Bling in the Brain: Platinum Coils Reduce Aneurysm Deaths

Physicians are beginning to use a novel therapy for treating aneurysms: the use of a platinum coil, which is threaded to the site of concern and seals off the potential rupture. (More, with pictures and info about aneurysms, under the fold.)

What is an Aneurysm?
Aneurysms among Americans are both quite prevalent and quite deadly. It describes a local dilation (ballooning or distortion) of a blood vessel, which is usually cause by a build up in pressure due to blockage. When this pressure builds up, the wall of the blood vessel is progressively weakened and the liklihood of bursting increases. Aneurysms often occur in the aorta (the heart's major artery) and in the brain at the Circle of Willis (ring of arteries at the base of the brain). When severe, an aneurysm can result in loss of blood flow to a organ, leading to brain damage or death.

What Causes Aneurysms?
Over 95% of aneuryms not located in the brain are caused by atherosclerosis, the hardening of the blood vessels. Often this is just called "heart disease," and is caused by an imbalance in "bad" cholesterol through an unhealthy lifestyle, smoking, trauma, genetic factors, and/or injestion of transfat. As the blood vessels harden they are less able to control increases in blood pressure. They lose their elasticity and become brittle and weak. This puts increased stress on distal portions of the blood vessels to "take up the slack" and expand when pressure increases. In addition, an atherosclerotic plaque (fatty cholesterol deposit) can efficiently plug a vessel, increasing pressure. Aneunysms can induce blot clots as well, increasing the chances of an embolism (a clot which can travel to another part of the body, causing damage).

How Do You Treat an Aneurysm?
To confirm an aneunysm, a doctor will perform either an CT scan with IV contrast (most commonly) or MRI scan to get a clear picture of the location and size of the aneurysm. Traditionally, the aneurysm could be either resected (removed) through elective surgical repair, and replaced with a synthetic conduit, or a graft of another vessel could be used to replace the damaged one. For aneurysms in the brain, this involves risky open-cranium surgery. And, sometimes aneurysms cannot be caught before they rupture.

New Platinum Coils Treat Ruptured Aneuryms
Aneurysm rupture is a serious surgical emergency, with survival at about 50% with traditional surgical methods. But now, as reported in BBC News and published in The Lancet, a new treatment involving platinum coils may increase survival rates. The method, which involves making a tiny puncture wound and threading the metal coil through blood vessels, was tested in 2002 but stopped because the results were so positive.

First, small hole is made near the groin and a flexible tube is threaded towards the site of the ruptured aneurysm. Next, the platinum coils are pushed into the aneurysm itself, providing it with structural support. When the aneurysm is full of coils, blood flow is obstructed. An electrical charge is used to then cut the coils from the tube, which is removed. Blood then clots around the coils in the coil-filled aneurysm, preventing further bleeding and bursting.

"The Oxford team assessed 2,143 patients from 42 neurosurgical centres in Europe, North America and Australia. They found 23.5% of patients treated with the coil technique were either dead or dependent on others one year after their treatment. But among the group who underwent full brain surgery the figure was 30.5%. The researchers also found that the coil patients were more likely to survive up to seven years after treatment than the brain surgery group. Coil patients were also much less likely to develop seizures. They were more likely to experience renewed bleeding - but the risk was still low. Researcher Dr Andrew Molyneux said use of the coil technique could reduce the risk of death or disability by about 24% - potentially saving 74 out of every 1,000 patients from severe problems. "