Can Postoperative Geometric Changes Help to Explain Pancreatic Leaks in Pancreaticoduodenectomy?

Abstract

Introduction: Pancreatic leaks (PLs) occur after pancreatic resection in up to 30% of cases; this rate has been unchanged for decades. Numerous associated factors and proposed theories as to the etiology of PL, as well as preventative strategies regarding PL, have been detailed in the literature. However, the effect of the geometric changes in pancreaticoduodenectomy (PD) has received scant attention. In this work, computational fluid dynamics[ CFD] surgical models are constructed with the aim of comparing geometry pre and post operatively in PD. Methods: The CFD analysis comparing preoperative and postoperative states was performed using commercial software Ansys with Multiphase flow modeling approach for reliable numerical simulation of internal human organs. Mixtures of Euler-Euler multiphase model were used to compute the interactions of multiple fluids. All phases were treated as inter-penetrating continua with mixture momentum solved and each dispersed phase velocity was prescribed. Results: CFD 3D streamline distribution revealed a higher peak fluid velocity because the post-operative stomach size is smaller and more vertically positioned compared to preoperatively. In addition, the postoperative pancreas duct junction fluid flow velocity distribution is highly restrictive and in combination with altered geometry postoperatively, fluid velocity is much lower resulting in stagnation. Conclusion: CFD of the postoperative state reveals altered geometry resulting in altered flow and pressure patterns which could potentially contribute to PL. Future work will evaluate the difference in geometry with resection alone as well as possible interventions for clinically significant PL.