An endoscopic procedure for accurate localisation of intraluminal pH electrodes.

An endoscopic procedure has been developed which permits the accurate fixation of pH electrodes to the mucosa of the upper gastrointestinal tract. The electrode is carried to the desired position tethered to the endoscope. A clip-fixing device is passed through the biopsy channel of the endoscope and the electrode is anchored to the mucosa with stainless steel clips. Repeat endoscopy in 20 patients has confirmed that the electrode remains firmly secured to the mucosa for at least 24 h. The electrode can be safely removed at any time by traction on its cable. This procedure should allow, for the first time, accurate 24 h ambulatory pH monitoring of specific regions of the upper gastrointestinal tract.