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.

Endovascular treatment of intracranial aneurysms in the flow diverter era: frequency of use and results in a consecutive series of 550 treatments in a single centre.

Flow diverter devices became available in our department in 2009. We considered treatment with flow diverters only in patients with aneurysms not suitable for surgery or conventional endovascular techniques. This paper presents our preliminary experience with flow diverters in a consecutive series of 550 endovascular aneurysm treatments.

The donut sign: a new angiographic sign for partially thrombosed aneurysms with flow-induced intraluminal thrombus.

Three patients are described with unruptured large partially thrombosed aneurysms with a peculiar donut-shaped remaining lumen. Observations suggest that the flow geometry of the aneurysm and parent vessels induces a preferential circular laminar flow inside the aneurysm followed by partial intraluminal thrombosis leaving a donut-shaped lumen to accommodate the circular flow. This flow mechanism of thrombus formation inside aneurysms is different from the more common repeated intramural dissections and hemorrhages that cause growth in most large and giant partially thrombosed aneurysms.