The coil also offers hope to patients you wouldn't consider operating on because of their medical conditions or because their aneurysms are deep in the brain or at the back of the brain. Miller switched his training from neurosurgery to interventional neuroradiology after being intrigued by the potential for using arteries as a conduit to reaching problems in the brain. A cerebral aneurysm is a ballooning or weakening of an artery deep in the brain. When it bursts, it causes a hemorrhagic stroke, which accounts for about 20 percent of all strokes and is fatal about 50 percent of the time. Coils treat a berry aneurysm, so called because its narrow neck and bulbous shape make it look like a blueberry stuck on an artery.
Berry aneurysms range from about one-fifth of an inch to one inch in diameter.
Ruptured berry aneurysms are the major cause of subarachnoid hemorrhage, a disease of young and middle-aged adults that kills half of those stricken and disables half its survivors. Berry aneurysms can be treated surgically by placing a tiny, stainless steel clamp across the aneurysm's neck. The operation takes three to five hours, about the same as placing coils, but requires cutting through the skull. Hospitalization for the surgery is usually about five days, compared to about a day with the coils. To place the coils, Miller first pushes a stiff, guiding catheter up the femoral artery in the leg and places it in the neck artery.