Experimental studies on small intestinal pouch motility and evacuation

Abstract

The aim of the study was to investigate pouch motility and evacuation under standardised conditions with a minimum of external influence.

Methods: Ileal J-pouches had been constructed 30 cm proximal to the ileocecal valve in 10 dogs (6 pelvic/4 gastric configuration). After 8 weeks the following examinations were performed: (1) measurement of pouch compliance by balloon distension, (2) measurement of pouch contractions by strain gauge transducers, (3) radiological imaging of pouch contractions and evacuation, (4) evacuation scintigraphy and (5) radiological determination of small intestinal transit time.

Results: Compliance (2.3 +/- 1.1 mmHg/ml) and small intestinal transit time (31.6 +/- 7.5 h) were significantly higher in the pouch group than in controls (0.5 +/- 0.2 mmHg/ml, 8.0 +/- 2.8 h; p < 0.05). Scintigraphy and radiography showed delayed pouch evacuation (t(1/2) = 109 +/- 52 min). Strain gauge measurements revealed irregular pouch contractions without detectable propagation. Contraction amplitudes (40.4 +/- 22.9 g) and frequencies (10.4 +/- 1.0/min) were equal all over the pouch. There were no functional differences between gastric and pelvic pouch configuration.

Conclusion: Small intestinal pouches act as reservoirs. Uncoordinated motility patterns contribute to this function. Other factors than pouch motility are responsible for evacuation.