Esophageal manometry

Pressure transients in the pharyngoesophagus vary widely, from about 2500 mm Hg/sec in the pharynx to 150 mm Hg/sec in the lower esophageal sphincter (LES). Perfused side-hole and Dent-sleeve manometry have limitations with respect to their inability to record pharyngeal pressure transients and their relative inability to record abrupt pressure increases in the upper esophageal sphincter (UES), although falling pressure changes, ie, relaxations, of more than 1000 mm Hg/sec can be detected easily by the Dent sleeve. Hence, accurate pharyngeal and UES recordings require pressure sensors that are able to record pressure transients faster than 2500 mm Hg/sec. Microtransducers meet this requirement. Except for their relatively high costs of acquisition, microtransducers have a lot of advantages in comparison with the perfused side-hole methods: the small outer diameter and flexibility enable easy intubation; baseline pressures are not affected by subject position; and plumbing necessary for infusion is eliminated. After presoaking in water, calibration is stable and the baseline drift is acceptable. They have an excellent linearity and a negligible hysteresis. Their durability is satisfactory. The microtransducer assemblies can be designed in almost any configuration and even circumferentially sensitive microtransducers for acute sphincter measurements have been developed. For long-interval recordings of the UES and the LES, however, microtransducers are not suitable: for these the Dent sleeve is required. Recently, microtransducers have been used more frequently because they are indispensable in the 24-hr ambulatory esophageal manometry technology.