Blinded comparison of esophageal capsule endoscopy versus conventional endoscopy for a diagnosis of Barrett's esophagus in patients with chronic gastroesophageal reflux

BackgroundEsophageal capsule endoscopy (ECE) is an alternative to EGD for Barrett's esophagus screening. A multicenter study found ECE to be safe, well tolerated, and accurate; however, a post hoc adjudication process was used that may have biased results.ObjectiveTo assess the accuracy of ECE for the diagnosis of Barrett's esophagus.DesignProspective and blinded, with no adjudication.PatientsScreening patients with chronic gastroesophageal reflux and surveillance patients with known Barrett's esophagus.InterventionsECE followed by EGD in each subject.Main Outcome MeasurementsSensitivity, specificity, and positive and negative predictive values of ECE for Barrett's esophagus by using EGD results, with histologic confirmation as the criterion standard.ResultsNinety-six subjects were enrolled, of whom 90 (94%) completed the study, including 66 screening and 24 surveillance patients. ECE was 67% sensitive and 84% specific for identifying Barrett's esophagus, diagnosing 14 of 21 cases of biopsy-confirmed Barrett's esophagus. Positive and negative predictive values were 22% and 98%, respectively (calculated for screening patients only). Sensitivity for short- and long-segment Barrett's esophagus was similar.ConclusionsOur blinded, unadjudicated study shows that ECE had only moderate sensitivity and specificity for identifying Barrett's esophagus. ECE in its present form is not suitable as a primary screening tool for Barrett's esophagus but may be used in patients unwilling to undergo EGD. Inadequate visualization of the gastroesophageal junction may be the cause of suboptimal ECE accuracy; this may be improved by advances in ingestion protocol and capsule calibration.