Esophageal Physiologic Testing of Obese Subjects as a Part of Bariatric Surgery Planning

Background: Choice of bariatric procedure may be impacted by esophageal motor disorders and reflux disease, which are not routinely evaluated in obese subjects. Methods: Clinical characteristics on validated questionnaires and esophageal physiologic test findings were collected in 110 consecutive obese subjects (median age 48.5 years, 82% F, median BMI 46.9 kg/m²) evaluated for bariatric surgery. High resolution manometry (HRM) metrics included intragastric pressure (IGP), basal lower esophageal sphincter pressures (LESP), end-expiratory LESP, EGJ contractile integral (EGJ-CI), integrated relaxation pressure (IRP), distal contractile integral (DCI), and Chicago classification (CC) v4.0 diagnoses; acid exposure time (AET, normal if <4%) was obtained from ambulatory reflux monitoring. Comparative analyses determined differences between obese subjects and 15 institutional normal controls (median age 24.7 years, 53% F, median BMI 24.7 kg/m²) and if symptoms predicted abnormal tests. Results: Basal LESP and EGJ-CI were higher in obese subjects (P =.03) compared to controls, while end-expiratory LESP was similar (P =.97). IGP was also higher in obese subjects (P <.0001), which modestly correlated with BMI. The most common CC 4.0 diagnosis was ineffective esophageal motility (IEM, 11.8%). EGJ outflow obstruction was seen in 9.1% and achalasia in 0.9%. Hiatus hernia (type 2 or 3 EGJ morphology) was found in 28%. Of 34 patients completing ambulatory reflux monitoring, 15 (44%) had elevated AET, without symptom or motor predictors. Conclusions: Achalasia, esophageal outflow obstruction, and reflux were encountered in higher than expected proportions without specific symptoms in pre-bariatric surgery patients. Thus, esophageal physiologic testing may be of value prior to bariatric surgery.