Effect of a catheter in the pharynx on the frequency of transient lower esophageal sphincter relaxations.

Transient relaxation of the lower esophageal sphincter (LES) is observed fairly frequently during prolonged continuous monitoring of the LES. The aim of this study was to test whether the presence of a catheter in the pharynx through the stimulation of mechanoreceptors may induce transient LES relaxation. LES and esophageal pressure recordings were obtained for 1 hour in six subjects with a manometric catheter placed via a gastrostomy tube. Swallowing was monitored by submental electromyographic recording. Additional recordings were obtained in these subjects with a catheter placed in the pharynx for 1 additional hour. Transient LES relaxations were recorded in both study periods, i.e., with and without a catheter in the pharynx. The frequency of transient LES relaxations was significantly higher in the presence of manometric catheters in the pharynx (6.4 +/- 2.2 vs. 2.0 +/- 1.1 total LES relaxations). The frequency of transient LES relaxation during the first and second hour after placement of the manometric catheter in a group of seven healthy subjects was not significant different. It is concluded that the pharynx is one of the sites that may mediate the induction of transient LES relaxation.