An aneurysm in which the wall of an artery rips (dissects) longitudinally.
This occurs because bleeding into the weakened wall splits the wall.
They are a particular danger in Marfan syndrome.
Children presenting after trauma with headache, seizures, hemiplegia and coma may have an intracranial dissecting aneurysm. Specific angiographic findings provide confirmation of this diagnosis. The dissection occurs subintimally and differs clinically and pathologically from dissecting aneurysms of extracranial arteries. The course in children beyond infancy is catastrophic, justifying consideration of potentially life saving surgical intervention 1).
Since the availability of endovascular treatment and the advantage of intraprocedural anticoagulation, an endovascular strategy has become the mainstay of their therapy. But in some cases selective aneurysm obliteration by the endovascular approach is impossible or associated with an unacceptable risk of morbidity. This is particularly true when the IDA is a blood blister-like aneurysm or when dissection affects peripheral branches of the internal carotid artery.
The literature dealing with surgical treatment of IDAs in the anterior circulation is heterogeneous, and formulation of general recommendations concerning the surgical strategy remains difficult. The aim of a study was to conduct a systematic review of the current knowledge on incidence, pathogenesis, clinical presentation, and diagnostic procedures with a special emphasis on the surgical treatment of intracranial dissections of anterior circulation 2).
A 42-year-old man with a history of sudden onset of severe headache followed by consciousness disturbance was brought to our hospital. Radiological examinations revealed subarachnoid hemorrhage, associated with rupture of a left vertebral artery dissecting aneurysm. Initially, internal trapping was attempted via the ipsilateral vertebral artery. However, the microcatheter could not be navigated through the true lumen to the distal side of the vertebral artery. Subsequently, therefore, the guiding catheter was placed in the right vertebral artery, and the microcatheter was retrogradely navigated successfully through the lesion to the proximal side of the left vertebral artery. Finally, the lesion was completely embolized with electrodetachable coils without complications. However, the patient died after the operation because of deterioration of the general condition. The postmortem examination revealed how an intimal flap had interfered with the antegrade navigation of the microcatheter in the lesion. The present case showed that endovascular treatment for a vertebral artery dissecting aneurysm via the contralateral vertebral artery may be a useful option in cases where antegrade navigation of the microcatheter via the ipsilateral vertebral artery is found to be difficult 3).