Talks & Posters

Comparative CFD Analysis of Pulmonary Hemodynamics in a Sheep Model of Fontan Circulation

N. Dorn, J.Szafron, C. DeShetler, F. Taha, C. Breuer, J. Kelly, A. Marsden

CMBBE 2025 · — Barcelona, Spain

We present a comparative study of pulmonary hemodynamics in a sheep model of the Fontan circulation versus a healthy control, using patient-specific 3D simulations and a novel boundary condition tuning approach. The Fontan procedure, which reroutes systemic venous return directly to the pulmonary arteries without a subpulmonary ventricle, creates non-physiological flow conditions that can impact vascular health. Using 4D-flow MRI data and SimVascular’s open-source tools, we generated CFD models with structured-tree outflow boundary conditions tuned to match catheter-measured pressures and flow splits. Results showed that the Fontan sheep exhibited lower inflow pulsatility, reduced microvascular stiffness, and a smaller outlet tree root diameter compared to the control, while wall shear stress remained similar. These findings suggest adaptive vascular remodeling in response to altered hemodynamics, potentially preserving homeostatic shear despite Fontan-induced flow disruption.

Modeling vascular adaptation for prediction of surgical outcomes in peripheral pulmonary artery stenosis repair

N. Dorn, J.Szafron, A. Marsden

Gordon Research Conference - Biomechanics in Vascular Biology and Disease · — Ventura, CA, USA

We present a novel boundary condition framework to improve virtual treatment planning for peripheral pulmonary artery stenosis by enabling more accurate post-operative hemodynamic predictions. Using patient-specific CFD and reduced-order models, we simulate microvascular adaptation to surgical or transcatheter intervention by constructing structured trees from 3D model outlets down to capillary-scale vessels. These trees are optimized to match clinical pre-operative pressure and flow data, then adapted based on mechanobiological stimuli—wall shear stress and intramural stress—that drive vessel remodeling. This approach captures physiologic changes in microvascular resistance after intervention and advances predictive modeling for surgical planning.

Multi-Fidelity Simulations of Microvascular Adaptation After Virtual Transcatheter Intervention

Nicholas C. Dorn, Jason M. Szafron, Jeffrey A. Feinstein, Daniele E. Schiavazzi, Alison L. Marsden

8th International Conference on Computational and Mathematical Biomedical Engineering · — Arlington, VA, USA

Virtual treatment planning is necessary to reduce the instance of unwarranted and unsuccessful transcatheter intervention in patients with complex pulmonary vascular disease. In order to make accurate predictions of interventional outcomes, adaptation of vessels outside of the simulation domain must be considered. In this work, we present a software package in the Simvascular solver suite capable of computing microvascular adaptation according to the constant wall shear stress hypothesis, enabling treatment planning in 0D and 3D patient-specific models. This allows for easy implementation of virtual surgical planning methods and takes a step towards uncertainty-aware treatment planning.

Epigenetic Modulation of T-cells in Inflammatory Disease

Nicholas C. Dorn

UCSD Summer Research Conference · — Virtual

Epigenetic Modulation of Inflammatory T cells in Autoimmune Disease

Nicholas C. Dorn, David A. McBride, Andrew J. Portell, Nisarg J. Shah

American Institute of Chemical Engineers Annual Meeting · — Virtual

Epigenetic Modulation of Inflammatory T cells in Autoimmune Disease

Nicholas C. Dorn, David A. McBride, Andrew J. Portell, Nisarg J. Shah

Biomedical Engineering Society Annual Meeting · — Virtual

Engineering Anti-inflammatory Biomaterials for Gut Autoimmune Disorders

Nicholas C. Dorn

UCSD Online Undergraduate Research Symposium · — Virtual