Endovascular Treatment of a Ruptured Flow Aneurysm of the Heubner Artery as Part of a Moyamoya Collateral Network in a Young Patient with an Occluded Middle Cerebral Artery

A young woman with an occluded middle cerebral artery presented with a ruptured flow aneurysm distal on a Heubner artery as part of a moyamoya collateral network. Leptomeningeal collateral supply was tested by occlusion of the A1 origin of the Heubner artery. This test occlusion demonstrated ample collateral leptomeningeal supply over the hemispheres to the M2. Subsequently, the Heubner artery harbouring the aneurysm could be safely proximally occluded with coils.