Effect of Distal Antrectomy on Gastric Emptying of Liquids and Solids

Abstract

The influence of the terminal antrum on gastric emptying of liquids and solids was investigated. Gastric emptying of liquids was assessed in 5 healthy, conscious, fasting dogs by instilling 500 ml of 154 mM NaCl via an oral gastric tube and by recovering the gastric contents 15, 30, or 45 min later. Gastric emptying of solids was assessed by introducing 15 radio-opaque, plastic spheres into the stomach and by determining cinefluorographically the number remaining in the stomach at 1, 2, and 4 hr. In another series, liquids and spheres were given together, and their rates of emptying were determined. A 3.5-cm segment of distal antrum including pylorus was then excised, gastroduodenostomy was performed, and after 3 weeks or more the tests were repeated. NaCl instillates emptied rapidly from the intact stomach (over-all mean time 50% emptied, 25 min). The square root of the volume remaining declined linearly with time. In contrast, plastic spheres emptied slowly. Four hours were required for discharge of 50% or more of the spheres into the duodenum in all tests. Rhythmic retropulsion of the spheres always was seen cinefluorographically. The simultaneous administration of spheres and liquids did not consistently alter the rate of emptying of either. Distal antrectomy hastened gastric emptying of liquids slightly (over-all mean time 50% emptied, 19 min), but the square root of the volume of the instillate remaining still declined linearly with time. In contrast, the resection markedly increased gastric emptying of spheres, so that at least 50% of the spheres had been discharged by 1 hr in all tests. Retropulsion of the spheres was not seen after antrectomy. After operation, solids still did not alter gastric emptying of liquids, and vice versa. The data indicate that the terminal antrum and pylorus are of minor importance in the regulation of the gastric emptying of liquids but are of great importance in the gastric emptying of solids.