Long-term outcomes of balloon dilation versus botulinum toxin injection in patients with primary achalasia

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.

Pathogenesis, clinical manifestations, diagnosis, and treatment progress of achalasia of cardia

Achalasia cardia, type of esophageal dynamic disorder, is a relatively rare primary motor esophageal disease characterized by the functional loss of plexus ganglion cells in the distal esophagus and lower esophageal sphincter. Loss of function of the distal and lower esophageal sphincter ganglion cells is the main cause of achalasia cardia, and is more likely to occur in the elderly. Histological changes in the esophageal mucosa are considered pathogenic; however, studies have found that inflammation and genetic changes at the molecular level may also cause achalasia cardia, resulting in dysphagia, reflux, aspiration, retrosternal pain, and weight loss. Currently, the treatment options for achalasia focus on reducing the resting pressure of the lower esophageal sphincter, helping to empty the esophagus and relieve symptoms. Treatment measures include botulinum toxin injection, inflatable dilation, stent insertion, and surgical myotomy (open or laparoscopic). Surgical procedures are often subject to controversy owing to concerns about safety and effectiveness, particularly in older patients. Herein, we review clinical epidemiological and experimental data to determine the prevalence, pathogenesis, clinical presentation, diagnostic criteria, and treatment options for achalasia to support its clinical management.

Comparison of fully coated anti-reflux metal stenting and per-oral endoscopic myotomy in patients with achalasia: a propensity score-matched retrospective study

Background

Achalasia is a rare primary esophageal motility disorder disease. It is reported that the long-term effect of fully coated anti-reflux metal stent (FCARMS) implantation is satisfactory. Operated by a skilled and experienced endoscopist, the effect of per-oral endoscopic myotomy (POEM) treatment is equivalent to that of surgical myotomy. So far, there is still few evidence to prove FCARMS implantation or POEM which is better for achalasia. The choice of treatment for achalasia is still controversial. The aim of this study is to find a more suitable therapy for achalasia by comparing the efficacy of FCARMS implantation and POEM.

Methods

A propensity score (PS) matching (1:2) was used in this retrospective cohort study. Data collected from consecutive patients of Achalasia, receiving FCARMS implantation or POEM therapy at the department of gastroenterology, the Seventh Medical Center of the Chinese People’s Liberation Army General Hospital from May 2007 to May 2018. According to their previous treatment, they are divided into two groups, FCARMS group and POEM group. Clinical efficacy and complications were compared between the two groups.

Results

A total of 166 cases were collected, including 113 cases of FCARMS and 53 cases of POEM. By PS matching, 150 patients were enrolled (100 cases of FCARMS and 50 cases of POEM). By comparison, the FCARMS group has shorter operation time, shorter fasting time and lower hospitalization costs than the POEM group (p < 0.05). Common complications in the FCARMS group are nausea, vomiting, and stent shift. Repetitions of gastroscopy in the FCARMS group was more often, which were 3.8 ± 2.4 (vs 2.1 ± 1.8 of POEM) (p = 0.00 < 0.05) The 6-month remission rates of the FCARMS combination POEM group were 89% and 94%, respectively (p = 0.39), and the 2-year remission rates were 61% and 90%, respectively (p = 0.00).

Conclusions

Stent placement is a cost-effective and safe treatment option for achalasia. The short-term effect (less than 6 months) of FCARMS is similar to that of POEM, the long-term effect (more than 2 years), POEM is better than FCARMS. HRMIIis most suitable for POEM treatment. It indicate that Patients can choose treatment methods according to their own conditions.

2019 Seoul Consensus on Esophageal Achalasia Guidelines

Esophageal achalasia is a primary motility disorder characterized by insufficient lower esophageal sphincter relaxation and loss of esophageal peristalsis. Achalasia is a chronic disease that causes progressive irreversible loss of esophageal motor function. The recent development of high-resolution manometry has facilitated the diagnosis of achalasia, and determining the achalasia subtypes based on high-resolution manometry can be important when deciding on treatment methods. Peroral endoscopic myotomy is less invasive than surgery with comparable efficacy. The present guidelines (the "2019 Seoul Consensus on Esophageal Achalasia Guidelines") were developed based on evidence-based medicine; the Asian Neurogastroenterology and Motility Association and Korean Society of Neurogastroenterology and Motility served as the operating and development committees, respectively. The development of the guidelines began in June 2018, and a draft consensus based on the Delphi process was achieved in April 2019. The guidelines consist of 18 recommendations: 2 pertaining to the definition and epidemiology of achalasia, 6 pertaining to diagnoses, and 10 pertaining to treatments. The endoscopic treatment section is based on the latest evidence from meta-analyses. Clinicians (including gastroenterologists, upper gastrointestinal tract surgeons, general physicians, nurses, and other hospital workers) and patients could use these guidelines to make an informed decision on the management of achalasia.

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 Esophageal Achalasia in Quebec

Background

Esophageal achalasia is a defective relaxation of the lower esophageal sphincter with a loss of esophageal peristalsis causing dysphagia. Treatment can be Heller myotomy, pneumatic balloon dilation, Botox injections, peroral endoscopic myotomy (POEM) or medical. The main objective of the study was to measure the extent of post-treatment dysphagia depending on the type of treatment.

Methods

This was a retrospective study conducted at the Centre Hospitalier de l’Universite de Montreal (CHUM) between 2011 and 2017. All patients with manometric diagnostic of achalasia in our department were included. Data were collected with the electronic health record and a standardized post-treatment telephone survey to evaluate the extent of dysphagia and the use of proton pump inhibitor (PPI).

Results

A total of 169 patients were included. The most frequent treatments were Heller myotomy (60%), Botox injection (18%) and endoscopic balloon dilation (16%). There was a significant difference in the management of patients treated at the CHUM and outside the CHUM for the frequency of pneumatic dilation (28 vs. 7%; P = 0.001) and Heller myotomy (49 vs. 69%; P = 0.02). An Eckardt score ≤ 3 was found in 80% of patients. No significant score difference was found between the CHUM and outside CHUM groups or between the different treatments. The post-treatment use of PPI was of 49% and was not significantly different depending on the site or the type of treatment.

Conclusion

Heller myotomy stays the most frequent treatment, especially outside our tertiary center. The rate of post-treatment dysphagia is low no matter the treatment choice. The use of PPI stays frequent regardless of the management site or the type of treatment used.

Botulinum Neurotoxin Light Chains Expressed by Defective Herpes Simplex Virus Type-1 Vectors Cleave SNARE Proteins and Inhibit CGRP Release in Rat Sensory Neurons

A set of herpes simplex virus type 1 (HSV-1) amplicon vectors expressing the light chains (LC) of botulinum neurotoxins (BoNT) A, B, C, D, E and F was constructed. Their properties have been assessed in primary cultures of rat embryonic dorsal root ganglia (DRG) neurons, and in organotypic cultures of explanted DRG from adult rats. Following infection of primary cultures of rat embryonic DRG neurons, the different BoNT LC induced efficient cleavage of their corresponding target Soluble N-ethylmaleimide-sensitive-factor Attachment protein Receptor (SNARE) protein (VAMP, SNAP25, syntaxin). A similar effect was observed following infection by BoNT-A LC of organotypic cultures of adult rat DRG. To quantify and compare the functional activities of the different BoNT LC, the inhibition of calcitonin gene-related protein (CGRP) secretion was assessed in DRG neurons following infection by the different vectors. All BoNT-LC were able to inhibit CGRP secretion although to different levels. Vectors expressing BoNT-F LC displayed the highest inhibitory activity, while those expressing BoNT-D and -E LC induced a significantly lower CGRP release inhibition. Cleavage of SNARE proteins and inhibition of CGRP release could be detected in neuron cultures infected at less than one transducing unit (TU) per neuron, showing the extreme efficacy of these vectors. To our knowledge this is the first study investigating the impact of vector-expressed transgenic BoNT LC in sensory neurons.

Bridging the Gap between Advancements in the Evolution of Diagnosis and Treatment towards Better Outcomes in Achalasia

Over the past few decades, there was an encouraging breakthrough in bridging the gap between advancements in the evolution of diagnosis and treatment towards a better outcome in achalasia. The purpose of this review is to provide updated knowledge on how the current evidence has bridged the gap between advancements in the evolution of diagnosis and treatment of esophageal achalasia. The advent of high-resolution manometry and standardization based on the Chicago classification has increased early recognition of the disease. These 3 clinical subtypes of achalasia can predict the outcomes of patients, and the introduction of POEM has revolutionized the choice of treatment. Previous evidence has shown that laparoscopic Heller myotomy (LHM) and anterior fundoplication were considered the most durable treatments for achalasia. Based on the current evidence, POEM has been evolving as a promising strategy and is effective against all 3 types of achalasia, but the efficacy of POEM is based on short- and medium-term outcome studies from a limited number of centers. Types I and II achalasia respond well to POEM, LHM, and PD, while most studies have shown that type III achalasia responds better to POEM than to LHM and PD. In general, among the 3 subtypes of achalasia, type II achalasia has the most favorable outcomes after medical or surgical therapies. The long-term efficacy of POEM is still unknown. The novel ENDOFLIP measures the changes in intraoperative esophagogastric junction dispensability, which enables a quantitative assessment of luminal patency and sphincter distension; however, this technology is in its infancy with little data to date supporting its intraoperative use. In the future, identifying immunomodulatory drugs and the advent of stem cell therapeutic treatments, including theoretically transplanting neuronal stem cells, may achieve a functional cure. In summary, it is important to identify the clinical subtype of achalasia to initiate target therapy for these patients.

The 2018 ISDE achalasia guidelines

Achalasia is a relatively rare primary motor esophageal disorder, characterized by absence of relaxations of the lower esophageal sphincter and of peristalsis along the esophageal body. As a result, patients typically present with dysphagia, regurgitation and occasionally chest pain, pulmonary complication and malnutrition. New diagnostic methodologies and therapeutic techniques have been recently added to the armamentarium for treating achalasia. With the aim to offer clinicians and patients an up-to-date framework for making informed decisions on the management of this disease, the International Society for Diseases of the Esophagus Guidelines proposed and endorsed the Esophageal Achalasia Guidelines (I-GOAL). The guidelines were prepared according the Appraisal of Guidelines for Research and Evaluation (AGREE-REX) tool, accredited for guideline production by NICE UK. A systematic literature search was performed and the quality of evidence and the strength of recommendations were graded according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE). Given the relative rarity of this disease and the paucity of high-level evidence in the literature, this process was integrated with a three-step process of anonymous voting on each statement (DELPHI). Only statements with an approval rate >80% were accepted in the guidelines. Fifty-one experts from 11 countries and 3 representatives from patient support associations participated to the preparations of the guidelines. These guidelines deal specifically with the following achalasia issues: Diagnostic workup, Definition of the disease, Severity of presentation, Medical treatment, Botulinum Toxin injection, Pneumatic dilatation, POEM, Other endoscopic treatments, Laparoscopic myotomy, Definition of recurrence, Follow up and risk of cancer, Management of end stage achalasia, Treatment options for failure, Achalasia in children, Achalasia secondary to Chagas' disease.

Clinical analysis of 86 botulism cases caused by cosmetic injection of botulinum toxin (BoNT)

This study was conducted to analyze the clinical characteristics of and treatment strategies for botulism among patients receiving cosmetic injection of botulinum toxin (BoNT).A total of 86 botulism patients caused by cosmetic injection of BoNT were enrolled in our study. All of the patients were diagnosed according to their history of cosmetic BoNT injection, clinical symptoms and signs, and other auxiliary examinations (including those on renal and liver functions, blood index detection, and chest X-ray). All of the patients received comprehensive treatments and botulinum antitoxin serum injection.The main symptoms of botulism patients included headache, dizziness, insomnia, fatigue, blurred vision, eye opening difficulty, slurred speech, dysphagia, bucking, constipation, and anxiety. These clinical symptoms occurred 0∼36 days after BoNT injection, especially from 2nd to 6th day after the operation. Furthermore, the usage dose of BoNT was negatively related to latent period. Finally, patients all discharged from our hospital 1∼20 days after treatments, and their symptoms relieved or disappeared.Botulism is a severe side effect for BoNT injection. Injecting botulinum antitoxin serum may be an effective approach to improve clinical outcomes of botulism cases.

Peroral endoscopic myotomy: a literature review and the first UK case series

Peroral endoscopic myotomy (POEM) is an established treatment for primary achalasia. It has gained endorsement from the American Society for Gastrointestinal Endoscopy with increasing clinical acceptance since the first procedure, performed in Japan in 2008. The first successful POEM in the UK was performed in November 2013 at King's College Hospital and this article presents the first UK case series. Prospective data were collected at 3 and 12-24 months for consecutive patients undergoing POEM. Post-POEM gastro-oesophageal reflux health-related quality of life scale (GORD-HRQoL) score was recorded. Statistical comparisons were made using paired non-parametric testing. In an initial series of 33 consecutive prospectively followed patients (12 female; 49.5±13 years; median follow-up 9 (3-28) months; 58% having had previous intervention), a 91% success rate has been achieved at 3 months. To date, 16 patients have reached the 12-month time point, with 13 (81%) sustaining response. This case series compares well with international cohorts and demonstrates excellent long-term safety and favourable efficacy.

Update on the endoscopic treatments for achalasia

Achalasia is the most common primary motility disorder of the esophagus and presents as dysphagia to solids and liquids. It is characterized by impaired deglutitive relaxation of the lower esophageal sphincter. High-resolution manometry allows for definitive diagnosis and classification of achalasia, with type II being the most responsive to therapy. Since no cure for achalasia exists, early diagnosis and treatment of the disease is critical to prevent end-stage disease. The central tenant of diagnosis is to first rule out mechanical obstruction due to stricture or malignancy, which is often accomplished by endoscopic and fluoroscopic examination. Therapeutic options include pneumatic dilation (PD), surgical myotomy, and endoscopic injection of botulinum toxin injection. Heller myotomy and PD are more efficacious than pharmacologic therapies and should be considered first-line treatment options. Per oral endoscopic myotomy (POEM) is a minimally-invasive endoscopic therapy that might be as effective as surgical myotomy when performed by a trained and experienced endoscopist, although long-term data are lacking. Overall, therapy should be individualized to each patient’s clinical situation and based upon his or her risk tolerance, operative candidacy, and life expectancy. In instances of therapeutic failure or symptom recurrence re-treatment is possible and can include PD or POEM of the wall opposite the site of prior myotomy. Patients undergoing therapy for achalasia require counseling, as the goal of therapy is to improve swallowing and prevent late manifestations of the disease rather than to restore normal swallowing, which is unfortunately impossible.

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.