Objective: Non-erosive reflux disease (NERD) constitutes the majority of patients with gastroesophageal reflux disease (GERD). Esophageal pH monitoring is useful in distinguishing patients with NERD from functional heartburn. The gastroenterologist often faces the dilemma of choosing the most appropriate investigative modality. The wireless Bravo capsule allows prolonged 48 hour monitoring with improved patient tolerance, but concerns regarding its reduced sensitivity compared to conventional pH catheter have been raised. We compared the prevalence of high esophageal acid exposure and positive symptom correlation profiles (using the symptom index [SI] and symptom association probability [SAP]) in patients who underwent Bravo compared to patients who underwent conventional pH catheter, and evaluated the efficacy of Bravo monitoring in a multiracial Asian cohort.
Methods: Retrospective analysis of all pH studies performed between January 2004 and February 2009 for patients with persistent reflux symptoms and a normal gastroscopy.
Results: 66 (27 Male, 42.4 +/- 13.4 years) and 55 (24 Male, 47.1 +/- 13.3 years) patients underwent wireless and pH catheter evaluation respectively. "True NERD" (abnormal acid exposure) was diagnosed in 26 (39.4%) and 20 (36.4%) patients (pNS) while "acid-sensitive esophagus" (SI > or = 50% and/or SAP > or = 95%) occurred in 14 (21.2%) and 12 (21.8%) patients (pNS) using the wireless and pH catheter respectively. Extended recording time with Bravo led to an incremental diagnostic yield of 30%.
Conclusion: The wireless capsule was well tolerated. The diagnostic yield was similar using both modalities. With the increasing availability of impedance-pH technology, it is uncertain if devices that detect only acid-reflux events will be surpassed.