Ileal reversal to compensate for the loss of the ileo-caecal valve

Disruption of canine jejunal interdigestive myoelectrical activity by artificial ileocolonic sphincter. Studies of intestinal motor response to surgically fashioned sphincter substitute

We studied the effects of an ileocolonic sphincter substitute on canine small intestine motor activity. Recordings of fasting and postprandial myoelectrical activity were performed in three groups of animals in whom the following procedures had been performed: (1) electrode placement alone, intestinal continuity undisturbed (controls); (2) ileocolonic sphincter substitute fashioned in mid-jejunum; and (3) transection and reanastomosis at a similar location in mid-jejunum. Transection alone resulted in a decrease in slow-wave frequency, a shortening of the period of the interdigestive myoelectrical complex (IDMEC) and a prolongation of phase III of the IDMEC in the jejunum distal to the site of transection. The IDMEC period was also shorter at proximal electrode sites, but the incidence of IDMEC phase III complexes was similar on either side of the transection. However, in those animals in whom a sphincter substitute had been fashioned at the site of the transection, the incidence of IDMEC phase III complexes was significantly suppressed in the proximal intestine; IDMEC phase III frequency per hour (mean +/- SD transection vs sphincter substitute) was 0.59 +/- 0.20 vs 0.23 +/- 0.24, P less than 0.002; 0.61 +/- 0.24 vs 0.28 +/- 0.30, P less than 0.006; 0.61 +/- 0.24 vs 0.29 +/- 0.30, P = 0.008, at electrodes 10, 35, and 85 cm proximal to the sphincter substitute, respectively. In addition, the sphincter-substitute animals alone demonstrated, during fasting, recurrent propagated bursts of spike clusters and occasional prolonged spike bursts in electrodes proximal to the sphincter substitute.(ABSTRACT TRUNCATED AT 250 WORDS)

Reflux from ileum to colon in the dog. Role of external ligamentous attachments

In four dogs we quantified the role of external ("coloileal") ligaments in preventing coloileal reflux. All animals were tested under control conditions, and then two had all external ligamentous attachments between ileum and colon divided; the other pair underwent a sham operation. Coloileal reflux was quantified scintigraphically at colonic pressures of 20, 40, and 60 mm Hg, and ileal motility was recorded concurrently. During control experiments and after sham operations, no dogs showed coloileal reflux at colonic pressures of 20 and 40 mm Hg. At a colonic pressure of 60 mm Hg, two control experiments and one in a dog after sham operation resulted in reflux of 9%, 4%, and 8% of counts, respectively. In contrast, both test dogs (after division of the ligaments) refluxed 30-70% of colonic content in all of four experiments at pressure below 20 mm Hg. In control dogs and in those with a continent ileocolonic junction, ileal motility consisted of scattered clusters of phasic contractions. In dogs with coloileal reflux, these clusters occurred with a similar frequency, but they lasted longer (P less than 0.005). Four weeks later, ileal motility indices in control dogs were significantly less (P less than 0.02) than in animals with divided coloileal ligaments. These observations establish an experimental model for coloileal reflux, support the hypothesis that external ligamentous attachments help maintain continence at the ileocolonic junction, and imply that coloileal reflux changes the motor pattern of the terminal ileum.