Wireless pH capsule – yield in clinical practice

Abstract

Wireless pH monitoring is one of the recent technologies that focus on improving the diagnosis of gastroesophageal reflux disease (GERD). The capsule, which is fixed within the esophagus, transmits data via telemetry to an external receiver. The capsule is usually inserted 6 cm above the squamocolumnar junction during an upper endoscopy. The standard recording duration is 48 hours but this can be extended to 96 hours. The wireless capsule has been shown to be at least as accurate as the conventional catheter for the monitoring of esophageal pH. Normal pH values have been established in three different series. The use of a wireless capsule provides an increased diagnostic yield for GERD compared with the conventional catheter. The increased yield is the result of higher sensitivity to detect both abnormal acid esophageal exposure and positive symptom-reflux association. This may be related both to the prolonged recording duration and to fewer dietary modifications and restrictions on activities. Several studies have shown that the pH capsule was better tolerated by patients than the conventional pH catheter. Mild-to-moderate chest pain represents the main side effect of the pH capsule: severe chest pain requiring endoscopic removal of the capsule is rare. The main indication for wireless capsule application is monitoring of distal esophageal pH for diagnostic purpose, particularly in patients with a normal endoscopic examination. The capsule technique has some limitations: costs are higher than conventional pH monitoring, misplacement may occur, and the sampling rate is lower. Finally, compared with pH-impedance monitoring, only acid reflux events can be evaluated.

BRAVO esophageal pH monitoring: more cost-effective than empiric medical therapy for suspected gastroesophageal reflux

“…Various studies have demonstrated a correlation between the catheter-based and wireless approaches with regard to esophageal pH recordings [9,16,[19][20][21]. In a study by Sweis et al [18], a total of 1751 patients underwent attempted catheter-based pH monitoring; however, 134 patients were intolerant of this approach and subsequently underwent wireless pH monitoring with the BRAVO system.…”

“…Two-way sensitivity analysis was also performed to test the cost model over the range of costs of different PPI regimens (low-dose generic vs. high-dose name-brand) and the range of reported sensitivities of BRAVO pH monitoring for diagnosing GERD, which range from 75 to 95 % [9][10][11].…”

“…A review of the literature demonstrated sensitivities for the BRAVO pH monitoring studies ranging from 75 to 95 % [9][10][11], which were then implemented into the cost model ( Table 2). Depending on sensitivity, PPI dosage, and PPI brand (generic vs. name-brand), performing BRAVO pH monitoring studies after an 8-week PPI trial would have (Fig.…”

“…On the other hand, patients with extraesophageal symptoms are more difficult to diagnose and thus should undergo pH monitoring sooner in the diagnostic algorithm. Various pH monitoring devices have been used, including 24-h transnasal catheter placement and BRAVO wireless esophageal pH probe monitoring, which have both been proven as effective modalities to accurately diagnose GERD [8][9][10][11].…”

Ösophageale Refluxdiagnostik – pH-Metrie, Impedanzmessung, Bilirubin-Messung: Empfehlungen der Deutschen Gesellschaft für Neurogastroenterologie und Motilität und der Arbeitsgruppe Neurogastroenterologie der Deutschen Gesellschaft für Verdauungs- und Stoffwechselkrankheiten

“…Weitere Kontraindikationen stellen erhöhte Blutungsneigung (Blutungsdiathese, Antikoagulation, Ösophagusvarizen) dar ebenso wie Patienten mit implantiertem Schrittmacher oder Defibrillator [277].…”