Controversy: Clipping of Asymptomatic Intracranial Aneurysm That is <7 mm

Abstract

Management of unruptured intracranial aneurysms (UIAs) has been controversial, and over recent decades, practice of neurologists and neurosurgeons has been governed more by bias than by scientific evidence. Given the high morbidity and mortality of aneurysmal subarachnoid hemorrhage (SAH), there is a consensus that prevention of hemorrhage is a desirable strategy,1 but it remains unproven and highly unlikely that a policy of treating all unruptured aneurysms will be effective in reducing overall morbidity and mortality in the affected population. The dilemma is well-summarized in a statement of prestigious aneurysm surgeon, Dr Bryce Weir: “It is essential that we preemptively treat patients deemed to be at high risk for aneurysm rupture to avoid both the horrendous risks of morbidity and mortality associated with SAH but also to prevent the delivery of an iatrogenic insult to patients destined to coexist peacefully with their unruptured aneurysms before dying of some other cause.”2 The International Study of Unruptured Intracranial Aneurysms (ISUIA) has clearly demonstrated that risk of rupture is related to aneurysm size and also location of the aneurysm in the posterior circulation or at the internal carotid/posterior communicating artery sites (ICA/P-Com).3 A recent meta-analysis by Wermer et al4 also has substantiated risk factors of larger aneurysm size and location, as well as female sex and Japanese or Finnish descent. Symptomatic aneurysms also are likely …