Because achalasia subtype is associated with therapeutic response, it is possible that regional differences in subtype distribution could lead to differences in therapeutic outcomes.Study Question:
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.Study Design:
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.Measures and Outcomes:
Clinical characteristics, manometric features, and treatment outcomes were compared.Results:
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.Conclusions:
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.