Some patients may be unable to tolerate the small catheter used in impedance-pH testing. In other cases a catheter test may provide insufficient evidence of reflux, despite your specialist believing that this is the cause of your symptoms. This can occur because some patients find it difficult to behave normally with a catheter in position - for instance, they may experience difficulty eating. It may also be the case that the impedance-pH test records insufficient results due to the normal day to day variation in reflux. A Bravo® test may therefore be recommended.
The test involves attaching a tiny capsule to the bottom of the oesophagus. This is done during an endoscopy which can be performed under sedation and takes just a few minutes. The capsule measures acid reflux in the oesophagus and relays the information to a small recorder in the same way as in a standard catheter test. The difference, however, is that this information is relayed wirelessly without a catheter and the patient is unaware of the physical presence of the monitoring capsule.
In the same way as an impedance test, the Bravo® will record reflux in the oesophagus. The test usually takes place over a much longer period (at least 48 hours). It therefore often demonstrates reflux when a catheter test has been negative as there is a greater chance of reflux occurring during the time period. However, the disadvantage is that it will not demonstrate non-acidic reflux and does not record any information regarding oesophageal function, and so does not replace a manometry test.
Currently the Bravo® is usually complementary to the other oesophageal tests and is used in conjunction with them.