The study, called the International Subarachnoid Aneurysm Trial, shows the technique, known as coiling, is more likely to result in survival without disability for one year, when compared to neurosurgical clipping, which involves a craniotomy and clipping of the aneurysm to prevent further bleeding.

For the coiling treatment, a tiny wound is punctured in the groin and through the blood vessels.

Andrew Molyneux and Richard Kerr, along with colleagues, recruited 2143 patients from 42 neurosurgical centers in Europe, North America, and Australia.

They found that 250 of 1063 patients treated with the coiling method were dead or dependent at least one year compared with 326 of 1055 patients allocated to neurosurgery and clipping. Researchers found the early survival advantage was maintained up to seven years.

The risk of late re-bleeding was low but more common after endovascular coiling than neurosurgical clipping. Patients who underwent clipping also had a lower risk of seizures.

Dr. Molyneux says this will save about 74 in 1000 patients from death or disability, reducing the risk of death by 24 percent.