Mechanosensation and Mucosal Blood Perfusion in the Esophagus of Healthy Volunteers Studied with a Multimodal Device Incorporating Laser Doppler Flowmetry and Endosonography

Abstract

Both mechanical and ischemic mechanisms can cause gastrointestinal pain. We investigated whether discomfort and pain caused by bag distension in the esophagus of healthy subjects correlated best with mechanical forces (stress), deformation (strain), or mucosal perfusion. Twenty-nine subjects underwent ramp bag distension using a novel catheter design incorporating high-frequency intraluminal ultrasound, laser Doppler flowmetry, and manometry. Perfusion, pressure, and geometric data were analyzed at visual analog scale (VAS) levels 1-7 in 19 subjects. The circumferential stress increased exponentially as a function of volume, whereas strain showed a linear increase. The perfusion showed a modest decline, on average 15% from baseline to VAS = 7. A significant association was found between the sensory response and stress and strain (P < 0.05). No significant association was found between the sensory response and perfusion. In conclusion, the discomfort and pain response to bag distension in the esophagus is likely to be caused by mechanical rather than ischemic mechanisms.