Well-established features of Moya Moya are demonstrated in both carotid circulations.
The extracranial carotid arteries are free of fibromuscular disease, focal stenosis or dissection, but of relatively small calibre.
Both vertebral arteries are large calibre vessels also free of significant disease.
On the left, there is a markedly enlarged posterior communicating artery supplying the posterior cerebral artery, with a high grade stenosis of the internal carotid artery above this adjacent to the anterior choroidal artery, and then with occlusion of the carotid "T".
Well-established Moya Moya collateral lenticulostriate vessels are shown, with some faint antegrade opacification of the A1 and A2 segments, but with most filling of the anterior cerebral circulation being retrograde from posterior cerebral artery pial collaterals.No definite macroscopic aneurysms are identified.
The left middle cerebral artery is predominantly filled through the craniotomy defect by branches of both the middle meningeal artery, and superficial temporal artery, with evidence of high flow retrograde filling of the middle cerebral artery branch to which it is attached, with then reflux and retrograde filling of the remainder of the middle cerebral artery Territory.
Despite oblique views, a single focal anastomosis was difficult to define, and there was an area of diffuse hypervascularity, the latter especially supplied by the middle meningeal artery, and more in keeping with parasitised vessels from a vascularised graft.
On the right carotid the appearances of the posterior communicating, posterior cerebral and Para ophthalmic internal carotid artery similar, with occlusion of the supraclinoid internal carotid artery, with prominent collateral vessels.
Prominent pial retrograde filling of anterior cerebral artery territory is again demonstrated.
There was no appreciable filling of the cerebral circulation from selective external carotid artery injection.
Vertebral artery injections demonstrated the prominent posterior cerebral circulation with pial collaterals reconstituting much of the middle cerebral artery territory on the right, and a small amount on the left, together with anterior cerebral artery filling.
Moya Moya disease with bilateral terminal internal carotid artery occlusion, Moya Moya lenticulostriate collaterals, and a high flow left external carotid-middle cerebral artery anastomosis, with supply from both middle meningeal and superficial temporal arteries