From the Guidelines
The three types of achalasia are Type I, Type II, and Type III, which are classified based on esophageal pressure patterns observed during high-resolution manometry. These types are differentiated by the presence or absence of esophageal body pressurization with test swallows, as well as the presence of spastic body contractions capable of luminal obliteration regardless of pressurization 1. The main characteristics of each type are:
- Type I: absence of esophageal body pressurization with test swallows
- Type II: presence of esophageal body pressurization with test swallows
- Type III: spastic body contractions capable of luminal obliteration regardless of pressurization This classification is important for treatment decisions, as the choice of therapy, such as POEM, LHM, or PD, should be based on shared decision making, taking into account patient and disease characteristics, patient preferences, and local expertise 1. Key points to consider when treating achalasia include:
- POEM should be considered the preferred treatment for type III achalasia
- The presence of esophageal outflow obstruction at the EGJ and esophageal aperistalsis unifies the achalasia subtypes and directs interventional therapies to the lower esophageal sphincter (LES) 1
- Treatment outcomes vary among the sub-types, with Type III achalasia appearing best palliated with a myotomy tailored to the proximal extent of esophageal body spasm rather than confined to the LES alone 1
From the Research
Types of Achalasia
The types of achalasia can be classified into three subtypes based on high-resolution manometry findings, as described in studies 2, 3, 4, 5, 6. These subtypes are:
- Type I: characterized by minimal esophageal pressurization, also known as classic achalasia
- Type II: characterized by increased isobaric panesophageal pressure, with esophageal compression
- Type III: characterized by distal esophageal spastic non-isobaric contractions, with spasm
Characteristics of Each Subtype
Each subtype has distinct characteristics, including:
- Clinical features: Type III tends to have the oldest age and most severe symptoms, such as chest pain, while Type I has a higher prevalence of lung complications, and Type II shows weight loss more frequently 6
- Histopathological features: Type I shows a high loss of ganglion cells in the esophagus 6
- Molecular basis: Type III has elevated serum pro-inflammatory cytokine levels 6
- Treatment response: Type II tends to have better responses to pneumatic dilatation, while Type III has less favorable responses 4, 6
Diagnostic Tools
High-resolution manometry is the gold standard for diagnosing achalasia and subclassifying it into these three types, as it provides detailed pressure recordings of esophageal motility 2, 3, 4. Other diagnostic tools, such as barium swallow tests and endoscopy, can also be used to evaluate esophageal dilation and other symptoms 3, 5.