BIOMECHANICAL AND SENSORY PARAMETERS OF THE HUMAN ESOPHAGUS AT 4 LEVELS

The biomechanical and sensory characteristics of the lower esophageal sphincter (LES) and those of the striated and smooth muscle portions o f the esophagus have not been compared in humans. Our aim was to deter mine sensory perception, cross-sectional area (CSA), and biomechanical parameters at different levels of the esophagus. We studied 11 health y volunteers, using impedance planimetry. Intermittent balloon distens ions (5-60 cmH(2)O) were performed at four sites: 1) the LES, 2) 5 cm above LES (distal), 3) 10 cm above LES (mid), and 4) 5 cm below the up per esophageal sphincter (proximal). During these distensions, CSAs, b iomechanical parameters, and sensory responses were measured. The mid- esophagus had a higher (P < 0.05) CSA than the distal esophagus. The L ES had the smallest CSA (P < 0.05). The LES and the proximal esophagus had greater (P < 0.05) wall tension and were less (P < 0.05) deformab le than the mid- or distal esophagus. Sensory thresholds were lower (P < 0.05) in the proximal compared with the mid- or distal esophagus. B iomechanical and sensory parameters are not uniform along the length o f the esophagus. The striated muscle portion is more sensitive and les s compliant than the smooth muscle portion. These differences could af fect the results of balloon distension tests of the esophagus.