EFFECTS OF TRANSECTION AND REANASTOMOSIS ON POSTPRANDIAL JEJUNAL TRANSIT AND CONTRACTILE ACTIVITY

Background. The purpose of this study was to determine how transection and reanastomosis of the intestinal wall influence postprandial motor activity and transit in the small intestine. Methods. Six dogs were e ach instrumented with 12 strain gauge transducers, two collection cann ulas, and an infusion catheter defining a 100 cm study segment in the midjejunum. The animals underwent baseline measurements of postprandia l motor activity and transit rate after 650 kcal solid and liquid meal s. Postprandial motor activity was analyzed by computer methods that i dentify frequency, duration, amplitude, and propagation behavior of sm ooth muscle contractions. After the baseline measurements were perform ed, each animal underwent transection and reanastomosis of the intesti nal wall at sites marked during the initial laparotomy. Measurements o f postprandial motor activity and transit were repeated and compared w ith control values. Results. Transection decreased frequency, amplitud e, and percent propagation Sor postprandial contractions. Total propag ating area per minute significantly decreased from 382 +/- 20 gram-sec onds/minute to 190 +/- 66 gram-seconds/minute after transection (p < 0 .05). Intestinal transit decreased from 13.5 +/- 1.5 cm/min to 8.5 +/- 2.4 cm/min (p < 0.05). The change in transit was related primarily to a change in frequency of propagating contractions (r = 0.767; p = 0.0 04). Conclusions. Transection and reanastomosis of the intestinal wall changes the temporal and spatial organization of contractions distal to the transection site. The net result is fewer distally propagating contractions and slower intestinal transit.