Subarachnoid hemorrhage from a ruptured intracranial aneurysm is a catastrophic event usually treated by craniotomy with clipping of the aneurysm. The surgery carries significant risks, and many surviving patients have neurologic deficits. Endovascular coiling was developed as a safer alternative to surgery. This newer procedure introduces platinum coils into the aneurysm to prompt occlusion. The International Subarachnoid Aneurysm Trial Collaborative Group conducted a large clinical trial to compare endovascular coiling with traditional craniotomy and clipping.
The trial randomized more than 2,000 patients who had a recent definite subarachnoid hemorrhage caused by an identified intracranial aneurysm and were suitable for either form of treatment. The principal outcome assessed was performance on a modified Rankin scale at two and 12 months. Data were also collected about subsequent episodes of bleeding, quality of life, and measures of health care costs.
The 1,073 patients randomized to endovascular treatment and the 1,070 allocated to neurosurgery were comparable, and almost all of the patients received their allocated treatment as the first procedure. Surgery was performed on average 1.7 days after the acute episode, and endovascular coiling was performed after 1.1 days. In the endovascular group, 190 patients (23.7 percent) were dead or dependent one year after the procedure compared with 243 patients (30.6 percent) allocated to neurosurgical treatment. This difference was statistically significant and represents a relative risk reduction of 22.6 percent and an absolute risk reduction of 6.9 percent. A greater proportion of patients treated neurosurgically also reported significant impairment of lifestyle (see accompanying table). Close to one half of the patients in each group reported no symptoms or only minor symptoms one year after the procedure. Rebleeding occurred rarely and was reported only in the endovascular group (two per 1,276 patient-years).
The authors conclude that endovascular coiling improves the chance of survival and good outcomes compared with neurosurgical clipping of intracranial aneurysms, but it is associated with a slight risk of delayed re-bleeding. While they acknowledge that the patients selected for the trial are not representative of all cases of subarachnoid hemorrhage, they believe that endovascular treatment is more likely to result in disability-free survival than is neurosurgical clipping.
editor's note: Subarachnoid hemorrhage occurs in six to eight per 100,000 adults annually. Besides making the diagnosis and arranging the urgent transfer to neurosurgical care, the family physician's most important role is to support family members who are making crucial decisions about surgery. As cautioned in a commentary accompanying this article, all the patients selected for the study had bleeds in the anterior circulation. Nevertheless, the evidence points in favor of the endovascular technique. In real life, the outcomes are highly dependent on the skill of the operator and the standards of perioperative care. Most cases in this study were managed at European regional centers with high patient volumes and significant experience in managing intracranial bleeding. For many of us, the hardest decision is between prompt local treatment or transfer to centers of excellence that offer more experience but necessitate a delay in intervention.—A.D.W.