1. Use of Direct, Endoscopic-Guided Measurements of Mucosal Impedance in Diagnosis of Gastroesophageal Reflux Disease 
Elif Saritas Yuksel, Tina Higginbotham, James C. Slaughter, Jerry Mabary, Robert T. Kavitt, C. Gaelyn Garrett, Michael F. Vaezi 
Clinical Gastroenterology and Hepatology 
Volume 10, Issue 10, Pages (October 2012)
DOI: /j.cgh
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2. Figure 1
Schematic representation of MI catheter. (A) Two 2-mm long impedance sensing electrodes positioned 1 mm from the tip of a 2-mm soft catheter advanced through an upper endoscope. MI measurements obtained by direct mucosal contact of sensors at the site of esophagitis (if present) and 2, 5, and 10 cm above the SCJ. (B) Photograph of the MI catheter (inset photo) and schematic comparison of the MI catheter with the traditional multichannel impedance-pH catheter.
Clinical Gastroenterology and Hepatology  , DOI: ( /j.cgh )
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3. Figure 2
Median (IQ) mucosal impedance measurements (Ω) among the study groups. MI measurements were significantly (P = .001) lower at the site of erosive mucosa than other nonerosive regions. In addition, the median (IQ) MI measurements were significantly (P = .008) less at 2 cm above the SCJ for patients with objective evidence of reflux (E+ and E−/pH+) than those with no objective evidence of reflux (E−/pH−).
Clinical Gastroenterology and Hepatology  , DOI: ( /j.cgh )
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4. Figure 3
The median MI measurements for the study groups at each of the measured sites (mucosal injury, 2, 5, and 10 cm above the SCJ). MI measurements were lowest at the site of mucosal lesion followed by measurements at 2 cm above the SCJ for those with objective GERD (E+ and E−/pH+). A similar but not statistically significant trend (P = .18) also was observed at 5 cm above the SCJ for the 2 groups. However, the MI measurements were similar for the 3 groups at 10 cm above the SCJ. Patients without objective GERD (E−/pH−) showed similar MI measurements at 2, 5, and 10 cm above the SCJ.
Clinical Gastroenterology and Hepatology  , DOI: ( /j.cgh )
Copyright © 2012 AGA Institute Terms and Conditions

5. Figure 4
Proposed mucosal changes associated with chronic GERD based on MI measurements in this study. We speculate that esophageal mucosa exposed to chronic injurious gastroduodenal refluxate would show graduated changes along the esophageal axis, which can be measured by the simple, minimally invasive MI device. Patients with severe reflux-causing esophageal mucosal erosions (A) would be expected to have a more pronounced reduction in MI as a marker of decreased mucosal integrity. (B) The findings would be expected to be similar, although attenuated, for those with reflux but without mucosal injury. (C) Patients without objective reflux whose symptoms may be caused by non-GERD factors would not be expected to have MI variation along the esophageal axis.
Clinical Gastroenterology and Hepatology  , DOI: ( /j.cgh )
Copyright © 2012 AGA Institute Terms and Conditions