Evaluation of in vivo measurement of transesophageal electrical resistance as an indicator of early experimental esophageal mucosal injury.

Experimental esophageal mucosal injury has been characterized by an increase in mucosal permeability to acid and a fall in transmucosal electrical potential difference (PD). We have developed a technique for measuring transesophageal electrical resistance in an in vivo rabbit model of esophageal injury and have performed experiments to assess this parameter as an index of esophageal injury. As expected, tissue resistance varied inversely with mucosal area. The current-voltage plot for the esophagus with or without trypsin, bile, or acid injury remained linear with no "breakpoints." Tissue resistance was compared with standard indices of mucosal injury such as acid flux, PD, and morphologic change in experimental esophageal injury due to acid, bile, and trypsin. Our results show that tissue resistance is more sensitive than either PD or acid flux in detecting early esophageal injury due to low concentrations of acid or trypsin and, as opposed to PD, always showed a persistent, unidirectional change with injury. Thus these data show that in vivo measurement of transesophageal electrical resistance is a useful technique for assessing esophageal mucosal injury, in that it is the most sensitive indicator of esophageal injury we have observed.