Molyneux AJ et al. (2005) International subarachnoid aneurysm trial (ISAT) of neurosurgical clipping versus endovascular coiling in 2143 patients with ruptured intracranial aneurysms: a randomised comparison of effects on survival, dependency, seizures, rebleeding, subgroups, and aneurysm occlusion. Lancet 366: 809–817

A recent paper published in The Lancet has compared neurosurgical clipping with endovascular coiling in patients with ruptured intracranial aneurysm. Of the two treatments, endovascular coiling was associated with the lowest risk of death or dependency at 1 year.

The International Subarachnoid Aneurysm Trial (ISAT) included 2,143 patients at 42 neurosurgical centers. All patients had subarachnoid hemorrhage due to intracranial aneurysm and were randomized to endovascular detachable-coil treatment (n = 1,073) or neurosurgical clipping (n = 1,070). In 2002, an interim analysis showed that patients treated with endovascular coiling were more likely to achieve independent survival at 1 year; the latest results confirm these findings and provide information on subgroup analyses and secondary outcomes.

After the first procedure, the endovascular group showed a highly significant reduction in seizures when compared with the neurosurgery group (relative risk 0.52; 95% CI 0.37–0.74). During the first year after treatment, death or dependency was reported in 23.5% of patients randomized to endovascular coiling, compared with 30.9% of those in the neurosurgical clipping group. This corresponded to an absolute risk reduction of 7.4% (95% CI 3.6–11.2%; P = 0.0001) in the endovascular treatment group. Although follow-up continues, the data available thus far suggest that the survival benefit might persist for up to 7 years.