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Current guidelines for patients with long-standing gastroesophageal reflux disease recommend that patients have endoscopic screening exams to exclude Barrett esophagus (BE). For some patients, however, the costs, risks, and sedation issues associated with standard endoscopy impede adherence to this recommendation. Capsule endoscopy works well for small-intestine imaging, and pilot studies have suggested that it is suitable for esophageal imaging as well.
In this prospective, blinded, multicenter study from Seattle, 66 patients underwent endoscopy for chronic GERD (screening group), and 24 patients underwent endoscopy for known BE (surveillance group). All patients underwent dual-headed capsule endoscopy (PillCam ESO) followed by sedated conventional endoscopy 1 to 4 hours later. Compared with conventional endoscopy, capsule endoscopy was 67% sensitive and 84% specific for identifying BE. The sensitivity findings were similar when the results were adjusted for long- (>3 cm) versus short-segment BE. Positive and negative predictive values for BE in the screening group were 22% and 98%, respectively.
Lin OS et al. Blinded comparison of esophageal capsule endoscopy versus conventional endoscopy for a diagnosis of Barrett’s esophagus in patients with chronic gastroesophageal reflux. Gastrointest Endosc 2007 Apr; 65:577-83.
Comment
These findings clearly contrast with the very favorable results derived from a previous pilot study and a multicenter validation study (Journal Watch Gastroenterology Oct 25 2005). This discrepancy is especially surprising because some earlier investigations had been performed with capsules that captured only 4 frames/second rather than the 14 frames/second captured by the capsule that was used in the current study. In the validation study, experts who were aware of both the endoscopy and the capsule findings adjudicated final diagnoses; as the current study did not include this protocol, its results could reflect “real-world” use more accurately. Although the convenience, safety, and patients’ tolerance of capsule endoscopy make it an attractive tool for esophageal imaging, at present, this device probably cannot be relied on for the one-time screening to exclude BE in patients with chronic GERD.