Carotid web arising in the common carotid artery and adjacent to a transverse process of the cervical spine: A case report

Background and importance: A carotid web (CaW) is an intraluminal membrane-like filling defect typically located in the posterior wall of the proximal internal carotid artery and is increasingly recognized as a potential cause of embolic stroke. We herein reported a case of a CaW that has an unusual location at the CCA; furthermore, an elongated transverse process of the cervical spine was adjacent to the CaW at the CCA. Clinical presentation: An 87-year-old woman with a history of minor stroke underwent thorough radiological examinations of her CCA lesion. Radiological examinations, including duplex ultrasonography, digital subtraction angiography (DSA), computed tomography, and magnetic resonance angiography, revealed that the morphological characteristics of the lesion were compatible with those of a typical CaW except for its location at the CCA. Furthermore, three-dimensional DSA revealed that the lesion was adjacent to the transverse process of the sixth cervical spine (C6), suggesting mechanical damage by the spinal transverse process as a possible pathogenesis of this CaW. Conclusion: This is the rare case of a CaW located in the CCA, far from the carotid bulb. Arterial dissection due to mechanical damage by the spinal transverse process may be a possible causative mechanism of the CaW in the present case.