Total Arch Replacement Versus Hemiarch Replacement in Hemodynamic Performance: A Simulation Study

Acute type A aortic dissection (ATAAD) is a life-threatening aortic emergency with high mortality. Currently, hemiarch replacement (HAR) and total arch replacement (TAR) are the primary surgeries for ATAAD, but their long-term outcomes remain debated, possibly due to the influence of clinical factors in multicenter studies. This study aims to evaluate the long-term outcomes of HAR and TAR by in silico analysis, mitigating the impact of clinical factors. A personalized model was reconstructed to simulate HAR and TAR by altering the material properties at the replacement regions, obtaining hemodynamic and wall response parameters through two-way fluid-structure interaction analysis. HAR exhibits a higher increase in von Mises stress at the anastomosis compared to pre-operation levels (HAR: 4.39 times normal, TAR: 2.42 times normal), increasing the risk of pseudoaneurysm formation. TAR induced more severe streamline absence in the arch branches, potentially resulting in intermittent blood flow to the upper limbs and brain. HAR poses a higher risk of pseudoaneurysm formation at the anastomosis, while TAR carries increased risks of upper limb and cerebral ischemia. Enhanced monitoring of the anastomosis in HAR patients and vigilance for upper limb fatigue and cerebral ischemic events in TAR patients are recommended. This study offers effective guidance for managing postoperative HAR and TAR patients, contributing to the prevention of complications and enhancing their postoperative quality of life.