Replacement of the pyloric sphincter with the ileocecal valve: an experimental study.

ABSTRACT

BACKGROUND: Several surgical methods have been devised and applied to overcome the complications associated with the loss of the pyloric sphincter after distal gastrectomy. However, none of these methods creates an efficient sphincteric mechanism at the anastomotic site. The purpose of this experimental study in dogs was to replace the pylorus with the ileocecal valve and determine whether its sphincteric function would be preserved in its new location without affecting gastrointestinal motility and the health of the animals. METHODS: Thirteen dogs underwent surgical removal of the pyloric sphincter and a partial distal gastrectomy. The ileocecal valve, with a short segment of ileum, was then relocated so that the ileal segment was anastomosed to the stomach while the cecal segment was anastomosed to the duodenum. Intestinal continuity was reestablished by anastomosing the distal ileum with the ascending colon. Intraileal and intracolic pressures were measured in all animals prior to and following transposition of the ileocecal valve. In 3 of these animals, pre-pyloric (intragastric) and post-pyloric (intraduodenal) pressures were also measured before the pylorus was removed. Pressure measurements on both sides of the transposed ileocecal valve were performed again 4-6 months later. All pressure measurements were made directly with a water manometer. Radiographic and fluoroscopic studies were carried out on all animals to assess gastrointestinal motility, gastric emptying times, and the sphincteric competence of the transposed ileocecal valve. Hematological and biochemical studies intended to assess the nutritional status of all animals were carried out. Also, postoperative measurements were made of gastric basic acid output. RESULTS: All animals were alive and well 4-6 months after the initial operative procedure. Hematological studies and biochemical tests and studies of liver function remained normal. There was a slight reduction in serum B12 levels and, as expected, a significant postoperative reduction in gastric basic acid output. The intraluminal pressure measurements and the radiographic and fluoroscopic studies all showed that the sphincteric mechanism of the ileocecal valve was preserved in its new location, that gastrointestinal motility was not impaired, and that the healthy condition of the animals was maintained. Gross and histological examination of the transposed segments of the intestinal tract did not reveal any abnormalities. CONCLUSION: Because the anatomy and physiology of the human alimentary tract are similar to those of the dog, this technique may be applicable clinically, when indicated, to avoid and/or relieve complications resulting from gastrectomy, when those complications do not respond or have not responded to conservative management.