Aneurysms
Aneurysms typically occur at the bifurcation or branch points of blood vessels within the brain. Their risk for rupture, which is the worst-case scenario, has been studied many times and the results are somewhat variable. However, it is safe to say that any aneurysm has the potential risk for rupture. Therefore, every patient needs to be evaluated on an individual basis.
The average size for ruptured aneurysms is 7.5 mm. However, there is some debate as to whether aneurysms less than 7 mm carry a lower risk for rupture. The most recently quoted statistic for aneurysms less than 7 mm is a 0.05% risk per year for rupture. Aneurysms greater than 7 mm carry ia 0.5%-1% per-year risk for rupture. As aneurysms get larger, there risk for rupture increases. It is well accepted in the literature that patients who present with aneurysms greater than 25 mm in size should consider therapy as long as the risks are appropriate. Again, this must be discussed with a neurosurgeon who has considerable experience in this arena. In addition to this, it is important to seek out a team of physicians who have experience with all of the modalities for therapy in the treatment of intracranial aneurysms.
Broadly speaking, there are three treatment options for cerebral aneurysms, one surgical, one endovascular and finally a combined approach.
- Surgical treatment of aneurysms involves fastening a tiny metal clip at the aneurysm's base to keep the blood from entering the weakened area of the vessel. This procedure prevents future bleeding and injury to nearby brain tissue.
- Neuroendovascular treatments involve inserving tiny coiled wires through a catheter into the aneurysm, which promotes clot formation and blockage.
- A combined surgical and neuroendovascular approach can be considered if the aneurysm is large. Several tests are performed to determine the viability of a surgical treatment option that involves rerouting blood flow around the aneurysm. This is called an extracranial-intracranial bypass. After the bypass, the aneurysm is treated neuroendovascularly.
