Computer simulation of flow and mixing at the duodenal stump after gastric resection

Figure 1 Normal physiological gastric outlet, pylorus, and superior duodenum.

Figure 2 Schematic representation of reconstruction of gastrointestinal continuity after gastric resection. A: Normal anatomy of gastroduodenal region with resection lines; B: Billroth II antiperistaltic anastomosis.

Figure 3 Schematic representation of the manometry equipment positioned in a patient during pressure measurement.

Figure 4 Computer simulation of pressure measurement inside duodenum bulb. A: Schematic representation of the computational model of balloon pressure measurement inside the duodenum. Geometry of the model (a); 3D model view (b); B: Distribution of solid deformation (wall displacement) at the maximum pressure measurement (a); Fluid pressure distribution inside the duodenum (b).

Figure 5 Geometry and finite element mesh of two selected cases. Case A showed a straight duodenal part with shorter length. Case B had a much longer and curved duodenal section.

Figure 6 Geometry and boundary conditions for a Billroth II Hoffmeister-Finsterer operation.

Figure 7 Velocity distribution for the steady state flow conditions [in (cm/s)].

Figure 8 Pressure distribution for the steady state flow conditions [in (mmHg)].

Figure 9 Mass concentration [in (g/cm³)] distribution for the diffusion coefficient D = 2. 0e-3 cm²/s.

Figure 10 Mass concentration [in (g/cm³)] distribution for the diffusion coefficient D = 8. 0e-3 cm²/s.

Figure 11 Pressure measurement of Miller-Abbott (MA) tube and connecting catheter in the duodenum at 3 d after gastric resection.