According to the Brain Aneurysm Foundation, there are almost 500,000 deaths worldwide each year due to brain aneurysms. The foundation also quotes that women are more prone to have brain aneurysms than men (ratio 3:2).
The cerebral aneurysm or intracranial aneurysm or brain aneurysm is bloat or ballooning in the blood vessel of the brain. The size of the aneurysm is virtually like a small berry. The brain aneurysm can leak or rupture causing bleeding in the brain, known as a hemorrhagic stroke. Bleeding due to the rupture of a brain aneurysm in the space between the brain and the soft tissue surrounding the brain is termed as subarachnoid hemorrhage (SAH). Ruptured brain aneurysm instantly becomes life-threatening as it leads to severe medical conditions like cerebral vasospasm (reduced blood supply to the brain), hydrocephalus (too much spinal fluid in the brain), coma and permanent brain damage, hence need quick medical attention.
Aneurysms leak when a microscopic hole is developed in their sac. The size of the hole determines the severity of the hemorrhage. Most brain aneurysms, however, don’t rupture. They may create other health problems and cause symptoms.
A number of factors are believed to cause brain aneurysm. Hypertension, cigarette smoking, congenital predisposition, injury or trauma to blood vessels and complications from some type of blood infections represent some important factors contributing to the formation of a brain aneurysm.
A sudden and severe headache is the characteristic symptom of the ruptured aneurysm. The other symptoms of the ruptured aneurysm include nausea vomiting, stiff neck, blurred or double vision, sensitivity to light, seizure, a drooping eyelid, loss of consciousness and confusion. An unruptured brain aneurysm may produce no symptom if its small in size. A large unruptured aneurysm may press on surrounding tissues and nerves and causes pain above and behind the eye, a dilated pupil, change in vision or double vision, numbness on one side of the face.
There are several ways of diagnosis of a brain aneurysm. The diagnosis of ruptured hemorrhage is made by tracking signs of subarachnoid hemorrhage on the computerized tomography (CT) scan technique. CT scan technique X-rays the body in cross-sectional slices.
There are three ways to determine the size, shape, and location of the aneurysm. Noninvasive options include Computed Tomographic Angiography (CTA) and Magnetic Resonance Angiography (MRA). The CTA comprises a regular CT scan with a contrast dye injected in the vein. The injected dye travels to brain arteries, and images are captured using CT scan. MRA uses magnetic pulses instead of X-rays. MRA has its limitations in patients with some metal or electrical implant in their bodies.
The third option includes the Cerebral Catheter Angiography. This technique provides the most extraordinary spatial resolution of all the three techniques and additionally provides an opportunity for endovascular treatment. This technique involves the injection of contrast dye into the arterial system through a catheter that is inserted to the artery in the groin.
There are three treatment options available for brain aneurysm:
1. Medical (non-surgical) therapy
3. Endovascular treatment (Endovascular coiling)
1. Medical Therapy: The therapy is used for treating an unruptured brain aneurysm. Smoking and blood pressure remain the 2 key factors that have demonstrated a significant effect on aneurysm formation, strategies under medical therapy revolve around smoking cessation and blood pressure control.
2. Surgical clipping: In this technique, craniotomy (opening the skull surgically) is performed initially. Subsequently, the aneurysm is isolated from the bloodstream and one or more clips are placed across the neck of the aneurysm. This reduces the blood flow to the aneurysm and also the risk of rupture. Once the clipping is done, the skull bone is secured at its native place and the wounds are closed.
3. Endovascular treatment (endovascular coiling): This technique occupies the existing spaces within the artery to convey the implant that stops further blood contact with the weakened aneurysm wall. Under X-ray guidance, a micro catheter is used to deliver coils at the destination and stagnate blood flow in the aneurysm sac. Sometimes, a device like an intracranial stent can also be used in addition to broadening the scope of treatment when it’s difficult to treat with coils alone.
Clipping or Coiling?
The choice of treatment to secure the aneurysm altogether depends on the agreement between a doctor and the patient. Nature of the aneurysm (ruptured or unruptured), size and location of the aneurysm, age of the patient and his/her general health decides the surgical risk and the outcome. Surgical clipping and endovascular coiling are both considered to be feasible treatment options today.