Feasibility of Dual Wireless Esophageal pH Monitoring: Randomized Blinded Sham-Controlled Trial

Objective. Wireless pH monitoring is currently employed in the distal esophagus. There are no controlled studies on the feasibility/safety of proximal esophageal wireless pH capsule placement. We tested the hypothesis that there will be no difference in patient perception of a more proximally placed pH capsule. Study Design. Randomized single-blinded sham-controlled trial. Setting. Tertiary care center. Subjects and Methods. All patients had a wireless pH capsule positioned 6 cm proximal to the gastroesophageal junction. They were randomized into intervention or sham groups after distal capsule placement. The delivery introducer was positioned 10 cm proximal to the distal esophageal capsule, and a second capsule was either deployed (intervention) or not (sham) based on group allocation. Patients were blinded to group assignment. Modified Edmonton Score was used to assess for chest pain, dysphagia, and odynophagia. The primary endpoints were (1) required endoscopic removal because of discomfort and (2) change in chest pain scores, controlling for baseline pain. Results. Patients were randomized to either the intervention, proximal esophageal capsule (n = 11), or sham (n = 11). Patients with proximal pH probes had higher odds of having their chest pain (odds ratio [OR], 8.44; 95% confidence interval [CI], 1.35-52.6; P = .02), odynophagia (OR, 49.5; 95% CI, 4.70-520; P = .001), and dysphagia (OR, 14.3; 95% CI, 2.12-96.6; P = .006) exacerbated. Two (2/11; 18%) proximally deployed probes required endoscopic removal because of patient intolerance or discomfort. Conclusion. A proximal esophageal wireless pH monitor placement is feasible but results in increased chest pain, odynophagia, and dysphagia that can be severe enough to require endoscopic removal. These limitations preclude its potential clinical benefit.