A Pathological Study of Intracranial Posterior Circulation Dissecting Aneurysms with Subarachnoid Hemorrhage

Long-term follow up of antegrade recanalization of vertebral artery dissecting aneurysm after internal trapping: case report

A 34-year-old female presented with subarachnoid hemorrhage caused by the rupture of a right vertebral artery (VA) dissecting aneurysm. The affected site, including the aneurysm and parent artery, was successfully occluded with detachable coils. Follow-up angiography performed 28 days after the endovascular treatment revealed recanalization of the parent artery. We decided to treat the patient conservatively without further intervention because the aneurysm had been completely occluded. Magnetic resonance imaging showed a normal VA configuration with a minor irregularity of the affected wall at 6 years after onset. Rebleeding tends to occur during the acute stage because spontaneous healing of the dissecting vascular wall typically occurs within one month after onset. Our case suggests that additional intervention is unnecessary during the chronic stage once the aneurysm has been occluded and no further signs of the development of VA dissection are found.

Rupture of a vertebral artery dissecting aneurysm developing immediately after trapping of a dissecting aneurysm on the contralateral vertebral artery: case report

The development of vertebral artery (VA) dissecting aneurysm after trapping of the contralateral VA is rare, and rupture of angiographically occult VA dissecting aneurysms immediately after trapping is even less common. A 39-year-old man suffered subarachnoid hemorrhage caused by rupture of a left VA dissecting aneurysm. The VA was trapped and the left occipital artery anastomosed to the posterior inferior cerebellar artery. Postoperatively, he suddenly developed apnea and died of rupture of a right VA dissecting aneurysm. Histological examination of the bilateral VAs and the basilar artery disclosed a hematoma between the media and the adventitia. This case further confirms the need for careful preoperative imaging study of the dissection and all segments of the dissected vessel in patients requiring trapping of a VA dissecting aneurysm, as well as preservation of VA anterograde flow.