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.
