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

Background: Esophageal capsule endoscopy (ECE) is an alternative to EGD for Barrett's esophagus screening. A multicenter study found ECE to he safe, well tolerated, and accurate; however, a post hoc adjudication process was used that may have biased results. Objective: To assess the accuracy of ECE for the diagnosis of Barrett's esophagus. Design: Prospective and blinded, with no adjudication. Patients: Screening patients with chronic gastroesophageal reflux and surveillance patients with known Barrett's esophagus. Interventions: ECE followed by EGD in each subject. Main Outcome Measurements: Sensitivity, specificity, and positive and negative predictive values of ECE for Barrett's esophagus by using EGD results, with histologic confirmation as the criterion standard. Results: Ninety-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. Conclusions: Our 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.