Intimal Dissection Suspected to Be a Carotid Web That Resolved Spontaneously

The carotid web (CW) is a shelf-like structure in the posterior wall of the origin of the internal carotid artery (ICA). This report discusses a case wherein surgical treatment was planned for a lesion suspected to be a CW, but the lesion disappeared over time. A 32-year-old male was found collapsed and was admitted to our hospital. Diffusion-weighted magnetic resonance imaging revealed hyperintensity in the left middle cerebral artery. Three-dimensional computed tomography angiography (3D-CTA) and cerebral angiography revealed a shelf-like structure in the posterior wall of the origin of the left cervical ICA. This was diagnosed as left middle cerebral artery occlusion secondary to a CW, which was initially treated medically. Surgical treatment was planned after being transferred from a recovery hospital. However, approximately 3 months later, 3D-CTA and cerebral angiography revealed that the shelf-like structure on the posterior wall of the origin of the left cervical ICA had disappeared. This CW-like lesion may have been an intimal dissection which spontaneously resolved before complete formation of the CW.