Residual lower esophageal sphincter pressure as a prognostic factor in the pneumatic balloon treatment of achalasia

Background and Aims: Pneumatic balloon dilatation (PD) is a mainstay in achalasia treatment. The aim of this study was to identify predictive factors for successful treatment. Methods: We retrospectively reviewed 76 patients with a diagnosis of achalasia who underwent PD from June 2010 to May 2013. Clinical symptoms were assessed using Eckardt score and manometry data were analyzed using resting and relaxation pressure (4sIRP) of lower esophageal sphincter (LES) and the distal contractile integral (DCI), which was calculated for 10s from the start of deglutition between the upper margin of the LES and lower margin of upper esophageal contraction. Patients with achalasia were classified into three groups based on the Chicago classification. Results: Among 76 patients, 52 patients received PD, and the treatment was unsuccessful in 9 patients (6 in class I and 3 in class III). When comparing prognostic factors between successful and unsuccessful treatment groups, the mean value for 4sIRP in the unsuccessful treatment group was significantly lower than that in the successful treatment group (P<0.05). However, no difference was noticed in resting LES pressure, DCI, age, and sex. Furthermore, a lower mean value of 4sIRP was significantly related to unsuccessful treatment of achalasia (odds ratio, 1.092; 95% confidence interval, 1.001-1.191) even after adjustment for a series of confounding factors. Conclusions: Lower 4sIRP may be a prognostic indicator for poor treatment outcome after PD.