[Comparison of clinical features and high-resolution esophageal motility characteristics between esophagogastric junction outflow obstruction and type Ⅱ achalasia patients].

OBJECTIVES: To compare the clinical features and high-resolution esophageal motility-impedance characteristics among esophagogastric junction outflow obstruction (Eoo) patients, type Ⅱ achalasia (Ach) patients and healthy controls (Con), in order to explore the values of esophageal high-resolution manometry (HRM) in diagnosis and treatment of Eoo patients.

METHODS: Patients with dysphagia were enrolled from December 2011 to December 2014 at the outpatient department of Peking University Third Hospital, so were age-matched healthy volunteers. All the patients with organic obstruction were excluded. All the participants were tested with high-resolution esophageal motility-impedance measurement, the patients were diagnosed as Eoo or Ach according to the Chicago classification criteria. Clinical features and esophageal motility characteristics of Eoo, Ach and Con were analyzed.

RESULTS: A total of 23 Eoo, 24 Ach and 20 Con were enrolled, whose gender ratios, average ages and body mass indexes were of no significant differences(all P>0.05). (1) The Eoo group had higher percentage of food reflux[21.7% (5/23) vs 0(0/24), P=0.005]and belching[17.4% (4/23) vs 0 (0/24), P=0.013], but lower percentage of dysphagia[47.8% (11/23) vs 79.2% (19/24), P=0.025]and vomiting[0(0/23) vs 12.5%(3/24), P=0.040]compared with the Ach group, with no significant differences in other symptoms(all P>0.05). Besides, the Eoo group had lower Eckardt scores than the Ach group[1(1, 2) vs 3 (2, 5), P<0.001]. (2) The lower esophageal sphincter (LES) basal pressure-minimum in the Eoo was higher than the Con[(26.73±2.77) vs (17.16±1.76) mmHg, P<0.05]. The mean LES basal pressure; and the LES integrated relaxation pressure (IRP), IRP-maximum, and LES relaxation percentage were significantly different among Eoo, Ach and Con[(19.80±1.25) vs (35.95±2.36), (8.43±0.72) mmHg, both P<0.05; (23.22±2.02) vs (48.37±3.71), (12.32±1.29) mmHg, bothP<0.05; 38.61%±3.10% vs 12.42%±5.66%, 64.00%±3.85%, both P<0.05]. (3) There were significant differences in velocity, amplitude, and duration of esophageal peristaltic wave and intrabolus pressure (all P<0.05) among Eoo, Ach and Con; and failed contraction percentage, panesophageal pressurization percentage, premature contraction percentage, and rapid contraction percentage of Eoo were lower than Ach (all P<0.05) while complete contraction percentage of Eoo was high compared with Ach (P<0.001), but no significant differences between Eoo and Con. (4) The Eoo had significantly less incomplete bolus clearance[0.00% (0.00%, 20.00%) vs 100.00% (90.00%, 100.00%), P<0.001]and shorter bolus transit time[(5.44±0.29) s vs (24.13±1.69) s, P<0.001]than Ach, but there were no significant differences between Eoo and Con in these two indexes[0.00% (0.00%, 20.00%) vs 0.00% (0.00%, 9.75%); (5.44±0.29) s vs (5.30±0.19) s; both P>0.05].

CONCLUSIONS: The clinical manifestations and esophageal HRM characteristics of Eoo appear to be between Ach and Con, which suggests that Eoo may be an early-stage of Ach. Further study of the pathophysiological characteristics of Eoo patients may provide more evidence to elucidate the pathogenesis of achalasia.