[An arterial dissection of the distal anterior inferior cerebellar artery treated by endovascular therapy].

A rare case of a dissection of the distal anterior inferior cerebellar artery (AICA) is presented. A 68-year-old woman with sudden onset of headache was admitted. Computed tomographic (CT) scan demonstrated no subarachnoid hemorrhage. Seven days later, CT scan revealed subarachnoid and intraventricular hemorrhage. Left vertebral angiogram showed an aneurysmal dilatation on the distal AICA with a diagnosis of suspected arterial dissection. At that time, we chose delayed craniotomy to observe the lesion directly. However, rebleeding causing aggravation of the patient's systemic condition delayed radical treatment. 19 days after rebleeding, by a superselective angiogram, endovascular treatment was selected to prevent further bleeding. The lesion was diagnosed as dissection of the AICA. The parent AICA was occluded with a Guglielmi detachable coil and fibered platinum coils. Dissection of the distal portion of the cerebellar artery is rare. Only six cases have been reported in the posterior inferior cerebellar artery (PICA) and two cases in the superior cerebellar artery (SCA). However, to our knowledge, no such case has been reported in the AICA. Ruptured dissection of distal PICA or SCA is reported to require early treatment to prevent further bleeding. Ruptured dissection of the distal AICA also requires early treatment. Two cases of distal dissection of PICA and SCA successfully treated by endovascular treatment are reported. Endovascular treatment has some benefits in that it does not always require general anesthesia and in that it can follow diagnostic angiography. On the other hand, saccular aneurysms of the distal AICA do not always require early treatment, such as removal of hematoma because of low incidence of vasospasm. So, to decide the treatment, precise diagnosis of the dissection is very important.