Bravo pH Monitoring in Gastroesophageal Reflux

PICHON-RIVIERE, A.; AUGUSTOVSKI, F.; GARCIA MARTI, S.; GLUJOVSKY, D.; LOPEZ, A.; ALCARAZ, A.; BARDACH, A.; CIAPPONI, A

Documento de Evaluación de Tecnologías Sanitarias

IECS

Año: 2013 p. 1 - 30

1668-2793

Gastroesophageal reflux causes a persistent heartburn feeling and/or regurgitation and affects 5-7% of the population worldwide.In some selected cases, usually in non responders to drug therapy, it is necessary to monitoresophageal pH on continued and ambulatory bases. The standard method used for pH monitoringis the nasogastric tube. To avoid the discomfort produced by the tube, monitoring using the Bravocapsule has been proposed because it allows a wireless measurement and without the discomfortcaused by the wires.TechnologyThe Bravo capsule is a small device containing a radio transmitter, a built-in battery and electrodesto measure pH. It is placed in the distal end of the esophageal wall through a vacuum pump. Thiscapsule is wireless and it transmits the pH information collected every 6 seconds to an externalreceptor through radiofrequency. Because of the capsule size, it can not be placed through thenose, but orally. After a 48-96-hour monitoring, the capsule detaches itself from the esophagealmucosa and it is passed with stools.PurposeTo assess the available evidence on the efficacy, safety and coverage related aspects regardingthe use of Bravo capsule for pH monitoring in gastroesophageal reflux.MethodsA bibliographic search was carried out on the main databases: DARE, NHS EED, on Internetgeneral search engines, in health technology evaluation agencies and health sponsors. Prioritywas given to the inclusion of systematic reviews; controlled, randomized clinical trials (RCTs);health technology assessments and economic evaluations; clinical practice guidelines andcoverage policies of other health systems.ResultsOne systematic review, two RCTs, one clinical practice guideline, one HTA and several coveragepolicy documents were found.One systematic review published in 2012 showed that the rate of success in the device placementand monitoring ranged between 85% and 97%. In seven studies, comparing standard monitoringwith those performed with the wireless device, a good correlation was observed between bothdevices in five of them; a similar amount of time with pH<4 was also seen. In the studies found,tolerability was higher for those patients using the wireless capsule, although it resulted inincreased chest pain.Two RCTs published in 2005 and 2012, randomized 50 and 86 patients who had indication forambulatory pH monitoring to undergo monitoring with a wireless or a standard capsule. Discomfortwas evaluated using a Visual Analog Scale (0-100), and the total discomfort assessment waslower in the wireless capsule group (26±4 mm vs. 39±4 mm, p<0.01), with less nose and throatdiscomfort and less disturbances when eating, drinking (36% vs. 68%, p=0.02) and performingregular activities. Nonetheless, they showed more chest discomfort (60% vs. 24%, p<0.01).Furthermore, there was a greater number (88% vs. 48-51%, p<0.05) of patients in the wirelessgroup that would accept to repeat the test, if necessary.The Clinical Practice Guidelines published in 2007 by the U.S. Gastroenterology Society mentionthat one of main advantages of the wireless capsule is its tolerability, similar to that of pH detectionif compared with those devices that use catheters, but allowing a longer assessment period whichwould increase sensitivity and marginally reduce specificity.Most health sponsors consulted agree to cover the Bravo capsule for some specific cases. Someconsider it a valid alternative to the standard method for ambulatory pH measurement, whereas insome other cases it is considered as an alternative only if the standard method has failed.ConclusionsNo evidence from trials comparing standard to wireless devices was found that would allowdrawing conclusions that would enable to change the current diagnostic or therapeutic algorithms.The evidence evaluated comes from few studies of adequate methodological quality.Although it can not be concluded that the wireless capsule has a better diagnostic profile than thestandard one, in general, it diagnoses a similar number of patients with ph under 4.The wireless device consistently showed less discomfort in the assessed subjects, although theyhad more chest discomfort.The health sponsors evaluated consider that the wireless device is a valid alternative for specificsituations, mainly in those cases where pH monitoring could not be carried out using the standarddevice. It is not clear, especially because of the expenses that need to incurred, if its use couldreplace the standard technique in other medical situations.Studies of good quality better assessing the diagnostic profile of this technology, its costs, as wellas its inclusion in the diagnosis and therapeutic algorithms need to be conducted to determine if itmay replace pH monitoring with a standard device