Resulting long-term intestinal motility in dogs following construction of a reversed jejunal segment after extensive small bowel resection

Abstract

To evaluate the long-term function and effective motility of a reversed jejunal segment after extensive small bowel resection, the authors continuously measured postoperative bowel motility during interdigestive and postprandial periods in conscious dogs 6 to 10 months after surgery. The long-term findings were compared with previously reported short-term results measured 2 to 4 weeks after the operation. In the long-term follow-up dogs with a 20-cm reversed jejunal segment constructed after extensive (75% to 80%) small bowel resection, the fasting duodenal migrating myoelectric (or motor) complex (MMC) was often interrupted in the jejunum above the reversed segment, and did not migrate smoothly to the reversed segment or terminal ileum. The MMCs arising from the duodenum predominantly propagated to the ileum through the inherent anatomic continuity of the bowel. In addition, brief small discordant contractions were frequent in the reversed segment and the jejunum, above the proximal anastomosis. These findings are similar to those of the MMC propagation pattern noted 2 to 4 weeks after surgery. However, the postprandial duration without duodenal MMC activity was significantly shorter in the dogs with long-term follow-up than in those with short-term follow-up (both were longer than in control dogs). Marked dilatation of the jejunum and reversed jejunal segment was noted across the proximal anastomosis. These results suggest that the transit time and passage of intestinal contents can be delayed and stagnated for at least 10 months after extensive small bowel resection with a 20-cm reversed jejunal segment. Although reports on the polarity of peristalsis in the reversed segment in long-term follow-up have been contradictory in both experimental and clinical studies, this research supports the conclusion that the reversed jejunal segment maintains its inherent propagative polarity and pattern over a long postoperative period.