Characterization of small intestinal pressure waves in ambulant subjects recorded with a novel portable manometric system.

The organization of lumen-occlusive pressure waves is believed to be an important determinant of luminal flow. At present, little is known about the organization of small intestinal pressure waves in humans. The aim of the present study was to characterize the spatiotemporal organization of small intestinal pressure waves using a portable 12-channel micromanometric system. Small intestinal pressures were recorded from six duodenal (1 cm apart) and six jejunal (1 cm apart) sites after a standard lunch (1892 kJ) and dinner (3305 kJ) and an overnight fast in seven ambulant subjects. Postprandially, the number of isolated pressure waves and the number of pressure wave sequences that spanned 1 and 2 cm decreased over time (P = 0.04, P = 0.003, and P = 0.0001) and were higher after lunch than dinner (P = 0.04, P = 0.02 and P = 0.04), in contrast to the number of long-spanned pressure wave sequences, which remained constant 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 early postprandial period were higher than during the 30-min period of nocturnal phase II (P < 0.01). In conclusion, prolonged recording of small intestinal motility in ambulant subjects using a perfused manometric system is feasible. Postprandial recordings showed that the spatiotemporal organization of pressure waves is time- and meal-dependent.