Particularities of the imagistic diagnosis of the cervical-cerebral arteries dissection. Flow-splitter dissection

Background: Dissection of the cervical-cerebral arteries is an important cause of stroke in all age groups, specifically in younger population. Dissection of the cervical-cerebral arteries is produced by rupture of the intima and media layers, leading to the occurrence of an intramural haematoma. In several circumstances dissection of the cervical-cerebral has a peculiar aspect, of a permeable double arterial lumen. Objective: We try to demonstrate the existence of this particularity in the dissection of the cervical-cerebral arteries, named as ’’flow-splitter” dissection. Method: We have used a battery of tests with which we have tried to show in a coherent and reproducible manner the flow-splitter dissection in a cohort of approx. 30 patients, man and women, selected on the general basis of a regular screening Echo-Doppler investigation of the cervical-cerebral arteries, when we found non-specific flow alterations in these arteries. The main methods of assessment were: Echo-Doppler evaluation of the cervical-cerebral arteries, with and without ultrasound contrast agent, CT-scan, MRI, angio-MRI, IVUS, DSA. Results: By using the imaging techniques described above, part of the patients from the population previously described had specific alterations of the affected artery showing dissection with permeable double lumen, with different Doppler flow characteristics in the two lumen. Administration of an ultrasound contrast agent is clearly showing the intravascular septum, which could be identified also during the IVUS. On the other hand DSA is not showing a narrowing of the artery caliber but only a prolonged remaining of the contrast agent at the level of suspected artery dissection. Conclusion: Based upon the data gathered using the investigation methods described, it could be demonstrated that there is a particular type of dissection of the cervical-cerebral arteries, permeable double lumen dissection or “flow-splitter” dissection.