Impairment of chemical clearance is relevant to the pathogenesis of refractory reflux oesophagitis

Background: The pathophysiological mechanisms underlying proton pump inhibitor-refractory reflux oesophagitis has been scarcely studied. Aims: To assess impedance-pH parameters relevant to the pathogenesis of refractory reflux oesophagitis. Methods: Cases referred for heartburn/regurgitation refractory to high-dosage proton pump inhibitors between January 2008 and December 2012 were reviewed and subdivided into refractory oesophagitis (29 patients, 72% males, median age 50 years), healed oesophagitis (18 patients, 67% males, median age 54 years), and non-erosive reflux disease (49 patients, 53% males, median age 42 years). On-therapy impedance-pH tracings were blindly re-analysed by one observer to assess gastric and oesophageal acid exposure time and chemical clearance as expressed by the post-reflux swallow-induced peristaltic wave index. Results: The median gastric and oesophageal acid exposure time did not differ among the three groups (35%, 34%, 41% and 1.2%, 0.7%, 0.8%, respectively; P> 0.05 for all comparisons). A normal oesophageal acid exposure time was found in two thirds of patients with refractory oesophagitis. The post-reflux swallow-induced peristaltic wave index was significantly lower in refractory oesophagitis (16%) than in healed oesophagitis (30%) and non-erosive reflux disease (29%) (P= 0.003). Conclusions: Refractory reflux oesophagitis is characterized by impairment of chemical clearance. Adequate acid suppression is found in the majority of patients who would likely not benefit from further proton pump inhibitor dose escalation. © 2014 Editrice Gastroenterologica Italiana S.r.l.