A relatively complex surgical intervention; such as, invasive surgery, was previously required in order to eliminate the potential risk of a brain aneurysm (a bulge in a blood vessel that bursts usually near the brain).

In this operation, called clipping, a craniotomy was performed, and afterwards a titanium clip was attached around the aneurysm's neck.

This operation became the standard of care for the treatment of cerebral aneurysms as microneurosurgical techniques were refined in the 1980s and 1990s.

In the mid to late 1990s, a different method of aneurysm treatment was developed which allowed for treatment without open surgery; namely, coil embolization of cerebral aneurysms which involves the insertion of a catheter through the groin with a small microcatheter navigated to the aneurysm itself through the cerebral arteries.

Coils (known as GDCs) are then deployed into the aneurysm filling it from within and thus preventing blood from entering the aneurysm itself.

Not every type of aneurysm can be treated with the previously described method; for example, certain wide-necked and inaccessible aneurysms currently still require surgical intervention, even though new methods (that use a type of stent) are already being studied and tested.

Surgery is also usually required for venous aneurysms as introducing foreign material in the low flow veins can produce a high risk blood clotting environment.