What are the types of achalasia cardia?

Achalasia Cardia Classification

Achalasia cardia is classified into three distinct subtypes (Types I, II, and III) based on high-resolution manometry findings using the Chicago Classification system, with each subtype demonstrating different esophageal pressurization patterns and treatment responses. 1, 2

The Three Subtypes

Type I Achalasia (Classic Achalasia)

• Characterized by minimal or negligible pressurization within the esophageal body, representing a decompensated, dilated esophagus that has progressed to end-stage disease 1
• Patients typically present with the longest history of dysphagia, most significant weight loss, and most dilated esophagus with residual food retention 3
• Shows intermediate treatment response across all therapeutic modalities, with overall success rates around 55-63% 2, 4, 5
• Represents approximately 21-31% of achalasia cases 6, 7

Type II Achalasia (Compression Pattern)

• Characterized by panesophageal pressurization with uniform simultaneous pressurization bands spanning from upper to lower sphincter 1
• Demonstrates the best treatment response across all therapeutic modalities, with success rates of 71% with botulinum toxin, 90-91% with pneumatic dilation, and 100% with Heller myotomy 1, 6
• Patients have higher resting lower esophageal sphincter (LES) pressure (64.7±22.6 mmHg) and 4-second integrated relaxation pressure (4s-IRP) (45.3±17.6 mmHg) compared to Type I 7
• Represents approximately 42-53% of achalasia cases, making it the most common or second most common subtype 6, 7

Type III Achalasia (Spastic Achalasia)

• Characterized by premature (spastic) contractions, consistently demonstrating the poorest response to standard LES-directed therapies with success rates of only 29-33% across all treatment modalities 1, 2, 6
• Patients present with the most severe chest pain symptoms and frequently have normal fluoroscopic and endoscopic findings, making diagnosis challenging 3
• Exhibits the highest basal LES pressure and maximal esophageal pressurization compared to Types I and II 4
• Requires specialized management with extended myotomy, with POEM (per-oral endoscopic myotomy) being the preferred treatment when expertise is available 1, 2
• Represents approximately 16-29% of achalasia cases and tends to occur in older patients 6, 7

Additional Entity: EGJ Outflow Obstruction

• The Chicago Classification recognizes esophagogastric junction (EGJ) outflow obstruction as a fourth entity that can mimic achalasia 1
• This requires intensive clinical evaluation (endoscopic ultrasound, computed tomography, timed barium esophagram) to clarify etiology before considering permanent interventions 1
• POEM in EGJ outflow obstruction has long-term success rates of 80-85%, somewhat lower compared to classic achalasia subtypes 1

Clinical Implications

Key Diagnostic Features

• All subtypes share the fundamental manometric findings of impaired LES relaxation and absent peristalsis 1
• The distinction between subtypes is based on esophageal body pressurization patterns visible on high-resolution manometry pressure topography 1, 4
• Endoscopy results are normal in 28% of achalasia patients, and barium swallow can be inconclusive in 31%, emphasizing the critical role of high-resolution manometry for accurate subtyping 3

Treatment Response Hierarchy

• Type II > Type I > Type III in terms of treatment success across all modalities 1, 2, 6
• The most critical error 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