Aneurysm configuration

Aneurysm configuration should influence treatment planning. Proximal and distal control should be obtained if the aneurysm itself cannot be occluded. It is typically easier to occlude short necks seen with the saccular form therefore many different treatment options exist. These will be discussed later in the chapter. Fusiform aneurysms may not allow for both proximal and distal control and are often better treated with surgical ligation or reconstruction. 

Multiple aneurysms occur in about 20%-30% of patients with an aneurysm Paraophthalmic aneurysms are very difficult aneurysms to treat due to their configuration with generally a wide neck and due to the difficulty to obtain a stable microcatheter position... 

Inflammatory transmural angiitis in systemic lupus erythematosus, polyarteritis nodosa, or giant cell arteritis causes focal fibrinoid necrosis and elastic tissue disruption. Subacute or chronic changes usually produce ectasia and may facilitate aneurysm formation. Aneurysms in acute arteritis tend to be multiple, peripheral and non side-wall in configuration. 

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