International Subarachnoid Aneurysm Trial (ISAT)
Ly-Mee Yu with Andrew Molyneux, Richard Kerr (Oxford) and the ISAT Collaborative Group
The rate of intracranial aneurysm rupture in patients with subarachnoid aneurysm haemorrhage (SAH) is between 6-8 per 100,000 in most western populations. Neurosurgical intervention to clip the aneurysm and prevent further bleeding carries both risks and benefits, but there have been incremental reductions in the risk of surgery for ruptured intracranial aneurysms. In recent years, endovascular coiling has increasing widely used in patients with rupture and unruptured intracranial aneurysms. The relative benefits of this alternative method to neurosurgical clipping have yet to be established.
The ISAT project was an international multicentre, randomised controlled trial to compare surgery with endovascular coil treatment of acute subarachnoid haemorrhage. The primary objective was to determine whether endovascular treatment reduces the proportion of patients with a moderate or poor outcome (defined by Rankin grade 3-6) by 25% at one year. Target sample size was 2,500 patients.
Preliminary results on 2143 patients were published in 2002. Full one-year follow-up was completed in November 2003;.a paper was submitted for peer review in September 2004.
Website: http://users.ox.ac.uk/~isat/
