Characterization of Small Intestinal Pressure Waves in Ambulant Subjects Recorded with a Novel Portable Manometric System

Abstract

The organization of lumen-occlusive pressurewaves is believed to be an important determinant ofluminal flow. At present, little is known about theorganization of small intestinal pressure waves inhumans. The aim of the present study was tocharacterize the spatiotemporal organization of smallintestinal pressure waves using a portable 12-channelmicromanometric system. Small intestinal pressures wererecorded from six duodenal (1 cm apart) and six jejunal(1 cm apart) sites after a standard lunch (1892 kJ) anddinner (3305 kJ) and an overnight fast in seven ambulantsubjects. Postprandially, the number of isolated pressure waves and the number of pressure wavesequences that spanned 1 and 2 cm decreased over time (P= 0.04, P = 0.003, and P = 0.0001) and were higher afterlunch than dinner (P = 0.04, P = 0.02 and P = 0.04), in contrast to the number oflong-spanned pressure wave sequences, which remainedconstant over time and were not influenced by the meal.The number of isolated pressure waves and pressure wave sequences over 1-5 cm recorded in the earlypostprandial period were higher than during the 30-minperiod of nocturnal phase II (P < 0.01). Inconclusion, prolonged recording of small intestinalmotility in ambulant subjects using a perfusedmanometric system is feasible. Postprandial recordingsshowed that the spatiotemporal organization of pressurewaves is time- and meal-dependent.