Effect of selective proximal vagotomy without and with pyloroplasty on gastroduodenal motility

The effect of selective proximal vagotomy (SPV) was examined in six dogs on the gastric emptying of solid food and the motility of the antrum and duodenum (basic rhythm, motility index, and contractile activity percentage). Emptying and motility were also examined in three dogs after additional submucosal pyloroplasty (SMP). Electrical and motor activities were tested in fasted and fed states. The meal consisted of 300 g of standard protein-mixed meal. Determination of gastric emptying by X ray were conducted with the same meal mixed with barium sulfate. All animals showed delayed emptying of solid food after SPV. Antral motility increased nonsignificantly in the digestive state, whereas duodenal motility decreased, resulting in an increased antroduodenal motor gradient. In the interdigestive state the motility of the antrum decreased significantly. Additional SMP normalized the emptying delay, but decreased digestive and interdigestive motility below the normal values. In conclusion, the emptying delay after SPV is caused at least in part by the altered functional condition of the immediate pyloric region.