Manometric heterogeneity in patients with idiopathic achalasia.

Background & Aims: In certain cases of achalasia, particularly those in early stages with minimal endoscopic or radiographic abnormalities, the diagnosis may rely on manometry, which is the most sensitive test for the disease. The aim of this study was to critically evaluate the manometric criteria in a population of patients with idiopathic achalasia.
Methods: Clinical histories and manometric recordings of 58 patients with idiopathic achalasia and 43 control subjects were analyzed with regard to esophageal body contraction amplitude, peristaltic effectiveness in terms of both completeness and propagation velocity, lower esophageal sphincter (LES) resting pressure, LES relaxation pressure, and intraesophageal-intragastric pressure gradient. Variants of achalasia were defined by finding manometric features that significantly differed from the remainder of achalasia patients, such that the diagnosis might be questioned.
Results: Four manometrically distinct variants were identified. These variants were characterized by (1) the presence of high amplitude esophageal body contractions, (2) a short segment of esophageal body aperistalsis, (3) retained complete deglutitive LES relaxation, and (4) intact transient LES relaxation. In each instance, the most extreme variant is discussed and compared with the remainder of the achalasia population and with controls.
Conclusions: The significance in defining these variants of achalasia lies in the recognition that these sometimes confusing manometric findings are consistent with achalasia when combined with additional clinical data supportive of the diagnosis. Furthermore, such variants provide important clues into the pathophysiology of this rare disorder.