Abstract

Endovascular treatment of intracranial aneurysms

Author(s): Timothy J Phillips and Peter J Mitchell

Subarachnoid hemorrhage (SAH) is a potentially lethal disease with high morbidity and mortality. The goal of endovascular intracranial aneurysm treatment of intracranial aneurysms is the prevention of rebleeding after primary SAH, the prevention of SAH in unruptured aneurysms or the alleviation of other symptoms attributable to the aneurysm. Securing ruptured aneurysms improves outcome after SAH, and there is high level evidence that endovascular coiling of ruptured aneurysms offers lower morbidity and mortality than neurosurgical clipping. However, the natural history and treatment of unruptured aneurysms is controversial. Endovascular techniques can be classified into deconstructive arterial sacrifice, and endosaccular and endoluminal reconstruction. Detachable microcoils, arterial stents, detachable balloons and liquid embolic agents are devices used in aneurysm treatment. The most serious neurological risks of endovascular techniques are thromboembolic infarction, aneurysm rupture and arterial dissection. Immediate angiographic outcome is measured by the degree of persistent aneurysm or neck filling and is often classified by the ‘modified Montreal’ or ‘Raymond’ system. A better immediate angiographic result is shown to reduce aneurysm recurrence. Immediate residual filling of the aneurysm sac and delayed aneurysm recurrence are both risk factors for repeat SAH. The aim of long-term follow-up is to monitor for aneurysm recurrence, and magnetic resonance angiography is now replacing catheter angiography as the first line follow-up imaging modality.