What are the types of achalasia cardia?

Types of Achalasia Cardia

Achalasia is classified into three distinct subtypes (Types I, II, and III) based on high-resolution manometry patterns, with Type II demonstrating the best treatment response, Type I showing intermediate outcomes, and Type III requiring specialized management due to consistently poor response to standard therapies. 1, 2, 3

Classification System

The Chicago Classification system defines achalasia subtypes based on esophageal body pressurization patterns in patients with impaired lower esophageal sphincter (LES) relaxation and absent peristalsis 1, 3:

Type I Achalasia (Classic Achalasia)

• Characterized by minimal or negligible pressurization within the esophageal body 1, 3
• Represents a decompensated, dilated esophagus that has progressed to end-stage disease 1, 3
• Patients typically present with the longest duration of dysphagia, most significant weight loss, and most dilated esophagus with residual food 4
• The integrated relaxation pressure (IRP) may be less than the upper limit of normal in Type I disease, making diagnosis more challenging 1
• Intermediate treatment response with overall success rates around 55-63% across therapies 5, 6, 7

Type II Achalasia

• Characterized by panesophageal pressurization with uniform simultaneous pressurization bands spanning from upper to lower sphincter 1, 3
• Most common presenting subtype in multiple reported series 1, 8
• Presumed to be the precursor to Type I achalasia 1
• Best treatment response across all therapeutic modalities (botulinum toxin 71%, pneumatic dilation 90-91%, Heller myotomy 100%) 2, 3, 5, 6
• Higher resting LES pressure (64.7±22.6 mmHg) and 4s-IRP (45.3±17.6 mmHg) compared to Type I 8, 7

Type III Achalasia (Spastic Achalasia)

• Characterized by premature (spastic) contractions where the distal latency between upper sphincter relaxation and arrival of rapidly propagated contraction is <4.5 seconds 1, 3
• Previously known as vigorous achalasia 1
• Patients present with the most severe chest pain and frequently have normal fluoroscopic and endoscopic findings, making diagnosis challenging 4
• Consistently demonstrates the poorest response to standard LES-directed therapies with success rates of only 29-33% across all treatment modalities 2, 3, 5, 6, 7
• Requires specialized management with extended myotomy (POEM preferred) to address spastic esophageal body contractions 2, 3

Additional Entity: Esophagogastric Junction (EGJ) Outflow Obstruction

Beyond the three achalasia subtypes, the Chicago Classification recognizes EGJ outflow obstruction as a fourth entity that can mimic achalasia 1:

• The IRP is elevated above the upper limit of normal, but the "absent peristalsis" criterion for achalasia is not met 1
• Peristalsis may be fragmented or even normal 1
• Represents a heterogeneous group with multiple potential etiologies including incompletely expressed or early achalasia, isolated impaired LES relaxation, esophageal wall stiffness from infiltrative disease, eosinophilic esophagitis, vascular obstruction, hiatal hernia, obesity, or opiate effects 1
• Always requires intensive clinical evaluation (endoscopic ultrasound, computed tomography, timed barium esophagram) to clarify etiology before considering permanent interventions 1
• Long-term success rates for POEM in EGJ outflow obstruction (80-85%) appear somewhat lower compared to classic achalasia subtypes 1

Clinical Implications

Treatment decisions should incorporate Chicago Classification subtype, with Type II responding best to all therapies, Type I showing intermediate response, and Type III requiring POEM with extended myotomy when expertise is available 2, 3. However, there is insufficient evidence to recommend different specific therapies between Type I and Type II achalasia, so decisions should be based on local expertise, therapeutic availability, and patient choice 1, 2, 3.

The most critical pitfall is treating Type III achalasia with standard LES-only directed therapy, which consistently yields poor outcomes because it fails to address the spastic esophageal body component 2.