Anatomic and hemodynamic investigation of an occluded common carotid chimney stent graft for hybrid thoracic aortic aneurysm repair

We examined the possible reasons for common carotid artery chimney stent graft occlusion through computational fluid dynamics analyses of follow-up imaging of a patient-specific aortic configuration reconstructed from computed tomography aortography. Anatomic and hemodynamic parameters were extracted for the bilateral common carotid and subclavian arteries before and after endograft placement. Results suggested that postoperative reduction in lumen diameter within the chimney stent graft combined with an increased flow rate led to complex hemodynamics with high wall shear stress, probably resulting in high-shear thrombogenesis and chimney stent graft occlusion 2.6 years after the primary repair. Early postoperative duplex ultrasound imaging might help identify at-risk conditions.