Tandem carotid artery stenosis (TCAS) presents significant hemodynamic challenges, necessitating a multidisciplinary approach to treatment. This study integrates imaging, pathology, and computational fluid dynamics (CFD) to analyze a patient-specific TCAS case. A three-dimensional (3D) model of the carotid bifurcation was reconstructed from computed tomography angiography (CTA) scans, and CFD simulations assessed hemodynamic parameters under different stenosis conditions. Preoperative imaging was cross-referenced with postoperative histology to identify regions of elevated time-averaged wall shear stress (TaWSS), indicative of plaque vulnerability, and areas of abrupt TaWSS reduction, which may signal potential rupture sites. Additionally, surgical intervention models revealed that internal carotid artery (ICA) stenosis had a more pronounced effect on blood flow and hemodynamics compared to common carotid artery (CCA) stenosis, emphasizing the complexity of tandem lesions. These findings suggest that integrating advanced imaging, pathology, and CFD could enhance personalized treatment strategies for TCAS, improving understanding of the associated hemodynamic risks.