Neurosurgeons at Jefferson Medical College have developed a method to reverse dangerous cerebral vasospasms. Vasospasm is a narrowing of cerebral arteries several days after aneurysm rupture. It is the leading cause of neurological disability and death in survivors of ruptured aneurysms.
Jeffrey Thomas, M.D., assistant professor of neurosurgery at Thomas Jefferson University in Philadelphia, and his colleagues have so far successfully treated 16 patients since March 1997. Each patient had failed conventional treatment for vasospasm.
"Clinical outcomes in treatment of these patients have been excellent, even in some patients with coma and partial paralysis before treatment," says Dr. Thomas. "Most of these patients have survived without significant neurological deficit from vasospasm." The neurosurgeons used a class of drug that dilates the cerebral blood vessels. According to Dr. Thomas, the drug is given by a specialized neurosurgical technique.
The drug is given immediately in the space around the brain and into the cerebrospinal fluid, which bathes the brain. The drug expands the brain's blood vessels, reversing the constricting effects of the vasospasm within about 30 minutes. The treatment currently is being evaluated as a preventive measure for ischemic stroke from vasospasm, with very encouraging initial results. Dr. Thomas presented his results last week at the Congress of Neurological Surgeons in Seattle.
A ruptured aneurysm is a hemorrhagic stroke, one of two types of stroke (the other is ischemic, caused by a reduced blood flow to the brain). When an aneurysm, which is a weakness in a blood vessel wall, erupts in the brain, it spills blood into the subarachnoid space around the brain. This is called a subarachnoid hemorrhage.
Neurosurgeons can operate and eliminate the aneurysm by placing a titanium clip or by a new less invasive procedure called coil embolization. In this procedure, the cerebral aneurysm is eliminated through a tiny incision in the patient's leg. These surgeries are generally successful. A week later, however, cerebral vasospasm can occur. Blood vessels constrict, which may be severe enough to cause ischemic stroke.
"Although patients survive the hemorrhage and come through surgery well, and the aneurysm is cured, the patient may suffer an ischemic stroke from vasospasm up to two weeks later, despite appearing well initially," Dr. Thomas explains. "The exact reasons are unclear, though recent advances in molecular biology have shed light on the mechanism." He has been studying this on the molecular level for about five years.
About 30,000 people a year in North America are candidates for such a procedure to treat cerebral vasospasm, he says, and about 10-12 of every 100,000 worldwide. Roughly 30 percent of patients develop the potentially life-threatening or disabling type of vasospasm.
"No one has ever had a specific and reliable treatment for cerebral vasospasm. It has potential to save lives and get people out of the hospital sooner, and save health care dollars as well," Dr. Thomas says.
"People with ruptured aneurysms are among the sickest patients in medicine, with hospital stays of months. A hospital stay for a patient complicated by vasospasm may cost a half million dollars. And half of those who survive the aneurysm need rehabilitation. If we can eliminate vasospasm as a complication, we can save resources as well as lives."