A cerebral aneurysm, also known as brain or intracranial aneurysms, is defined as weakening of a blood vessel wall in the brain. In particular, an aneurysm is of significance when this weakening causes a ballooning of the vessel wall, as the aneurysm is at increased risk of rupture. If the aneurysm ruptures, bleeding will occur in the subarachnoid space around the brain, also known as a subarachnoid hemorrhage. As a result, patients can undergo hemorrhagic stroke which may result in death or other neurologic deficits.
It is currently estimated that between 2-5% of the population has a brain aneurysm(1). Although risk of rupture is relatively low, morbidity & mortality rates following rupture is incredibly high at over 50% (2). Thus, it it is critical to diagnose cerebral aneurysms early and obtain treatment, as mortality & morbidity rates of aneurysm treatment before rupture are between 0-2.5% (3).
1) Wiebers DO, Whisnant JP, Huston J, 3rd, et al. Unruptured intracranial aneurysms: natural history, clinical outcome, and risks of surgical and endovascular treatment. Lancet 2003;362(9378):103-10.
2) International Study of Unruptured Intracranial Aneurysms Investigators (1998). Unruptured intracranial aneurysms--risk of rupture and risks of surgical intervention. The New England journal of medicine, 339(24), 1725–1733. https://doi.org/10.1056/NEJM199812103392401
3) Raaymakers, T. W., Rinkel, G. J., Limburg, M., & Algra, A. (1998). Mortality and morbidity of surgery for unruptured intracranial aneurysms: a meta-analysis. Stroke, 29(8), 1531–1538. https://doi.org/10.1161/01.str.29.8.1531
Current Clinical Pathways
Current cerebral aneurysm management is based on incidental discovery on advanced brain imaging as 85%-90% of unruptured cerebral aneurysms are asymptomatic (1). Other arms of the management paradigm involve presentations during rupture event or surveillance based on a known lesion.
When deemed ready for intervention, cerebral aneurysms are primarily treated in one of two ways: clipping of the aneurysm neck or endovascular coiling. Occasionally, a bypass method may be used in surgery for treatment.
1) Keedy A. (2006). An overview of intracranial aneurysms. McGill journal of medicine : MJM : an international forum for the advancement of medical sciences by students, 9(2), 141–146.