For Patients & Their Families

Subarachnoid Hemorrhage & Cerebral Aneurysms:
(For pictures of "Cerebral aneurysms", click here)

Cerebral aneurysms are abnormal bubbles that arise from the wall of an artery in the brain, much like that in a weak spot of a car tyre. They usually start out very small (the size of a pinhead) and grow (usually over years) to anywhere from the size of a pea to the size of a walnut. They can be hereditary. As they get larger, the aneurysm wall gets thinner and the likelihood of its rupture increases.

When the aneurysm ruptures, it causes ‘Subarachnoid hemorrhage’ (SAH), which can be life threatening. About 30% of the people with ruptured aneurysms die before reaching the hospital. Patients typically complain of sudden onset of the worst headache of their lives, & the headache may be accompanied by vomiting, convulsions, paralysis of one side of the body or even coma. In some patients the headache starts during strenuous activity like straining in the toilet, a bout of cough, lifting a weight or sexual intercourse.

Whatever the initial presentation in a patient of SAH, the aneurysm has to be detected by doing a Digital Subtraction Angiogram (DSA) & occluded as fast as possible. This is to prevent it from rupturing again, as about 70- 80 % of patients do not survive if the aneurysm ruptures again within two weeks. On the positive side, there has been tremendous improvement in techniques to treat aneurysms and the outcomes of patients that do make it to the hospital. In addition, because of newer minimally invasive treatment, the patients stay in the hospital tends to be considerably shorter.

From the 1950’s to the mid 1990’s, the standard of care was brain surgery and the placement of a metal clip (clipping) across the base of the aneurysm. This is a very invasive surgery, and many aneurysms cannot be treated safely due to their location. Also the surgery involves handling of the already swollen brain and the blood vessels. This might cause worsening of the brain swelling or vasospasm. Due to this, many surgeons avoid doing the surgery in the first two weeks after the SAH, which defeats the very purpose of the treatment, as the maximum risk of the aneurysm rupturing again is in this period.

In the early 1990’s a revolutionary new technique was developed called “Coiling” which only requires a tiny puncture  into an artery in the leg. There is no head shaving, opening up of the skull or stitches involved. With this technique, a tiny tube is actually placed into the aneurysm under X-ray guidance in a sophisticated ‘cath-lab’and it is filled with thin, very soft platinum coils. The coils fill the aneurysm from inside & prevent it from rupturing again. Coiling can be performed even immediately after the SAH & there is no need to wait for the brain swelling or vasospasm to subside. It was approved by US FDA in 1995 as a standard treatment modality for cerebral aneurysms & since then, world over, coiling is steadily replacing clipping (Surgery), except for a small percentage of patients (about 10%), where coiling is not technically feasible.

Once a ruptured aneurysm has been plugged, the patient of SAH still must be very carefully monitored for 2 other potential problems. They are 1) Vasospasm, and 2)Hydrocephalus.
Vasospasm, seen in about 30% of SAH patients, usually occurs 3 – 14 days after the initial bleeding. When the blood spills outside the ruptured aneurysm, it lies at the base of the brain & surrounds the main blood vessels supplying the brain. This free blood is very irritating to the blood vessels, and they react by narrowing (vasospasm) & sometimes even totally clamping down. This makes it harder to get the proper amount of blood flow to the brain & can lead to minor or major strokes. There are a number of techniques to fight vasospasm, but they are not perfect. Early occlusion of the aneurysm allows for aggressive prevention & treatment of vasospasm.

The other main problem is Hydrocephalus, seen in less than 10% of SAH patients. In the center of the brain are reservoirs filled with clear fluid, called ventricles. There are drains along the lining of the skull which reabsorb this fluid. When an aneurysm ruptures, these drains get clogged, and there is build up of fluid within the ventricles. As the skull is a fixed space, there is no place for this fluid to go, and there is pressure build up in the brain. This results in worsening headaches, disorientation, and can even lead to coma. This is treated in a number of ways, but a very common way to quickly address this problem is to put a tube through the skull and into the ventricles to drain the excess fluid (Ventriculostomy).

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