Alterations in Gastrointestinal Emptying of 99m-Technetium-Labeled Solids Following Sequential Antrectomy, Truncal Vagotomy and Roux-Y Gastroenterostomy

Abstract

Recent reviews have documented significant delayed gastric emptying following Roux-Y biliary diversion for alkaline gastritis. This study establishes the use of radionuclide imaging in the experimental model and evaluates the following: (1) gastric emptying following antrectomy with and without vagal denervation; (2) the effect of Roux-Y diversion on gastric and upper gastrointestinal emptying using animals as their own controls; and (3) the role of truncal vagotomy in the "Roux-Y delayed emptying syndrome." Upper gastrointestinal emptying was evaluated in 8 dogs using the radionuclide technetium 99 labeled egg white method with continuous visualization by gamma camera. Eight dogs underwent B-II antrectomy without vagotomy and were divided into two groups. Four underwent vagotomy, re-evaluation, and Roux-Y diversion. Four underwent Roux-Y diversion first, re-evaluation, then truncal vagotomy. Control dogs retained 65% +/- 4% (SEM) and 45% +/- 6% of ingested food at 2 and 4 hours, respectively. Following antrectomy only, rapid gastric emptying of radionuclide solid is observed with 35% +/- 7%, 16% +/- 4% and 7% +/- 4% retention and 2, 3, and 4 hours, respectively. Roux-Y antrectomy without vagotomy results in similar rapid gastric emptying. Truncal vagotomy following B-II antrectomy delays gastric emptying compared to antrectomy only. Truncal vagotomy and Roux diversion results in varied patterns of gastrointestinal emptying. Significant gastric retention and gastric and Roux limb retention are observed in 25% of trials. Significant Roux limb retention is observed in 45% of the group. Prior to vagotomy there is no retention or altered transit in the Roux limb. In general, no delay in gastrointestinal emptying is observed in the absence of vagal denervation. These data corroborate our clinical experience in observing both Roux and gastric retention following radionuclide evaluation in Roux-Y patients.