Effect of loperamide on lower oesophageal sphincter pressure in idiopathic achalasia

Codeine induces increased resistance at the esophagogastric junction but has no effect on motility and bolus flow in the pharynx and upper esophageal sphincter in healthy volunteers: A randomized, double-blind, placebo-controlled, cross-over trial

BACKGROUND

Chronic opioid use can induce esophageal dysfunction with symptoms resembling achalasia and a manometric pattern of esophagogastric junction-outflow obstruction (EGJ-OO). However, the effect of opioids in acute setting on pharyngeal function and esophageal body contractility has not been investigated.

METHODS

After positioning the high-resolution impedance manometry (HRiM) catheter, codeine (60 mg) or placebo (glucose syrup) was infused intragastrically. Forty-five minutes post-infusion, participants received liquid, semi-solid, and solid boluses to assess esophageal and pharyngeal function. HRiM analysis was performed adhering to the Chicago classification v3.0. (CC v3.0). Pressure flow analysis (PFA) for the esophageal body and the pharynx was performed using the SwallowGateway™ online platform.

KEY RESULTS

Nineteen healthy volunteers (HV) [5 male; age 38.3] were included. After codeine administration, higher integrated relaxation pressure 4 s values resulted in significantly reduced deglutitive EGJ relaxation and distal latency was significantly shorter. Distal contractility was similar in both conditions. Bolus flow resistance at the EGJ and distention pressures increased significantly after codeine infusion. Based on CC v3.0, acute infusion of codeine induced EGJ-OO in six HV (p = 0.0003 vs. placebo). Codeine administration induced no significant alterations in any of the pharyngeal PFA metrics.

CONCLUSIONS & INFERENCES

In HV, acute administration of codeine increased bolus resistance at the EGJ secondary to induced incomplete EGJ relaxation leading to major motility disorders in a subset of subjects including EGJ-OO. However, an acute single dose of codeine did not affect motility or bolus flow in pharynx and UES. ClinicalTrials.gov number, NCT03784105.

Updated Systematic Review of Achalasia, with a Focus on POEM Therapy

AIM

To systematically review clinical presentation, diagnosis, and therapy of achalasia, focusing on recent developments in high-resolution esophageal manometry (HREM) for diagnosis and peroral endoscopic myotomy (POEM) for therapy.

METHODS

Systematic review of achalasia using computerized literature search via PubMed and Ovid of articles published since 2005 with keywords ("achalasia") AND ("high resolution" or "HREM" or "peroral endoscopic myotomy" or "POEM"). Two authors independently performed literature searches and incorporated articles into this review by consensus according to prospectively determined criteria.

RESULTS

Achalasia is an uncommon esophageal motility disorder, usually manifested by dysphagia to solids and liquids, and sometimes manifested by chest pain, regurgitation, and weight loss. Symptoms often suggest more common disorders, such as gastroesophageal reflux disease (GERD), thus often delaying diagnosis. Achalasia is a predominantly idiopathic chronic disease. Diagnosis is typically suggested by barium swallow showing esophageal dilation; absent distal esophageal peristalsis; smoothly tapered narrowing ("bird's beak") at esophagogastric junction; and delayed passage of contrast into stomach. Diagnostic findings at high-resolution esophageal manometry (HREM) include: distal esophageal aperistalsis and integrated relaxation pressure (trough LES pressure during 4 s) > 15 mmHg. Achalasia is classified by HREM into: type 1 classic; type 2 compartmentalized high pressure in esophageal body, and type 3 spastic. This classification impacts therapeutic decisions. Esophagogastroduodenoscopy is required before therapy to assess esophagus and esophagogastric junction and to exclude distal esophageal malignancy. POEM is a revolutionizing achalasia therapy. POEM creates a myotomy via interventional endoscopy. Numerous studies demonstrate that POEM produces comparable, if not superior, results compared to standard laparoscopic Heller myotomy (LHM), as determined by LES pressure, dysphagia frequency, Eckardt score, hospital length of stay, therapy durability, and incidence of GERD. Other therapies, including botulinum toxin injection and pneumatic dilation, have moderately less efficacy and much less durability than POEM.

CONCLUSION

This comprehensive review suggests that POEM is equivalent or perhaps superior to LHM for achalasia in terms of cost efficiency, hospital length of stay, and relief of dysphagia, with comparable side effects. The data are, however, not conclusive due to sparse long-term follow-up and lack of randomized comparative clinical trials. POEM therapy is currently limited by a shortage of trained endoscopists.

Management of achalasia cardia: Expert consensus statements

Achalasia cardia (AC) is a frequently encountered motility disorder of the esophagus resulting from an irreversible degeneration of neurons. Treatment modalities are palliative in nature, and there is no curative treatment available for AC as of now. Significant advancements have been made in the management of AC over last decade. The introduction of high resolution manometry and per-oral endoscopic myotomy (POEM) has strengthened the diagnostic and therapeutic armamentarium of AC. High resolution manometry allows for the characterization of the type of achalasia, which in turn has important therapeutic implications. The endoscopic management of AC has been reinforced with the introduction of POEM that has been found to be highly effective and safe in palliating the symptoms in short-term to mid-term follow-up studies. POEM is less invasive than Heller's myotomy and provides the endoscopist with the opportunity of adjusting the length and orientation of esophageal myotomy according to the type of AC. The management of achalasia needs to be tailored for each patient, and the role of pneumatic balloon dilatation, POEM, or Heller's myotomy needs to be revisited. In this review, we discuss the important aspects of diagnosis as well as management of AC. The statements presented in the manuscript reflect the cumulative efforts of an expert consensus group.

Pharmacotherapy for the management of achalasia: Current status, challenges and future directions

This article reviews currently available pharmacological options available for the treatment of achalasia, with a special focus on the role of botulinum toxin (BT) injection due to its superior therapeutic effect and side effect profile. The discussion on BT includes the role of different BT serotypes, better pharmacological formulations, improved BT injection techniques, the use of sprouting inhibitors, designer recombinant BT formulations and alternative substances used in endoscopic injections. The large body of ongoing research into achalasia and BT may provide a stronger role for BT injection as a form of minimally invasive, cost effective and efficacious form of therapy for patients with achalasia. The article also explores current issues and future research avenues that may prove beneficial in improving the efficacy of pharmacological treatment approaches in patients with achalasia.

Therapeutic options in oesophageal dysphagia

High-resolution manometry enables the categorization of patients with oesophageal dysphagia caused by oesophageal motility disorders into diagnostic categories according to the Chicago Classification. This Review provides an overview of the literature concerning treatment options for patients with dysphagia associated with achalasia, hypercontractile disorders and hypocontractility disorders of the oesophagus. In achalasia, pharmacotherapy and botulinum toxin are less effective than pneumatic dilation or surgical Heller myotomy, which had comparable efficacy in the largest controlled trial to date. Peroral endoscopic myotomy is a novel therapeutic modality that is currently being evaluated in controlled trials versus pneumatic dilation or surgical myotomy. A variety of medical treatments have been evaluated in hypermotility disorders, but only botulinum toxin injection yielded favourable results in a single controlled trial. Few studies have addressed the treatment of dysphagia in patients with oesophageal hypomotility. A variety of prokinetic agents have been studied, but there is no evidence of clinically relevant efficacy from controlled trials.

A controversy that has been tough to swallow: is the treatment of achalasia now digested?

Esophageal achalasia is a rare neurodegenerative disease of the esophagus and the lower esophageal sphincter that presents within a spectrum of disease severity related to progressive pathological changes, most commonly resulting in dysphagia. The pathophysiology of achalasia is still incompletely understood, but recent evidence suggests that degeneration of the postganglionic inhibitory nerves of the myenteric plexus could be due to an infectious or autoimmune mechanism, and nitric oxide is the neurotransmitter affected. Current treatment of achalasia is directed at palliation of symptoms. Therapies include pharmacological therapy, endoscopic injection of botulinum toxin, endoscopic dilation, and surgery. Until the late 1980s, endoscopic dilation was the first line of therapy. The advent of safe and effective minimally invasive surgical techniques in the early 1990s paved the way for the introduction of laparoscopic myotomy. This review will discuss the most up-to-date information regarding the pathophysiology, diagnosis, and treatment of achalasia, including a historical perspective. The laparoscopic Heller myotomy with partial fundoplication performed at an experienced center is currently the first line of therapy because it offers a low complication rate, the most durable symptom relief, and the lowest incidence of postoperative gastroesophageal reflux.

Opioids and the gut: pharmacology and current clinical experience

This article reviews the pharmacology and physiology of opiate receptors and the current and potential uses of opioid agonists and antagonists in clinical gastroenterology. Mu-receptors are involved in motor and sensory functions, and their modulation is established for treatment of diarrhea. Mu-antagonists have potential to reverse endogenous (e.g., postoperative ileus) or iatrogenic dysmotility (e.g., opioid bowel dysfunction). Modulation of the function of kappa-receptors may be a novel approach to control visceral pain in functional gut disorders. Results of formal testing of novel opioid modulators are keenly awaited.

Esophageal pharmacology and treatment of primary motility disorders

Swallowing is a complex mechanism based on the coordinated collaboration of tongue, pharynx and esophagus. Disturbances of this interplay or disorders of one or several of these components lead to dysphagia, non-cardiac chest pain or regurgitation. The major primary esophageal motility disorders--achalasia, diffuse esophageal spasm, hypercontractile esophagus ('nutcracker esophagus') and non-specific motility disorder--are of unknown etiology. Other esophageal diseases, such as cervical diverticula or gastroesophageal reflux disease, might also be caused by a primary esophageal motility disorder. Medical treatment of esophageal disorders with esophageal hyper- or dysmotility requires agents that reduce esophageal contractile force (anticholinergic agents, nitrates, calcium antagonists). Despite the beneficial effect of the various drugs on esophageal motility parameters, the clinical benefit of medical treatment of esophageal motility disorders is rather disappointing. Calcium channel antagonist, alone or in combination with anticholinergics or nitrates, can be used as a medical trial, especially in mild achalasia. However, medical therapy is clearly inferior to pneumatic balloon dilation therapy. Recently, botulinum toxin injection was suggested as a therapeutic option in achalasia patients with good results on lower esophageal sphincter pressure (LESP) and symptom scores that were similar to the results achieved by pneumatic balloon dilation. Hypercontractile esophagus shows a good manometric response to calcium channel antagonists, but only little clinical effect in terms of improvement of symptoms. Diffuse esophageal spasm is a relatively rare disease and few clinical studies are available. The use of calcium channel antagonists can be beneficial, at least in some patients with diffuse esophageal spasm. From clinical and epidemiological studies, there is some evidence of a 'psychological' component in the pathogenesis or perception of esophageal symptoms. There is some clinical benefit from centrally acting drugs such as benzodiazepines or antidepressants. With the exception of botulinum toxin for achalasia, medical therapy of primary esophageal motility disorders is rather limited and the clinical results are poor. Further understanding of esophageal pathophysiology as well as development of new receptor-selective drugs might increase our chances of a successful treatment of primary esophageal motility disorders.

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.

Current therapies for achalasia: comparison and efficacy

Achalasia is a primary esophageal motor disorder of unknown etiology producing complaints of dysphagia, regurgitation, and chest pain. The current treatments for achalasia involve the reduction of lower esophageal sphincter (LES) pressure resulting in improved esophageal emptying. Calcium channel blockers and nitrates, once used as initial treatment strategy for early achalasia, are now only used in patients who are not candidates for pneumatic dilation or surgery and those not responding to botulinum toxin injections. By virtue of the more rigid balloons, the current pneumatic dilators are more effective and have better efficacy than the older more compliant balloons. The graded approach to pneumatic dilation using the Rigiflex balloons (3.0, 3.5, and 4.0 cm) are now the most commonly used nonsurgical means of treating patients with achalasia, resulting in symptom improvement in up to 90% of patients. Surgical myotomy, once with high morbidity and long hospital stay, can now be performed laparoscopically with similar efficacy to the open surgical approach (94% vs. 84%, respectively), reduced morbidity, and hospitalization time. Given the advances in both balloon dilation and laparoscopic myotomy, most patients with achalasia can now choose between these two equally efficacious treatment options. Botulinum toxin injection of the LES should be reserved for patients who cannot undergo balloon dilation and are not surgical candidates.