Bile-induced laryngitis: is there a basis in evidence?

Most agree that bile reflux occurs with regularity in an otherwise healthy population and that biliary and acid reflux may play a synergistic role in damaging esophageal mucosa. But to what extent is laryngeal mucosa at risk? We constructed a saline-controlled rat model (n = 40) in which active component solutions of bile--taurocholic acid and chenodeoxycholic acid--were applied to intact laryngeal mucosa at various pH levels. Histologic sampling of the laryngeal mucosa allowed inflammation scores to be generated by a pathologist blinded to the solutions used. Both taurocholic acid at acid pH and chenodeoxycholic acid at basic pH preferentially induced statistically greater inflammation scores than did the saline control, approaching or exceeding inflammation scores attributed to hydrochloric acid at pH 1.2. These observations may clarify reasons for failure to uniformly control laryngeal injury by adequate suppression of gastric acid alone and may further justify alternative methods of laryngeal protection in patients refractory to adequate acid control.