Use of simultaneous high-resolution endoluminal sonography (HRES) and manometry to characterize high pressure zone of distal esophagus

The purpose of this investigation was to separate the high pressure zone (H PZ) of the distal esophagus into its two components, the intrinsic lower es ophageal sphincter (LES) and the extrinsic crural diaphragm (CD), using sim ultaneous esophageal manometry and high-resolution endoluminal sonography. Five normal subjects were studied during end inspiration using a dual manom etry/ultrasound catheter, The HPZ in the distal esophagus was characterized ultrasonographically as the CD distally and as an overlap of CD and LES pr oximally. In four of five volunteers, the initial distal rise in pressure a t the HPZ corresponded to imaging of CD rather than imaging of the LES. In all subjects, peak pressure corresponded to an overlap of CD and LES. In co nclusion, it is possible to divide the HPZ into its two components, the LES and CD using simultaneous high-resolution endoluminal sonography and esoph ageal manometry. During end inspiration, the CD contributes to the initial distal rise in pressure at the HPZ, Peak pressure of the HPZ corresponds to an overlap of the LES with the CD.