Hemodynamic Evaluation of the WeFlow-Tribranch Modular Triple-Branched Endograft System for Aortic Arch Pathologies: An Initial Computational Fluid Dynamics Study

Purpose: To evaluate the hemodynamic performance and clinical implications of the WeFlow-Tribranch modular endograft system using patient-specific computational fluid dynamics (CFD) analysis. Methods: Pre- and postoperative CTA data sets from 3 patients treated with the WeFlow-Tribranch system were used to reconstruct 3-dimensional aortic models. CFD simulations were performed to compare changes in blood flow patterns, branch perfusion, and wall shear stress (WSS) parameters. The analysis focused on clinical metrics including branch perfusion distribution and hemodynamic markers associated with thrombus risk (TAWSS: time-averaged wall shear stress, OSI: oscillatory shear index, and RRT: relative residence time). Results: In the 3 analyzed cases, postoperative simulations showed that the device successfully restored more organized flow patterns in the aortic arch and effectively excluded aneurysms. Perfusion to the left common carotid artery (LCCA) improved in all 3 cases (+13% to +56%). However, perfusion to the brachiocephalic trunk (BCT) and left subclavian artery (LSA) varied substantially among the cases. Furthermore, simulations identified localized regions of low TAWSS and high OSI within the reconstructed branch tunnels, indicating potential sites for flow stagnation despite improvements in the main aortic flow. Conclusion: This preliminary CFD evaluation suggests that the WeFlow-Tribranch system has the potential to restore aortic arch hemodynamics and enhance LCCA perfusion in these specific cases. However, simulations indicated that the embedded branch design may compromise flow to the BCT or LSA in certain anatomical configurations, potentially inducing localized flow disturbances. These findings underscore the importance of patient-specific preoperative planning to anticipate perfusion changes and suggest that meticulous monitoring of branch patency is warranted. To fully evaluate its long-term performance and optimize its use, further studies involving larger patient cohorts and correlation with clinical outcomes are recommended. Clinical Impact The WeFlow-Tribranch ™ system offers a modular, minimally invasive solution for complex aortic arch pathologies. This CFD study demonstrates that while the device restores organized aortic flow and improves LCCA perfusion, its embedded branch design introduces localized flow disturbances and patient-specific variations in BCT and LSA perfusion. For clinicians, these findings emphasize that anatomical feasibility alone is insufficient for patient selection. Meticulous pre-operative planning and rigorous post-operative surveillance of branch patency are essential to mitigate risks of thrombosis or ischemia induced by non-physiological wall shear stress.