Therapeutic Outcome of Achalasia Based on High-Resolution Manometry: A Korean Multicenter Study

Because achalasia subtype is associated with therapeutic response, it is possible that regional differences in subtype distribution could lead to differences in therapeutic outcomes.

We aimed to evaluate and compare high-resolution manometry (HRM) profiles among the different subtypes of achalasia and to elucidate predictive factors associated with treatment outcomes.

Patients who were diagnosed with achalasia using HRM at 4 Korean university hospitals were retrospectively identified and analyzed. Sixty-four patients with untreated achalasia were divided into 3 subtypes using the Chicago classification system.

Clinical characteristics, manometric features, and treatment outcomes were compared.

Among 64 patients diagnosed with achalasia, 31 patients were classified as type I, 27 as type II, and 6 as type III. Regarding HRM parameters, there were statistically significant differences in basal lower esophageal sphincter pressure, 4-second-integrated relaxation pressure, residual upper esophageal sphincter pressure, body amplitude, and maximal intrabolus pressure between subtypes. Regarding therapeutic outcome, type II patients (overall success rate of 80.0%) were more likely to respond than type I (55.2%) or type III (33.2%) patients. Multivariate analysis demonstrated that achalasia subtype (type I vs. III, P = 0.072; type II vs. III, P = 0.005), therapeutic modality (dilation vs. pharmacologic, P = 0.013; laparoscopic Heller's myotomy vs. pharmacologic, P = 0.006), and HRM-measured esophageal length (<27.5 vs. ≥27.5 cm, P = 0.014) are independent predictive factors for therapeutic failure.

Patients with type II achalasia had better treatment outcomes than patients with other achalasia subtypes. Achalasia subtype, therapeutic modality, and esophageal length are independent predictive factors of therapeutic outcome.