In 2002 the International Subarachnoid Aneurysm Trial (ISAT) was stopped early because it showed that the minimally invasive technique, coiling, was more likely to result in survival without disability at one year when compared to neurosurgical clipping. The traditional neurosurgical treatment involves a craniotomy and clipping of the aneurysm to stop further bleeding. The coiling treatment is performed by way of a tiny puncture wound in the groin and through the blood vessels.
At the time of the first report (The Lancet 2002; 360:1267-1274) the 1-year follow-up data was available for only 1594 of the 2143 patients enrolled and long-term follow up was not available. Now the researchers report the complete 1-year data and results of long-term follow-up.
Andrew Molyneux and Richard Kerr (Radcliffe Infirmary, Oxford and University of Oxford) and colleagues recruited 2143 patients from 42 neurosurgical centres in Europe, North America, and Australia. The investigators found that 250 of 1063 (23.5%) patients allocated to endovascular coiling treatment were dead or dependent at one year compared with 326 of 1055 (30.9%) patients allocated to neurosurgery and clipping. The researchers found that the early survival advantage was maintained up to 7 years. They also found that the risk of late re-bleeding was low but more common after endovascular coiling than after neurosurgical clipping. Patients assigned coiling also had a substantially lower risk of seizures than patients allocated to clipping.
Dr Molyneux comments: "The complete 1-year data from ISAT confirm and reinforce our preliminary findings. Minimally invasive endovascular coil treatment of ruptured brain aneurysms, when a patient is in good clinical condition and the aneurysm is suitable for coiling, is more likely to lead to independent survival at 1 year than neurosurgical clipping.
He adds: "A crucial issue for endovascular techniques was the uncertainty about the long-term durability of aneurysm occlusion with coils and whether it protects from further aneurysm rupture. ISAT gives the most reliable evidence to date to answer this question."
"This will save about 74 patients in 1000 from death or disability, reducing the risk of death or disability by about 24%". The reassuring thing is that we now have good evidence that the coil treatment is not only better short-term but it is also better in the medium to long-term". (Quote by e-mail; does not appear in published paper)
In an accompanying comment Gavin Britz (Harborview Medical Centre, Seattle, WA, USA) states: "Each patient and their aneurysm is different and the decision has to be made about what is in the best interest for each patient…Some patients should be clipped and some should be coiled. The ultimate decision is complex, including many variables to ensure the most appropriate care."
Contact: Dr Andrew J Molyneux, Mr Richard Kerr or Julia Yarnold, ISAT Trial Headquarters, Neurovascular Research Unit, Radcliffe Infirmary, Oxford OX2 6HE, UK. T) 01865 224 929 andy.molyneux@nds.ox.ac.uk
Comment: Dr Gavin W Britz, Department of Neurological Surgery and Radiology, University of Washington, Harborview Medical Center, Box 359766 Patricia Steel Mem. Bldg, 401 Broadway, Seattle WA 98104, USA. T) +1 206 744 9300 L gbritz@u.washington.edu
Notes to editors
Further information is available from the website URL:
http://www.surgery.ox.ac.uk/nvru/isat
Every year in the UK about 6000 patients suffer this kind of stroke (brain haemorrhage from an aneurysm). Many patients with this condition are quite young, half are in their 40s and 50s.
Further data about the Trial will be published in the near future on the Health Economics differences. Neuropsychological outcomes in a selected group of about 500 patients who took part in the trial will also be reported.
Funding for the Trial was primarily from the UK Medical Research Council, with additional support from the French Health Ministry and Canadian Institute of Health Research, and the Stroke Association of the UK.
Journal
The Lancet