ISAT and ISUIA: the impact on informed consent

The International Subarachnoid Aneurysm Trial (ISAT) was a multicenter randomized trial that compared the safety and efficacy of endovascular coil treatment versus surgical clipping for the treatment of ruptured brain aneurysms. To be eligible for enrollment in the ISAT trial, each patient had to be deemed equally suitable for either coiling or clipping. The investigators used the term "clinical equipoise" to describe this balance. This study more than any other has set the playing field for the future of interventional radiology/endovascular neurosurgery politics.