In silico study of luminal transport of bile salts from the duodenum to the gastric mucosa: Role of small intestinal peristalsis

Abstract

Biliary reflux plays a key role in the progression of gastric carcinoma over the long term. The reflux of alkaline duodenal contents (Duodenogastric Reflux) is presumed to be mediated by changes in the gastroduodenal motility, with no clear insights into the mechanisms. Considering mechanism comes under the perspective of fluid transport, a mathematical model is formulated for investigating the transport of the bile as a non-reactive species, assuming non-Newtonian nature as the power law fluids in the antropyloroduodenal segment using lubrication approximation. An analytical approach is employed to derive the exact solutions, and further computational results are simulated using MATLAB coding. To assess the pathophysiology of reflux, transport of the bile salt was quantified for various duodenal motility patterns by considering the following peristalsis parameters, such as elementary contraction (Antegrade Propagating Wave, Retrograde Propagating Wave, and Stationary Wave), wavelength, velocity and occlusion of the wave, and frequency of the contraction. Results of the bile transport are presented for the duodenal peristalsis and analyzed for the relative displacement from its initial position across various motility patterns. The particle transport is driven by wave traversal in the vicinity at the duodenum, whereas at the pylorus and proximal pylorus, transport of the imaginary particles, such as bile salts, is accelerated by increased occlusion of the wave (particles travel longer distances owing to higher occlusion, with 90% occlusion showing more transit than 70% occlusion) and wave speed, with pylorus contributing to hydrodynamic hindrance (owing to pyloric channel width, where the resistance scales to 1/R4) with oscillatory excursion.