ISUIA, Lancet - 2003

Unruptured Intracranial Aneurysms: Natural History, Clinical Outcome, and Risks of Surgical and Endovascular Treatment | The Lancet

In this paper[1], the authors enrolled patients with unruptured intracranial aneurysms from multiple centers in the USA, Canada, and Europe from 1991 to 1998 for prospective assessment. They concluded that site, size, and group specific risks

Study Specifics

* The original paper reads as 12 mm. Typo? Should be >12 mm?

Reference Points



Since the publication of this paper, the management landscape for unruptured intracranial aneurysms has witnessed substantial transformation over the past two decades. Notably, there has been a discernible shift from traditional open surgery towards a predominant reliance on endovascular interventions. In light of this evolution, we reviewed solely on the natural history of these aneurysms in this paper, excluding the surgical aspects.


  1. Unruptured intracranial aneurysms: natural history, clinical outcome, and risks of surgical and endovascular treatment - The Lancet ↩︎