Changes in Vertebrobasilar Artery Dissection Visible with High-Resolution Vessel Wall Imaging: A Serial Follow-Up Study

Background: High-resolution vessel wall imaging (HR-VWI) can identify vertebrobasilar artery dissections (VBADs) due to its good intramural hematoma and intimal flap visualization. Although the clinical course of VBADs is known to be benign, changes in VBADs visible using HR-VWI at follow-up are unknown. Thus, this study aimed to assess serial changes in VBADs using HR-VWI at follow-up. Materials and methods: Patients with neurological symptoms from VBADs who had undergone both initial and follow-up HR-VWI examinations were retrospectively enrolled. Enrolled patients with VBADs at the initial HR-VWI after acute symptom onset underwent serial follow-up with HR-VWI at 3, 6, 12, and 24 months. Patients were classified into three groups based on the results of follow-up HR-VWI examinations: type 1 = wall thickness of the dissected artery; type 2 = no interval change; and type 3 = occlusion. Results: Fifteen patients (median age: 50 years, nine males) were enrolled in this study. All patients initially showed an intimal flap and a double lumen. Twelve (80%) patients showed strong wall enhancement. Nine (60%) patients had an intramural hematoma. During serial follow-up, nine (60.0%) patients showed type 1 lesions due to attachment of the intimal flap to the vessel wall, five (33.3%) showed type 2, and one showed type 3. Four patients with BA dissection showed type 2 lesions without change in the intimal flap or the double lumen. Conclusions: Changes in VBADs in HR-VWI were observed during the follow-up period. Most patients with VBADs showed the healing process, such as the disappearance of the intimal flap and the double lumen.