Peristaltic pressure profiles of the human esophagus

Using a low-compliance pneumohydraulic infusion system, we mapped the entir e esophagus of nine volunteers with no history of esophageal disease, centi meter by centimeter, to see if there was pressure symmetry throughout the e sophagus during 5 mt wet swallows. We found that esophageal length varied f rom 21-25 cm. The esophageal low-pressure zone (LPZ) varies in distance fro m the upper esophageal sphincter (UES) (4-8 cm). The length of this LPZ is 2-3 cm in most subjects but low pressures (<50 mmHg) may occur for longer i ntervals in some. The amplitudes of most paired swallows were within 10 mmH g of each other, and in only 10% of swallows was the pressure difference mo re than 15 mmHg. We conclude that there is radial pressure symmetry through out the normal esophagus. The LPZ coincides closely to the 50-50 point wher e the percentage of striated and smooth muscle distribution in the circular and longitudinal muscles is equal.