title: Change in cross-sectional area of esophageal muscle does not correlate with the outcome of achalasia after pneumatic balloon dilatation.
abstract: OBJECTIVE
  Patients with achalasia have a thicker muscularis propria compared to normal patients. Because pneumatic balloon dilatation (PD) is an effective treatment for achalasia, the changes in the esophageal muscles after PD may predict treatment outcomes, if muscular change is of primary importance. In the present study, we aimed to observe the changes in esophageal muscle thickness following PD and assessed whether symptom relapse can be predicted on the basis of the esophageal muscle cross-sectional area (CSA), as measured by high-frequency intraluminal ultrasound (HFIUS).
  
  
  METHODS
  Fifteen patients treated by PD were studied and followed up for a median of 3.6 years. An HFIUS was done before PD and 6 months after PD. The esophageal muscle CSA measured at the lower esophageal sphincter (LES), and 3 and 6 cm above the LES, was used to see whether any association was present between symptom recurrence and the esophageal muscle CSA.
  
  
  RESULTS
  A single PD resulted in a 2-year remission rate of 66%. A significance variance in change (-65%-248%) was noticed in the muscle CSA after PD. The predilation muscle CSA, post-dilation muscle CSA, and change in the muscle CSA after PD was not associated with symptom recurrence.
  
  
  CONCLUSIONS
  Our findings suggest that measuring the muscle CSA does not help to predict treatment outcome. Muscular changes in achalasia might be just reactive changes.
authors.affiliation: Department of Medicine, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Korea.
authors.forename: Dong Hyun
authors.initials: DH
authors.lastname: Sinn
authors.forename: Yong Sung
authors.initials: YS
authors.lastname: Choi
authors.forename: Jeong Hwan
authors.initials: JH
authors.lastname: Kim
authors.forename: Eun Ran
authors.initials: ER
authors.lastname: Kim
authors.forename: Hee Jung
authors.initials: HJ
authors.lastname: Son
authors.forename: Jae J
authors.initials: JJ
authors.lastname: Kim
authors.forename: Jong Chul
authors.initials: JC
authors.lastname: Rhee
authors.forename: Poong-Lyul
authors.initials: PL
authors.lastname: Rhee
mesh_terms: D000328:Adult; D002404:Catheterization; D019160:Endosonography; D004931:Esophageal Achalasia / Q000175:diagnosis / Q000628:therapy*; D049630:Esophageal Sphincter, Lower; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008365:Manometry; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000473:pathology / Q000503:physiopathology; D009130:Muscle, Smooth / Q000473:pathology* / Q000503:physiopathology*; D020127:Recovery of Function; D012189:Retrospective Studies; D012720:Severity of Illness Index; D016896:Treatment Outcome