BACKGROUND: Cervical carotid dissections are a significant cause of thromboembolic events in young adults. While endovascular treatment is often used for large or enlarging lesions, smaller lesions are frequently managed conservatively. However, there is limited research on the hemodynamic differences between conservatively managed and endovascularly treated cervical carotid pseudoaneurysms. This study aims to explore these hemodynamic variations. METHODS: A retrospective analysis was performed on patients with extracranial carotid pseudoaneurysms treated conservatively or endovascularly. Vessel and pseudoaneurysm volumes were reconstructed from pre-treatment digital angiographies using 3D Slicer software. Numerical simulations were performed using ANSYS® Fluent. Hemodynamic variables evaluated included: wall shear stress (WSS), low shear areas (LSA), and the parent artery WSS ratio (PAWSSR) RESULTS: Six male patients with seven cervical carotid pseudoaneurysms, aged 48-65 years, were included. Among the lesions, five were spontaneous, one occurred post-endovascular treatment of an anterior communicating artery aneurysm, and one was due to a post-gunshot wound in the neck. The average volume and area of the lesions evaluated were 311.1 mm³ and 238.7 mm², respectively. Three pseudoaneurysms were treated with stents (two flow diverters and one overed VIABAHN stent), and four lesions were managed conservatively with aspirin. Computational fluid dynamics (CFD) simulations revealed that the three pseudoaneurysms treated endovascularly displayed a higher volume (482.4 vs. 182.6 mm³), larger area (367.9 vs 158.0 mm²), greater parent vessel WSS (4.8 vs. 3.01 Pa), higher average LSA (44.9 % vs. 7.6 %), higher PAWSSR (3.95 vs. 1.46), and slightly higher average area-weighted aneurysmal WSS (2.4 vs. 2.1 Pa) compared to those managed conservatively. CONCLUSIONS: Extracranial carotid pseudoaneurysms undergoing endovascular treatment experience more hemodynamic stressors, including higher WSS, larger LSAs, and higher PAWSSR than those treated conservatively. Individual assessment of these hemodynamic characteristics can aid clinicians in treatment decision-making.