A COMPARISON OF MICROMANOMETRIC AND STANDARD MANOMETRIC TECHNIQUES FOR RECORDING OF ESOPHAGEAL MOTILITY

Perfused micromanometric assemblies with an outer diameter of 2 mm or less have been developed for use in premature infants and small labora tory animals. Such assemblies offer advantages with regard to subject comfort and low perfusion rates that make them attractive for use in a dults. The aim of this study was to investigate the recording fidelity of micromanometric assemblies in the measurement of oesophageal peris talsis in adults. Two micromanometric assemblies with an outer diamete r of 1.8-2.0 mm and a length suitable for use in adults (265 cm), and containing micromanometric lumina of 0.28-0.35 mm i.d. and a standard lumen of 0.60. 75 mm i.d. were evaluated. Each assembly was tested by measurement of pressure rise rate in response to sudden occlusion, and in vivo during oesophageal peristalsis by simultaneous comparison wit h an intraluminal strain gauge. At perfusion rates of 0.01-0.15 mt min (-1) microlumina achieved pressure rise rates of 21-430 mmHg sec(-1) t hat were comparable to 37-390 mmHg sec(-1) for the standard lumina per fused at 0.25-0.6 mi. min(-1). During oesophageal peristalsis, microma nometric lumina recorded the occurrence and timing of all pressure wav es accurately when compared with standard lumina and the microtransduc er. However, microlumina under-recorded pressure wave amplitude to var ying degrees dependent upon perfusion rate although the performance of microlumina could be improved to that of the standard lumen by shorte ning their length to 70 cm. Micromanometric assemblies are suitable fo r recording oesophageal peristalsis in adults although there is some i mpairment of absolute manometric fidelity. Fidelity can be improved by minimizing total assembly length.