A NOVEL PORTABLE PERFUSED MANOMETRIC SYSTEM FOR RECORDING OF SMALL-INTESTINAL MOTILITY

The development of solid-state catheters with miniature pressure trans ducers and portable dataloggers with a large memory capacity has allow ed recording of gastrointestinal motility in ambulant subjects. Develo pments in silicone rubber extrusion technology made it possible to bui ld a perfused manometric system, using a perfused manometric assembly requiring a low volume of perfusate. In the present study the feasibil ity of recording and automated analysis of small intestinal motility u sing a perfused multiple lumen manometric system was evaluated in seve n healthy volunteers. Pressures were recorded from 12 sideholes arrang ed in lour clusters spaced at 10-cm intervals from the catheter tip. E ach channel was perfused at 0.15 mL min(-1) with degassed water by a p ortable, low-compliance, perfusion pump. The 12 sidehole recording cha nnels were connected to external transducers mounted on a belt. Pressu re data were stored in two dataloggers. Motility was recorded in the s itting (30 min), and supine (30 min) position, during walking (30 min) and postprandially (90 min). Using purpose-built software baseline va riations were corrected for and manometric variables (number of pressu re waves, mean amplitude and motility index) calculated. Bench testing of the manometric assembly showed a median baseline pressure offset o f 4.2 kPa (range 3.7-10.1) and upon occlusion a rise rate of 27.8 kPa sec(-1) (range 19.7-30.8). Changes in body position affected baseline pressures so that compared to the supine position changes in baseline pressure varied between 1.5 +/- 0.7 kPa and 1.9 +/- 0.6 kPa during sit ting (P < 0.02), and between 1.7 +/- 0.7 kPa and 1.5 +/- 0.9 kPa durin g walking (P < 0.03). Manometric recordings obtained during the fastin g period showed an increase in small intestinal motor activity during walking. In the postprandial period no differences in motility variabl es were observed within one cluster and in time. Recording of small in testinal motility with a multiple-channel silicone rubber manometric a ssembly with a portable perfusion system is a feasible technique which is relatively inexpensive. Computer-assisted data processing allows f or adequate elimination of artefacts and automated numerical analysis.