Mechanisms of satiety and gastric emptying after gastric partitioning and bypass.

The patterns of fundic and antral motility as well as changes in fundic pressure in response to balloon distention were evaluated in 26 patients before and after gastric partitioning (18 patients) or gastric bypass (8 patients). In addition, the rate of gastric emptying, as measured by the ingestion of 99mTc-tagged chicken liver, was determined after gastric partitioning (12 patients) and bypass (7 patients). A striking alteration in the motility of the fundus occurs after both gastric partitioning and bypass. Normal pressure waves of the fundus disappear with both procedures. Fullness after both operations is secondary to distension of the pouch rather than to an increase in pressure. Changes in antral motility, inhibition, and recovery seem to be neurally mediated. The gastric emptying rate was 6.9% +/0 2.9% per minute after gastric bypass and 1.8% +/- 0.4% per minute after partitioning. Delayed emptying could be an additional benefit of gastric partitioning.