Atypical Variants of Classic Achalasia Are Common and Currently Under-Recognized: A Study of Prevalence and Clinical Features

BackgroundAdvances in esophageal manometry have facilitated identification of variants of achalasia, suggesting they are more common than previously thought. This study assesses the frequency and clinical characteristics of patients with motility abnormalities similar to, but not meeting criteria for, classic achalasia.Study DesignRecords of patients undergoing high-resolution esophageal manometry between January 2008 and January 2010 were screened for diagnosis of achalasia, impaired lower esophageal sphincter (LES) relaxation, or severe peristaltic dysfunction of the esophageal body. Forty-four patients with classic achalasia and 31 with variant characteristics were identified. Clinical and manometric characteristics were recorded and compared.ResultsVariant achalasia was almost as common as the classic type (31 versus 44 patients). Eighty-two percent (36 of 44) of those with classic and 48% (15 of 31) of those with variant characteristics had dysphagia. Classic achalasia patients' mean age was 62 years (SD 19 years) versus 53 years (SD 14 years) in the variant group. The classic achalasia group had 26 male patients and 18 female patients and the variant group had 9 male patients and 22 female patients. Two thirds (21 of 31) of the variant group had impaired LES relaxation. Three variant patterns emerged: impaired LES relaxation with normal/hypertensive peristalsis (n = 10), impaired/borderline LES relaxation with mixed peristalsis/simultaneous contractions (n = 14), and impaired/normal LES and aperistalsis with occasional short segment peristalsis (n = 7). Mean intrabolus pressure was 16.3 mmHg in variant patients with normal LES relaxation and 23.1 mmHg in those with impaired relaxation.ConclusionsVariants of achalasia are more common than previously recognized. LES dysfunction defined by high relaxation pressure occurs in two-thirds of variant achalasia patients and might be a hallmark that could direct therapy. The notion that esophageal body dysfunction/aperistalsis in achalasia is all or none should be reconsidered.