Risk factors for growth of conservatively managed unruptured intracranial aneurysms.

Conservatively managed UIAs in patients without prior history of SAH have a 2.9% risk of growth per aneurysm-year. UIAs greater than 5 mm in diameter, those located at the basilar artery apex, or patients who experience a decrease in BMI are more likely to grow and warrant closer follow-up. The risk of aneurysm growth is increased in the few years after diagnosis and decreases afterward.