From the AGA Journals

Advancements help guide achalasia management, experts say

16% of the U.S. population experience dysphagia, only half of whom seek medical care and the others manage their symptoms by modifying diet.

X-ray barium swallow and endoscopy with biopsy to exclude eosinophilic esophagitis are the initial tests for dysphagia diagnosis. If the above are normal, a high-resolution esophageal manometry impedance (HRMZ) is recommended to diagnose primary and secondary esophageal motility disorder.

Ravinder Mittal, MD, is with the division of digestive diseases at University of California, San Diego.

Dr. Ravinder Mittal

Studies before and after the advent of HRM show that the primary esophageal motility disorders such as achalasia, diffuse esophageal spasm, and nutcracker esophagus/jackhammer esophagus when combined together, are seen in only about 20% of patients presenting with dysphagia symptom. Esophagogastric junction outflow obstruction (EGJOO), another primary esophageal motility disorder characterized by impaired lower esophageal sphincter relaxation (integrated relaxation pressure > 15) in the presence of normal peristalsis is seen in 5%-24% of patients with dysphagia.

However, only in a minority of patients is it likely to cause dysphagia because uncontrolled studies show that therapeutic strategies to address EGJOO (botox, dilation, and myotomy) relieve dysphagia symptoms in a minority of patients. Hence, in significant number of patients the cause of dysphagia symptoms remains obscure. It might be that our testing is inadequate, or possibly, patients have functional dysphagia (sensory dysfunction of the esophagus). My opinion is that it is the former.

The esophagus has only one simple function, that is, to transfer the pharyngeal pump driven, that is, swallowed contents to the stomach, for which its luminal cross-sectional area must be larger than that of the swallowed bolus and contraction (measured by manometry) behind the bolus must be of adequate strength. The latter is likely less relevant because humans eat in the upright position and gravity provides propulsion for the bolus. Stated simply, as long as esophagus can distend well and there is no resistance to the outflow at the EGJ, esophagus can achieve its goal. However, until recently, there was no single test to determine the distension and contraction, the two essential elements of primary esophageal peristalsis.

Endoscopy and x-ray barium swallow are tests to determine the luminal diameter but have limitations. Endoflip measures the opening function of the EGJ and is useful when the HRM is normal. However, pressures that are currently being used to measure the EGJ distensibility by Endoflip are not physiological. Furthermore, esophageal body motor function assessed by a bag that distends a long segment of the esophagus under high pressure is unphysiological. The distension-contraction plots, which determines the luminal CSA and contraction simultaneously during primary peristalsis is ideally suited to study the pathophysiology of esophageal motility disorders. Several studies from my laboratory show that in patients with nutcracker esophagus, EGJOO and normal HRM, the esophagus distends significantly less than that of normal subjects during primary peristalsis. I suspect that an esophageal contraction pushing bolus through a narrow lumen esophagus is the cause of dysphagia sensation in many patients that have been labeled as functional dysphagia.

The last 2 decades have seen significant progress in the diagnosis of esophageal motility disorders using HRM, Endoflip, and distension-contraction plots of peristalsis. Furthermore, endoscopic treatment of achalasia and “achalasia-like syndromes” is revolutionary. What is desperately needed is an understanding of the pathogenesis of esophageal motor disorders, pharmacotherapy of esophageal symptoms, such as chest pain, proton pump inhibitor–resistant heartburn, and others because dysfunctional esophagus is a huge burden on health care expenditures worldwide.

Ravinder K. Mittal, MD, is a professor of medicine and gastroenterologist with UC San Diego Health. He has patent application pending on the computer software Dplots.



Advancements in tools for assessing the function of the esophagus have led to important refinements in the diagnosis of achalasia and achalasia-like conditions, at a pace that has left the line-tracing technology considered to have debatable merit just 15 years ago “now as obsolete as a typewriter,” experts said recently in a review in Gastro Hep Advances.

“We have come to conceptualize esophageal motility disorders by specific aspects of physiological dysfunction,” wrote a trio of experts – Peter Kahrilas, MD, professor of medicine; Dustin Carlson, MD, MS, assistant professor of medicine, and John Pandolfino, MD, chief of gastroenterology and hepatology, all at Northwestern University, Chicago. “A major implication of this approach is a shift in management strategy toward rendering treatment in a phenotype-specific manner.”

High-resolution manometry (HRM) was trail-blazing, they said, as it replaced line-tracing manometry in evaluating the motility of the esophagus. HRM led to the subtyping of achalasia based on the three patterns of pressurization in the esophagus that are associated with obstruction at the esophagogastric junction. But the field has continued to advance.

“It has since become clear that obstructive physiology also occurs in syndromes besides achalasia involving the esophagogastric junction and/or distal esophagus,” Dr. Kahrilas, Dr. Carlson, and Dr. Pandolfino said. “In fact, obstructive physiology is increasingly recognized as the fundamental abnormality leading to the perception of dysphagia with esophageal motility disorders. This concept of obstructive physiology as the fundamental abnormality has substantially morphed the clinical management of esophageal motility disorders.”

HRM, has many limitations, but in cases of an uncertain achalasia diagnosis, functional luminal imaging probe (FLIP) technology can help, they said. FLIP can also help surgeons tailor myotomy procedures.

In FLIP, a probe is carefully filled with fluid, causing distension of the esophagus. In the test, the distensibility of the esophagogastric junction is measured. The procedure allows a more refined assessment of the movement of the esophagus, and the subtypes of achalasia.

Identifying the achalasia subtype is crucial to choosing the right treatment, data suggests. There have been no randomized controlled trials on achalasia management that prospectively consider achalasia subtype, but retrospective analysis of RCT data “suggests that achalasia subtypes are of great relevance in forecasting treatment effectiveness,” they said.

In one trial, pneumatic dilation was effective in 100% of type II achalasia, which involves panesophageal pressurization, significantly better than laparoscopic Heller myotomy (LHM). But it was much less effective than LHM in type III achalasia, the spastic form, although a significance couldn’t be established because of the number of cases. Data from a meta-analysis showed that peroral endoscopic myotomy, which allows for a longer myotomy if needed, was better than LHM for classic achalasia and spastic achalasia and was most efficacious overall.

The writers said that the diagnostic classifications for achalasia are likely to continue to evolve, pointing to the dynamic nature of the Chicago Classification for the disorder.

“The fact that it has now gone through four iterations since 2008 emphasizes that this is a work in progress and that no classification scheme of esophageal motility disorders based on a single test will ever be perfect,” they said. “After all, there are no biomarkers of esophageal motility disorders and, in the absence of a biomarker, there can be no ‘gold standard’ for diagnosis.”

Dr. Pandolfino, Dr. Kahrilas, and Northwestern University hold shared intellectual property rights and ownership surrounding FLIP Panometry systems, methods, and apparatus with Medtronic. Dr. Kahrilas reported consulting with Ironwood, Reckitt, and Phathom. Dr. Carlson reported conflicts of interest with Medtronic and Phathom Pharmaceuticals. Dr. Pandolfino reported conflicts of interest with Sandhill Scientific/Diversatek, Takeda, AstraZeneca, Medtronic, Torax, and Ironwood.

Next Article:

Can ChatGPT help clinicians manage GERD?