Although results of a previous trial suggested that coiling was superior to surgical clipping one year after treatment, a lack of data on long-term outcomes has been a major concern, according to Johnston. The study results are published in the June 2006 issue of the journal Stroke, a publication of the American Heart Association.
"Aneurysms are very serious. Half of those who suffer a ruptured aneurysm will die from it, and another 30 percent will be permanently disabled," Johnston said. "Aneurysms that rupture once are very likely to bleed again, so treatment is definitely indicated. However, there has been concern that coiling may not work as well to prevent new bleeding, and this has limited its use, particularly in the U.S."
There are two main courses of treatment for an aneurysm: clipping the aneurysm, which involves invasive brain surgery, or coiling, which is a procedure in which a small catheter is placed into the groin and threaded up to the brain where a small platinum wire is released into the aneurysm to clot it off from the inside.
"While it is true that some aneurysms can only be treated with clipping and some only with coiling, most patients can be treated with either method," Johnston explained. "This leaves the physician and the patient in the awkward position to decide which is best. Without good data on long term results, the choice is difficult and may be based on purely anecdotal evidence or the preference of the physician. My hope is that this study will help both patients and physicians make better informed decisions based on that particular patient's situation."
In the study, eight institutions with expertise in intracranial aneurysm treatment identified all ruptured saccular aneurysms treated between 1996 and 1998. After an initial medical record review, all patients meeting entry criteria were contacted through a mailed questionnaire or by telephone. The possibility of a rerupture was judged independently by a neurologist, a neurosurgeon, and a neurointerventional radiologist.
A total of 1,010 patients (711 surgically clipped, 299 treated with coiling) were included in the study. Maximum duration of follow-up was 9.6 years for clipped patients and 8.9 years for coiled patients. Patients treated with coiling were older, more likely to have smaller aneurysms, and less likely to have middle cerebral artery aneurysms. Rerupture of the aneurysm at 14 months occurred in one patient initially treated with coiling. Aneurysm retreatment after one year was more frequent in patients treated with coiling, but major complications were rare during retreatment.
"Because it is less invasive, coiling may be the first choice of treatment for many patients," Johnston said, "but there are a number of issues to be considered. With coiling, a patient should have follow-up, including another angiogram. Also, with coiling, there is the possibility of having to have another coiling procedure. With clipping, it's over and done."
"Johnston and colleagues have conducted a seminal study in responding to the single most important question in the management of intracranial aneurysms, namely, the comparative long-term results of endovascular coiling versus intracranial clipping," said Charles B. Wilson, MD, MSHA, ScD, professor of neurosurgery emeritus and senior advisor and surgery program coordinator, UCSF Global Health Sciences. "The answer provided by this report is validation of the anticipated favorable outcome of coiling, a result that compares in critical respects with the established outcomes of surgical clipping. I congratulate the authors and their collaborators."
In addition to UCSF Medical Center, study sites were Barrow Neurological Institute of St. Joseph's Hospital and Medical Center in Phoenix, Mayo Clinic, Houston Methodist Hospital, Stanford University Medical Center, University of California, Los Angeles, University of Southern California, and University of Texas, Southwestern.
The study was supported by grants from Boston Scientific, Inc., and the National Institutes of Health.
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