasm (HFS) is characterized by involuntary irregular clonic or tonic movements of the muscles innervated by cranial nerve VII on one side of the face, and is most often a result of vascular compression of the facial nerve at the root exit zone (Muscle and Nerve 1998;21:1740). Disability associated with this disorder ranges from social embarrassment to interference with vision resulting from involuntary eye closure. Treatment of HFS most often involves botulinum toxin injections, but may also include medications and surgery. We describe treatment with the three types of botulinum toxin currently commercially available--Botox, Dysport and Myobloc/NeuroBloc.

The effect of botulinum-A toxin on patients with severe urge urinary incontinence

PURPOSE

We determined the effect of 150 units of botulinum-A toxin (Botox, Allergan, Irvine, California) on subjects with severe urge urinary incontinence (UUI).

MATERIALS AND METHODS

This was an open label uncontrolled clinical trial. Subjects were recruited from the female urology and urogynecology clinics at Duke University. Inclusion criteria included evidence of UUI on 3-day bladder diary, a 24-hour pad weight of 100 gm or greater, absent or minimal stress leakage, absent detrusor dysfunction, and a history of failed anticholinergic and physical therapies. Exclusion criteria included evidence of a urinary tract infection, or other correctable or neurological etiology for UUI. The detrusor of each subject was injected with 150 units of botulinum-A toxin. Evaluations were performed at 2 weeks, 6 weeks, 3 months and 6 months after injection. Outcome measures included daily incontinence episodes, Urogenital Distress Inventory and the Incontinence Impact Questionnaire, 24-hour pad weights, daily pad usage and urinalysis at all visits. Urodynamic studies were performed at the 6-week and 3-month visits.

RESULTS

Three subjects had uncomplicated urinary tract infections during followup. No other adverse effects occurred. Statistically and clinically significant decreases greater than 50% were seen in virtually all outcome measures at all visits up to 3 months. Most subjects showed signs of recurrent UUI by 6 months. All subjects reported remarkable subjective improvement in incontinence. No significant changes in maximal cystometric capacity, maximal detrusor pressure, peak flow or post-void residual volumes were seen.

CONCLUSIONS

Botulinum-A toxin can significantly decrease urge urinary incontinence and improve quality of life for 3 months after injection. Additional studies are needed to determine ideal doses, dosing intervals, safety and cost-effectiveness of this therapy.

Gender effect on clinical features of achalasia: a prospective study

BACKGROUND

Achalasia is a well-characterized esophageal motor disorder but the rarity of the disease limits performing large studies on its demographic and clinical features.

METHODS

Prospectively, 213 achalasia patients (110 men and 103 women) were enrolled in the study. The diagnosis established by clinical, radiographic, and endoscopic as well as manometry criteria. All patients underwent a pre-designed clinical evaluation before and within 6 months after the treatment.

RESULTS

Solid dysphagia was the most common clinical symptom in men and women. Chest pain was the only symptom which was significantly different between two groups and was more complained by women than men (70.9% vs. 54.5% P value = 0.03). Although the occurrence of chest pain significantly reduced after treatment in both groups (P < 0.001), it was still higher among women (32% vs. 20.9% P value = 0.04). In both sexes, chest pain did not relate to the symptom duration, LES pressure and type of treatment patients received. Also no significant relation was found between chest pain and other symptoms expressed by men and women before and after treatment. Chest pain was less frequently reported by patients over 56 yrs of age in comparison to those less than 56 yrs (p < 0.05).

CONCLUSION

It seems that chest pain is the distinct symptom of achalasia which is affected by sex as well as age and does not relate to the duration of illness, LESP and the type of treatment achalasia patients receive.

Botulinum toxin in blepharospasm and oromandibular dystonia: comparing different botulinum toxin preparations

Amongst all regions of the body, the craniocervical region is the one most frequently affected by dystonia. Whilst blepharospasm--involuntary bilateral eye closure--is produced by spasmodic contractions of the orbicularis oculi muscles, oromandibular dystonia may cause jaw closure with trismus and bruxism, or involuntary jaw opening or deviation, interfering with speaking and chewing. Both forms of dystonia can be effectively treated with botulinum toxin injection. This article summarizes injection techniques in both forms of dystonia and compares doses, potency and efficacy of different commercially available toxins, including Botox, Dysport, Xeomin and Myobloc/NeuroBloc.

Dysport

Since the commercial launch of Dysport in 1991, after 10 years of clinical studies on its predecessor formulations, this BTX-A product has shown great therapeutic promise with a good safety profile and low incidence of treatment failures. As with all BTX products, Dysport should not be seen as a generic equivalent but as a specific product with individual unit dosing requirements and side effect profiles. Its role as an important BTX-A molecule looks set to expand as new indications for botulinum toxin arise, and as the cosmetic usage of Dysport is approved in countries outside of South America.

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.

Clinical comparability of marketed formulations of botulinum toxin

The majority of pharmaceutical products are patented in early phases of their discovery to preclude competition by similar products. Due to unusual circumstances (botulinum toxin is an unpatentable natural product and it is considered to be a biological weapon), technology know-how for botulinum toxin production was classified rather then available in the scientific community. Botulinum toxin type A was marketed in two pharmaceutical distinct formulations from competitor companies. Serendipity proved that the two formulations were not equipotent in terms of mouse units. From a regulatory point of view, differences in potency of distinct formulations are not a matter of concern because each formulation is licensed based on its own set of data. As far as the data in each case is sufficient to prove that a particular formulation is safe and efficacious at its defined dosage, a license for use can be granted. On the other hand, generation of data on comparability is the only way that clinicians and managers can ascertain which product (formulation, serotype) is most cost-effectiveness and to determine whether there are relevant differences in their safety profiles. The results of the systematic review of head-to-head randomised trials comparing BOTOX to Dysport suggest that the two formulations are not bioequivalent whatever the dose relationship. Data on comparative immunogenicity are not available. The indirect comparison of the results obtained in randomised clinical trials comparing BOTOX to placebo and Dysport to placebo support that intrinsic differences are present in the two products. It is concluded that comparative economic evaluations of different botulinum toxin formulations should move away from cost-minimization approaches based on the presumption of bioequivalence and move toward cost-effectiveness or cost-utility models.

Treatment of patients with achalasia with botulinum toxin: a multicenter prospective cohort study

Botulinum toxin (BT) injection is an alternative treatment of achalasia. The aim of the study was to examine outcomes of patients treated with BT in the Czech Republic. Since 1997, 49 patients with achalasia have been treated with BT. We prospectively evaluated the effect of BT injection on 41 patients during a median follow-up of 24 months (range 9-62). Esophageal manometry was performed before and at 3-5 months after the injection. In 16 patients, BT was injected from the antegrade angle only (subgroup A), in 15 patients, BT was injected from both retrograde and antegrade angles (subgroup B) and, in 10 patients, BT injection was combined with subsequent balloon dilatation (subgroup C). Immediate clinical response was achieved in 93% of patients. Clinical remission was sustained beyond 3 months in 83% of patients (responders). Fourteen responders (41%) did not experience a relapse during the median of 22 months. Twenty responders (59%) experienced symptomatic relapse approximately 8 months after the injection. Ten relapsers underwent BT reinjection, five (50%) of them were asymptomatic for another 14 months. The remaining five (50%) patients reported a second relapse approximately 6 months after the reinjection. Median duration of the symptom-free period was 11.5 months after the first BT injection, and 10.5 months after the second (P = 0.21). We did not find any significant predictor of a favorable outcome; responders tended to be older and to have a lower basal lower-esophageal-sphincter pressure. Patients in subgroup C were more likely to be in remission at 1 and 2 years as compared with patients in subgroup A. BT injection is an effective treatment of achalasia in the short term. However, almost 70% of patients experience a relapse within 2 years. BT injection should therefore be reserved for patients at risk for more invasive procedures or for patients who prefer this treatment.

[Digestive tract and botulinum toxin]

INTRODUCTION

the aim of this work was to check literature to assess botulinum toxin injection efficacy in gastrointestinal motor disorders with special emphasis on controlled clinical trials.

METHODS

literature was carried out with the Medline data bank.

RESULTS

seventy three articles in French and in English including a recent general review were retained. Comparative clinical trials only concerned achalasia and anal fissure. The other gastrointestinal motor disorders only gave rise to open non-controlled trials assessed on clinical end points.

DISCUSSION

this review of literature helps to determine usefulness and safety of Botulinum toxin injection in the treatment of esophageal achalasia and anal fissure. The main limitation is its brief duration of action. Studies concerning the others spastic motor disorders are based on unknown physiopathology and controlled trials are required to assess its efficacy.

CONCLUSION

botulinum toxin is increasingly used for gastrointestinal motor disorders with worthwhile results. Its efficacy has been yet established for only two disorders : it has a valuable palliative role in achalasia and may be curative for anal fissure.

Randomized controlled trial comparing botulinum toxin injection to pneumatic dilatation for the treatment of achalasia

BACKGROUND

Therapeutic options for achalasia include pharmacological therapy, surgical myotomy, pneumatic dilatation and intrasphincteric botulinum toxin injection.

AIM

To compare botulinum toxin injection with pneumatic dilatation in a randomized trial.

PATIENTS/METHODS

Forty adults with newly diagnosed achalasia were randomized to receive botulinum toxin (n=20) or pneumatic dilatation (n=20). Symptom scores were evaluated at 1, 6 and 12 months. Clinical relapse was defined as a symptom score greater than 50% of baseline. Relapsers received a second botulinum toxin injection or pneumatic dilatation.

RESULTS

The cumulative 12-month remission rate was significantly higher after a single pneumatic dilatation (53%) compared to a single botulinum toxin injection (15%)(P < 0.01). The 12-month estimated adjusted hazard for relapse and need for retreatment for the botulinum toxin group was 2.69 times that of the pneumatic dilatation group (95% confidence interval; 1.18-6.14). When a second treatment was administered to the relapsers in each group, the cumulative remission rate 1 year after initial treatment was significantly higher in the pneumatic dilatation group (100%) compared to the botulinum toxin group (60%) (P < 0.01). There were no major complications in either group.

CONCLUSIONS

Pneumatic dilatation is more efficacious than botulinum toxin in providing sustained symptomatic relief in patients with achalasia. The efficacy of a single pneumatic dilatation is similar to that of two botulinum toxin injections.

Review article: pharmacological options in achalasia

Achalasia is a common primary oesophageal motor disorder. Treatment has been based traditionally on a surgical approach; however, there is new evidence that some medical strategies may be of benefit. The purpose of the present article was to review the current medical management of achalasia. A Medline search identified original articles and reviews published in the English-language literature between 1966 and 1998. This search has revealed that the pharmacological treatment of achalasia is limited to some subgroups of patients (for example, early stages of the disease and elderly patients), and that nitrates, nifedipine, and botulinum toxin are the best studied and most effective compounds.