Characteristics of intracranial aneurysms associated with moyamoya disease

Abstract

A retrospective analysis of 111 patients with aneurysms associated with Moyamoya disease is presented. The subjects comprised of our 12 cases and 99 other well-documented cases. These 111 cases had 131 aneurysms. There were 48 males and 63 females. The average age was 40.3 years. The clinical manifestations were intracranial haemorrhage in 99 cases (89%), and ischaemic events in 9 cases (8%), but no mention was made of these in the last three cases (2%). The Hunt and Kosnik grades were grade 1 in 8%, grade 2 in 23%, grade 3 in 31%, grade 4 in 35%, and grade 5 in 3%. Of the 131 aneurysms, 73 (56%) were found distributed around the circle of Willis, 24 (18%) in the basal ganglia, 29 (22%) on collateral vessels, and 5 (4%) on other vessels. Forty-six percent of the cases were treated surgically, 51% conservatively, and 3% by endovascular procedures. The surgical procedures for the aneurysms were; neck clipping in 49%, aneurysmectomy in 18%, wrapping of the aneurysm in 11%, coating or cautery of the aneurysm in 7%, and revascularization only in 11%. The outcomes were Glasgow Outcome Scale 1 in 30%, 2 in 22%, 3 in 11%, 4 in 1%, and 5 in 25%. The main reasons for the unfavourable outcome were initial poor clinical grade and rebleeding. Follow-up angiography of 25 aneurysms demonstrated that all aneurysms in the basal ganglia or on the collateral vessels disappeared. We recommend surgical intervention for aneurysms associated with Moyamoya disease to prevent rupture or rebleeding, especially for aneurysms around the circle of Willis. However, direct surgery is not recommended for aneurysms found in the basal ganglia or on the collateral vessels.

Paradoxical Association of Moyamoya Syndrome With Large Middle Cerebral Artery Aneurysm and Subarachnoid Hemorrhage -Case Report-

“…5) Aneurysms around the circle of Willis predominantly developed in the posterior circulation, and only 2 of the 73 aneurysms within the circle of Willis arose on the MCA (2.7%), indicating that the association of moyamoya disease with MCA aneurysm is relatively rare, probably due to the lower hemodynamic stress on the MCA bifurcation in moyamoya disease. Few cases have discussed the size of the aneurysms, and moyamoya disease in association with large MCA aneurysm was unknown.…”

“…6) In contrast, the clinical manifestations of hemorrhagic moyamoya disease associated with intracranial aneurysms tend to be SAH (74%) rather than ICH (34%) or IVH (29%). 5) The incidence of aneurysm rupture associated with moyamoya disease is unclear. In the present case, the intraoperative findings indicated that the cause of SAH was not related to aneurysm rupture.…”

“…Based on the observation that the peculiar hemodynamic stress in moyamoya disease contributes to the formation of cerebral aneurysm at the circle of the Willis, 5,7,8) the formation of large MCA aneurysm at the vascular territory of occlusive vessel is apparently unique. Furthermore, the intraoperative findings showed relatively low intra-aneurysmal pressure and no evidence of aneurysm rupture.…”

“…12) Moyamoya disease is frequently associated with intracranial aneurysms located within the abnormal basal network or the circle of Willis, probably as a result of the intrinsic pathology of moyamoya disease such as hemodynamic stress and fragile structure of the collateral vessels. 4,5,7,8) Most saccular aneurysms on the circle of Willis are located on the posterior circulation, and the association of moyamoya disease with middle cerebral artery (MCA) aneurysm is rare. 5) Furthermore, the association of moyamoya vasculopathy with large MCA aneurysm has not been reported previously.…”

“…4,5,7,8) Most saccular aneurysms on the circle of Willis are located on the posterior circulation, and the association of moyamoya disease with middle cerebral artery (MCA) aneurysm is rare. 5) Furthermore, the association of moyamoya vasculopathy with large MCA aneurysm has not been reported previously. Here we report a rare case with adult onset moyamoya syndrome associated with large MCA aneurysm and subarachnoid hemorrhage (SAH).…”