Progress in aneurysm treatment

Inserting platinum coils often more effective than using clips, study shows

October 25, 2002|By Jonathan Bor | Jonathan Bor,SUN STAFF

Tiny platinum coils inserted into ruptured brain aneurysms are more effective in many cases than surgery in preventing disability and death, according to a study published today.

Doctors said yesterday that the coils offer an exciting therapy for aneurysms, which kill more than 20,000 people annually in the United States alone. They can be inserted without cutting into brain tissue and subjecting patients to quite as much risk.

"This is really a profound change in neurosurgery," said Dr. Kieran Murphy, an interventional radiologist who treated patients in the study at the Johns Hopkins School of Medicine.

Compared to surgery, "coiling" reduced by 25 percent the relatively large chance that a patient would die or suffer lasting disabilities such as coma, intellectual declines or personality changes.

Resembling miniature versions of toy springs, the coils fill the sac created when the wall of a blood vessel weakens, balloons and sometimes bursts. The coils promote clotting and the formation of new tissue, which seals off the aneurysm from the blood vessel.

Depending on the aneurysm's size, doctors might feed four to seven coils to the defective vessel. Doctors open an artery in the patient's leg and snake a catheter past the heart to the brain. Then, they push a wire through the catheter that packs the coils one by one into the aneurysm sac.

In contrast, surgeons who close aneurysms with spring-loaded clips must cut through the skull and brain tissue. Surgical "clipping," introduced in the 1950s, is widely used at large and small hospitals; coiling has been used about a decade, mainly in academic medical centers.

In the study, doctors at 44 centers in Europe, Australia and the United States randomly assigned more than 2,143 patients to receive either the coils or clips. The plan was to enroll 2,500 patients, but doctors called an early halt to the study because data showed that coiling held clear advantages.

Results of the study, the largest to compare the techniques, appear in this week's edition of The Lancet, a British medical journal. The research was sponsored by the Medical Research Council of the United Kingdom.

Doctors have observed the patients for a year after treatment, so long-term benefits and risks are not yet known. Doctors also pointed out that coiling is suitable only if the aneurysm sac appears to hang off the blood vessel by a narrow neck. If coils are inserted into sacs with wide necks, they could slip out and trigger strokes.

Each year, about 30,000 Americans suffer ruptured aneurysms, and up to 15 percent die before reaching the hospital. Treatments - either coiling or clips - are given on an emergency basis for those who survive long enough to be treated.

Even when treated, patients face a significant risk of death. In the study, 65 of 1,073 patients who were treated with coils died within a year, compared to 80 of 1,070 patients who were treated surgically. But patients receiving the new treatment were more likely to return to work or carry out ordinary activities without assistance.

Dr. Daniel Hanley, chairman of the National Stroke Association's professional advisory council, said the study means that doctors can tailor treatment to individual cases. Although surgery might be better for patients whose aneurysms lack clear "necks," coiling might be preferred for many patients whose aneurysms are severe or hard to reach, he said.

"There is now more than one treatment, which is always good news for the patient," Hanley said. "I think what's clear in this study is that coiling will definitely compete for the standard of care."

Dr. Julio Chalela, a neurologist at the National Institute of Neurological Disorders and Stroke, said the study would spur doctors outside major medical centers to learn and offer the coiling technique.

Although the study was limited to patients with ruptured aneurysms, doctors have also used coils to prevent intact aneurysms from bursting. Dr. Gregg Zoarski of the University of Maryland Medical Center said the study would probably make that practice more common.

"Most patients, if they can, would like to avoid a lengthy operation and a lengthy period after surgery where they may be out of work and restricted in their activities," said Zoarski, a professor of neuroradiology and neurosurgery who performs coiling.

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