Effects of Intestinal Muscular Wrapping on Remnant Intestinal Motility after Massive Small Bowel Resection in Conscious Canines

We searched the effect of the muscular valve on the management of short bowel syndrome. The motility of the remnant intestine with a special muscular valve after 80% massive distal small bowel resection (MSBR) was evaluated in conscious dogs. The valve (muscular ring) was made by the autointestinal muscle layer holding vascular pedicle. Interdigestive and postprandial bowel motility using bipolar electrodes and/or contractile strain gauge force transducers 2-4 weeks after the surgery, and data of this group (Group I) were compared to the motility in dogs after MSBR without valve construction (Group II) and in controls (Control). Results; Fasting duodenal migrating myoelectric (or motor) complexes (MMCs) in Group I occurred at longer intervals than in Control and almost similarly to those in Group II. MMCs arising from the duodenum were often interrupted before the jejunum above the valve and the anastomosis. The velocity of duodenal MMC propagation was slowed in every intestinal segment including that from the duodenum to the proximal jejunum, and to the jejunum above the anastomosis. Transit time in MSBR group (I and II) from the duodenum to the terminal ileum was extremely shorter than in Control, but there were no differences between in Groups I and II. The duration of the postprandial period without duodenal MMCs in Group I was significantly prolonged than in Control, but was shorter than that in Group II. The muscular valve was frequently activated, and the jejunum covered with the valve was contracted frequently which synchronized with the valve activity. It seemed the valve worked as sphincter. However, intestinal obstruction was not occurred through the jejunum covered by the valve. In conclusion, changes in gut motility after MSBR with the valve construction compensate for the shortened intestine and maintain the bowel content earlier postoperatively in comparison with the MSBR alone, and also contribute to the adaptive increase in the remnant intestinal absorption.