To evaluate the clinical and esophageal dynamics characteristics, and initial treatment effect of patients with untreated achalasia using high resolution manometry.

From January 2012 to June 2016, patients newly diagnosed with achalasia were retrospectively recruited. Clinical information, endoscopy and X-ray findings, manometric variables and treatment outcomes were collected and compared among manometric subtypes.

Among 133 patients with achalasia, 32 (24.0%) were classified as type I, 84 (63.2%) as type Ⅱ and 17 (12.8%) as type Ⅲ. Compared with the type Ⅲ, the symptom of regurgitation was more common in the types I and type Ⅱ achalasia patients (P=0.020). While compared with the type I, the score of chest pain was higher in the patients with type Ⅱ and type Ⅲ (P=0.006), as well as the basal lower esophageal sphincter pressure (P=0.015, P=0.023 for type Ⅱ and type Ⅲ, respectively). Integrated relaxation pressure was similar among the 3 subtypes (P=0.158). Forty-five and 47 patients received pneumatic dilation (PD) and peroral endoscopic myotomy (POEM) respectively, and all of the patients were followed-up for at least 6 months. The success rate was higher in the POEM group than that of the PD group in all the 3 manometric subtypes, but only the difference between POEM and PD in the type Ⅲ was statistically significant (90.0% VS 40.0%, P=0.041).

The clinical characteristics and treatment response are different among the 3 achalasia subtypes. Patients with type Ⅲ achalasia are probably the best candidates for POEM.

Esophageal achalasia; Manometry; Peroral endoscopic myotomy; Pneumatic dilation