Type II Achalasia Is Increasing in Prevalence

Area of Science:

• Gastroenterology
• Esophageal Motility Disorders
• Diagnostic Classification

Background:

• The Chicago Classification defined three manometric subtypes of achalasia: type I (aperistalsis), type II (pan-pressurization), and type III (spastic).
• The evolving prevalence of these subtypes since the classification's adoption has not been well-documented.

Purpose of the Study:

• To determine the prevalence of achalasia subtypes a decade after the widespread adoption of the Chicago Classification.
• To compare current subtype prevalence with historical data.

Main Methods:

• Retrospective cohort analysis of patients diagnosed with achalasia via high-resolution manometry (HRM) between 2015-2018.
• Exclusion of patients with other esophageal motility disorders, prior treatment, or foregut surgery.
• Comparison of demographic data, manometric subtype, and endoscopic dilatation grade with a historical control cohort (2004-2007) using statistical tests.

Main Results:

• Contemporary cohort (n=147) showed prevalence of type I achalasia at 8% (vs. 21% historical), type II at 63% (vs. 50% historical), and type III at 29% (vs. 29% historical).
• A significant shift in prevalence was observed (p=0.01), with increased type II and decreased type I achalasia.
• No significant differences in age, sex, or mean endoscopic dilatation grade were found between cohorts.

Conclusions:

• The prevalence of type II achalasia has significantly increased, while type I has decreased, compared to historical data.
• Increased prevalence of type II may be linked to earlier disease detection, potentially due to advancements like HRM and increased awareness.
• These findings highlight a shift in achalasia subtype epidemiology over the past decade.